Pileus Git - ~andy/linux/blob - fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_jbd2.h"
  48 #include "xattr.h"
  49 #include "acl.h"
  50 #include "mballoc.h"
  51
  52 #define CREATE_TRACE_POINTS
  53 #include <trace/events/ext4.h>
  54
  55 static struct proc_dir_entry *ext4_proc_root;
  56 static struct kset *ext4_kset;
  57 static struct ext4_lazy_init *ext4_li_info;
  58 static struct mutex ext4_li_mtx;
  59 static struct ext4_features *ext4_feat;
  60
  61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  62                              unsigned long journal_devnum);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static const char *ext4_decode_error(struct super_block *sb, int errno,
  70                                      char nbuf[16]);
  71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  73 static int ext4_unfreeze(struct super_block *sb);
  74 static void ext4_write_super(struct super_block *sb);
  75 static int ext4_freeze(struct super_block *sb);
  76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  77                        const char *dev_name, void *data);
  78 static inline int ext2_feature_set_ok(struct super_block *sb);
  79 static inline int ext3_feature_set_ok(struct super_block *sb);
  80 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
  81 static void ext4_destroy_lazyinit_thread(void);
  82 static void ext4_unregister_li_request(struct super_block *sb);
  83 static void ext4_clear_request_list(void);
  84
  85 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  86 static struct file_system_type ext2_fs_type = {
  87         .owner          = THIS_MODULE,
  88         .name           = "ext2",
  89         .mount          = ext4_mount,
  90         .kill_sb        = kill_block_super,
  91         .fs_flags       = FS_REQUIRES_DEV,
  92 };
  93 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
  94 #else
  95 #define IS_EXT2_SB(sb) (0)
  96 #endif
  97
  98
  99 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
 100 static struct file_system_type ext3_fs_type = {
 101         .owner          = THIS_MODULE,
 102         .name           = "ext3",
 103         .mount          = ext4_mount,
 104         .kill_sb        = kill_block_super,
 105         .fs_flags       = FS_REQUIRES_DEV,
 106 };
 107 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
 108 #else
 109 #define IS_EXT3_SB(sb) (0)
 110 #endif
 111
 112 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
 113                                struct ext4_group_desc *bg)
 114 {
 115         return le32_to_cpu(bg->bg_block_bitmap_lo) |
 116                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 117                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 118 }
 119
 120 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 121                                struct ext4_group_desc *bg)
 122 {
 123         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 124                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 125                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 126 }
 127
 128 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 129                               struct ext4_group_desc *bg)
 130 {
 131         return le32_to_cpu(bg->bg_inode_table_lo) |
 132                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 133                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 134 }
 135
 136 __u32 ext4_free_blks_count(struct super_block *sb,
 137                               struct ext4_group_desc *bg)
 138 {
 139         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 140                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 141                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 142 }
 143
 144 __u32 ext4_free_inodes_count(struct super_block *sb,
 145                               struct ext4_group_desc *bg)
 146 {
 147         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 148                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 149                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 150 }
 151
 152 __u32 ext4_used_dirs_count(struct super_block *sb,
 153                               struct ext4_group_desc *bg)
 154 {
 155         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 156                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 157                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 158 }
 159
 160 __u32 ext4_itable_unused_count(struct super_block *sb,
 161                               struct ext4_group_desc *bg)
 162 {
 163         return le16_to_cpu(bg->bg_itable_unused_lo) |
 164                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 165                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 166 }
 167
 168 void ext4_block_bitmap_set(struct super_block *sb,
 169                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 170 {
 171         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 172         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 173                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 174 }
 175
 176 void ext4_inode_bitmap_set(struct super_block *sb,
 177                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 178 {
 179         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 180         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 181                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 182 }
 183
 184 void ext4_inode_table_set(struct super_block *sb,
 185                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 186 {
 187         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 188         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 189                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 190 }
 191
 192 void ext4_free_blks_set(struct super_block *sb,
 193                           struct ext4_group_desc *bg, __u32 count)
 194 {
 195         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 196         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 197                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 198 }
 199
 200 void ext4_free_inodes_set(struct super_block *sb,
 201                           struct ext4_group_desc *bg, __u32 count)
 202 {
 203         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 204         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 205                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 206 }
 207
 208 void ext4_used_dirs_set(struct super_block *sb,
 209                           struct ext4_group_desc *bg, __u32 count)
 210 {
 211         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 212         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 213                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 214 }
 215
 216 void ext4_itable_unused_set(struct super_block *sb,
 217                           struct ext4_group_desc *bg, __u32 count)
 218 {
 219         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 220         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 221                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 222 }
 223
 224
 225 /* Just increment the non-pointer handle value */
 226 static handle_t *ext4_get_nojournal(void)
 227 {
 228         handle_t *handle = current->journal_info;
 229         unsigned long ref_cnt = (unsigned long)handle;
 230
 231         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 232
 233         ref_cnt++;
 234         handle = (handle_t *)ref_cnt;
 235
 236         current->journal_info = handle;
 237         return handle;
 238 }
 239
 240
 241 /* Decrement the non-pointer handle value */
 242 static void ext4_put_nojournal(handle_t *handle)
 243 {
 244         unsigned long ref_cnt = (unsigned long)handle;
 245
 246         BUG_ON(ref_cnt == 0);
 247
 248         ref_cnt--;
 249         handle = (handle_t *)ref_cnt;
 250
 251         current->journal_info = handle;
 252 }
 253
 254 /*
 255  * Wrappers for jbd2_journal_start/end.
 256  *
 257  * The only special thing we need to do here is to make sure that all
 258  * journal_end calls result in the superblock being marked dirty, so
 259  * that sync() will call the filesystem's write_super callback if
 260  * appropriate.
 261  *
 262  * To avoid j_barrier hold in userspace when a user calls freeze(),
 263  * ext4 prevents a new handle from being started by s_frozen, which
 264  * is in an upper layer.
 265  */
 266 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 267 {
 268         journal_t *journal;
 269         handle_t  *handle;
 270
 271         if (sb->s_flags & MS_RDONLY)
 272                 return ERR_PTR(-EROFS);
 273
 274         journal = EXT4_SB(sb)->s_journal;
 275         handle = ext4_journal_current_handle();
 276
 277         /*
 278          * If a handle has been started, it should be allowed to
 279          * finish, otherwise deadlock could happen between freeze
 280          * and others(e.g. truncate) due to the restart of the
 281          * journal handle if the filesystem is forzen and active
 282          * handles are not stopped.
 283          */
 284         if (!handle)
 285                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
 286
 287         if (!journal)
 288                 return ext4_get_nojournal();
 289         /*
 290          * Special case here: if the journal has aborted behind our
 291          * backs (eg. EIO in the commit thread), then we still need to
 292          * take the FS itself readonly cleanly.
 293          */
 294         if (is_journal_aborted(journal)) {
 295                 ext4_abort(sb, "Detected aborted journal");
 296                 return ERR_PTR(-EROFS);
 297         }
 298         return jbd2_journal_start(journal, nblocks);
 299 }
 300
 301 /*
 302  * The only special thing we need to do here is to make sure that all
 303  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 304  * that sync() will call the filesystem's write_super callback if
 305  * appropriate.
 306  */
 307 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 308 {
 309         struct super_block *sb;
 310         int err;
 311         int rc;
 312
 313         if (!ext4_handle_valid(handle)) {
 314                 ext4_put_nojournal(handle);
 315                 return 0;
 316         }
 317         sb = handle->h_transaction->t_journal->j_private;
 318         err = handle->h_err;
 319         rc = jbd2_journal_stop(handle);
 320
 321         if (!err)
 322                 err = rc;
 323         if (err)
 324                 __ext4_std_error(sb, where, line, err);
 325         return err;
 326 }
 327
 328 void ext4_journal_abort_handle(const char *caller, unsigned int line,
 329                                const char *err_fn, struct buffer_head *bh,
 330                                handle_t *handle, int err)
 331 {
 332         char nbuf[16];
 333         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 334
 335         BUG_ON(!ext4_handle_valid(handle));
 336
 337         if (bh)
 338                 BUFFER_TRACE(bh, "abort");
 339
 340         if (!handle->h_err)
 341                 handle->h_err = err;
 342
 343         if (is_handle_aborted(handle))
 344                 return;
 345
 346         printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
 347                caller, line, errstr, err_fn);
 348
 349         jbd2_journal_abort_handle(handle);
 350 }
 351
 352 static void __save_error_info(struct super_block *sb, const char *func,
 353                             unsigned int line)
 354 {
 355         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 356
 357         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 358         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 359         es->s_last_error_time = cpu_to_le32(get_seconds());
 360         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 361         es->s_last_error_line = cpu_to_le32(line);
 362         if (!es->s_first_error_time) {
 363                 es->s_first_error_time = es->s_last_error_time;
 364                 strncpy(es->s_first_error_func, func,
 365                         sizeof(es->s_first_error_func));
 366                 es->s_first_error_line = cpu_to_le32(line);
 367                 es->s_first_error_ino = es->s_last_error_ino;
 368                 es->s_first_error_block = es->s_last_error_block;
 369         }
 370         /*
 371          * Start the daily error reporting function if it hasn't been
 372          * started already
 373          */
 374         if (!es->s_error_count)
 375                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 376         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
 377 }
 378
 379 static void save_error_info(struct super_block *sb, const char *func,
 380                             unsigned int line)
 381 {
 382         __save_error_info(sb, func, line);
 383         ext4_commit_super(sb, 1);
 384 }
 385
 386
 387 /* Deal with the reporting of failure conditions on a filesystem such as
 388  * inconsistencies detected or read IO failures.
 389  *
 390  * On ext2, we can store the error state of the filesystem in the
 391  * superblock.  That is not possible on ext4, because we may have other
 392  * write ordering constraints on the superblock which prevent us from
 393  * writing it out straight away; and given that the journal is about to
 394  * be aborted, we can't rely on the current, or future, transactions to
 395  * write out the superblock safely.
 396  *
 397  * We'll just use the jbd2_journal_abort() error code to record an error in
 398  * the journal instead.  On recovery, the journal will complain about
 399  * that error until we've noted it down and cleared it.
 400  */
 401
 402 static void ext4_handle_error(struct super_block *sb)
 403 {
 404         if (sb->s_flags & MS_RDONLY)
 405                 return;
 406
 407         if (!test_opt(sb, ERRORS_CONT)) {
 408                 journal_t *journal = EXT4_SB(sb)->s_journal;
 409
 410                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 411                 if (journal)
 412                         jbd2_journal_abort(journal, -EIO);
 413         }
 414         if (test_opt(sb, ERRORS_RO)) {
 415                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 416                 sb->s_flags |= MS_RDONLY;
 417         }
 418         if (test_opt(sb, ERRORS_PANIC))
 419                 panic("EXT4-fs (device %s): panic forced after error\n",
 420                         sb->s_id);
 421 }
 422
 423 void __ext4_error(struct super_block *sb, const char *function,
 424                   unsigned int line, const char *fmt, ...)
 425 {
 426         struct va_format vaf;
 427         va_list args;
 428
 429         va_start(args, fmt);
 430         vaf.fmt = fmt;
 431         vaf.va = &args;
 432         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 433                sb->s_id, function, line, current->comm, &vaf);
 434         va_end(args);
 435
 436         ext4_handle_error(sb);
 437 }
 438
 439 void ext4_error_inode(struct inode *inode, const char *function,
 440                       unsigned int line, ext4_fsblk_t block,
 441                       const char *fmt, ...)
 442 {
 443         va_list args;
 444         struct va_format vaf;
 445         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 446
 447         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 448         es->s_last_error_block = cpu_to_le64(block);
 449         save_error_info(inode->i_sb, function, line);
 450         va_start(args, fmt);
 451         vaf.fmt = fmt;
 452         vaf.va = &args;
 453         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 454                inode->i_sb->s_id, function, line, inode->i_ino);
 455         if (block)
 456                 printk(KERN_CONT "block %llu: ", block);
 457         printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
 458         va_end(args);
 459
 460         ext4_handle_error(inode->i_sb);
 461 }
 462
 463 void ext4_error_file(struct file *file, const char *function,
 464                      unsigned int line, ext4_fsblk_t block,
 465                      const char *fmt, ...)
 466 {
 467         va_list args;
 468         struct va_format vaf;
 469         struct ext4_super_block *es;
 470         struct inode *inode = file->f_dentry->d_inode;
 471         char pathname[80], *path;
 472
 473         es = EXT4_SB(inode->i_sb)->s_es;
 474         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 475         save_error_info(inode->i_sb, function, line);
 476         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 477         if (IS_ERR(path))
 478                 path = "(unknown)";
 479         printk(KERN_CRIT
 480                "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 481                inode->i_sb->s_id, function, line, inode->i_ino);
 482         if (block)
 483                 printk(KERN_CONT "block %llu: ", block);
 484         va_start(args, fmt);
 485         vaf.fmt = fmt;
 486         vaf.va = &args;
 487         printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
 488         va_end(args);
 489
 490         ext4_handle_error(inode->i_sb);
 491 }
 492
 493 static const char *ext4_decode_error(struct super_block *sb, int errno,
 494                                      char nbuf[16])
 495 {
 496         char *errstr = NULL;
 497
 498         switch (errno) {
 499         case -EIO:
 500                 errstr = "IO failure";
 501                 break;
 502         case -ENOMEM:
 503                 errstr = "Out of memory";
 504                 break;
 505         case -EROFS:
 506                 if (!sb || (EXT4_SB(sb)->s_journal &&
 507                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 508                         errstr = "Journal has aborted";
 509                 else
 510                         errstr = "Readonly filesystem";
 511                 break;
 512         default:
 513                 /* If the caller passed in an extra buffer for unknown
 514                  * errors, textualise them now.  Else we just return
 515                  * NULL. */
 516                 if (nbuf) {
 517                         /* Check for truncated error codes... */
 518                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 519                                 errstr = nbuf;
 520                 }
 521                 break;
 522         }
 523
 524         return errstr;
 525 }
 526
 527 /* __ext4_std_error decodes expected errors from journaling functions
 528  * automatically and invokes the appropriate error response.  */
 529
 530 void __ext4_std_error(struct super_block *sb, const char *function,
 531                       unsigned int line, int errno)
 532 {
 533         char nbuf[16];
 534         const char *errstr;
 535
 536         /* Special case: if the error is EROFS, and we're not already
 537          * inside a transaction, then there's really no point in logging
 538          * an error. */
 539         if (errno == -EROFS && journal_current_handle() == NULL &&
 540             (sb->s_flags & MS_RDONLY))
 541                 return;
 542
 543         errstr = ext4_decode_error(sb, errno, nbuf);
 544         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 545                sb->s_id, function, line, errstr);
 546         save_error_info(sb, function, line);
 547
 548         ext4_handle_error(sb);
 549 }
 550
 551 /*
 552  * ext4_abort is a much stronger failure handler than ext4_error.  The
 553  * abort function may be used to deal with unrecoverable failures such
 554  * as journal IO errors or ENOMEM at a critical moment in log management.
 555  *
 556  * We unconditionally force the filesystem into an ABORT|READONLY state,
 557  * unless the error response on the fs has been set to panic in which
 558  * case we take the easy way out and panic immediately.
 559  */
 560
 561 void __ext4_abort(struct super_block *sb, const char *function,
 562                 unsigned int line, const char *fmt, ...)
 563 {
 564         va_list args;
 565
 566         save_error_info(sb, function, line);
 567         va_start(args, fmt);
 568         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 569                function, line);
 570         vprintk(fmt, args);
 571         printk("\n");
 572         va_end(args);
 573
 574         if ((sb->s_flags & MS_RDONLY) == 0) {
 575                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 576                 sb->s_flags |= MS_RDONLY;
 577                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 578                 if (EXT4_SB(sb)->s_journal)
 579                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 580                 save_error_info(sb, function, line);
 581         }
 582         if (test_opt(sb, ERRORS_PANIC))
 583                 panic("EXT4-fs panic from previous error\n");
 584 }
 585
 586 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 587 {
 588         struct va_format vaf;
 589         va_list args;
 590
 591         va_start(args, fmt);
 592         vaf.fmt = fmt;
 593         vaf.va = &args;
 594         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 595         va_end(args);
 596 }
 597
 598 void __ext4_warning(struct super_block *sb, const char *function,
 599                     unsigned int line, const char *fmt, ...)
 600 {
 601         struct va_format vaf;
 602         va_list args;
 603
 604         va_start(args, fmt);
 605         vaf.fmt = fmt;
 606         vaf.va = &args;
 607         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 608                sb->s_id, function, line, &vaf);
 609         va_end(args);
 610 }
 611
 612 void __ext4_grp_locked_error(const char *function, unsigned int line,
 613                              struct super_block *sb, ext4_group_t grp,
 614                              unsigned long ino, ext4_fsblk_t block,
 615                              const char *fmt, ...)
 616 __releases(bitlock)
 617 __acquires(bitlock)
 618 {
 619         struct va_format vaf;
 620         va_list args;
 621         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 622
 623         es->s_last_error_ino = cpu_to_le32(ino);
 624         es->s_last_error_block = cpu_to_le64(block);
 625         __save_error_info(sb, function, line);
 626
 627         va_start(args, fmt);
 628
 629         vaf.fmt = fmt;
 630         vaf.va = &args;
 631         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
 632                sb->s_id, function, line, grp);
 633         if (ino)
 634                 printk(KERN_CONT "inode %lu: ", ino);
 635         if (block)
 636                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 637         printk(KERN_CONT "%pV\n", &vaf);
 638         va_end(args);
 639
 640         if (test_opt(sb, ERRORS_CONT)) {
 641                 ext4_commit_super(sb, 0);
 642                 return;
 643         }
 644
 645         ext4_unlock_group(sb, grp);
 646         ext4_handle_error(sb);
 647         /*
 648          * We only get here in the ERRORS_RO case; relocking the group
 649          * may be dangerous, but nothing bad will happen since the
 650          * filesystem will have already been marked read/only and the
 651          * journal has been aborted.  We return 1 as a hint to callers
 652          * who might what to use the return value from
 653          * ext4_grp_locked_error() to distinguish between the
 654          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 655          * aggressively from the ext4 function in question, with a
 656          * more appropriate error code.
 657          */
 658         ext4_lock_group(sb, grp);
 659         return;
 660 }
 661
 662 void ext4_update_dynamic_rev(struct super_block *sb)
 663 {
 664         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 665
 666         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 667                 return;
 668
 669         ext4_warning(sb,
 670                      "updating to rev %d because of new feature flag, "
 671                      "running e2fsck is recommended",
 672                      EXT4_DYNAMIC_REV);
 673
 674         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 675         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 676         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 677         /* leave es->s_feature_*compat flags alone */
 678         /* es->s_uuid will be set by e2fsck if empty */
 679
 680         /*
 681          * The rest of the superblock fields should be zero, and if not it
 682          * means they are likely already in use, so leave them alone.  We
 683          * can leave it up to e2fsck to clean up any inconsistencies there.
 684          */
 685 }
 686
 687 /*
 688  * Open the external journal device
 689  */
 690 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 691 {
 692         struct block_device *bdev;
 693         char b[BDEVNAME_SIZE];
 694
 695         bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
 696         if (IS_ERR(bdev))
 697                 goto fail;
 698         return bdev;
 699
 700 fail:
 701         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 702                         __bdevname(dev, b), PTR_ERR(bdev));
 703         return NULL;
 704 }
 705
 706 /*
 707  * Release the journal device
 708  */
 709 static int ext4_blkdev_put(struct block_device *bdev)
 710 {
 711         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 712 }
 713
 714 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 715 {
 716         struct block_device *bdev;
 717         int ret = -ENODEV;
 718
 719         bdev = sbi->journal_bdev;
 720         if (bdev) {
 721                 ret = ext4_blkdev_put(bdev);
 722                 sbi->journal_bdev = NULL;
 723         }
 724         return ret;
 725 }
 726
 727 static inline struct inode *orphan_list_entry(struct list_head *l)
 728 {
 729         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 730 }
 731
 732 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 733 {
 734         struct list_head *l;
 735
 736         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 737                  le32_to_cpu(sbi->s_es->s_last_orphan));
 738
 739         printk(KERN_ERR "sb_info orphan list:\n");
 740         list_for_each(l, &sbi->s_orphan) {
 741                 struct inode *inode = orphan_list_entry(l);
 742                 printk(KERN_ERR "  "
 743                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 744                        inode->i_sb->s_id, inode->i_ino, inode,
 745                        inode->i_mode, inode->i_nlink,
 746                        NEXT_ORPHAN(inode));
 747         }
 748 }
 749
 750 static void ext4_put_super(struct super_block *sb)
 751 {
 752         struct ext4_sb_info *sbi = EXT4_SB(sb);
 753         struct ext4_super_block *es = sbi->s_es;
 754         int i, err;
 755
 756         ext4_unregister_li_request(sb);
 757         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 758
 759         flush_workqueue(sbi->dio_unwritten_wq);
 760         destroy_workqueue(sbi->dio_unwritten_wq);
 761
 762         lock_super(sb);
 763         if (sb->s_dirt)
 764                 ext4_commit_super(sb, 1);
 765
 766         if (sbi->s_journal) {
 767                 err = jbd2_journal_destroy(sbi->s_journal);
 768                 sbi->s_journal = NULL;
 769                 if (err < 0)
 770                         ext4_abort(sb, "Couldn't clean up the journal");
 771         }
 772
 773         del_timer(&sbi->s_err_report);
 774         ext4_release_system_zone(sb);
 775         ext4_mb_release(sb);
 776         ext4_ext_release(sb);
 777         ext4_xattr_put_super(sb);
 778
 779         if (!(sb->s_flags & MS_RDONLY)) {
 780                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 781                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 782                 ext4_commit_super(sb, 1);
 783         }
 784         if (sbi->s_proc) {
 785                 remove_proc_entry(sb->s_id, ext4_proc_root);
 786         }
 787         kobject_del(&sbi->s_kobj);
 788
 789         for (i = 0; i < sbi->s_gdb_count; i++)
 790                 brelse(sbi->s_group_desc[i]);
 791         kfree(sbi->s_group_desc);
 792         if (is_vmalloc_addr(sbi->s_flex_groups))
 793                 vfree(sbi->s_flex_groups);
 794         else
 795                 kfree(sbi->s_flex_groups);
 796         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 797         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 798         percpu_counter_destroy(&sbi->s_dirs_counter);
 799         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 800         brelse(sbi->s_sbh);
 801 #ifdef CONFIG_QUOTA
 802         for (i = 0; i < MAXQUOTAS; i++)
 803                 kfree(sbi->s_qf_names[i]);
 804 #endif
 805
 806         /* Debugging code just in case the in-memory inode orphan list
 807          * isn't empty.  The on-disk one can be non-empty if we've
 808          * detected an error and taken the fs readonly, but the
 809          * in-memory list had better be clean by this point. */
 810         if (!list_empty(&sbi->s_orphan))
 811                 dump_orphan_list(sb, sbi);
 812         J_ASSERT(list_empty(&sbi->s_orphan));
 813
 814         invalidate_bdev(sb->s_bdev);
 815         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 816                 /*
 817                  * Invalidate the journal device's buffers.  We don't want them
 818                  * floating about in memory - the physical journal device may
 819                  * hotswapped, and it breaks the `ro-after' testing code.
 820                  */
 821                 sync_blockdev(sbi->journal_bdev);
 822                 invalidate_bdev(sbi->journal_bdev);
 823                 ext4_blkdev_remove(sbi);
 824         }
 825         sb->s_fs_info = NULL;
 826         /*
 827          * Now that we are completely done shutting down the
 828          * superblock, we need to actually destroy the kobject.
 829          */
 830         unlock_super(sb);
 831         kobject_put(&sbi->s_kobj);
 832         wait_for_completion(&sbi->s_kobj_unregister);
 833         kfree(sbi->s_blockgroup_lock);
 834         kfree(sbi);
 835 }
 836
 837 static struct kmem_cache *ext4_inode_cachep;
 838
 839 /*
 840  * Called inside transaction, so use GFP_NOFS
 841  */
 842 static struct inode *ext4_alloc_inode(struct super_block *sb)
 843 {
 844         struct ext4_inode_info *ei;
 845
 846         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 847         if (!ei)
 848                 return NULL;
 849
 850         ei->vfs_inode.i_version = 1;
 851         ei->vfs_inode.i_data.writeback_index = 0;
 852         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 853         INIT_LIST_HEAD(&ei->i_prealloc_list);
 854         spin_lock_init(&ei->i_prealloc_lock);
 855         ei->i_reserved_data_blocks = 0;
 856         ei->i_reserved_meta_blocks = 0;
 857         ei->i_allocated_meta_blocks = 0;
 858         ei->i_da_metadata_calc_len = 0;
 859         spin_lock_init(&(ei->i_block_reservation_lock));
 860 #ifdef CONFIG_QUOTA
 861         ei->i_reserved_quota = 0;
 862 #endif
 863         ei->jinode = NULL;
 864         INIT_LIST_HEAD(&ei->i_completed_io_list);
 865         spin_lock_init(&ei->i_completed_io_lock);
 866         ei->cur_aio_dio = NULL;
 867         ei->i_sync_tid = 0;
 868         ei->i_datasync_tid = 0;
 869         atomic_set(&ei->i_ioend_count, 0);
 870         atomic_set(&ei->i_aiodio_unwritten, 0);
 871
 872         return &ei->vfs_inode;
 873 }
 874
 875 static int ext4_drop_inode(struct inode *inode)
 876 {
 877         int drop = generic_drop_inode(inode);
 878
 879         trace_ext4_drop_inode(inode, drop);
 880         return drop;
 881 }
 882
 883 static void ext4_i_callback(struct rcu_head *head)
 884 {
 885         struct inode *inode = container_of(head, struct inode, i_rcu);
 886         INIT_LIST_HEAD(&inode->i_dentry);
 887         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 888 }
 889
 890 static void ext4_destroy_inode(struct inode *inode)
 891 {
 892         ext4_ioend_wait(inode);
 893         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 894                 ext4_msg(inode->i_sb, KERN_ERR,
 895                          "Inode %lu (%p): orphan list check failed!",
 896                          inode->i_ino, EXT4_I(inode));
 897                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 898                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 899                                 true);
 900                 dump_stack();
 901         }
 902         call_rcu(&inode->i_rcu, ext4_i_callback);
 903 }
 904
 905 static void init_once(void *foo)
 906 {
 907         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 908
 909         INIT_LIST_HEAD(&ei->i_orphan);
 910 #ifdef CONFIG_EXT4_FS_XATTR
 911         init_rwsem(&ei->xattr_sem);
 912 #endif
 913         init_rwsem(&ei->i_data_sem);
 914         inode_init_once(&ei->vfs_inode);
 915 }
 916
 917 static int init_inodecache(void)
 918 {
 919         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 920                                              sizeof(struct ext4_inode_info),
 921                                              0, (SLAB_RECLAIM_ACCOUNT|
 922                                                 SLAB_MEM_SPREAD),
 923                                              init_once);
 924         if (ext4_inode_cachep == NULL)
 925                 return -ENOMEM;
 926         return 0;
 927 }
 928
 929 static void destroy_inodecache(void)
 930 {
 931         kmem_cache_destroy(ext4_inode_cachep);
 932 }
 933
 934 void ext4_clear_inode(struct inode *inode)
 935 {
 936         invalidate_inode_buffers(inode);
 937         end_writeback(inode);
 938         dquot_drop(inode);
 939         ext4_discard_preallocations(inode);
 940         if (EXT4_I(inode)->jinode) {
 941                 jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
 942                                                EXT4_I(inode)->jinode);
 943                 jbd2_free_inode(EXT4_I(inode)->jinode);
 944                 EXT4_I(inode)->jinode = NULL;
 945         }
 946 }
 947
 948 static inline void ext4_show_quota_options(struct seq_file *seq,
 949                                            struct super_block *sb)
 950 {
 951 #if defined(CONFIG_QUOTA)
 952         struct ext4_sb_info *sbi = EXT4_SB(sb);
 953
 954         if (sbi->s_jquota_fmt) {
 955                 char *fmtname = "";
 956
 957                 switch (sbi->s_jquota_fmt) {
 958                 case QFMT_VFS_OLD:
 959                         fmtname = "vfsold";
 960                         break;
 961                 case QFMT_VFS_V0:
 962                         fmtname = "vfsv0";
 963                         break;
 964                 case QFMT_VFS_V1:
 965                         fmtname = "vfsv1";
 966                         break;
 967                 }
 968                 seq_printf(seq, ",jqfmt=%s", fmtname);
 969         }
 970
 971         if (sbi->s_qf_names[USRQUOTA])
 972                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 973
 974         if (sbi->s_qf_names[GRPQUOTA])
 975                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 976
 977         if (test_opt(sb, USRQUOTA))
 978                 seq_puts(seq, ",usrquota");
 979
 980         if (test_opt(sb, GRPQUOTA))
 981                 seq_puts(seq, ",grpquota");
 982 #endif
 983 }
 984
 985 /*
 986  * Show an option if
 987  *  - it's set to a non-default value OR
 988  *  - if the per-sb default is different from the global default
 989  */
 990 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 991 {
 992         int def_errors;
 993         unsigned long def_mount_opts;
 994         struct super_block *sb = vfs->mnt_sb;
 995         struct ext4_sb_info *sbi = EXT4_SB(sb);
 996         struct ext4_super_block *es = sbi->s_es;
 997
 998         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 999         def_errors     = le16_to_cpu(es->s_errors);
1000
1001         if (sbi->s_sb_block != 1)
1002                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
1003         if (test_opt(sb, MINIX_DF))
1004                 seq_puts(seq, ",minixdf");
1005         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
1006                 seq_puts(seq, ",grpid");
1007         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
1008                 seq_puts(seq, ",nogrpid");
1009         if (sbi->s_resuid != EXT4_DEF_RESUID ||
1010             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
1011                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
1012         }
1013         if (sbi->s_resgid != EXT4_DEF_RESGID ||
1014             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
1015                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
1016         }
1017         if (test_opt(sb, ERRORS_RO)) {
1018                 if (def_errors == EXT4_ERRORS_PANIC ||
1019                     def_errors == EXT4_ERRORS_CONTINUE) {
1020                         seq_puts(seq, ",errors=remount-ro");
1021                 }
1022         }
1023         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1024                 seq_puts(seq, ",errors=continue");
1025         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1026                 seq_puts(seq, ",errors=panic");
1027         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
1028                 seq_puts(seq, ",nouid32");
1029         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
1030                 seq_puts(seq, ",debug");
1031         if (test_opt(sb, OLDALLOC))
1032                 seq_puts(seq, ",oldalloc");
1033 #ifdef CONFIG_EXT4_FS_XATTR
1034         if (test_opt(sb, XATTR_USER))
1035                 seq_puts(seq, ",user_xattr");
1036         if (!test_opt(sb, XATTR_USER))
1037                 seq_puts(seq, ",nouser_xattr");
1038 #endif
1039 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1040         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1041                 seq_puts(seq, ",acl");
1042         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1043                 seq_puts(seq, ",noacl");
1044 #endif
1045         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1046                 seq_printf(seq, ",commit=%u",
1047                            (unsigned) (sbi->s_commit_interval / HZ));
1048         }
1049         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1050                 seq_printf(seq, ",min_batch_time=%u",
1051                            (unsigned) sbi->s_min_batch_time);
1052         }
1053         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1054                 seq_printf(seq, ",max_batch_time=%u",
1055                            (unsigned) sbi->s_min_batch_time);
1056         }
1057
1058         /*
1059          * We're changing the default of barrier mount option, so
1060          * let's always display its mount state so it's clear what its
1061          * status is.
1062          */
1063         seq_puts(seq, ",barrier=");
1064         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1065         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1066                 seq_puts(seq, ",journal_async_commit");
1067         else if (test_opt(sb, JOURNAL_CHECKSUM))
1068                 seq_puts(seq, ",journal_checksum");
1069         if (test_opt(sb, I_VERSION))
1070                 seq_puts(seq, ",i_version");
1071         if (!test_opt(sb, DELALLOC) &&
1072             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1073                 seq_puts(seq, ",nodelalloc");
1074
1075         if (!test_opt(sb, MBLK_IO_SUBMIT))
1076                 seq_puts(seq, ",nomblk_io_submit");
1077         if (sbi->s_stripe)
1078                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1079         /*
1080          * journal mode get enabled in different ways
1081          * So just print the value even if we didn't specify it
1082          */
1083         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1084                 seq_puts(seq, ",data=journal");
1085         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1086                 seq_puts(seq, ",data=ordered");
1087         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1088                 seq_puts(seq, ",data=writeback");
1089
1090         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1091                 seq_printf(seq, ",inode_readahead_blks=%u",
1092                            sbi->s_inode_readahead_blks);
1093
1094         if (test_opt(sb, DATA_ERR_ABORT))
1095                 seq_puts(seq, ",data_err=abort");
1096
1097         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1098                 seq_puts(seq, ",noauto_da_alloc");
1099
1100         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1101                 seq_puts(seq, ",discard");
1102
1103         if (test_opt(sb, NOLOAD))
1104                 seq_puts(seq, ",norecovery");
1105
1106         if (test_opt(sb, DIOREAD_NOLOCK))
1107                 seq_puts(seq, ",dioread_nolock");
1108
1109         if (test_opt(sb, BLOCK_VALIDITY) &&
1110             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1111                 seq_puts(seq, ",block_validity");
1112
1113         if (!test_opt(sb, INIT_INODE_TABLE))
1114                 seq_puts(seq, ",noinit_inode_table");
1115         else if (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)
1116                 seq_printf(seq, ",init_inode_table=%u",
1117                            (unsigned) sbi->s_li_wait_mult);
1118
1119         ext4_show_quota_options(seq, sb);
1120
1121         return 0;
1122 }
1123
1124 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1125                                         u64 ino, u32 generation)
1126 {
1127         struct inode *inode;
1128
1129         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1130                 return ERR_PTR(-ESTALE);
1131         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1132                 return ERR_PTR(-ESTALE);
1133
1134         /* iget isn't really right if the inode is currently unallocated!!
1135          *
1136          * ext4_read_inode will return a bad_inode if the inode had been
1137          * deleted, so we should be safe.
1138          *
1139          * Currently we don't know the generation for parent directory, so
1140          * a generation of 0 means "accept any"
1141          */
1142         inode = ext4_iget(sb, ino);
1143         if (IS_ERR(inode))
1144                 return ERR_CAST(inode);
1145         if (generation && inode->i_generation != generation) {
1146                 iput(inode);
1147                 return ERR_PTR(-ESTALE);
1148         }
1149
1150         return inode;
1151 }
1152
1153 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1154                                         int fh_len, int fh_type)
1155 {
1156         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1157                                     ext4_nfs_get_inode);
1158 }
1159
1160 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1161                                         int fh_len, int fh_type)
1162 {
1163         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1164                                     ext4_nfs_get_inode);
1165 }
1166
1167 /*
1168  * Try to release metadata pages (indirect blocks, directories) which are
1169  * mapped via the block device.  Since these pages could have journal heads
1170  * which would prevent try_to_free_buffers() from freeing them, we must use
1171  * jbd2 layer's try_to_free_buffers() function to release them.
1172  */
1173 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1174                                  gfp_t wait)
1175 {
1176         journal_t *journal = EXT4_SB(sb)->s_journal;
1177
1178         WARN_ON(PageChecked(page));
1179         if (!page_has_buffers(page))
1180                 return 0;
1181         if (journal)
1182                 return jbd2_journal_try_to_free_buffers(journal, page,
1183                                                         wait & ~__GFP_WAIT);
1184         return try_to_free_buffers(page);
1185 }
1186
1187 #ifdef CONFIG_QUOTA
1188 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1189 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1190
1191 static int ext4_write_dquot(struct dquot *dquot);
1192 static int ext4_acquire_dquot(struct dquot *dquot);
1193 static int ext4_release_dquot(struct dquot *dquot);
1194 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1195 static int ext4_write_info(struct super_block *sb, int type);
1196 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1197                          struct path *path);
1198 static int ext4_quota_off(struct super_block *sb, int type);
1199 static int ext4_quota_on_mount(struct super_block *sb, int type);
1200 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1201                                size_t len, loff_t off);
1202 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1203                                 const char *data, size_t len, loff_t off);
1204
1205 static const struct dquot_operations ext4_quota_operations = {
1206         .get_reserved_space = ext4_get_reserved_space,
1207         .write_dquot    = ext4_write_dquot,
1208         .acquire_dquot  = ext4_acquire_dquot,
1209         .release_dquot  = ext4_release_dquot,
1210         .mark_dirty     = ext4_mark_dquot_dirty,
1211         .write_info     = ext4_write_info,
1212         .alloc_dquot    = dquot_alloc,
1213         .destroy_dquot  = dquot_destroy,
1214 };
1215
1216 static const struct quotactl_ops ext4_qctl_operations = {
1217         .quota_on       = ext4_quota_on,
1218         .quota_off      = ext4_quota_off,
1219         .quota_sync     = dquot_quota_sync,
1220         .get_info       = dquot_get_dqinfo,
1221         .set_info       = dquot_set_dqinfo,
1222         .get_dqblk      = dquot_get_dqblk,
1223         .set_dqblk      = dquot_set_dqblk
1224 };
1225 #endif
1226
1227 static const struct super_operations ext4_sops = {
1228         .alloc_inode    = ext4_alloc_inode,
1229         .destroy_inode  = ext4_destroy_inode,
1230         .write_inode    = ext4_write_inode,
1231         .dirty_inode    = ext4_dirty_inode,
1232         .drop_inode     = ext4_drop_inode,
1233         .evict_inode    = ext4_evict_inode,
1234         .put_super      = ext4_put_super,
1235         .sync_fs        = ext4_sync_fs,
1236         .freeze_fs      = ext4_freeze,
1237         .unfreeze_fs    = ext4_unfreeze,
1238         .statfs         = ext4_statfs,
1239         .remount_fs     = ext4_remount,
1240         .show_options   = ext4_show_options,
1241 #ifdef CONFIG_QUOTA
1242         .quota_read     = ext4_quota_read,
1243         .quota_write    = ext4_quota_write,
1244 #endif
1245         .bdev_try_to_free_page = bdev_try_to_free_page,
1246 };
1247
1248 static const struct super_operations ext4_nojournal_sops = {
1249         .alloc_inode    = ext4_alloc_inode,
1250         .destroy_inode  = ext4_destroy_inode,
1251         .write_inode    = ext4_write_inode,
1252         .dirty_inode    = ext4_dirty_inode,
1253         .drop_inode     = ext4_drop_inode,
1254         .evict_inode    = ext4_evict_inode,
1255         .write_super    = ext4_write_super,
1256         .put_super      = ext4_put_super,
1257         .statfs         = ext4_statfs,
1258         .remount_fs     = ext4_remount,
1259         .show_options   = ext4_show_options,
1260 #ifdef CONFIG_QUOTA
1261         .quota_read     = ext4_quota_read,
1262         .quota_write    = ext4_quota_write,
1263 #endif
1264         .bdev_try_to_free_page = bdev_try_to_free_page,
1265 };
1266
1267 static const struct export_operations ext4_export_ops = {
1268         .fh_to_dentry = ext4_fh_to_dentry,
1269         .fh_to_parent = ext4_fh_to_parent,
1270         .get_parent = ext4_get_parent,
1271 };
1272
1273 enum {
1274         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1275         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1276         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1277         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1278         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1279         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1280         Opt_journal_update, Opt_journal_dev,
1281         Opt_journal_checksum, Opt_journal_async_commit,
1282         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1283         Opt_data_err_abort, Opt_data_err_ignore,
1284         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1285         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1286         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1287         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1288         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1289         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1290         Opt_inode_readahead_blks, Opt_journal_ioprio,
1291         Opt_dioread_nolock, Opt_dioread_lock,
1292         Opt_discard, Opt_nodiscard,
1293         Opt_init_inode_table, Opt_noinit_inode_table,
1294 };
1295
1296 static const match_table_t tokens = {
1297         {Opt_bsd_df, "bsddf"},
1298         {Opt_minix_df, "minixdf"},
1299         {Opt_grpid, "grpid"},
1300         {Opt_grpid, "bsdgroups"},
1301         {Opt_nogrpid, "nogrpid"},
1302         {Opt_nogrpid, "sysvgroups"},
1303         {Opt_resgid, "resgid=%u"},
1304         {Opt_resuid, "resuid=%u"},
1305         {Opt_sb, "sb=%u"},
1306         {Opt_err_cont, "errors=continue"},
1307         {Opt_err_panic, "errors=panic"},
1308         {Opt_err_ro, "errors=remount-ro"},
1309         {Opt_nouid32, "nouid32"},
1310         {Opt_debug, "debug"},
1311         {Opt_oldalloc, "oldalloc"},
1312         {Opt_orlov, "orlov"},
1313         {Opt_user_xattr, "user_xattr"},
1314         {Opt_nouser_xattr, "nouser_xattr"},
1315         {Opt_acl, "acl"},
1316         {Opt_noacl, "noacl"},
1317         {Opt_noload, "noload"},
1318         {Opt_noload, "norecovery"},
1319         {Opt_nobh, "nobh"},
1320         {Opt_bh, "bh"},
1321         {Opt_commit, "commit=%u"},
1322         {Opt_min_batch_time, "min_batch_time=%u"},
1323         {Opt_max_batch_time, "max_batch_time=%u"},
1324         {Opt_journal_update, "journal=update"},
1325         {Opt_journal_dev, "journal_dev=%u"},
1326         {Opt_journal_checksum, "journal_checksum"},
1327         {Opt_journal_async_commit, "journal_async_commit"},
1328         {Opt_abort, "abort"},
1329         {Opt_data_journal, "data=journal"},
1330         {Opt_data_ordered, "data=ordered"},
1331         {Opt_data_writeback, "data=writeback"},
1332         {Opt_data_err_abort, "data_err=abort"},
1333         {Opt_data_err_ignore, "data_err=ignore"},
1334         {Opt_offusrjquota, "usrjquota="},
1335         {Opt_usrjquota, "usrjquota=%s"},
1336         {Opt_offgrpjquota, "grpjquota="},
1337         {Opt_grpjquota, "grpjquota=%s"},
1338         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1339         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1340         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1341         {Opt_grpquota, "grpquota"},
1342         {Opt_noquota, "noquota"},
1343         {Opt_quota, "quota"},
1344         {Opt_usrquota, "usrquota"},
1345         {Opt_barrier, "barrier=%u"},
1346         {Opt_barrier, "barrier"},
1347         {Opt_nobarrier, "nobarrier"},
1348         {Opt_i_version, "i_version"},
1349         {Opt_stripe, "stripe=%u"},
1350         {Opt_resize, "resize"},
1351         {Opt_delalloc, "delalloc"},
1352         {Opt_nodelalloc, "nodelalloc"},
1353         {Opt_mblk_io_submit, "mblk_io_submit"},
1354         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1355         {Opt_block_validity, "block_validity"},
1356         {Opt_noblock_validity, "noblock_validity"},
1357         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1358         {Opt_journal_ioprio, "journal_ioprio=%u"},
1359         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1360         {Opt_auto_da_alloc, "auto_da_alloc"},
1361         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1362         {Opt_dioread_nolock, "dioread_nolock"},
1363         {Opt_dioread_lock, "dioread_lock"},
1364         {Opt_discard, "discard"},
1365         {Opt_nodiscard, "nodiscard"},
1366         {Opt_init_inode_table, "init_itable=%u"},
1367         {Opt_init_inode_table, "init_itable"},
1368         {Opt_noinit_inode_table, "noinit_itable"},
1369         {Opt_err, NULL},
1370 };
1371
1372 static ext4_fsblk_t get_sb_block(void **data)
1373 {
1374         ext4_fsblk_t    sb_block;
1375         char            *options = (char *) *data;
1376
1377         if (!options || strncmp(options, "sb=", 3) != 0)
1378                 return 1;       /* Default location */
1379
1380         options += 3;
1381         /* TODO: use simple_strtoll with >32bit ext4 */
1382         sb_block = simple_strtoul(options, &options, 0);
1383         if (*options && *options != ',') {
1384                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1385                        (char *) *data);
1386                 return 1;
1387         }
1388         if (*options == ',')
1389                 options++;
1390         *data = (void *) options;
1391
1392         return sb_block;
1393 }
1394
1395 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1396 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1397         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1398
1399 #ifdef CONFIG_QUOTA
1400 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1401 {
1402         struct ext4_sb_info *sbi = EXT4_SB(sb);
1403         char *qname;
1404
1405         if (sb_any_quota_loaded(sb) &&
1406                 !sbi->s_qf_names[qtype]) {
1407                 ext4_msg(sb, KERN_ERR,
1408                         "Cannot change journaled "
1409                         "quota options when quota turned on");
1410                 return 0;
1411         }
1412         qname = match_strdup(args);
1413         if (!qname) {
1414                 ext4_msg(sb, KERN_ERR,
1415                         "Not enough memory for storing quotafile name");
1416                 return 0;
1417         }
1418         if (sbi->s_qf_names[qtype] &&
1419                 strcmp(sbi->s_qf_names[qtype], qname)) {
1420                 ext4_msg(sb, KERN_ERR,
1421                         "%s quota file already specified", QTYPE2NAME(qtype));
1422                 kfree(qname);
1423                 return 0;
1424         }
1425         sbi->s_qf_names[qtype] = qname;
1426         if (strchr(sbi->s_qf_names[qtype], '/')) {
1427                 ext4_msg(sb, KERN_ERR,
1428                         "quotafile must be on filesystem root");
1429                 kfree(sbi->s_qf_names[qtype]);
1430                 sbi->s_qf_names[qtype] = NULL;
1431                 return 0;
1432         }
1433         set_opt(sb, QUOTA);
1434         return 1;
1435 }
1436
1437 static int clear_qf_name(struct super_block *sb, int qtype)
1438 {
1439
1440         struct ext4_sb_info *sbi = EXT4_SB(sb);
1441
1442         if (sb_any_quota_loaded(sb) &&
1443                 sbi->s_qf_names[qtype]) {
1444                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1445                         " when quota turned on");
1446                 return 0;
1447         }
1448         /*
1449          * The space will be released later when all options are confirmed
1450          * to be correct
1451          */
1452         sbi->s_qf_names[qtype] = NULL;
1453         return 1;
1454 }
1455 #endif
1456
1457 static int parse_options(char *options, struct super_block *sb,
1458                          unsigned long *journal_devnum,
1459                          unsigned int *journal_ioprio,
1460                          ext4_fsblk_t *n_blocks_count, int is_remount)
1461 {
1462         struct ext4_sb_info *sbi = EXT4_SB(sb);
1463         char *p;
1464         substring_t args[MAX_OPT_ARGS];
1465         int data_opt = 0;
1466         int option;
1467 #ifdef CONFIG_QUOTA
1468         int qfmt;
1469 #endif
1470
1471         if (!options)
1472                 return 1;
1473
1474         while ((p = strsep(&options, ",")) != NULL) {
1475                 int token;
1476                 if (!*p)
1477                         continue;
1478
1479                 /*
1480                  * Initialize args struct so we know whether arg was
1481                  * found; some options take optional arguments.
1482                  */
1483                 args[0].to = args[0].from = NULL;
1484                 token = match_token(p, tokens, args);
1485                 switch (token) {
1486                 case Opt_bsd_df:
1487                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1488                         clear_opt(sb, MINIX_DF);
1489                         break;
1490                 case Opt_minix_df:
1491                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1492                         set_opt(sb, MINIX_DF);
1493
1494                         break;
1495                 case Opt_grpid:
1496                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1497                         set_opt(sb, GRPID);
1498
1499                         break;
1500                 case Opt_nogrpid:
1501                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1502                         clear_opt(sb, GRPID);
1503
1504                         break;
1505                 case Opt_resuid:
1506                         if (match_int(&args[0], &option))
1507                                 return 0;
1508                         sbi->s_resuid = option;
1509                         break;
1510                 case Opt_resgid:
1511                         if (match_int(&args[0], &option))
1512                                 return 0;
1513                         sbi->s_resgid = option;
1514                         break;
1515                 case Opt_sb:
1516                         /* handled by get_sb_block() instead of here */
1517                         /* *sb_block = match_int(&args[0]); */
1518                         break;
1519                 case Opt_err_panic:
1520                         clear_opt(sb, ERRORS_CONT);
1521                         clear_opt(sb, ERRORS_RO);
1522                         set_opt(sb, ERRORS_PANIC);
1523                         break;
1524                 case Opt_err_ro:
1525                         clear_opt(sb, ERRORS_CONT);
1526                         clear_opt(sb, ERRORS_PANIC);
1527                         set_opt(sb, ERRORS_RO);
1528                         break;
1529                 case Opt_err_cont:
1530                         clear_opt(sb, ERRORS_RO);
1531                         clear_opt(sb, ERRORS_PANIC);
1532                         set_opt(sb, ERRORS_CONT);
1533                         break;
1534                 case Opt_nouid32:
1535                         set_opt(sb, NO_UID32);
1536                         break;
1537                 case Opt_debug:
1538                         set_opt(sb, DEBUG);
1539                         break;
1540                 case Opt_oldalloc:
1541                         set_opt(sb, OLDALLOC);
1542                         break;
1543                 case Opt_orlov:
1544                         clear_opt(sb, OLDALLOC);
1545                         break;
1546 #ifdef CONFIG_EXT4_FS_XATTR
1547                 case Opt_user_xattr:
1548                         set_opt(sb, XATTR_USER);
1549                         break;
1550                 case Opt_nouser_xattr:
1551                         clear_opt(sb, XATTR_USER);
1552                         break;
1553 #else
1554                 case Opt_user_xattr:
1555                 case Opt_nouser_xattr:
1556                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1557                         break;
1558 #endif
1559 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1560                 case Opt_acl:
1561                         set_opt(sb, POSIX_ACL);
1562                         break;
1563                 case Opt_noacl:
1564                         clear_opt(sb, POSIX_ACL);
1565                         break;
1566 #else
1567                 case Opt_acl:
1568                 case Opt_noacl:
1569                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1570                         break;
1571 #endif
1572                 case Opt_journal_update:
1573                         /* @@@ FIXME */
1574                         /* Eventually we will want to be able to create
1575                            a journal file here.  For now, only allow the
1576                            user to specify an existing inode to be the
1577                            journal file. */
1578                         if (is_remount) {
1579                                 ext4_msg(sb, KERN_ERR,
1580                                          "Cannot specify journal on remount");
1581                                 return 0;
1582                         }
1583                         set_opt(sb, UPDATE_JOURNAL);
1584                         break;
1585                 case Opt_journal_dev:
1586                         if (is_remount) {
1587                                 ext4_msg(sb, KERN_ERR,
1588                                         "Cannot specify journal on remount");
1589                                 return 0;
1590                         }
1591                         if (match_int(&args[0], &option))
1592                                 return 0;
1593                         *journal_devnum = option;
1594                         break;
1595                 case Opt_journal_checksum:
1596                         set_opt(sb, JOURNAL_CHECKSUM);
1597                         break;
1598                 case Opt_journal_async_commit:
1599                         set_opt(sb, JOURNAL_ASYNC_COMMIT);
1600                         set_opt(sb, JOURNAL_CHECKSUM);
1601                         break;
1602                 case Opt_noload:
1603                         set_opt(sb, NOLOAD);
1604                         break;
1605                 case Opt_commit:
1606                         if (match_int(&args[0], &option))
1607                                 return 0;
1608                         if (option < 0)
1609                                 return 0;
1610                         if (option == 0)
1611                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1612                         sbi->s_commit_interval = HZ * option;
1613                         break;
1614                 case Opt_max_batch_time:
1615                         if (match_int(&args[0], &option))
1616                                 return 0;
1617                         if (option < 0)
1618                                 return 0;
1619                         if (option == 0)
1620                                 option = EXT4_DEF_MAX_BATCH_TIME;
1621                         sbi->s_max_batch_time = option;
1622                         break;
1623                 case Opt_min_batch_time:
1624                         if (match_int(&args[0], &option))
1625                                 return 0;
1626                         if (option < 0)
1627                                 return 0;
1628                         sbi->s_min_batch_time = option;
1629                         break;
1630                 case Opt_data_journal:
1631                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1632                         goto datacheck;
1633                 case Opt_data_ordered:
1634                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1635                         goto datacheck;
1636                 case Opt_data_writeback:
1637                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1638                 datacheck:
1639                         if (is_remount) {
1640                                 if (test_opt(sb, DATA_FLAGS) != data_opt) {
1641                                         ext4_msg(sb, KERN_ERR,
1642                                                 "Cannot change data mode on remount");
1643                                         return 0;
1644                                 }
1645                         } else {
1646                                 clear_opt(sb, DATA_FLAGS);
1647                                 sbi->s_mount_opt |= data_opt;
1648                         }
1649                         break;
1650                 case Opt_data_err_abort:
1651                         set_opt(sb, DATA_ERR_ABORT);
1652                         break;
1653                 case Opt_data_err_ignore:
1654                         clear_opt(sb, DATA_ERR_ABORT);
1655                         break;
1656 #ifdef CONFIG_QUOTA
1657                 case Opt_usrjquota:
1658                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1659                                 return 0;
1660                         break;
1661                 case Opt_grpjquota:
1662                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1663                                 return 0;
1664                         break;
1665                 case Opt_offusrjquota:
1666                         if (!clear_qf_name(sb, USRQUOTA))
1667                                 return 0;
1668                         break;
1669                 case Opt_offgrpjquota:
1670                         if (!clear_qf_name(sb, GRPQUOTA))
1671                                 return 0;
1672                         break;
1673
1674                 case Opt_jqfmt_vfsold:
1675                         qfmt = QFMT_VFS_OLD;
1676                         goto set_qf_format;
1677                 case Opt_jqfmt_vfsv0:
1678                         qfmt = QFMT_VFS_V0;
1679                         goto set_qf_format;
1680                 case Opt_jqfmt_vfsv1:
1681                         qfmt = QFMT_VFS_V1;
1682 set_qf_format:
1683                         if (sb_any_quota_loaded(sb) &&
1684                             sbi->s_jquota_fmt != qfmt) {
1685                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1686                                         "journaled quota options when "
1687                                         "quota turned on");
1688                                 return 0;
1689                         }
1690                         sbi->s_jquota_fmt = qfmt;
1691                         break;
1692                 case Opt_quota:
1693                 case Opt_usrquota:
1694                         set_opt(sb, QUOTA);
1695                         set_opt(sb, USRQUOTA);
1696                         break;
1697                 case Opt_grpquota:
1698                         set_opt(sb, QUOTA);
1699                         set_opt(sb, GRPQUOTA);
1700                         break;
1701                 case Opt_noquota:
1702                         if (sb_any_quota_loaded(sb)) {
1703                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1704                                         "options when quota turned on");
1705                                 return 0;
1706                         }
1707                         clear_opt(sb, QUOTA);
1708                         clear_opt(sb, USRQUOTA);
1709                         clear_opt(sb, GRPQUOTA);
1710                         break;
1711 #else
1712                 case Opt_quota:
1713                 case Opt_usrquota:
1714                 case Opt_grpquota:
1715                         ext4_msg(sb, KERN_ERR,
1716                                 "quota options not supported");
1717                         break;
1718                 case Opt_usrjquota:
1719                 case Opt_grpjquota:
1720                 case Opt_offusrjquota:
1721                 case Opt_offgrpjquota:
1722                 case Opt_jqfmt_vfsold:
1723                 case Opt_jqfmt_vfsv0:
1724                 case Opt_jqfmt_vfsv1:
1725                         ext4_msg(sb, KERN_ERR,
1726                                 "journaled quota options not supported");
1727                         break;
1728                 case Opt_noquota:
1729                         break;
1730 #endif
1731                 case Opt_abort:
1732                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1733                         break;
1734                 case Opt_nobarrier:
1735                         clear_opt(sb, BARRIER);
1736                         break;
1737                 case Opt_barrier:
1738                         if (args[0].from) {
1739                                 if (match_int(&args[0], &option))
1740                                         return 0;
1741                         } else
1742                                 option = 1;     /* No argument, default to 1 */
1743                         if (option)
1744                                 set_opt(sb, BARRIER);
1745                         else
1746                                 clear_opt(sb, BARRIER);
1747                         break;
1748                 case Opt_ignore:
1749                         break;
1750                 case Opt_resize:
1751                         if (!is_remount) {
1752                                 ext4_msg(sb, KERN_ERR,
1753                                         "resize option only available "
1754                                         "for remount");
1755                                 return 0;
1756                         }
1757                         if (match_int(&args[0], &option) != 0)
1758                                 return 0;
1759                         *n_blocks_count = option;
1760                         break;
1761                 case Opt_nobh:
1762                         ext4_msg(sb, KERN_WARNING,
1763                                  "Ignoring deprecated nobh option");
1764                         break;
1765                 case Opt_bh:
1766                         ext4_msg(sb, KERN_WARNING,
1767                                  "Ignoring deprecated bh option");
1768                         break;
1769                 case Opt_i_version:
1770                         set_opt(sb, I_VERSION);
1771                         sb->s_flags |= MS_I_VERSION;
1772                         break;
1773                 case Opt_nodelalloc:
1774                         clear_opt(sb, DELALLOC);
1775                         break;
1776                 case Opt_mblk_io_submit:
1777                         set_opt(sb, MBLK_IO_SUBMIT);
1778                         break;
1779                 case Opt_nomblk_io_submit:
1780                         clear_opt(sb, MBLK_IO_SUBMIT);
1781                         break;
1782                 case Opt_stripe:
1783                         if (match_int(&args[0], &option))
1784                                 return 0;
1785                         if (option < 0)
1786                                 return 0;
1787                         sbi->s_stripe = option;
1788                         break;
1789                 case Opt_delalloc:
1790                         set_opt(sb, DELALLOC);
1791                         break;
1792                 case Opt_block_validity:
1793                         set_opt(sb, BLOCK_VALIDITY);
1794                         break;
1795                 case Opt_noblock_validity:
1796                         clear_opt(sb, BLOCK_VALIDITY);
1797                         break;
1798                 case Opt_inode_readahead_blks:
1799                         if (match_int(&args[0], &option))
1800                                 return 0;
1801                         if (option < 0 || option > (1 << 30))
1802                                 return 0;
1803                         if (option && !is_power_of_2(option)) {
1804                                 ext4_msg(sb, KERN_ERR,
1805                                          "EXT4-fs: inode_readahead_blks"
1806                                          " must be a power of 2");
1807                                 return 0;
1808                         }
1809                         sbi->s_inode_readahead_blks = option;
1810                         break;
1811                 case Opt_journal_ioprio:
1812                         if (match_int(&args[0], &option))
1813                                 return 0;
1814                         if (option < 0 || option > 7)
1815                                 break;
1816                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1817                                                             option);
1818                         break;
1819                 case Opt_noauto_da_alloc:
1820                         set_opt(sb, NO_AUTO_DA_ALLOC);
1821                         break;
1822                 case Opt_auto_da_alloc:
1823                         if (args[0].from) {
1824                                 if (match_int(&args[0], &option))
1825                                         return 0;
1826                         } else
1827                                 option = 1;     /* No argument, default to 1 */
1828                         if (option)
1829                                 clear_opt(sb, NO_AUTO_DA_ALLOC);
1830                         else
1831                                 set_opt(sb,NO_AUTO_DA_ALLOC);
1832                         break;
1833                 case Opt_discard:
1834                         set_opt(sb, DISCARD);
1835                         break;
1836                 case Opt_nodiscard:
1837                         clear_opt(sb, DISCARD);
1838                         break;
1839                 case Opt_dioread_nolock:
1840                         set_opt(sb, DIOREAD_NOLOCK);
1841                         break;
1842                 case Opt_dioread_lock:
1843                         clear_opt(sb, DIOREAD_NOLOCK);
1844                         break;
1845                 case Opt_init_inode_table:
1846                         set_opt(sb, INIT_INODE_TABLE);
1847                         if (args[0].from) {
1848                                 if (match_int(&args[0], &option))
1849                                         return 0;
1850                         } else
1851                                 option = EXT4_DEF_LI_WAIT_MULT;
1852                         if (option < 0)
1853                                 return 0;
1854                         sbi->s_li_wait_mult = option;
1855                         break;
1856                 case Opt_noinit_inode_table:
1857                         clear_opt(sb, INIT_INODE_TABLE);
1858                         break;
1859                 default:
1860                         ext4_msg(sb, KERN_ERR,
1861                                "Unrecognized mount option \"%s\" "
1862                                "or missing value", p);
1863                         return 0;
1864                 }
1865         }
1866 #ifdef CONFIG_QUOTA
1867         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1868                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1869                         clear_opt(sb, USRQUOTA);
1870
1871                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1872                         clear_opt(sb, GRPQUOTA);
1873
1874                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1875                         ext4_msg(sb, KERN_ERR, "old and new quota "
1876                                         "format mixing");
1877                         return 0;
1878                 }
1879
1880                 if (!sbi->s_jquota_fmt) {
1881                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1882                                         "not specified");
1883                         return 0;
1884                 }
1885         } else {
1886                 if (sbi->s_jquota_fmt) {
1887                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1888                                         "specified with no journaling "
1889                                         "enabled");
1890                         return 0;
1891                 }
1892         }
1893 #endif
1894         return 1;
1895 }
1896
1897 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1898                             int read_only)
1899 {
1900         struct ext4_sb_info *sbi = EXT4_SB(sb);
1901         int res = 0;
1902
1903         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1904                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1905                          "forcing read-only mode");
1906                 res = MS_RDONLY;
1907         }
1908         if (read_only)
1909                 return res;
1910         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1911                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1912                          "running e2fsck is recommended");
1913         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1914                 ext4_msg(sb, KERN_WARNING,
1915                          "warning: mounting fs with errors, "
1916                          "running e2fsck is recommended");
1917         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1918                  le16_to_cpu(es->s_mnt_count) >=
1919                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1920                 ext4_msg(sb, KERN_WARNING,
1921                          "warning: maximal mount count reached, "
1922                          "running e2fsck is recommended");
1923         else if (le32_to_cpu(es->s_checkinterval) &&
1924                 (le32_to_cpu(es->s_lastcheck) +
1925                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1926                 ext4_msg(sb, KERN_WARNING,
1927                          "warning: checktime reached, "
1928                          "running e2fsck is recommended");
1929         if (!sbi->s_journal)
1930                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1931         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1932                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1933         le16_add_cpu(&es->s_mnt_count, 1);
1934         es->s_mtime = cpu_to_le32(get_seconds());
1935         ext4_update_dynamic_rev(sb);
1936         if (sbi->s_journal)
1937                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1938
1939         ext4_commit_super(sb, 1);
1940         if (test_opt(sb, DEBUG))
1941                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1942                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1943                         sb->s_blocksize,
1944                         sbi->s_groups_count,
1945                         EXT4_BLOCKS_PER_GROUP(sb),
1946                         EXT4_INODES_PER_GROUP(sb),
1947                         sbi->s_mount_opt, sbi->s_mount_opt2);
1948
1949         return res;
1950 }
1951
1952 static int ext4_fill_flex_info(struct super_block *sb)
1953 {
1954         struct ext4_sb_info *sbi = EXT4_SB(sb);
1955         struct ext4_group_desc *gdp = NULL;
1956         ext4_group_t flex_group_count;
1957         ext4_group_t flex_group;
1958         int groups_per_flex = 0;
1959         size_t size;
1960         int i;
1961
1962         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1964
1965         if (groups_per_flex < 2) {
1966                 sbi->s_log_groups_per_flex = 0;
1967                 return 1;
1968         }
1969
1970         /* We allocate both existing and potentially added groups */
1971         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1972                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1973                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1974         size = flex_group_count * sizeof(struct flex_groups);
1975         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1976         if (sbi->s_flex_groups == NULL) {
1977                 sbi->s_flex_groups = vzalloc(size);
1978                 if (sbi->s_flex_groups == NULL) {
1979                         ext4_msg(sb, KERN_ERR,
1980                                  "not enough memory for %u flex groups",
1981                                  flex_group_count);
1982                         goto failed;
1983                 }
1984         }
1985
1986         for (i = 0; i < sbi->s_groups_count; i++) {
1987                 gdp = ext4_get_group_desc(sb, i, NULL);
1988
1989                 flex_group = ext4_flex_group(sbi, i);
1990                 atomic_add(ext4_free_inodes_count(sb, gdp),
1991                            &sbi->s_flex_groups[flex_group].free_inodes);
1992                 atomic_add(ext4_free_blks_count(sb, gdp),
1993                            &sbi->s_flex_groups[flex_group].free_blocks);
1994                 atomic_add(ext4_used_dirs_count(sb, gdp),
1995                            &sbi->s_flex_groups[flex_group].used_dirs);
1996         }
1997
1998         return 1;
1999 failed:
2000         return 0;
2001 }
2002
2003 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
2004                             struct ext4_group_desc *gdp)
2005 {
2006         __u16 crc = 0;
2007
2008         if (sbi->s_es->s_feature_ro_compat &
2009             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
2010                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
2011                 __le32 le_group = cpu_to_le32(block_group);
2012
2013                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2014                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2015                 crc = crc16(crc, (__u8 *)gdp, offset);
2016                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
2017                 /* for checksum of struct ext4_group_desc do the rest...*/
2018                 if ((sbi->s_es->s_feature_incompat &
2019                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2020                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
2021                         crc = crc16(crc, (__u8 *)gdp + offset,
2022                                     le16_to_cpu(sbi->s_es->s_desc_size) -
2023                                         offset);
2024         }
2025
2026         return cpu_to_le16(crc);
2027 }
2028
2029 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2030                                 struct ext4_group_desc *gdp)
2031 {
2032         if ((sbi->s_es->s_feature_ro_compat &
2033              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2034             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2035                 return 0;
2036
2037         return 1;
2038 }
2039
2040 /* Called at mount-time, super-block is locked */
2041 static int ext4_check_descriptors(struct super_block *sb,
2042                                   ext4_group_t *first_not_zeroed)
2043 {
2044         struct ext4_sb_info *sbi = EXT4_SB(sb);
2045         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2046         ext4_fsblk_t last_block;
2047         ext4_fsblk_t block_bitmap;
2048         ext4_fsblk_t inode_bitmap;
2049         ext4_fsblk_t inode_table;
2050         int flexbg_flag = 0;
2051         ext4_group_t i, grp = sbi->s_groups_count;
2052
2053         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2054                 flexbg_flag = 1;
2055
2056         ext4_debug("Checking group descriptors");
2057
2058         for (i = 0; i < sbi->s_groups_count; i++) {
2059                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2060
2061                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2062                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2063                 else
2064                         last_block = first_block +
2065                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2066
2067                 if ((grp == sbi->s_groups_count) &&
2068                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2069                         grp = i;
2070
2071                 block_bitmap = ext4_block_bitmap(sb, gdp);
2072                 if (block_bitmap < first_block || block_bitmap > last_block) {
2073                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2074                                "Block bitmap for group %u not in group "
2075                                "(block %llu)!", i, block_bitmap);
2076                         return 0;
2077                 }
2078                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2079                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2080                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2081                                "Inode bitmap for group %u not in group "
2082                                "(block %llu)!", i, inode_bitmap);
2083                         return 0;
2084                 }
2085                 inode_table = ext4_inode_table(sb, gdp);
2086                 if (inode_table < first_block ||
2087                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2088                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2089                                "Inode table for group %u not in group "
2090                                "(block %llu)!", i, inode_table);
2091                         return 0;
2092                 }
2093                 ext4_lock_group(sb, i);
2094                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2095                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2096                                  "Checksum for group %u failed (%u!=%u)",
2097                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2098                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2099                         if (!(sb->s_flags & MS_RDONLY)) {
2100                                 ext4_unlock_group(sb, i);
2101                                 return 0;
2102                         }
2103                 }
2104                 ext4_unlock_group(sb, i);
2105                 if (!flexbg_flag)
2106                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2107         }
2108         if (NULL != first_not_zeroed)
2109                 *first_not_zeroed = grp;
2110
2111         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
2112         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2113         return 1;
2114 }
2115
2116 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2117  * the superblock) which were deleted from all directories, but held open by
2118  * a process at the time of a crash.  We walk the list and try to delete these
2119  * inodes at recovery time (only with a read-write filesystem).
2120  *
2121  * In order to keep the orphan inode chain consistent during traversal (in
2122  * case of crash during recovery), we link each inode into the superblock
2123  * orphan list_head and handle it the same way as an inode deletion during
2124  * normal operation (which journals the operations for us).
2125  *
2126  * We only do an iget() and an iput() on each inode, which is very safe if we
2127  * accidentally point at an in-use or already deleted inode.  The worst that
2128  * can happen in this case is that we get a "bit already cleared" message from
2129  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2130  * e2fsck was run on this filesystem, and it must have already done the orphan
2131  * inode cleanup for us, so we can safely abort without any further action.
2132  */
2133 static void ext4_orphan_cleanup(struct super_block *sb,
2134                                 struct ext4_super_block *es)
2135 {
2136         unsigned int s_flags = sb->s_flags;
2137         int nr_orphans = 0, nr_truncates = 0;
2138 #ifdef CONFIG_QUOTA
2139         int i;
2140 #endif
2141         if (!es->s_last_orphan) {
2142                 jbd_debug(4, "no orphan inodes to clean up\n");
2143                 return;
2144         }
2145
2146         if (bdev_read_only(sb->s_bdev)) {
2147                 ext4_msg(sb, KERN_ERR, "write access "
2148                         "unavailable, skipping orphan cleanup");
2149                 return;
2150         }
2151
2152         /* Check if feature set would not allow a r/w mount */
2153         if (!ext4_feature_set_ok(sb, 0)) {
2154                 ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2155                          "unknown ROCOMPAT features");
2156                 return;
2157         }
2158
2159         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2160                 if (es->s_last_orphan)
2161                         jbd_debug(1, "Errors on filesystem, "
2162                                   "clearing orphan list.\n");
2163                 es->s_last_orphan = 0;
2164                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2165                 return;
2166         }
2167
2168         if (s_flags & MS_RDONLY) {
2169                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2170                 sb->s_flags &= ~MS_RDONLY;
2171         }
2172 #ifdef CONFIG_QUOTA
2173         /* Needed for iput() to work correctly and not trash data */
2174         sb->s_flags |= MS_ACTIVE;
2175         /* Turn on quotas so that they are updated correctly */
2176         for (i = 0; i < MAXQUOTAS; i++) {
2177                 if (EXT4_SB(sb)->s_qf_names[i]) {
2178                         int ret = ext4_quota_on_mount(sb, i);
2179                         if (ret < 0)
2180                                 ext4_msg(sb, KERN_ERR,
2181                                         "Cannot turn on journaled "
2182                                         "quota: error %d", ret);
2183                 }
2184         }
2185 #endif
2186
2187         while (es->s_last_orphan) {
2188                 struct inode *inode;
2189
2190                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2191                 if (IS_ERR(inode)) {
2192                         es->s_last_orphan = 0;
2193                         break;
2194                 }
2195
2196                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2197                 dquot_initialize(inode);
2198                 if (inode->i_nlink) {
2199                         ext4_msg(sb, KERN_DEBUG,
2200                                 "%s: truncating inode %lu to %lld bytes",
2201                                 __func__, inode->i_ino, inode->i_size);
2202                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2203                                   inode->i_ino, inode->i_size);
2204                         ext4_truncate(inode);
2205                         nr_truncates++;
2206                 } else {
2207                         ext4_msg(sb, KERN_DEBUG,
2208                                 "%s: deleting unreferenced inode %lu",
2209                                 __func__, inode->i_ino);
2210                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2211                                   inode->i_ino);
2212                         nr_orphans++;
2213                 }
2214                 iput(inode);  /* The delete magic happens here! */
2215         }
2216
2217 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2218
2219         if (nr_orphans)
2220                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2221                        PLURAL(nr_orphans));
2222         if (nr_truncates)
2223                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2224                        PLURAL(nr_truncates));
2225 #ifdef CONFIG_QUOTA
2226         /* Turn quotas off */
2227         for (i = 0; i < MAXQUOTAS; i++) {
2228                 if (sb_dqopt(sb)->files[i])
2229                         dquot_quota_off(sb, i);
2230         }
2231 #endif
2232         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2233 }
2234
2235 /*
2236  * Maximal extent format file size.
2237  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2238  * extent format containers, within a sector_t, and within i_blocks
2239  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2240  * so that won't be a limiting factor.
2241  *
2242  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2243  */
2244 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2245 {
2246         loff_t res;
2247         loff_t upper_limit = MAX_LFS_FILESIZE;
2248
2249         /* small i_blocks in vfs inode? */
2250         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2251                 /*
2252                  * CONFIG_LBDAF is not enabled implies the inode
2253                  * i_block represent total blocks in 512 bytes
2254                  * 32 == size of vfs inode i_blocks * 8
2255                  */
2256                 upper_limit = (1LL << 32) - 1;
2257
2258                 /* total blocks in file system block size */
2259                 upper_limit >>= (blkbits - 9);
2260                 upper_limit <<= blkbits;
2261         }
2262
2263         /* 32-bit extent-start container, ee_block */
2264         res = 1LL << 32;
2265         res <<= blkbits;
2266         res -= 1;
2267
2268         /* Sanity check against vm- & vfs- imposed limits */
2269         if (res > upper_limit)
2270                 res = upper_limit;
2271
2272         return res;
2273 }
2274
2275 /*
2276  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2277  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2278  * We need to be 1 filesystem block less than the 2^48 sector limit.
2279  */
2280 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2281 {
2282         loff_t res = EXT4_NDIR_BLOCKS;
2283         int meta_blocks;
2284         loff_t upper_limit;
2285         /* This is calculated to be the largest file size for a dense, block
2286          * mapped file such that the file's total number of 512-byte sectors,
2287          * including data and all indirect blocks, does not exceed (2^48 - 1).
2288          *
2289          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2290          * number of 512-byte sectors of the file.
2291          */
2292
2293         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2294                 /*
2295                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2296                  * the inode i_block field represents total file blocks in
2297                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2298                  */
2299                 upper_limit = (1LL << 32) - 1;
2300
2301                 /* total blocks in file system block size */
2302                 upper_limit >>= (bits - 9);
2303
2304         } else {
2305                 /*
2306                  * We use 48 bit ext4_inode i_blocks
2307                  * With EXT4_HUGE_FILE_FL set the i_blocks
2308                  * represent total number of blocks in
2309                  * file system block size
2310                  */
2311                 upper_limit = (1LL << 48) - 1;
2312
2313         }
2314
2315         /* indirect blocks */
2316         meta_blocks = 1;
2317         /* double indirect blocks */
2318         meta_blocks += 1 + (1LL << (bits-2));
2319         /* tripple indirect blocks */
2320         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2321
2322         upper_limit -= meta_blocks;
2323         upper_limit <<= bits;
2324
2325         res += 1LL << (bits-2);
2326         res += 1LL << (2*(bits-2));
2327         res += 1LL << (3*(bits-2));
2328         res <<= bits;
2329         if (res > upper_limit)
2330                 res = upper_limit;
2331
2332         if (res > MAX_LFS_FILESIZE)
2333                 res = MAX_LFS_FILESIZE;
2334
2335         return res;
2336 }
2337
2338 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2339                                    ext4_fsblk_t logical_sb_block, int nr)
2340 {
2341         struct ext4_sb_info *sbi = EXT4_SB(sb);
2342         ext4_group_t bg, first_meta_bg;
2343         int has_super = 0;
2344
2345         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2346
2347         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2348             nr < first_meta_bg)
2349                 return logical_sb_block + nr + 1;
2350         bg = sbi->s_desc_per_block * nr;
2351         if (ext4_bg_has_super(sb, bg))
2352                 has_super = 1;
2353
2354         return (has_super + ext4_group_first_block_no(sb, bg));
2355 }
2356
2357 /**
2358  * ext4_get_stripe_size: Get the stripe size.
2359  * @sbi: In memory super block info
2360  *
2361  * If we have specified it via mount option, then
2362  * use the mount option value. If the value specified at mount time is
2363  * greater than the blocks per group use the super block value.
2364  * If the super block value is greater than blocks per group return 0.
2365  * Allocator needs it be less than blocks per group.
2366  *
2367  */
2368 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2369 {
2370         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2371         unsigned long stripe_width =
2372                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2373
2374         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2375                 return sbi->s_stripe;
2376
2377         if (stripe_width <= sbi->s_blocks_per_group)
2378                 return stripe_width;
2379
2380         if (stride <= sbi->s_blocks_per_group)
2381                 return stride;
2382
2383         return 0;
2384 }
2385
2386 /* sysfs supprt */
2387
2388 struct ext4_attr {
2389         struct attribute attr;
2390         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2391         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2392                          const char *, size_t);
2393         int offset;
2394 };
2395
2396 static int parse_strtoul(const char *buf,
2397                 unsigned long max, unsigned long *value)
2398 {
2399         char *endp;
2400
2401         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2402         endp = skip_spaces(endp);
2403         if (*endp || *value > max)
2404                 return -EINVAL;
2405
2406         return 0;
2407 }
2408
2409 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2410                                               struct ext4_sb_info *sbi,
2411                                               char *buf)
2412 {
2413         return snprintf(buf, PAGE_SIZE, "%llu\n",
2414                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2415 }
2416
2417 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2418                                          struct ext4_sb_info *sbi, char *buf)
2419 {
2420         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2421
2422         if (!sb->s_bdev->bd_part)
2423                 return snprintf(buf, PAGE_SIZE, "0\n");
2424         return snprintf(buf, PAGE_SIZE, "%lu\n",
2425                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2426                          sbi->s_sectors_written_start) >> 1);
2427 }
2428
2429 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2430                                           struct ext4_sb_info *sbi, char *buf)
2431 {
2432         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2433
2434         if (!sb->s_bdev->bd_part)
2435                 return snprintf(buf, PAGE_SIZE, "0\n");
2436         return snprintf(buf, PAGE_SIZE, "%llu\n",
2437                         (unsigned long long)(sbi->s_kbytes_written +
2438                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2439                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2440 }
2441
2442 static ssize_t extent_cache_hits_show(struct ext4_attr *a,
2443                                       struct ext4_sb_info *sbi, char *buf)
2444 {
2445         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_hits);
2446 }
2447
2448 static ssize_t extent_cache_misses_show(struct ext4_attr *a,
2449                                         struct ext4_sb_info *sbi, char *buf)
2450 {
2451         return snprintf(buf, PAGE_SIZE, "%lu\n", sbi->extent_cache_misses);
2452 }
2453
2454 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2455                                           struct ext4_sb_info *sbi,
2456                                           const char *buf, size_t count)
2457 {
2458         unsigned long t;
2459
2460         if (parse_strtoul(buf, 0x40000000, &t))
2461                 return -EINVAL;
2462
2463         if (t && !is_power_of_2(t))
2464                 return -EINVAL;
2465
2466         sbi->s_inode_readahead_blks = t;
2467         return count;
2468 }
2469
2470 static ssize_t sbi_ui_show(struct ext4_attr *a,
2471                            struct ext4_sb_info *sbi, char *buf)
2472 {
2473         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2474
2475         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2476 }
2477
2478 static ssize_t sbi_ui_store(struct ext4_attr *a,
2479                             struct ext4_sb_info *sbi,
2480                             const char *buf, size_t count)
2481 {
2482         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2483         unsigned long t;
2484
2485         if (parse_strtoul(buf, 0xffffffff, &t))
2486                 return -EINVAL;
2487         *ui = t;
2488         return count;
2489 }
2490
2491 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2492 static struct ext4_attr ext4_attr_##_name = {                   \
2493         .attr = {.name = __stringify(_name), .mode = _mode },   \
2494         .show   = _show,                                        \
2495         .store  = _store,                                       \
2496         .offset = offsetof(struct ext4_sb_info, _elname),       \
2497 }
2498 #define EXT4_ATTR(name, mode, show, store) \
2499 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2500
2501 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2502 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2503 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2504 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2505         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2506 #define ATTR_LIST(name) &ext4_attr_##name.attr
2507
2508 EXT4_RO_ATTR(delayed_allocation_blocks);
2509 EXT4_RO_ATTR(session_write_kbytes);
2510 EXT4_RO_ATTR(lifetime_write_kbytes);
2511 EXT4_RO_ATTR(extent_cache_hits);
2512 EXT4_RO_ATTR(extent_cache_misses);
2513 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2514                  inode_readahead_blks_store, s_inode_readahead_blks);
2515 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2516 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2517 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2518 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2519 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2520 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2521 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2522 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2523
2524 static struct attribute *ext4_attrs[] = {
2525         ATTR_LIST(delayed_allocation_blocks),
2526         ATTR_LIST(session_write_kbytes),
2527         ATTR_LIST(lifetime_write_kbytes),
2528         ATTR_LIST(extent_cache_hits),
2529         ATTR_LIST(extent_cache_misses),
2530         ATTR_LIST(inode_readahead_blks),
2531         ATTR_LIST(inode_goal),
2532         ATTR_LIST(mb_stats),
2533         ATTR_LIST(mb_max_to_scan),
2534         ATTR_LIST(mb_min_to_scan),
2535         ATTR_LIST(mb_order2_req),
2536         ATTR_LIST(mb_stream_req),
2537         ATTR_LIST(mb_group_prealloc),
2538         ATTR_LIST(max_writeback_mb_bump),
2539         NULL,
2540 };
2541
2542 /* Features this copy of ext4 supports */
2543 EXT4_INFO_ATTR(lazy_itable_init);
2544 EXT4_INFO_ATTR(batched_discard);
2545
2546 static struct attribute *ext4_feat_attrs[] = {
2547         ATTR_LIST(lazy_itable_init),
2548         ATTR_LIST(batched_discard),
2549         NULL,
2550 };
2551
2552 static ssize_t ext4_attr_show(struct kobject *kobj,
2553                               struct attribute *attr, char *buf)
2554 {
2555         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2556                                                 s_kobj);
2557         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2558
2559         return a->show ? a->show(a, sbi, buf) : 0;
2560 }
2561
2562 static ssize_t ext4_attr_store(struct kobject *kobj,
2563                                struct attribute *attr,
2564                                const char *buf, size_t len)
2565 {
2566         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2567                                                 s_kobj);
2568         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2569
2570         return a->store ? a->store(a, sbi, buf, len) : 0;
2571 }
2572
2573 static void ext4_sb_release(struct kobject *kobj)
2574 {
2575         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2576                                                 s_kobj);
2577         complete(&sbi->s_kobj_unregister);
2578 }
2579
2580 static const struct sysfs_ops ext4_attr_ops = {
2581         .show   = ext4_attr_show,
2582         .store  = ext4_attr_store,
2583 };
2584
2585 static struct kobj_type ext4_ktype = {
2586         .default_attrs  = ext4_attrs,
2587         .sysfs_ops      = &ext4_attr_ops,
2588         .release        = ext4_sb_release,
2589 };
2590
2591 static void ext4_feat_release(struct kobject *kobj)
2592 {
2593         complete(&ext4_feat->f_kobj_unregister);
2594 }
2595
2596 static struct kobj_type ext4_feat_ktype = {
2597         .default_attrs  = ext4_feat_attrs,
2598         .sysfs_ops      = &ext4_attr_ops,
2599         .release        = ext4_feat_release,
2600 };
2601
2602 /*
2603  * Check whether this filesystem can be mounted based on
2604  * the features present and the RDONLY/RDWR mount requested.
2605  * Returns 1 if this filesystem can be mounted as requested,
2606  * 0 if it cannot be.
2607  */
2608 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2609 {
2610         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2611                 ext4_msg(sb, KERN_ERR,
2612                         "Couldn't mount because of "
2613                         "unsupported optional features (%x)",
2614                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2615                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2616                 return 0;
2617         }
2618
2619         if (readonly)
2620                 return 1;
2621
2622         /* Check that feature set is OK for a read-write mount */
2623         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2624                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2625                          "unsupported optional features (%x)",
2626                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2627                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2628                 return 0;
2629         }
2630         /*
2631          * Large file size enabled file system can only be mounted
2632          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2633          */
2634         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2635                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2636                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2637                                  "cannot be mounted RDWR without "
2638                                  "CONFIG_LBDAF");
2639                         return 0;
2640                 }
2641         }
2642         return 1;
2643 }
2644
2645 /*
2646  * This function is called once a day if we have errors logged
2647  * on the file system
2648  */
2649 static void print_daily_error_info(unsigned long arg)
2650 {
2651         struct super_block *sb = (struct super_block *) arg;
2652         struct ext4_sb_info *sbi;
2653         struct ext4_super_block *es;
2654
2655         sbi = EXT4_SB(sb);
2656         es = sbi->s_es;
2657
2658         if (es->s_error_count)
2659                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2660                          le32_to_cpu(es->s_error_count));
2661         if (es->s_first_error_time) {
2662                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2663                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2664                        (int) sizeof(es->s_first_error_func),
2665                        es->s_first_error_func,
2666                        le32_to_cpu(es->s_first_error_line));
2667                 if (es->s_first_error_ino)
2668                         printk(": inode %u",
2669                                le32_to_cpu(es->s_first_error_ino));
2670                 if (es->s_first_error_block)
2671                         printk(": block %llu", (unsigned long long)
2672                                le64_to_cpu(es->s_first_error_block));
2673                 printk("\n");
2674         }
2675         if (es->s_last_error_time) {
2676                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2677                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2678                        (int) sizeof(es->s_last_error_func),
2679                        es->s_last_error_func,
2680                        le32_to_cpu(es->s_last_error_line));
2681                 if (es->s_last_error_ino)
2682                         printk(": inode %u",
2683                                le32_to_cpu(es->s_last_error_ino));
2684                 if (es->s_last_error_block)
2685                         printk(": block %llu", (unsigned long long)
2686                                le64_to_cpu(es->s_last_error_block));
2687                 printk("\n");
2688         }
2689         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2690 }
2691
2692 /* Find next suitable group and run ext4_init_inode_table */
2693 static int ext4_run_li_request(struct ext4_li_request *elr)
2694 {
2695         struct ext4_group_desc *gdp = NULL;
2696         ext4_group_t group, ngroups;
2697         struct super_block *sb;
2698         unsigned long timeout = 0;
2699         int ret = 0;
2700
2701         sb = elr->lr_super;
2702         ngroups = EXT4_SB(sb)->s_groups_count;
2703
2704         for (group = elr->lr_next_group; group < ngroups; group++) {
2705                 gdp = ext4_get_group_desc(sb, group, NULL);
2706                 if (!gdp) {
2707                         ret = 1;
2708                         break;
2709                 }
2710
2711                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2712                         break;
2713         }
2714
2715         if (group == ngroups)
2716                 ret = 1;
2717
2718         if (!ret) {
2719                 timeout = jiffies;
2720                 ret = ext4_init_inode_table(sb, group,
2721                                             elr->lr_timeout ? 0 : 1);
2722                 if (elr->lr_timeout == 0) {
2723                         timeout = (jiffies - timeout) *
2724                                   elr->lr_sbi->s_li_wait_mult;
2725                         elr->lr_timeout = timeout;
2726                 }
2727                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2728                 elr->lr_next_group = group + 1;
2729         }
2730
2731         return ret;
2732 }
2733
2734 /*
2735  * Remove lr_request from the list_request and free the
2736  * request structure. Should be called with li_list_mtx held
2737  */
2738 static void ext4_remove_li_request(struct ext4_li_request *elr)
2739 {
2740         struct ext4_sb_info *sbi;
2741
2742         if (!elr)
2743                 return;
2744
2745         sbi = elr->lr_sbi;
2746
2747         list_del(&elr->lr_request);
2748         sbi->s_li_request = NULL;
2749         kfree(elr);
2750 }
2751
2752 static void ext4_unregister_li_request(struct super_block *sb)
2753 {
2754         mutex_lock(&ext4_li_mtx);
2755         if (!ext4_li_info) {
2756                 mutex_unlock(&ext4_li_mtx);
2757                 return;
2758         }
2759
2760         mutex_lock(&ext4_li_info->li_list_mtx);
2761         ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2762         mutex_unlock(&ext4_li_info->li_list_mtx);
2763         mutex_unlock(&ext4_li_mtx);
2764 }
2765
2766 static struct task_struct *ext4_lazyinit_task;
2767
2768 /*
2769  * This is the function where ext4lazyinit thread lives. It walks
2770  * through the request list searching for next scheduled filesystem.
2771  * When such a fs is found, run the lazy initialization request
2772  * (ext4_rn_li_request) and keep track of the time spend in this
2773  * function. Based on that time we compute next schedule time of
2774  * the request. When walking through the list is complete, compute
2775  * next waking time and put itself into sleep.
2776  */
2777 static int ext4_lazyinit_thread(void *arg)
2778 {
2779         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2780         struct list_head *pos, *n;
2781         struct ext4_li_request *elr;
2782         unsigned long next_wakeup, cur;
2783
2784         BUG_ON(NULL == eli);
2785
2786 cont_thread:
2787         while (true) {
2788                 next_wakeup = MAX_JIFFY_OFFSET;
2789
2790                 mutex_lock(&eli->li_list_mtx);
2791                 if (list_empty(&eli->li_request_list)) {
2792                         mutex_unlock(&eli->li_list_mtx);
2793                         goto exit_thread;
2794                 }
2795
2796                 list_for_each_safe(pos, n, &eli->li_request_list) {
2797                         elr = list_entry(pos, struct ext4_li_request,
2798                                          lr_request);
2799
2800                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2801                                 if (ext4_run_li_request(elr) != 0) {
2802                                         /* error, remove the lazy_init job */
2803                                         ext4_remove_li_request(elr);
2804                                         continue;
2805                                 }
2806                         }
2807
2808                         if (time_before(elr->lr_next_sched, next_wakeup))
2809                                 next_wakeup = elr->lr_next_sched;
2810                 }
2811                 mutex_unlock(&eli->li_list_mtx);
2812
2813                 if (freezing(current))
2814                         refrigerator();
2815
2816                 cur = jiffies;
2817                 if ((time_after_eq(cur, next_wakeup)) ||
2818                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2819                         cond_resched();
2820                         continue;
2821                 }
2822
2823                 schedule_timeout_interruptible(next_wakeup - cur);
2824
2825                 if (kthread_should_stop()) {
2826                         ext4_clear_request_list();
2827                         goto exit_thread;
2828                 }
2829         }
2830
2831 exit_thread:
2832         /*
2833          * It looks like the request list is empty, but we need
2834          * to check it under the li_list_mtx lock, to prevent any
2835          * additions into it, and of course we should lock ext4_li_mtx
2836          * to atomically free the list and ext4_li_info, because at
2837          * this point another ext4 filesystem could be registering
2838          * new one.
2839          */
2840         mutex_lock(&ext4_li_mtx);
2841         mutex_lock(&eli->li_list_mtx);
2842         if (!list_empty(&eli->li_request_list)) {
2843                 mutex_unlock(&eli->li_list_mtx);
2844                 mutex_unlock(&ext4_li_mtx);
2845                 goto cont_thread;
2846         }
2847         mutex_unlock(&eli->li_list_mtx);
2848         kfree(ext4_li_info);
2849         ext4_li_info = NULL;
2850         mutex_unlock(&ext4_li_mtx);
2851
2852         return 0;
2853 }
2854
2855 static void ext4_clear_request_list(void)
2856 {
2857         struct list_head *pos, *n;
2858         struct ext4_li_request *elr;
2859
2860         mutex_lock(&ext4_li_info->li_list_mtx);
2861         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2862                 elr = list_entry(pos, struct ext4_li_request,
2863                                  lr_request);
2864                 ext4_remove_li_request(elr);
2865         }
2866         mutex_unlock(&ext4_li_info->li_list_mtx);
2867 }
2868
2869 static int ext4_run_lazyinit_thread(void)
2870 {
2871         ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2872                                          ext4_li_info, "ext4lazyinit");
2873         if (IS_ERR(ext4_lazyinit_task)) {
2874                 int err = PTR_ERR(ext4_lazyinit_task);
2875                 ext4_clear_request_list();
2876                 kfree(ext4_li_info);
2877                 ext4_li_info = NULL;
2878                 printk(KERN_CRIT "EXT4: error %d creating inode table "
2879                                  "initialization thread\n",
2880                                  err);
2881                 return err;
2882         }
2883         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2884         return 0;
2885 }
2886
2887 /*
2888  * Check whether it make sense to run itable init. thread or not.
2889  * If there is at least one uninitialized inode table, return
2890  * corresponding group number, else the loop goes through all
2891  * groups and return total number of groups.
2892  */
2893 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2894 {
2895         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2896         struct ext4_group_desc *gdp = NULL;
2897
2898         for (group = 0; group < ngroups; group++) {
2899                 gdp = ext4_get_group_desc(sb, group, NULL);
2900                 if (!gdp)
2901                         continue;
2902
2903                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2904                         break;
2905         }
2906
2907         return group;
2908 }
2909
2910 static int ext4_li_info_new(void)
2911 {
2912         struct ext4_lazy_init *eli = NULL;
2913
2914         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2915         if (!eli)
2916                 return -ENOMEM;
2917
2918         INIT_LIST_HEAD(&eli->li_request_list);
2919         mutex_init(&eli->li_list_mtx);
2920
2921         eli->li_state |= EXT4_LAZYINIT_QUIT;
2922
2923         ext4_li_info = eli;
2924
2925         return 0;
2926 }
2927
2928 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2929                                             ext4_group_t start)
2930 {
2931         struct ext4_sb_info *sbi = EXT4_SB(sb);
2932         struct ext4_li_request *elr;
2933         unsigned long rnd;
2934
2935         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2936         if (!elr)
2937                 return NULL;
2938
2939         elr->lr_super = sb;
2940         elr->lr_sbi = sbi;
2941         elr->lr_next_group = start;
2942
2943         /*
2944          * Randomize first schedule time of the request to
2945          * spread the inode table initialization requests
2946          * better.
2947          */
2948         get_random_bytes(&rnd, sizeof(rnd));
2949         elr->lr_next_sched = jiffies + (unsigned long)rnd %
2950                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2951
2952         return elr;
2953 }
2954
2955 static int ext4_register_li_request(struct super_block *sb,
2956                                     ext4_group_t first_not_zeroed)
2957 {
2958         struct ext4_sb_info *sbi = EXT4_SB(sb);
2959         struct ext4_li_request *elr;
2960         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2961         int ret = 0;
2962
2963         if (sbi->s_li_request != NULL) {
2964                 /*
2965                  * Reset timeout so it can be computed again, because
2966                  * s_li_wait_mult might have changed.
2967                  */
2968                 sbi->s_li_request->lr_timeout = 0;
2969                 return 0;
2970         }
2971
2972         if (first_not_zeroed == ngroups ||
2973             (sb->s_flags & MS_RDONLY) ||
2974             !test_opt(sb, INIT_INODE_TABLE))
2975                 return 0;
2976
2977         elr = ext4_li_request_new(sb, first_not_zeroed);
2978         if (!elr)
2979                 return -ENOMEM;
2980
2981         mutex_lock(&ext4_li_mtx);
2982
2983         if (NULL == ext4_li_info) {
2984                 ret = ext4_li_info_new();
2985                 if (ret)
2986                         goto out;
2987         }
2988
2989         mutex_lock(&ext4_li_info->li_list_mtx);
2990         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2991         mutex_unlock(&ext4_li_info->li_list_mtx);
2992
2993         sbi->s_li_request = elr;
2994         /*
2995          * set elr to NULL here since it has been inserted to
2996          * the request_list and the removal and free of it is
2997          * handled by ext4_clear_request_list from now on.
2998          */
2999         elr = NULL;
3000
3001         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3002                 ret = ext4_run_lazyinit_thread();
3003                 if (ret)
3004                         goto out;
3005         }
3006 out:
3007         mutex_unlock(&ext4_li_mtx);
3008         if (ret)
3009                 kfree(elr);
3010         return ret;
3011 }
3012
3013 /*
3014  * We do not need to lock anything since this is called on
3015  * module unload.
3016  */
3017 static void ext4_destroy_lazyinit_thread(void)
3018 {
3019         /*
3020          * If thread exited earlier
3021          * there's nothing to be done.
3022          */
3023         if (!ext4_li_info || !ext4_lazyinit_task)
3024                 return;
3025
3026         kthread_stop(ext4_lazyinit_task);
3027 }
3028
3029 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3030                                 __releases(kernel_lock)
3031                                 __acquires(kernel_lock)
3032 {
3033         char *orig_data = kstrdup(data, GFP_KERNEL);
3034         struct buffer_head *bh;
3035         struct ext4_super_block *es = NULL;
3036         struct ext4_sb_info *sbi;
3037         ext4_fsblk_t block;
3038         ext4_fsblk_t sb_block = get_sb_block(&data);
3039         ext4_fsblk_t logical_sb_block;
3040         unsigned long offset = 0;
3041         unsigned long journal_devnum = 0;
3042         unsigned long def_mount_opts;
3043         struct inode *root;
3044         char *cp;
3045         const char *descr;
3046         int ret = -ENOMEM;
3047         int blocksize;
3048         unsigned int db_count;
3049         unsigned int i;
3050         int needs_recovery, has_huge_files;
3051         __u64 blocks_count;
3052         int err;
3053         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3054         ext4_group_t first_not_zeroed;
3055
3056         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3057         if (!sbi)
3058                 goto out_free_orig;
3059
3060         sbi->s_blockgroup_lock =
3061                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3062         if (!sbi->s_blockgroup_lock) {
3063                 kfree(sbi);
3064                 goto out_free_orig;
3065         }
3066         sb->s_fs_info = sbi;
3067         sbi->s_mount_opt = 0;
3068         sbi->s_resuid = EXT4_DEF_RESUID;
3069         sbi->s_resgid = EXT4_DEF_RESGID;
3070         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3071         sbi->s_sb_block = sb_block;
3072         if (sb->s_bdev->bd_part)
3073                 sbi->s_sectors_written_start =
3074                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3075
3076         /* Cleanup superblock name */
3077         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3078                 *cp = '!';
3079
3080         ret = -EINVAL;
3081         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3082         if (!blocksize) {
3083                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3084                 goto out_fail;
3085         }
3086
3087         /*
3088          * The ext4 superblock will not be buffer aligned for other than 1kB
3089          * block sizes.  We need to calculate the offset from buffer start.
3090          */
3091         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3092                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3093                 offset = do_div(logical_sb_block, blocksize);
3094         } else {
3095                 logical_sb_block = sb_block;
3096         }
3097
3098         if (!(bh = sb_bread(sb, logical_sb_block))) {
3099                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3100                 goto out_fail;
3101         }
3102         /*
3103          * Note: s_es must be initialized as soon as possible because
3104          *       some ext4 macro-instructions depend on its value
3105          */
3106         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3107         sbi->s_es = es;
3108         sb->s_magic = le16_to_cpu(es->s_magic);
3109         if (sb->s_magic != EXT4_SUPER_MAGIC)
3110                 goto cantfind_ext4;
3111         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3112
3113         /* Set defaults before we parse the mount options */
3114         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3115         set_opt(sb, INIT_INODE_TABLE);
3116         if (def_mount_opts & EXT4_DEFM_DEBUG)
3117                 set_opt(sb, DEBUG);
3118         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3119                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3120                         "2.6.38");
3121                 set_opt(sb, GRPID);
3122         }
3123         if (def_mount_opts & EXT4_DEFM_UID16)
3124                 set_opt(sb, NO_UID32);
3125         /* xattr user namespace & acls are now defaulted on */
3126 #ifdef CONFIG_EXT4_FS_XATTR
3127         set_opt(sb, XATTR_USER);
3128 #endif
3129 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3130         set_opt(sb, POSIX_ACL);
3131 #endif
3132         set_opt(sb, MBLK_IO_SUBMIT);
3133         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3134                 set_opt(sb, JOURNAL_DATA);
3135         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3136                 set_opt(sb, ORDERED_DATA);
3137         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3138                 set_opt(sb, WRITEBACK_DATA);
3139
3140         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3141                 set_opt(sb, ERRORS_PANIC);
3142         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3143                 set_opt(sb, ERRORS_CONT);
3144         else
3145                 set_opt(sb, ERRORS_RO);
3146         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3147                 set_opt(sb, BLOCK_VALIDITY);
3148         if (def_mount_opts & EXT4_DEFM_DISCARD)
3149                 set_opt(sb, DISCARD);
3150
3151         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3152         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3153         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3154         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3155         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3156
3157         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3158                 set_opt(sb, BARRIER);
3159
3160         /*
3161          * enable delayed allocation by default
3162          * Use -o nodelalloc to turn it off
3163          */
3164         if (!IS_EXT3_SB(sb) &&
3165             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3166                 set_opt(sb, DELALLOC);
3167
3168         /*
3169          * set default s_li_wait_mult for lazyinit, for the case there is
3170          * no mount option specified.
3171          */
3172         sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3173
3174         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3175                            &journal_devnum, &journal_ioprio, NULL, 0)) {
3176                 ext4_msg(sb, KERN_WARNING,
3177                          "failed to parse options in superblock: %s",
3178                          sbi->s_es->s_mount_opts);
3179         }
3180         if (!parse_options((char *) data, sb, &journal_devnum,
3181                            &journal_ioprio, NULL, 0))
3182                 goto failed_mount;
3183
3184         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3185                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3186
3187         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3188             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3189              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3190              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3191                 ext4_msg(sb, KERN_WARNING,
3192                        "feature flags set on rev 0 fs, "
3193                        "running e2fsck is recommended");
3194
3195         if (IS_EXT2_SB(sb)) {
3196                 if (ext2_feature_set_ok(sb))
3197                         ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3198                                  "using the ext4 subsystem");
3199                 else {
3200                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3201                                  "to feature incompatibilities");
3202                         goto failed_mount;
3203                 }
3204         }
3205
3206         if (IS_EXT3_SB(sb)) {
3207                 if (ext3_feature_set_ok(sb))
3208                         ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3209                                  "using the ext4 subsystem");
3210                 else {
3211                         ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3212                                  "to feature incompatibilities");
3213                         goto failed_mount;
3214                 }
3215         }
3216
3217         /*
3218          * Check feature flags regardless of the revision level, since we
3219          * previously didn't change the revision level when setting the flags,
3220          * so there is a chance incompat flags are set on a rev 0 filesystem.
3221          */
3222         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3223                 goto failed_mount;
3224
3225         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3226
3227         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3228             blocksize > EXT4_MAX_BLOCK_SIZE) {
3229                 ext4_msg(sb, KERN_ERR,
3230                        "Unsupported filesystem blocksize %d", blocksize);
3231                 goto failed_mount;
3232         }
3233
3234         if (sb->s_blocksize != blocksize) {
3235                 /* Validate the filesystem blocksize */
3236                 if (!sb_set_blocksize(sb, blocksize)) {
3237                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3238                                         blocksize);
3239                         goto failed_mount;
3240                 }
3241
3242                 brelse(bh);
3243                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3244                 offset = do_div(logical_sb_block, blocksize);
3245                 bh = sb_bread(sb, logical_sb_block);
3246                 if (!bh) {
3247                         ext4_msg(sb, KERN_ERR,
3248                                "Can't read superblock on 2nd try");
3249                         goto failed_mount;
3250                 }
3251                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3252                 sbi->s_es = es;
3253                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3254                         ext4_msg(sb, KERN_ERR,
3255                                "Magic mismatch, very weird!");
3256                         goto failed_mount;
3257                 }
3258         }
3259
3260         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3261                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3262         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3263                                                       has_huge_files);
3264         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3265
3266         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3267                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3268                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3269         } else {
3270                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3271                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3272                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3273                     (!is_power_of_2(sbi->s_inode_size)) ||
3274                     (sbi->s_inode_size > blocksize)) {
3275                         ext4_msg(sb, KERN_ERR,
3276                                "unsupported inode size: %d",
3277                                sbi->s_inode_size);
3278                         goto failed_mount;
3279                 }
3280                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3281                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3282         }
3283
3284         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3285         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3286                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3287                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3288                     !is_power_of_2(sbi->s_desc_size)) {
3289                         ext4_msg(sb, KERN_ERR,
3290                                "unsupported descriptor size %lu",
3291                                sbi->s_desc_size);
3292                         goto failed_mount;
3293                 }
3294         } else
3295                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3296
3297         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3298         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3299         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3300                 goto cantfind_ext4;
3301
3302         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3303         if (sbi->s_inodes_per_block == 0)
3304                 goto cantfind_ext4;
3305         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3306                                         sbi->s_inodes_per_block;
3307         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3308         sbi->s_sbh = bh;
3309         sbi->s_mount_state = le16_to_cpu(es->s_state);
3310         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3311         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3312
3313         for (i = 0; i < 4; i++)
3314                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3315         sbi->s_def_hash_version = es->s_def_hash_version;
3316         i = le32_to_cpu(es->s_flags);
3317         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3318                 sbi->s_hash_unsigned = 3;
3319         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3320 #ifdef __CHAR_UNSIGNED__
3321                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3322                 sbi->s_hash_unsigned = 3;
3323 #else
3324                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3325 #endif
3326                 sb->s_dirt = 1;
3327         }
3328
3329         if (sbi->s_blocks_per_group > blocksize * 8) {
3330                 ext4_msg(sb, KERN_ERR,
3331                        "#blocks per group too big: %lu",
3332                        sbi->s_blocks_per_group);
3333                 goto failed_mount;
3334         }
3335         if (sbi->s_inodes_per_group > blocksize * 8) {
3336                 ext4_msg(sb, KERN_ERR,
3337                        "#inodes per group too big: %lu",
3338                        sbi->s_inodes_per_group);
3339                 goto failed_mount;
3340         }
3341
3342         /*
3343          * Test whether we have more sectors than will fit in sector_t,
3344          * and whether the max offset is addressable by the page cache.
3345          */
3346         err = generic_check_addressable(sb->s_blocksize_bits,
3347                                         ext4_blocks_count(es));
3348         if (err) {
3349                 ext4_msg(sb, KERN_ERR, "filesystem"
3350                          " too large to mount safely on this system");
3351                 if (sizeof(sector_t) < 8)
3352                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3353                 ret = err;
3354                 goto failed_mount;
3355         }
3356
3357         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3358                 goto cantfind_ext4;
3359
3360         /* check blocks count against device size */
3361         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3362         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3363                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3364                        "exceeds size of device (%llu blocks)",
3365                        ext4_blocks_count(es), blocks_count);
3366                 goto failed_mount;
3367         }
3368
3369         /*
3370          * It makes no sense for the first data block to be beyond the end
3371          * of the filesystem.
3372          */
3373         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3374                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3375                          "block %u is beyond end of filesystem (%llu)",
3376                          le32_to_cpu(es->s_first_data_block),
3377                          ext4_blocks_count(es));
3378                 goto failed_mount;
3379         }
3380         blocks_count = (ext4_blocks_count(es) -
3381                         le32_to_cpu(es->s_first_data_block) +
3382                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3383         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3384         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3385                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3386                        "(block count %llu, first data block %u, "
3387                        "blocks per group %lu)", sbi->s_groups_count,
3388                        ext4_blocks_count(es),
3389                        le32_to_cpu(es->s_first_data_block),
3390                        EXT4_BLOCKS_PER_GROUP(sb));
3391                 goto failed_mount;
3392         }
3393         sbi->s_groups_count = blocks_count;
3394         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3395                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3396         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3397                    EXT4_DESC_PER_BLOCK(sb);
3398         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
3399                                     GFP_KERNEL);
3400         if (sbi->s_group_desc == NULL) {
3401                 ext4_msg(sb, KERN_ERR, "not enough memory");
3402                 goto failed_mount;
3403         }
3404
3405 #ifdef CONFIG_PROC_FS
3406         if (ext4_proc_root)
3407                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3408 #endif
3409
3410         bgl_lock_init(sbi->s_blockgroup_lock);
3411
3412         for (i = 0; i < db_count; i++) {
3413                 block = descriptor_loc(sb, logical_sb_block, i);
3414                 sbi->s_group_desc[i] = sb_bread(sb, block);
3415                 if (!sbi->s_group_desc[i]) {
3416                         ext4_msg(sb, KERN_ERR,
3417                                "can't read group descriptor %d", i);
3418                         db_count = i;
3419                         goto failed_mount2;
3420                 }
3421         }
3422         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3423                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3424                 goto failed_mount2;
3425         }
3426         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3427                 if (!ext4_fill_flex_info(sb)) {
3428                         ext4_msg(sb, KERN_ERR,
3429                                "unable to initialize "
3430                                "flex_bg meta info!");
3431                         goto failed_mount2;
3432                 }
3433
3434         sbi->s_gdb_count = db_count;
3435         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3436         spin_lock_init(&sbi->s_next_gen_lock);
3437
3438         init_timer(&sbi->s_err_report);
3439         sbi->s_err_report.function = print_daily_error_info;
3440         sbi->s_err_report.data = (unsigned long) sb;
3441
3442         err = percpu_counter_init(&sbi->s_freeblocks_counter,
3443                         ext4_count_free_blocks(sb));
3444         if (!err) {
3445                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3446                                 ext4_count_free_inodes(sb));
3447         }
3448         if (!err) {
3449                 err = percpu_counter_init(&sbi->s_dirs_counter,
3450                                 ext4_count_dirs(sb));
3451         }
3452         if (!err) {
3453                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
3454         }
3455         if (err) {
3456                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3457                 goto failed_mount3;
3458         }
3459
3460         sbi->s_stripe = ext4_get_stripe_size(sbi);
3461         sbi->s_max_writeback_mb_bump = 128;
3462
3463         /*
3464          * set up enough so that it can read an inode
3465          */
3466         if (!test_opt(sb, NOLOAD) &&
3467             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3468                 sb->s_op = &ext4_sops;
3469         else
3470                 sb->s_op = &ext4_nojournal_sops;
3471         sb->s_export_op = &ext4_export_ops;
3472         sb->s_xattr = ext4_xattr_handlers;
3473 #ifdef CONFIG_QUOTA
3474         sb->s_qcop = &ext4_qctl_operations;
3475         sb->dq_op = &ext4_quota_operations;
3476 #endif
3477         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3478
3479         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3480         mutex_init(&sbi->s_orphan_lock);
3481         mutex_init(&sbi->s_resize_lock);
3482
3483         sb->s_root = NULL;
3484
3485         needs_recovery = (es->s_last_orphan != 0 ||
3486                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3487                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3488
3489         /*
3490          * The first inode we look at is the journal inode.  Don't try
3491          * root first: it may be modified in the journal!
3492          */
3493         if (!test_opt(sb, NOLOAD) &&
3494             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3495                 if (ext4_load_journal(sb, es, journal_devnum))
3496                         goto failed_mount3;
3497         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3498               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3499                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3500                        "suppressed and not mounted read-only");
3501                 goto failed_mount_wq;
3502         } else {
3503                 clear_opt(sb, DATA_FLAGS);
3504                 sbi->s_journal = NULL;
3505                 needs_recovery = 0;
3506                 goto no_journal;
3507         }
3508
3509         if (ext4_blocks_count(es) > 0xffffffffULL &&
3510             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3511                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3512                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3513                 goto failed_mount_wq;
3514         }
3515
3516         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3517                 jbd2_journal_set_features(sbi->s_journal,
3518                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3519                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3520         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3521                 jbd2_journal_set_features(sbi->s_journal,
3522                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3523                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3524                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3525         } else {
3526                 jbd2_journal_clear_features(sbi->s_journal,
3527                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3528                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3529         }
3530
3531         /* We have now updated the journal if required, so we can
3532          * validate the data journaling mode. */
3533         switch (test_opt(sb, DATA_FLAGS)) {
3534         case 0:
3535                 /* No mode set, assume a default based on the journal
3536                  * capabilities: ORDERED_DATA if the journal can
3537                  * cope, else JOURNAL_DATA
3538                  */
3539                 if (jbd2_journal_check_available_features
3540                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3541                         set_opt(sb, ORDERED_DATA);
3542                 else
3543                         set_opt(sb, JOURNAL_DATA);
3544                 break;
3545
3546         case EXT4_MOUNT_ORDERED_DATA:
3547         case EXT4_MOUNT_WRITEBACK_DATA:
3548                 if (!jbd2_journal_check_available_features
3549                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3550                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3551                                "requested data journaling mode");
3552                         goto failed_mount_wq;
3553                 }
3554         default:
3555                 break;
3556         }
3557         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3558
3559         /*
3560          * The journal may have updated the bg summary counts, so we
3561          * need to update the global counters.
3562          */
3563         percpu_counter_set(&sbi->s_freeblocks_counter,
3564                            ext4_count_free_blocks(sb));
3565         percpu_counter_set(&sbi->s_freeinodes_counter,
3566                            ext4_count_free_inodes(sb));
3567         percpu_counter_set(&sbi->s_dirs_counter,
3568                            ext4_count_dirs(sb));
3569         percpu_counter_set(&sbi->s_dirtyblocks_counter, 0);
3570
3571 no_journal:
3572         /*
3573          * The maximum number of concurrent works can be high and
3574          * concurrency isn't really necessary.  Limit it to 1.
3575          */
3576         EXT4_SB(sb)->dio_unwritten_wq =
3577                 alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3578         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3579                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3580                 goto failed_mount_wq;
3581         }
3582
3583         /*
3584          * The jbd2_journal_load will have done any necessary log recovery,
3585          * so we can safely mount the rest of the filesystem now.
3586          */
3587
3588         root = ext4_iget(sb, EXT4_ROOT_INO);
3589         if (IS_ERR(root)) {
3590                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3591                 ret = PTR_ERR(root);
3592                 root = NULL;
3593                 goto failed_mount4;
3594         }
3595         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3596                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3597                 goto failed_mount4;
3598         }
3599         sb->s_root = d_alloc_root(root);
3600         if (!sb->s_root) {
3601                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3602                 ret = -ENOMEM;
3603                 goto failed_mount4;
3604         }
3605
3606         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3607
3608         /* determine the minimum size of new large inodes, if present */
3609         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3610                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3611                                                      EXT4_GOOD_OLD_INODE_SIZE;
3612                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3613                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3614                         if (sbi->s_want_extra_isize <
3615                             le16_to_cpu(es->s_want_extra_isize))
3616                                 sbi->s_want_extra_isize =
3617                                         le16_to_cpu(es->s_want_extra_isize);
3618                         if (sbi->s_want_extra_isize <
3619                             le16_to_cpu(es->s_min_extra_isize))
3620                                 sbi->s_want_extra_isize =
3621                                         le16_to_cpu(es->s_min_extra_isize);
3622                 }
3623         }
3624         /* Check if enough inode space is available */
3625         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3626                                                         sbi->s_inode_size) {
3627                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3628                                                        EXT4_GOOD_OLD_INODE_SIZE;
3629                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3630                          "available");
3631         }
3632
3633         if (test_opt(sb, DELALLOC) &&
3634             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
3635                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
3636                          "requested data journaling mode");
3637                 clear_opt(sb, DELALLOC);
3638         }
3639         if (test_opt(sb, DIOREAD_NOLOCK)) {
3640                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3641                         ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3642                                 "option - requested data journaling mode");
3643                         clear_opt(sb, DIOREAD_NOLOCK);
3644                 }
3645                 if (sb->s_blocksize < PAGE_SIZE) {
3646                         ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3647                                 "option - block size is too small");
3648                         clear_opt(sb, DIOREAD_NOLOCK);
3649                 }
3650         }
3651
3652         err = ext4_setup_system_zone(sb);
3653         if (err) {
3654                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3655                          "zone (%d)", err);
3656                 goto failed_mount4;
3657         }
3658
3659         ext4_ext_init(sb);
3660         err = ext4_mb_init(sb, needs_recovery);
3661         if (err) {
3662                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3663                          err);
3664                 goto failed_mount4;
3665         }
3666
3667         err = ext4_register_li_request(sb, first_not_zeroed);
3668         if (err)
3669                 goto failed_mount4;
3670
3671         sbi->s_kobj.kset = ext4_kset;
3672         init_completion(&sbi->s_kobj_unregister);
3673         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3674                                    "%s", sb->s_id);
3675         if (err) {
3676                 ext4_mb_release(sb);
3677                 ext4_ext_release(sb);
3678                 goto failed_mount4;
3679         };
3680
3681         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3682         ext4_orphan_cleanup(sb, es);
3683         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3684         if (needs_recovery) {
3685                 ext4_msg(sb, KERN_INFO, "recovery complete");
3686                 ext4_mark_recovery_complete(sb, es);
3687         }
3688         if (EXT4_SB(sb)->s_journal) {
3689                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3690                         descr = " journalled data mode";
3691                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3692                         descr = " ordered data mode";
3693                 else
3694                         descr = " writeback data mode";
3695         } else
3696                 descr = "out journal";
3697
3698         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3699                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3700                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3701
3702         if (es->s_error_count)
3703                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3704
3705         kfree(orig_data);
3706         return 0;
3707
3708 cantfind_ext4:
3709         if (!silent)
3710                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3711         goto failed_mount;
3712
3713 failed_mount4:
3714         iput(root);
3715         sb->s_root = NULL;
3716         ext4_msg(sb, KERN_ERR, "mount failed");
3717         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3718 failed_mount_wq:
3719         ext4_release_system_zone(sb);
3720         if (sbi->s_journal) {
3721                 jbd2_journal_destroy(sbi->s_journal);
3722                 sbi->s_journal = NULL;
3723         }
3724 failed_mount3:
3725         del_timer(&sbi->s_err_report);
3726         if (sbi->s_flex_groups) {
3727                 if (is_vmalloc_addr(sbi->s_flex_groups))
3728                         vfree(sbi->s_flex_groups);
3729                 else
3730                         kfree(sbi->s_flex_groups);
3731         }
3732         percpu_counter_destroy(&sbi->s_freeblocks_counter);
3733         percpu_counter_destroy(&sbi->s_freeinodes_counter);
3734         percpu_counter_destroy(&sbi->s_dirs_counter);
3735         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
3736 failed_mount2:
3737         for (i = 0; i < db_count; i++)
3738                 brelse(sbi->s_group_desc[i]);
3739         kfree(sbi->s_group_desc);
3740 failed_mount:
3741         if (sbi->s_proc) {
3742                 remove_proc_entry(sb->s_id, ext4_proc_root);
3743         }
3744 #ifdef CONFIG_QUOTA
3745         for (i = 0; i < MAXQUOTAS; i++)
3746                 kfree(sbi->s_qf_names[i]);
3747 #endif
3748         ext4_blkdev_remove(sbi);
3749         brelse(bh);
3750 out_fail:
3751         sb->s_fs_info = NULL;
3752         kfree(sbi->s_blockgroup_lock);
3753         kfree(sbi);
3754 out_free_orig:
3755         kfree(orig_data);
3756         return ret;
3757 }
3758
3759 /*
3760  * Setup any per-fs journal parameters now.  We'll do this both on
3761  * initial mount, once the journal has been initialised but before we've
3762  * done any recovery; and again on any subsequent remount.
3763  */
3764 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3765 {
3766         struct ext4_sb_info *sbi = EXT4_SB(sb);
3767
3768         journal->j_commit_interval = sbi->s_commit_interval;
3769         journal->j_min_batch_time = sbi->s_min_batch_time;
3770         journal->j_max_batch_time = sbi->s_max_batch_time;
3771
3772         write_lock(&journal->j_state_lock);
3773         if (test_opt(sb, BARRIER))
3774                 journal->j_flags |= JBD2_BARRIER;
3775         else
3776                 journal->j_flags &= ~JBD2_BARRIER;
3777         if (test_opt(sb, DATA_ERR_ABORT))
3778                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3779         else
3780                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3781         write_unlock(&journal->j_state_lock);
3782 }
3783
3784 static journal_t *ext4_get_journal(struct super_block *sb,
3785                                    unsigned int journal_inum)
3786 {
3787         struct inode *journal_inode;
3788         journal_t *journal;
3789
3790         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3791
3792         /* First, test for the existence of a valid inode on disk.  Bad
3793          * things happen if we iget() an unused inode, as the subsequent
3794          * iput() will try to delete it. */
3795
3796         journal_inode = ext4_iget(sb, journal_inum);
3797         if (IS_ERR(journal_inode)) {
3798                 ext4_msg(sb, KERN_ERR, "no journal found");
3799                 return NULL;
3800         }
3801         if (!journal_inode->i_nlink) {
3802                 make_bad_inode(journal_inode);
3803                 iput(journal_inode);
3804                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3805                 return NULL;
3806         }
3807
3808         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3809                   journal_inode, journal_inode->i_size);
3810         if (!S_ISREG(journal_inode->i_mode)) {
3811                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3812                 iput(journal_inode);
3813                 return NULL;
3814         }
3815
3816         journal = jbd2_journal_init_inode(journal_inode);
3817         if (!journal) {
3818                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3819                 iput(journal_inode);
3820                 return NULL;
3821         }
3822         journal->j_private = sb;
3823         ext4_init_journal_params(sb, journal);
3824         return journal;
3825 }
3826
3827 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3828                                        dev_t j_dev)
3829 {
3830         struct buffer_head *bh;
3831         journal_t *journal;
3832         ext4_fsblk_t start;
3833         ext4_fsblk_t len;
3834         int hblock, blocksize;
3835         ext4_fsblk_t sb_block;
3836         unsigned long offset;
3837         struct ext4_super_block *es;
3838         struct block_device *bdev;
3839
3840         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3841
3842         bdev = ext4_blkdev_get(j_dev, sb);
3843         if (bdev == NULL)
3844                 return NULL;
3845
3846         blocksize = sb->s_blocksize;
3847         hblock = bdev_logical_block_size(bdev);
3848         if (blocksize < hblock) {
3849                 ext4_msg(sb, KERN_ERR,
3850                         "blocksize too small for journal device");
3851                 goto out_bdev;
3852         }
3853
3854         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3855         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3856         set_blocksize(bdev, blocksize);
3857         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3858                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3859                        "external journal");
3860                 goto out_bdev;
3861         }
3862
3863         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3864         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3865             !(le32_to_cpu(es->s_feature_incompat) &
3866               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3867                 ext4_msg(sb, KERN_ERR, "external journal has "
3868                                         "bad superblock");
3869                 brelse(bh);
3870                 goto out_bdev;
3871         }
3872
3873         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3874                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3875                 brelse(bh);
3876                 goto out_bdev;
3877         }
3878
3879         len = ext4_blocks_count(es);
3880         start = sb_block + 1;
3881         brelse(bh);     /* we're done with the superblock */
3882
3883         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3884                                         start, len, blocksize);
3885         if (!journal) {
3886                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3887                 goto out_bdev;
3888         }
3889         journal->j_private = sb;
3890         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3891         wait_on_buffer(journal->j_sb_buffer);
3892         if (!buffer_uptodate(journal->j_sb_buffer)) {
3893                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3894                 goto out_journal;
3895         }
3896         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3897                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3898                                         "user (unsupported) - %d",
3899                         be32_to_cpu(journal->j_superblock->s_nr_users));
3900                 goto out_journal;
3901         }
3902         EXT4_SB(sb)->journal_bdev = bdev;
3903         ext4_init_journal_params(sb, journal);
3904         return journal;
3905
3906 out_journal:
3907         jbd2_journal_destroy(journal);
3908 out_bdev:
3909         ext4_blkdev_put(bdev);
3910         return NULL;
3911 }
3912
3913 static int ext4_load_journal(struct super_block *sb,
3914                              struct ext4_super_block *es,
3915                              unsigned long journal_devnum)
3916 {
3917         journal_t *journal;
3918         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3919         dev_t journal_dev;
3920         int err = 0;
3921         int really_read_only;
3922
3923         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3924
3925         if (journal_devnum &&
3926             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3927                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3928                         "numbers have changed");
3929                 journal_dev = new_decode_dev(journal_devnum);
3930         } else
3931                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3932
3933         really_read_only = bdev_read_only(sb->s_bdev);
3934
3935         /*
3936          * Are we loading a blank journal or performing recovery after a
3937          * crash?  For recovery, we need to check in advance whether we
3938          * can get read-write access to the device.
3939          */
3940         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3941                 if (sb->s_flags & MS_RDONLY) {
3942                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3943                                         "required on readonly filesystem");
3944                         if (really_read_only) {
3945                                 ext4_msg(sb, KERN_ERR, "write access "
3946                                         "unavailable, cannot proceed");
3947                                 return -EROFS;
3948                         }
3949                         ext4_msg(sb, KERN_INFO, "write access will "
3950                                "be enabled during recovery");
3951                 }
3952         }
3953
3954         if (journal_inum && journal_dev) {
3955                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3956                        "and inode journals!");
3957                 return -EINVAL;
3958         }
3959
3960         if (journal_inum) {
3961                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3962                         return -EINVAL;
3963         } else {
3964                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3965                         return -EINVAL;
3966         }
3967
3968         if (!(journal->j_flags & JBD2_BARRIER))
3969                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3970
3971         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3972                 err = jbd2_journal_update_format(journal);
3973                 if (err)  {
3974                         ext4_msg(sb, KERN_ERR, "error updating journal");
3975                         jbd2_journal_destroy(journal);
3976                         return err;
3977                 }
3978         }
3979
3980         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3981                 err = jbd2_journal_wipe(journal, !really_read_only);
3982         if (!err) {
3983                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
3984                 if (save)
3985                         memcpy(save, ((char *) es) +
3986                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
3987                 err = jbd2_journal_load(journal);
3988                 if (save)
3989                         memcpy(((char *) es) + EXT4_S_ERR_START,
3990                                save, EXT4_S_ERR_LEN);
3991                 kfree(save);
3992         }
3993
3994         if (err) {
3995                 ext4_msg(sb, KERN_ERR, "error loading journal");
3996                 jbd2_journal_destroy(journal);
3997                 return err;
3998         }
3999
4000         EXT4_SB(sb)->s_journal = journal;
4001         ext4_clear_journal_err(sb, es);
4002
4003         if (!really_read_only && journal_devnum &&
4004             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4005                 es->s_journal_dev = cpu_to_le32(journal_devnum);
4006
4007                 /* Make sure we flush the recovery flag to disk. */
4008                 ext4_commit_super(sb, 1);
4009         }
4010
4011         return 0;
4012 }
4013
4014 static int ext4_commit_super(struct super_block *sb, int sync)
4015 {
4016         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4017         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4018         int error = 0;
4019
4020         if (!sbh)
4021                 return error;
4022         if (buffer_write_io_error(sbh)) {
4023                 /*
4024                  * Oh, dear.  A previous attempt to write the
4025                  * superblock failed.  This could happen because the
4026                  * USB device was yanked out.  Or it could happen to
4027                  * be a transient write error and maybe the block will
4028                  * be remapped.  Nothing we can do but to retry the
4029                  * write and hope for the best.
4030                  */
4031                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
4032                        "superblock detected");
4033                 clear_buffer_write_io_error(sbh);
4034                 set_buffer_uptodate(sbh);
4035         }
4036         /*
4037          * If the file system is mounted read-only, don't update the
4038          * superblock write time.  This avoids updating the superblock
4039          * write time when we are mounting the root file system
4040          * read/only but we need to replay the journal; at that point,
4041          * for people who are east of GMT and who make their clock
4042          * tick in localtime for Windows bug-for-bug compatibility,
4043          * the clock is set in the future, and this will cause e2fsck
4044          * to complain and force a full file system check.
4045          */
4046         if (!(sb->s_flags & MS_RDONLY))
4047                 es->s_wtime = cpu_to_le32(get_seconds());
4048         if (sb->s_bdev->bd_part)
4049                 es->s_kbytes_written =
4050                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4051                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4052                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
4053         else
4054                 es->s_kbytes_written =
4055                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4056         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
4057                                            &EXT4_SB(sb)->s_freeblocks_counter));
4058         es->s_free_inodes_count =
4059                 cpu_to_le32(percpu_counter_sum_positive(
4060                                 &EXT4_SB(sb)->s_freeinodes_counter));
4061         sb->s_dirt = 0;
4062         BUFFER_TRACE(sbh, "marking dirty");
4063         mark_buffer_dirty(sbh);
4064         if (sync) {
4065                 error = sync_dirty_buffer(sbh);
4066                 if (error)
4067                         return error;
4068
4069                 error = buffer_write_io_error(sbh);
4070                 if (error) {
4071                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4072                                "superblock");
4073                         clear_buffer_write_io_error(sbh);
4074                         set_buffer_uptodate(sbh);
4075                 }
4076         }
4077         return error;
4078 }
4079
4080 /*
4081  * Have we just finished recovery?  If so, and if we are mounting (or
4082  * remounting) the filesystem readonly, then we will end up with a
4083  * consistent fs on disk.  Record that fact.
4084  */
4085 static void ext4_mark_recovery_complete(struct super_block *sb,
4086                                         struct ext4_super_block *es)
4087 {
4088         journal_t *journal = EXT4_SB(sb)->s_journal;
4089
4090         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4091                 BUG_ON(journal != NULL);
4092                 return;
4093         }
4094         jbd2_journal_lock_updates(journal);
4095         if (jbd2_journal_flush(journal) < 0)
4096                 goto out;
4097
4098         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4099             sb->s_flags & MS_RDONLY) {
4100                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4101                 ext4_commit_super(sb, 1);
4102         }
4103
4104 out:
4105         jbd2_journal_unlock_updates(journal);
4106 }
4107
4108 /*
4109  * If we are mounting (or read-write remounting) a filesystem whose journal
4110  * has recorded an error from a previous lifetime, move that error to the
4111  * main filesystem now.
4112  */
4113 static void ext4_clear_journal_err(struct super_block *sb,
4114                                    struct ext4_super_block *es)
4115 {
4116         journal_t *journal;
4117         int j_errno;
4118         const char *errstr;
4119
4120         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4121
4122         journal = EXT4_SB(sb)->s_journal;
4123
4124         /*
4125          * Now check for any error status which may have been recorded in the
4126          * journal by a prior ext4_error() or ext4_abort()
4127          */
4128
4129         j_errno = jbd2_journal_errno(journal);
4130         if (j_errno) {
4131                 char nbuf[16];
4132
4133                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4134                 ext4_warning(sb, "Filesystem error recorded "
4135                              "from previous mount: %s", errstr);
4136                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4137
4138                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4139                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4140                 ext4_commit_super(sb, 1);
4141
4142                 jbd2_journal_clear_err(journal);
4143         }
4144 }
4145
4146 /*
4147  * Force the running and committing transactions to commit,
4148  * and wait on the commit.
4149  */
4150 int ext4_force_commit(struct super_block *sb)
4151 {
4152         journal_t *journal;
4153         int ret = 0;
4154
4155         if (sb->s_flags & MS_RDONLY)
4156                 return 0;
4157
4158         journal = EXT4_SB(sb)->s_journal;
4159         if (journal) {
4160                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
4161                 ret = ext4_journal_force_commit(journal);
4162         }
4163
4164         return ret;
4165 }
4166
4167 static void ext4_write_super(struct super_block *sb)
4168 {
4169         lock_super(sb);
4170         ext4_commit_super(sb, 1);
4171         unlock_super(sb);
4172 }
4173
4174 static int ext4_sync_fs(struct super_block *sb, int wait)
4175 {
4176         int ret = 0;
4177         tid_t target;
4178         struct ext4_sb_info *sbi = EXT4_SB(sb);
4179
4180         trace_ext4_sync_fs(sb, wait);
4181         flush_workqueue(sbi->dio_unwritten_wq);
4182         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4183                 if (wait)
4184                         jbd2_log_wait_commit(sbi->s_journal, target);
4185         }
4186         return ret;
4187 }
4188
4189 /*
4190  * LVM calls this function before a (read-only) snapshot is created.  This
4191  * gives us a chance to flush the journal completely and mark the fs clean.
4192  *
4193  * Note that only this function cannot bring a filesystem to be in a clean
4194  * state independently, because ext4 prevents a new handle from being started
4195  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4196  * the upper layer.
4197  */
4198 static int ext4_freeze(struct super_block *sb)
4199 {
4200         int error = 0;
4201         journal_t *journal;
4202
4203         if (sb->s_flags & MS_RDONLY)
4204                 return 0;
4205
4206         journal = EXT4_SB(sb)->s_journal;
4207
4208         /* Now we set up the journal barrier. */
4209         jbd2_journal_lock_updates(journal);
4210
4211         /*
4212          * Don't clear the needs_recovery flag if we failed to flush
4213          * the journal.
4214          */
4215         error = jbd2_journal_flush(journal);
4216         if (error < 0)
4217                 goto out;
4218
4219         /* Journal blocked and flushed, clear needs_recovery flag. */
4220         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4221         error = ext4_commit_super(sb, 1);
4222 out:
4223         /* we rely on s_frozen to stop further updates */
4224         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4225         return error;
4226 }
4227
4228 /*
4229  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4230  * flag here, even though the filesystem is not technically dirty yet.
4231  */
4232 static int ext4_unfreeze(struct super_block *sb)
4233 {
4234         if (sb->s_flags & MS_RDONLY)
4235                 return 0;
4236
4237         lock_super(sb);
4238         /* Reset the needs_recovery flag before the fs is unlocked. */
4239         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4240         ext4_commit_super(sb, 1);
4241         unlock_super(sb);
4242         return 0;
4243 }
4244
4245 /*
4246  * Structure to save mount options for ext4_remount's benefit
4247  */
4248 struct ext4_mount_options {
4249         unsigned long s_mount_opt;
4250         unsigned long s_mount_opt2;
4251         uid_t s_resuid;
4252         gid_t s_resgid;
4253         unsigned long s_commit_interval;
4254         u32 s_min_batch_time, s_max_batch_time;
4255 #ifdef CONFIG_QUOTA
4256         int s_jquota_fmt;
4257         char *s_qf_names[MAXQUOTAS];
4258 #endif
4259 };
4260
4261 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4262 {
4263         struct ext4_super_block *es;
4264         struct ext4_sb_info *sbi = EXT4_SB(sb);
4265         ext4_fsblk_t n_blocks_count = 0;
4266         unsigned long old_sb_flags;
4267         struct ext4_mount_options old_opts;
4268         int enable_quota = 0;
4269         ext4_group_t g;
4270         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4271         int err;
4272 #ifdef CONFIG_QUOTA
4273         int i;
4274 #endif
4275         char *orig_data = kstrdup(data, GFP_KERNEL);
4276
4277         /* Store the original options */
4278         lock_super(sb);
4279         old_sb_flags = sb->s_flags;
4280         old_opts.s_mount_opt = sbi->s_mount_opt;
4281         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4282         old_opts.s_resuid = sbi->s_resuid;
4283         old_opts.s_resgid = sbi->s_resgid;
4284         old_opts.s_commit_interval = sbi->s_commit_interval;
4285         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4286         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4287 #ifdef CONFIG_QUOTA
4288         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4289         for (i = 0; i < MAXQUOTAS; i++)
4290                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4291 #endif
4292         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4293                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4294
4295         /*
4296          * Allow the "check" option to be passed as a remount option.
4297          */
4298         if (!parse_options(data, sb, NULL, &journal_ioprio,
4299                            &n_blocks_count, 1)) {
4300                 err = -EINVAL;
4301                 goto restore_opts;
4302         }
4303
4304         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4305                 ext4_abort(sb, "Abort forced by user");
4306
4307         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4308                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4309
4310         es = sbi->s_es;
4311
4312         if (sbi->s_journal) {
4313                 ext4_init_journal_params(sb, sbi->s_journal);
4314                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4315         }
4316
4317         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4318                 n_blocks_count > ext4_blocks_count(es)) {
4319                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4320                         err = -EROFS;
4321                         goto restore_opts;
4322                 }
4323
4324                 if (*flags & MS_RDONLY) {
4325                         err = dquot_suspend(sb, -1);
4326                         if (err < 0)
4327                                 goto restore_opts;
4328
4329                         /*
4330                          * First of all, the unconditional stuff we have to do
4331                          * to disable replay of the journal when we next remount
4332                          */
4333                         sb->s_flags |= MS_RDONLY;
4334
4335                         /*
4336                          * OK, test if we are remounting a valid rw partition
4337                          * readonly, and if so set the rdonly flag and then
4338                          * mark the partition as valid again.
4339                          */
4340                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4341                             (sbi->s_mount_state & EXT4_VALID_FS))
4342                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4343
4344                         if (sbi->s_journal)
4345                                 ext4_mark_recovery_complete(sb, es);
4346                 } else {
4347                         /* Make sure we can mount this feature set readwrite */
4348                         if (!ext4_feature_set_ok(sb, 0)) {
4349                                 err = -EROFS;
4350                                 goto restore_opts;
4351                         }
4352                         /*
4353                          * Make sure the group descriptor checksums
4354                          * are sane.  If they aren't, refuse to remount r/w.
4355                          */
4356                         for (g = 0; g < sbi->s_groups_count; g++) {
4357                                 struct ext4_group_desc *gdp =
4358                                         ext4_get_group_desc(sb, g, NULL);
4359
4360                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4361                                         ext4_msg(sb, KERN_ERR,
4362                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4363                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4364                                                le16_to_cpu(gdp->bg_checksum));
4365                                         err = -EINVAL;
4366                                         goto restore_opts;
4367                                 }
4368                         }
4369
4370                         /*
4371                          * If we have an unprocessed orphan list hanging
4372                          * around from a previously readonly bdev mount,
4373                          * require a full umount/remount for now.
4374                          */
4375                         if (es->s_last_orphan) {
4376                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4377                                        "remount RDWR because of unprocessed "
4378                                        "orphan inode list.  Please "
4379                                        "umount/remount instead");
4380                                 err = -EINVAL;
4381                                 goto restore_opts;
4382                         }
4383
4384                         /*
4385                          * Mounting a RDONLY partition read-write, so reread
4386                          * and store the current valid flag.  (It may have
4387                          * been changed by e2fsck since we originally mounted
4388                          * the partition.)
4389                          */
4390                         if (sbi->s_journal)
4391                                 ext4_clear_journal_err(sb, es);
4392                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4393                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4394                                 goto restore_opts;
4395                         if (!ext4_setup_super(sb, es, 0))
4396                                 sb->s_flags &= ~MS_RDONLY;
4397                         enable_quota = 1;
4398                 }
4399         }
4400
4401         /*
4402          * Reinitialize lazy itable initialization thread based on
4403          * current settings
4404          */
4405         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4406                 ext4_unregister_li_request(sb);
4407         else {
4408                 ext4_group_t first_not_zeroed;
4409                 first_not_zeroed = ext4_has_uninit_itable(sb);
4410                 ext4_register_li_request(sb, first_not_zeroed);
4411         }
4412
4413         ext4_setup_system_zone(sb);
4414         if (sbi->s_journal == NULL)
4415                 ext4_commit_super(sb, 1);
4416
4417 #ifdef CONFIG_QUOTA
4418         /* Release old quota file names */
4419         for (i = 0; i < MAXQUOTAS; i++)
4420                 if (old_opts.s_qf_names[i] &&
4421                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4422                         kfree(old_opts.s_qf_names[i]);
4423 #endif
4424         unlock_super(sb);
4425         if (enable_quota)
4426                 dquot_resume(sb, -1);
4427
4428         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4429         kfree(orig_data);
4430         return 0;
4431
4432 restore_opts:
4433         sb->s_flags = old_sb_flags;
4434         sbi->s_mount_opt = old_opts.s_mount_opt;
4435         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4436         sbi->s_resuid = old_opts.s_resuid;
4437         sbi->s_resgid = old_opts.s_resgid;
4438         sbi->s_commit_interval = old_opts.s_commit_interval;
4439         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4440         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4441 #ifdef CONFIG_QUOTA
4442         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4443         for (i = 0; i < MAXQUOTAS; i++) {
4444                 if (sbi->s_qf_names[i] &&
4445                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4446                         kfree(sbi->s_qf_names[i]);
4447                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4448         }
4449 #endif
4450         unlock_super(sb);
4451         kfree(orig_data);
4452         return err;
4453 }
4454
4455 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4456 {
4457         struct super_block *sb = dentry->d_sb;
4458         struct ext4_sb_info *sbi = EXT4_SB(sb);
4459         struct ext4_super_block *es = sbi->s_es;
4460         u64 fsid;
4461
4462         if (test_opt(sb, MINIX_DF)) {
4463                 sbi->s_overhead_last = 0;
4464         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4465                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4466                 ext4_fsblk_t overhead = 0;
4467
4468                 /*
4469                  * Compute the overhead (FS structures).  This is constant
4470                  * for a given filesystem unless the number of block groups
4471                  * changes so we cache the previous value until it does.
4472                  */
4473
4474                 /*
4475                  * All of the blocks before first_data_block are
4476                  * overhead
4477                  */
4478                 overhead = le32_to_cpu(es->s_first_data_block);
4479
4480                 /*
4481                  * Add the overhead attributed to the superblock and
4482                  * block group descriptors.  If the sparse superblocks
4483                  * feature is turned on, then not all groups have this.
4484                  */
4485                 for (i = 0; i < ngroups; i++) {
4486                         overhead += ext4_bg_has_super(sb, i) +
4487                                 ext4_bg_num_gdb(sb, i);
4488                         cond_resched();
4489                 }
4490
4491                 /*
4492                  * Every block group has an inode bitmap, a block
4493                  * bitmap, and an inode table.
4494                  */
4495                 overhead += ngroups * (2 + sbi->s_itb_per_group);
4496                 sbi->s_overhead_last = overhead;
4497                 smp_wmb();
4498                 sbi->s_blocks_last = ext4_blocks_count(es);
4499         }
4500
4501         buf->f_type = EXT4_SUPER_MAGIC;
4502         buf->f_bsize = sb->s_blocksize;
4503         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
4504         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
4505                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
4506         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4507         if (buf->f_bfree < ext4_r_blocks_count(es))
4508                 buf->f_bavail = 0;
4509         buf->f_files = le32_to_cpu(es->s_inodes_count);
4510         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4511         buf->f_namelen = EXT4_NAME_LEN;
4512         fsid = le64_to_cpup((void *)es->s_uuid) ^
4513                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4514         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4515         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4516
4517         return 0;
4518 }
4519
4520 /* Helper function for writing quotas on sync - we need to start transaction
4521  * before quota file is locked for write. Otherwise the are possible deadlocks:
4522  * Process 1                         Process 2
4523  * ext4_create()                     quota_sync()
4524  *   jbd2_journal_start()                  write_dquot()
4525  *   dquot_initialize()                         down(dqio_mutex)
4526  *     down(dqio_mutex)                    jbd2_journal_start()
4527  *
4528  */
4529
4530 #ifdef CONFIG_QUOTA
4531
4532 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4533 {
4534         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4535 }
4536
4537 static int ext4_write_dquot(struct dquot *dquot)
4538 {
4539         int ret, err;
4540         handle_t *handle;
4541         struct inode *inode;
4542
4543         inode = dquot_to_inode(dquot);
4544         handle = ext4_journal_start(inode,
4545                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4546         if (IS_ERR(handle))
4547                 return PTR_ERR(handle);
4548         ret = dquot_commit(dquot);
4549         err = ext4_journal_stop(handle);
4550         if (!ret)
4551                 ret = err;
4552         return ret;
4553 }
4554
4555 static int ext4_acquire_dquot(struct dquot *dquot)
4556 {
4557         int ret, err;
4558         handle_t *handle;
4559
4560         handle = ext4_journal_start(dquot_to_inode(dquot),
4561                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4562         if (IS_ERR(handle))
4563                 return PTR_ERR(handle);
4564         ret = dquot_acquire(dquot);
4565         err = ext4_journal_stop(handle);
4566         if (!ret)
4567                 ret = err;
4568         return ret;
4569 }
4570
4571 static int ext4_release_dquot(struct dquot *dquot)
4572 {
4573         int ret, err;
4574         handle_t *handle;
4575
4576         handle = ext4_journal_start(dquot_to_inode(dquot),
4577                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4578         if (IS_ERR(handle)) {
4579                 /* Release dquot anyway to avoid endless cycle in dqput() */
4580                 dquot_release(dquot);
4581                 return PTR_ERR(handle);
4582         }
4583         ret = dquot_release(dquot);
4584         err = ext4_journal_stop(handle);
4585         if (!ret)
4586                 ret = err;
4587         return ret;
4588 }
4589
4590 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4591 {
4592         /* Are we journaling quotas? */
4593         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4594             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4595                 dquot_mark_dquot_dirty(dquot);
4596                 return ext4_write_dquot(dquot);
4597         } else {
4598                 return dquot_mark_dquot_dirty(dquot);
4599         }
4600 }
4601
4602 static int ext4_write_info(struct super_block *sb, int type)
4603 {
4604         int ret, err;
4605         handle_t *handle;
4606
4607         /* Data block + inode block */
4608         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4609         if (IS_ERR(handle))
4610                 return PTR_ERR(handle);
4611         ret = dquot_commit_info(sb, type);
4612         err = ext4_journal_stop(handle);
4613         if (!ret)
4614                 ret = err;
4615         return ret;
4616 }
4617
4618 /*
4619  * Turn on quotas during mount time - we need to find
4620  * the quota file and such...
4621  */
4622 static int ext4_quota_on_mount(struct super_block *sb, int type)
4623 {
4624         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4625                                         EXT4_SB(sb)->s_jquota_fmt, type);
4626 }
4627
4628 /*
4629  * Standard function to be called on quota_on
4630  */
4631 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4632                          struct path *path)
4633 {
4634         int err;
4635
4636         if (!test_opt(sb, QUOTA))
4637                 return -EINVAL;
4638
4639         /* Quotafile not on the same filesystem? */
4640         if (path->mnt->mnt_sb != sb)
4641                 return -EXDEV;
4642         /* Journaling quota? */
4643         if (EXT4_SB(sb)->s_qf_names[type]) {
4644                 /* Quotafile not in fs root? */
4645                 if (path->dentry->d_parent != sb->s_root)
4646                         ext4_msg(sb, KERN_WARNING,
4647                                 "Quota file not on filesystem root. "
4648                                 "Journaled quota will not work");
4649         }
4650
4651         /*
4652          * When we journal data on quota file, we have to flush journal to see
4653          * all updates to the file when we bypass pagecache...
4654          */
4655         if (EXT4_SB(sb)->s_journal &&
4656             ext4_should_journal_data(path->dentry->d_inode)) {
4657                 /*
4658                  * We don't need to lock updates but journal_flush() could
4659                  * otherwise be livelocked...
4660                  */
4661                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4662                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4663                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4664                 if (err)
4665                         return err;
4666         }
4667
4668         return dquot_quota_on(sb, type, format_id, path);
4669 }
4670
4671 static int ext4_quota_off(struct super_block *sb, int type)
4672 {
4673         struct inode *inode = sb_dqopt(sb)->files[type];
4674         handle_t *handle;
4675
4676         /* Force all delayed allocation blocks to be allocated.
4677          * Caller already holds s_umount sem */
4678         if (test_opt(sb, DELALLOC))
4679                 sync_filesystem(sb);
4680
4681         if (!inode)
4682                 goto out;
4683
4684         /* Update modification times of quota files when userspace can
4685          * start looking at them */
4686         handle = ext4_journal_start(inode, 1);
4687         if (IS_ERR(handle))
4688                 goto out;
4689         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4690         ext4_mark_inode_dirty(handle, inode);
4691         ext4_journal_stop(handle);
4692
4693 out:
4694         return dquot_quota_off(sb, type);
4695 }
4696
4697 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4698  * acquiring the locks... As quota files are never truncated and quota code
4699  * itself serializes the operations (and no one else should touch the files)
4700  * we don't have to be afraid of races */
4701 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4702                                size_t len, loff_t off)
4703 {
4704         struct inode *inode = sb_dqopt(sb)->files[type];
4705         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4706         int err = 0;
4707         int offset = off & (sb->s_blocksize - 1);
4708         int tocopy;
4709         size_t toread;
4710         struct buffer_head *bh;
4711         loff_t i_size = i_size_read(inode);
4712
4713         if (off > i_size)
4714                 return 0;
4715         if (off+len > i_size)
4716                 len = i_size-off;
4717         toread = len;
4718         while (toread > 0) {
4719                 tocopy = sb->s_blocksize - offset < toread ?
4720                                 sb->s_blocksize - offset : toread;
4721                 bh = ext4_bread(NULL, inode, blk, 0, &err);
4722                 if (err)
4723                         return err;
4724                 if (!bh)        /* A hole? */
4725                         memset(data, 0, tocopy);
4726                 else
4727                         memcpy(data, bh->b_data+offset, tocopy);
4728                 brelse(bh);
4729                 offset = 0;
4730                 toread -= tocopy;
4731                 data += tocopy;
4732                 blk++;
4733         }
4734         return len;
4735 }
4736
4737 /* Write to quotafile (we know the transaction is already started and has
4738  * enough credits) */
4739 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4740                                 const char *data, size_t len, loff_t off)
4741 {
4742         struct inode *inode = sb_dqopt(sb)->files[type];
4743         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4744         int err = 0;
4745         int offset = off & (sb->s_blocksize - 1);
4746         struct buffer_head *bh;
4747         handle_t *handle = journal_current_handle();
4748
4749         if (EXT4_SB(sb)->s_journal && !handle) {
4750                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4751                         " cancelled because transaction is not started",
4752                         (unsigned long long)off, (unsigned long long)len);
4753                 return -EIO;
4754         }
4755         /*
4756          * Since we account only one data block in transaction credits,
4757          * then it is impossible to cross a block boundary.
4758          */
4759         if (sb->s_blocksize - offset < len) {
4760                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4761                         " cancelled because not block aligned",
4762                         (unsigned long long)off, (unsigned long long)len);
4763                 return -EIO;
4764         }
4765
4766         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4767         bh = ext4_bread(handle, inode, blk, 1, &err);
4768         if (!bh)
4769                 goto out;
4770         err = ext4_journal_get_write_access(handle, bh);
4771         if (err) {
4772                 brelse(bh);
4773                 goto out;
4774         }
4775         lock_buffer(bh);
4776         memcpy(bh->b_data+offset, data, len);
4777         flush_dcache_page(bh->b_page);
4778         unlock_buffer(bh);
4779         err = ext4_handle_dirty_metadata(handle, NULL, bh);
4780         brelse(bh);
4781 out:
4782         if (err) {
4783                 mutex_unlock(&inode->i_mutex);
4784                 return err;
4785         }
4786         if (inode->i_size < off + len) {
4787                 i_size_write(inode, off + len);
4788                 EXT4_I(inode)->i_disksize = inode->i_size;
4789                 ext4_mark_inode_dirty(handle, inode);
4790         }
4791         mutex_unlock(&inode->i_mutex);
4792         return len;
4793 }
4794
4795 #endif
4796
4797 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4798                        const char *dev_name, void *data)
4799 {
4800         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4801 }
4802
4803 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4804 static inline void register_as_ext2(void)
4805 {
4806         int err = register_filesystem(&ext2_fs_type);
4807         if (err)
4808                 printk(KERN_WARNING
4809                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4810 }
4811
4812 static inline void unregister_as_ext2(void)
4813 {
4814         unregister_filesystem(&ext2_fs_type);
4815 }
4816
4817 static inline int ext2_feature_set_ok(struct super_block *sb)
4818 {
4819         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
4820                 return 0;
4821         if (sb->s_flags & MS_RDONLY)
4822                 return 1;
4823         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
4824                 return 0;
4825         return 1;
4826 }
4827 MODULE_ALIAS("ext2");
4828 #else
4829 static inline void register_as_ext2(void) { }
4830 static inline void unregister_as_ext2(void) { }
4831 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
4832 #endif
4833
4834 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4835 static inline void register_as_ext3(void)
4836 {
4837         int err = register_filesystem(&ext3_fs_type);
4838         if (err)
4839                 printk(KERN_WARNING
4840                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4841 }
4842
4843 static inline void unregister_as_ext3(void)
4844 {
4845         unregister_filesystem(&ext3_fs_type);
4846 }
4847
4848 static inline int ext3_feature_set_ok(struct super_block *sb)
4849 {
4850         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
4851                 return 0;
4852         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
4853                 return 0;
4854         if (sb->s_flags & MS_RDONLY)
4855                 return 1;
4856         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
4857                 return 0;
4858         return 1;
4859 }
4860 MODULE_ALIAS("ext3");
4861 #else
4862 static inline void register_as_ext3(void) { }
4863 static inline void unregister_as_ext3(void) { }
4864 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
4865 #endif
4866
4867 static struct file_system_type ext4_fs_type = {
4868         .owner          = THIS_MODULE,
4869         .name           = "ext4",
4870         .mount          = ext4_mount,
4871         .kill_sb        = kill_block_super,
4872         .fs_flags       = FS_REQUIRES_DEV,
4873 };
4874
4875 static int __init ext4_init_feat_adverts(void)
4876 {
4877         struct ext4_features *ef;
4878         int ret = -ENOMEM;
4879
4880         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
4881         if (!ef)
4882                 goto out;
4883
4884         ef->f_kobj.kset = ext4_kset;
4885         init_completion(&ef->f_kobj_unregister);
4886         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
4887                                    "features");
4888         if (ret) {
4889                 kfree(ef);
4890                 goto out;
4891         }
4892
4893         ext4_feat = ef;
4894         ret = 0;
4895 out:
4896         return ret;
4897 }
4898
4899 static void ext4_exit_feat_adverts(void)
4900 {
4901         kobject_put(&ext4_feat->f_kobj);
4902         wait_for_completion(&ext4_feat->f_kobj_unregister);
4903         kfree(ext4_feat);
4904 }
4905
4906 /* Shared across all ext4 file systems */
4907 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
4908 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
4909
4910 static int __init ext4_init_fs(void)
4911 {
4912         int i, err;
4913
4914         ext4_check_flag_values();
4915
4916         for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
4917                 mutex_init(&ext4__aio_mutex[i]);
4918                 init_waitqueue_head(&ext4__ioend_wq[i]);
4919         }
4920
4921         err = ext4_init_pageio();
4922         if (err)
4923                 return err;
4924         err = ext4_init_system_zone();
4925         if (err)
4926                 goto out7;
4927         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4928         if (!ext4_kset)
4929                 goto out6;
4930         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4931         if (!ext4_proc_root)
4932                 goto out5;
4933
4934         err = ext4_init_feat_adverts();
4935         if (err)
4936                 goto out4;
4937
4938         err = ext4_init_mballoc();
4939         if (err)
4940                 goto out3;
4941
4942         err = ext4_init_xattr();
4943         if (err)
4944                 goto out2;
4945         err = init_inodecache();
4946         if (err)
4947                 goto out1;
4948         register_as_ext3();
4949         register_as_ext2();
4950         err = register_filesystem(&ext4_fs_type);
4951         if (err)
4952                 goto out;
4953
4954         ext4_li_info = NULL;
4955         mutex_init(&ext4_li_mtx);
4956         return 0;
4957 out:
4958         unregister_as_ext2();
4959         unregister_as_ext3();
4960         destroy_inodecache();
4961 out1:
4962         ext4_exit_xattr();
4963 out2:
4964         ext4_exit_mballoc();
4965 out3:
4966         ext4_exit_feat_adverts();
4967 out4:
4968         remove_proc_entry("fs/ext4", NULL);
4969 out5:
4970         kset_unregister(ext4_kset);
4971 out6:
4972         ext4_exit_system_zone();
4973 out7:
4974         ext4_exit_pageio();
4975         return err;
4976 }
4977
4978 static void __exit ext4_exit_fs(void)
4979 {
4980         ext4_destroy_lazyinit_thread();
4981         unregister_as_ext2();
4982         unregister_as_ext3();
4983         unregister_filesystem(&ext4_fs_type);
4984         destroy_inodecache();
4985         ext4_exit_xattr();
4986         ext4_exit_mballoc();
4987         ext4_exit_feat_adverts();
4988         remove_proc_entry("fs/ext4", NULL);
4989         kset_unregister(ext4_kset);
4990         ext4_exit_system_zone();
4991         ext4_exit_pageio();
4992 }
4993
4994 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4995 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4996 MODULE_LICENSE("GPL");
4997 module_init(ext4_init_fs)
4998 module_exit(ext4_exit_fs)