Pileus Git - ~andy/linux/blob - fs/jffs2/super.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 2001-2007 Red Hat, Inc.
   5  *
   6  * Created by David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * For licensing information, see the file 'LICENCE' in this directory.
   9  *
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/init.h>
  18 #include <linux/list.h>
  19 #include <linux/fs.h>
  20 #include <linux/err.h>
  21 #include <linux/mount.h>
  22 #include <linux/parser.h>
  23 #include <linux/jffs2.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/mtd/super.h>
  26 #include <linux/ctype.h>
  27 #include <linux/namei.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/exportfs.h>
  30 #include "compr.h"
  31 #include "nodelist.h"
  32
  33 static void jffs2_put_super(struct super_block *);
  34
  35 static struct kmem_cache *jffs2_inode_cachep;
  36
  37 static struct inode *jffs2_alloc_inode(struct super_block *sb)
  38 {
  39         struct jffs2_inode_info *f;
  40
  41         f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
  42         if (!f)
  43                 return NULL;
  44         return &f->vfs_inode;
  45 }
  46
  47 static void jffs2_i_callback(struct rcu_head *head)
  48 {
  49         struct inode *inode = container_of(head, struct inode, i_rcu);
  50         kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
  51 }
  52
  53 static void jffs2_destroy_inode(struct inode *inode)
  54 {
  55         call_rcu(&inode->i_rcu, jffs2_i_callback);
  56 }
  57
  58 static void jffs2_i_init_once(void *foo)
  59 {
  60         struct jffs2_inode_info *f = foo;
  61
  62         mutex_init(&f->sem);
  63         inode_init_once(&f->vfs_inode);
  64 }
  65
  66 static void jffs2_write_super(struct super_block *sb)
  67 {
  68         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
  69
  70         sb->s_dirt = 0;
  71
  72         if (!(sb->s_flags & MS_RDONLY)) {
  73                 jffs2_dbg(1, "%s()\n", __func__);
  74                 jffs2_flush_wbuf_gc(c, 0);
  75         }
  76 }
  77
  78 static const char *jffs2_compr_name(unsigned int compr)
  79 {
  80         switch (compr) {
  81         case JFFS2_COMPR_MODE_NONE:
  82                 return "none";
  83 #ifdef CONFIG_JFFS2_LZO
  84         case JFFS2_COMPR_MODE_FORCELZO:
  85                 return "lzo";
  86 #endif
  87 #ifdef CONFIG_JFFS2_ZLIB
  88         case JFFS2_COMPR_MODE_FORCEZLIB:
  89                 return "zlib";
  90 #endif
  91         default:
  92                 /* should never happen; programmer error */
  93                 WARN_ON(1);
  94                 return "";
  95         }
  96 }
  97
  98 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
  99 {
 100         struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
 101         struct jffs2_mount_opts *opts = &c->mount_opts;
 102
 103         if (opts->override_compr)
 104                 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
 105         if (opts->rp_size)
 106                 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
 107
 108         return 0;
 109 }
 110
 111 static int jffs2_sync_fs(struct super_block *sb, int wait)
 112 {
 113         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 114
 115         mutex_lock(&c->alloc_sem);
 116         jffs2_flush_wbuf_pad(c);
 117         mutex_unlock(&c->alloc_sem);
 118         return 0;
 119 }
 120
 121 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
 122                                          uint32_t generation)
 123 {
 124         /* We don't care about i_generation. We'll destroy the flash
 125            before we start re-using inode numbers anyway. And even
 126            if that wasn't true, we'd have other problems...*/
 127         return jffs2_iget(sb, ino);
 128 }
 129
 130 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
 131                                          int fh_len, int fh_type)
 132 {
 133         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 134                                     jffs2_nfs_get_inode);
 135 }
 136
 137 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
 138                                          int fh_len, int fh_type)
 139 {
 140         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 141                                     jffs2_nfs_get_inode);
 142 }
 143
 144 static struct dentry *jffs2_get_parent(struct dentry *child)
 145 {
 146         struct jffs2_inode_info *f;
 147         uint32_t pino;
 148
 149         BUG_ON(!S_ISDIR(child->d_inode->i_mode));
 150
 151         f = JFFS2_INODE_INFO(child->d_inode);
 152
 153         pino = f->inocache->pino_nlink;
 154
 155         JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
 156                     f->inocache->ino, pino);
 157
 158         return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino));
 159 }
 160
 161 static const struct export_operations jffs2_export_ops = {
 162         .get_parent = jffs2_get_parent,
 163         .fh_to_dentry = jffs2_fh_to_dentry,
 164         .fh_to_parent = jffs2_fh_to_parent,
 165 };
 166
 167 /*
 168  * JFFS2 mount options.
 169  *
 170  * Opt_override_compr: override default compressor
 171  * Opt_rp_size: size of reserved pool in KiB
 172  * Opt_err: just end of array marker
 173  */
 174 enum {
 175         Opt_override_compr,
 176         Opt_rp_size,
 177         Opt_err,
 178 };
 179
 180 static const match_table_t tokens = {
 181         {Opt_override_compr, "compr=%s"},
 182         {Opt_rp_size, "rp_size=%u"},
 183         {Opt_err, NULL},
 184 };
 185
 186 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
 187 {
 188         substring_t args[MAX_OPT_ARGS];
 189         char *p, *name;
 190         unsigned int opt;
 191
 192         if (!data)
 193                 return 0;
 194
 195         while ((p = strsep(&data, ","))) {
 196                 int token;
 197
 198                 if (!*p)
 199                         continue;
 200
 201                 token = match_token(p, tokens, args);
 202                 switch (token) {
 203                 case Opt_override_compr:
 204                         name = match_strdup(&args[0]);
 205
 206                         if (!name)
 207                                 return -ENOMEM;
 208                         if (!strcmp(name, "none"))
 209                                 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
 210 #ifdef CONFIG_JFFS2_LZO
 211                         else if (!strcmp(name, "lzo"))
 212                                 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
 213 #endif
 214 #ifdef CONFIG_JFFS2_ZLIB
 215                         else if (!strcmp(name, "zlib"))
 216                                 c->mount_opts.compr =
 217                                                 JFFS2_COMPR_MODE_FORCEZLIB;
 218 #endif
 219                         else {
 220                                 pr_err("Error: unknown compressor \"%s\"\n",
 221                                        name);
 222                                 kfree(name);
 223                                 return -EINVAL;
 224                         }
 225                         kfree(name);
 226                         c->mount_opts.override_compr = true;
 227                         break;
 228                 case Opt_rp_size:
 229                         if (match_int(&args[0], &opt))
 230                                 return -EINVAL;
 231                         opt *= 1024;
 232                         if (opt > c->mtd->size) {
 233                                 pr_warn("Too large reserve pool specified, max "
 234                                         "is %llu KB\n", c->mtd->size / 1024);
 235                                 return -EINVAL;
 236                         }
 237                         c->mount_opts.rp_size = opt;
 238                         break;
 239                 default:
 240                         pr_err("Error: unrecognized mount option '%s' or missing value\n",
 241                                p);
 242                         return -EINVAL;
 243                 }
 244         }
 245
 246         return 0;
 247 }
 248
 249 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
 250 {
 251         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 252         int err;
 253
 254         err = jffs2_parse_options(c, data);
 255         if (err)
 256                 return -EINVAL;
 257
 258         return jffs2_do_remount_fs(sb, flags, data);
 259 }
 260
 261 static const struct super_operations jffs2_super_operations =
 262 {
 263         .alloc_inode =  jffs2_alloc_inode,
 264         .destroy_inode =jffs2_destroy_inode,
 265         .put_super =    jffs2_put_super,
 266         .write_super =  jffs2_write_super,
 267         .statfs =       jffs2_statfs,
 268         .remount_fs =   jffs2_remount_fs,
 269         .evict_inode =  jffs2_evict_inode,
 270         .dirty_inode =  jffs2_dirty_inode,
 271         .show_options = jffs2_show_options,
 272         .sync_fs =      jffs2_sync_fs,
 273 };
 274
 275 /*
 276  * fill in the superblock
 277  */
 278 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
 279 {
 280         struct jffs2_sb_info *c;
 281         int ret;
 282
 283         jffs2_dbg(1, "jffs2_get_sb_mtd():"
 284                   " New superblock for device %d (\"%s\")\n",
 285                   sb->s_mtd->index, sb->s_mtd->name);
 286
 287         c = kzalloc(sizeof(*c), GFP_KERNEL);
 288         if (!c)
 289                 return -ENOMEM;
 290
 291         c->mtd = sb->s_mtd;
 292         c->os_priv = sb;
 293         sb->s_fs_info = c;
 294
 295         ret = jffs2_parse_options(c, data);
 296         if (ret) {
 297                 kfree(c);
 298                 return -EINVAL;
 299         }
 300
 301         /* Initialize JFFS2 superblock locks, the further initialization will
 302          * be done later */
 303         mutex_init(&c->alloc_sem);
 304         mutex_init(&c->erase_free_sem);
 305         init_waitqueue_head(&c->erase_wait);
 306         init_waitqueue_head(&c->inocache_wq);
 307         spin_lock_init(&c->erase_completion_lock);
 308         spin_lock_init(&c->inocache_lock);
 309
 310         sb->s_op = &jffs2_super_operations;
 311         sb->s_export_op = &jffs2_export_ops;
 312         sb->s_flags = sb->s_flags | MS_NOATIME;
 313         sb->s_xattr = jffs2_xattr_handlers;
 314 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 315         sb->s_flags |= MS_POSIXACL;
 316 #endif
 317         ret = jffs2_do_fill_super(sb, data, silent);
 318         return ret;
 319 }
 320
 321 static struct dentry *jffs2_mount(struct file_system_type *fs_type,
 322                         int flags, const char *dev_name,
 323                         void *data)
 324 {
 325         return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
 326 }
 327
 328 static void jffs2_put_super (struct super_block *sb)
 329 {
 330         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 331
 332         jffs2_dbg(2, "%s()\n", __func__);
 333
 334         mutex_lock(&c->alloc_sem);
 335         jffs2_flush_wbuf_pad(c);
 336         mutex_unlock(&c->alloc_sem);
 337
 338         jffs2_sum_exit(c);
 339
 340         jffs2_free_ino_caches(c);
 341         jffs2_free_raw_node_refs(c);
 342         if (jffs2_blocks_use_vmalloc(c))
 343                 vfree(c->blocks);
 344         else
 345                 kfree(c->blocks);
 346         jffs2_flash_cleanup(c);
 347         kfree(c->inocache_list);
 348         jffs2_clear_xattr_subsystem(c);
 349         mtd_sync(c->mtd);
 350         jffs2_dbg(1, "%s(): returning\n", __func__);
 351 }
 352
 353 static void jffs2_kill_sb(struct super_block *sb)
 354 {
 355         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 356         if (!(sb->s_flags & MS_RDONLY))
 357                 jffs2_stop_garbage_collect_thread(c);
 358         kill_mtd_super(sb);
 359         kfree(c);
 360 }
 361
 362 static struct file_system_type jffs2_fs_type = {
 363         .owner =        THIS_MODULE,
 364         .name =         "jffs2",
 365         .mount =        jffs2_mount,
 366         .kill_sb =      jffs2_kill_sb,
 367 };
 368
 369 static int __init init_jffs2_fs(void)
 370 {
 371         int ret;
 372
 373         /* Paranoia checks for on-medium structures. If we ask GCC
 374            to pack them with __attribute__((packed)) then it _also_
 375            assumes that they're not aligned -- so it emits crappy
 376            code on some architectures. Ideally we want an attribute
 377            which means just 'no padding', without the alignment
 378            thing. But GCC doesn't have that -- we have to just
 379            hope the structs are the right sizes, instead. */
 380         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
 381         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
 382         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
 383         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
 384
 385         pr_info("version 2.2."
 386 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 387                " (NAND)"
 388 #endif
 389 #ifdef CONFIG_JFFS2_SUMMARY
 390                " (SUMMARY) "
 391 #endif
 392                " © 2001-2006 Red Hat, Inc.\n");
 393
 394         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
 395                                              sizeof(struct jffs2_inode_info),
 396                                              0, (SLAB_RECLAIM_ACCOUNT|
 397                                                 SLAB_MEM_SPREAD),
 398                                              jffs2_i_init_once);
 399         if (!jffs2_inode_cachep) {
 400                 pr_err("error: Failed to initialise inode cache\n");
 401                 return -ENOMEM;
 402         }
 403         ret = jffs2_compressors_init();
 404         if (ret) {
 405                 pr_err("error: Failed to initialise compressors\n");
 406                 goto out;
 407         }
 408         ret = jffs2_create_slab_caches();
 409         if (ret) {
 410                 pr_err("error: Failed to initialise slab caches\n");
 411                 goto out_compressors;
 412         }
 413         ret = register_filesystem(&jffs2_fs_type);
 414         if (ret) {
 415                 pr_err("error: Failed to register filesystem\n");
 416                 goto out_slab;
 417         }
 418         return 0;
 419
 420  out_slab:
 421         jffs2_destroy_slab_caches();
 422  out_compressors:
 423         jffs2_compressors_exit();
 424  out:
 425         kmem_cache_destroy(jffs2_inode_cachep);
 426         return ret;
 427 }
 428
 429 static void __exit exit_jffs2_fs(void)
 430 {
 431         unregister_filesystem(&jffs2_fs_type);
 432         jffs2_destroy_slab_caches();
 433         jffs2_compressors_exit();
 434         kmem_cache_destroy(jffs2_inode_cachep);
 435 }
 436
 437 module_init(init_jffs2_fs);
 438 module_exit(exit_jffs2_fs);
 439
 440 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
 441 MODULE_AUTHOR("Red Hat, Inc.");
 442 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
 443                        // the sake of this tag. It's Free Software.