1 /* AFS superblock handling
3 * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
5 * This software may be freely redistributed under the terms of the
6 * GNU General Public License.
8 * You should have received a copy of the GNU General Public License
9 * along with this program; if not, write to the Free Software
10 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
12 * Authors: David Howells <dhowells@redhat.com>
13 * David Woodhouse <dwmw2@infradead.org>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/mount.h>
20 #include <linux/init.h>
21 #include <linux/slab.h>
23 #include <linux/pagemap.h>
24 #include <linux/parser.h>
25 #include <linux/statfs.h>
26 #include <linux/sched.h>
27 #include <linux/nsproxy.h>
28 #include <net/net_namespace.h>
31 #define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
33 static void afs_i_init_once(void *foo);
34 static struct dentry *afs_mount(struct file_system_type *fs_type,
35 int flags, const char *dev_name, void *data);
36 static void afs_kill_super(struct super_block *sb);
37 static struct inode *afs_alloc_inode(struct super_block *sb);
38 static void afs_destroy_inode(struct inode *inode);
39 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
41 struct file_system_type afs_fs_type = {
45 .kill_sb = afs_kill_super,
49 static const struct super_operations afs_super_ops = {
51 .alloc_inode = afs_alloc_inode,
52 .drop_inode = afs_drop_inode,
53 .destroy_inode = afs_destroy_inode,
54 .evict_inode = afs_evict_inode,
55 .show_options = generic_show_options,
58 static struct kmem_cache *afs_inode_cachep;
59 static atomic_t afs_count_active_inodes;
69 static const match_table_t afs_options_list = {
70 { afs_opt_cell, "cell=%s" },
71 { afs_opt_rwpath, "rwpath" },
72 { afs_opt_vol, "vol=%s" },
73 { afs_opt_autocell, "autocell" },
78 * initialise the filesystem
80 int __init afs_fs_init(void)
86 /* create ourselves an inode cache */
87 atomic_set(&afs_count_active_inodes, 0);
90 afs_inode_cachep = kmem_cache_create("afs_inode_cache",
91 sizeof(struct afs_vnode),
95 if (!afs_inode_cachep) {
96 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
100 /* now export our filesystem to lesser mortals */
101 ret = register_filesystem(&afs_fs_type);
103 kmem_cache_destroy(afs_inode_cachep);
104 _leave(" = %d", ret);
113 * clean up the filesystem
115 void __exit afs_fs_exit(void)
119 afs_mntpt_kill_timer();
120 unregister_filesystem(&afs_fs_type);
122 if (atomic_read(&afs_count_active_inodes) != 0) {
123 printk("kAFS: %d active inode objects still present\n",
124 atomic_read(&afs_count_active_inodes));
129 * Make sure all delayed rcu free inodes are flushed before we
133 kmem_cache_destroy(afs_inode_cachep);
138 * parse the mount options
139 * - this function has been shamelessly adapted from the ext3 fs which
140 * shamelessly adapted it from the msdos fs
142 static int afs_parse_options(struct afs_mount_params *params,
143 char *options, const char **devname)
145 struct afs_cell *cell;
146 substring_t args[MAX_OPT_ARGS];
150 _enter("%s", options);
152 options[PAGE_SIZE - 1] = 0;
154 while ((p = strsep(&options, ","))) {
158 token = match_token(p, afs_options_list, args);
161 cell = afs_cell_lookup(args[0].from,
162 args[0].to - args[0].from,
165 return PTR_ERR(cell);
166 afs_put_cell(params->cell);
175 *devname = args[0].from;
178 case afs_opt_autocell:
179 params->autocell = 1;
183 printk(KERN_ERR "kAFS:"
184 " Unknown or invalid mount option: '%s'\n", p);
194 * parse a device name to get cell name, volume name, volume type and R/W
196 * - this can be one of the following:
197 * "%[cell:]volume[.]" R/W volume
198 * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
199 * or R/W (rwpath=1) volume
200 * "%[cell:]volume.readonly" R/O volume
201 * "#[cell:]volume.readonly" R/O volume
202 * "%[cell:]volume.backup" Backup volume
203 * "#[cell:]volume.backup" Backup volume
205 static int afs_parse_device_name(struct afs_mount_params *params,
208 struct afs_cell *cell;
209 const char *cellname, *suffix;
215 printk(KERN_ERR "kAFS: no volume name specified\n");
219 if ((name[0] != '%' && name[0] != '#') || !name[1]) {
220 printk(KERN_ERR "kAFS: unparsable volume name\n");
224 /* determine the type of volume we're looking for */
225 params->type = AFSVL_ROVOL;
226 params->force = false;
227 if (params->rwpath || name[0] == '%') {
228 params->type = AFSVL_RWVOL;
229 params->force = true;
233 /* split the cell name out if there is one */
234 params->volname = strchr(name, ':');
235 if (params->volname) {
237 cellnamesz = params->volname - name;
240 params->volname = name;
245 /* the volume type is further affected by a possible suffix */
246 suffix = strrchr(params->volname, '.');
248 if (strcmp(suffix, ".readonly") == 0) {
249 params->type = AFSVL_ROVOL;
250 params->force = true;
251 } else if (strcmp(suffix, ".backup") == 0) {
252 params->type = AFSVL_BACKVOL;
253 params->force = true;
254 } else if (suffix[1] == 0) {
260 params->volnamesz = suffix ?
261 suffix - params->volname : strlen(params->volname);
263 _debug("cell %*.*s [%p]",
264 cellnamesz, cellnamesz, cellname ?: "", params->cell);
266 /* lookup the cell record */
267 if (cellname || !params->cell) {
268 cell = afs_cell_lookup(cellname, cellnamesz, true);
270 printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
271 cellnamesz, cellnamesz, cellname ?: "");
272 return PTR_ERR(cell);
274 afs_put_cell(params->cell);
278 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
279 params->cell->name, params->cell,
280 params->volnamesz, params->volnamesz, params->volname,
281 suffix ?: "-", params->type, params->force ? " FORCE" : "");
287 * check a superblock to see if it's the one we're looking for
289 static int afs_test_super(struct super_block *sb, void *data)
291 struct afs_super_info *as1 = data;
292 struct afs_super_info *as = sb->s_fs_info;
294 return as->volume == as1->volume;
297 static int afs_set_super(struct super_block *sb, void *data)
299 sb->s_fs_info = data;
300 return set_anon_super(sb, NULL);
304 * fill in the superblock
306 static int afs_fill_super(struct super_block *sb,
307 struct afs_mount_params *params)
309 struct afs_super_info *as = sb->s_fs_info;
311 struct inode *inode = NULL;
316 /* fill in the superblock */
317 sb->s_blocksize = PAGE_CACHE_SIZE;
318 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
319 sb->s_magic = AFS_FS_MAGIC;
320 sb->s_op = &afs_super_ops;
321 sb->s_bdi = &as->volume->bdi;
322 strlcpy(sb->s_id, as->volume->vlocation->vldb.name, sizeof(sb->s_id));
324 /* allocate the root inode and dentry */
325 fid.vid = as->volume->vid;
328 inode = afs_iget(sb, params->key, &fid, NULL, NULL);
330 return PTR_ERR(inode);
332 if (params->autocell)
333 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
336 sb->s_root = d_make_root(inode);
340 sb->s_d_op = &afs_fs_dentry_operations;
346 _leave(" = %d", ret);
351 * get an AFS superblock
353 static struct dentry *afs_mount(struct file_system_type *fs_type,
354 int flags, const char *dev_name, void *options)
356 struct afs_mount_params params;
357 struct super_block *sb;
358 struct afs_volume *vol;
360 char *new_opts = kstrdup(options, GFP_KERNEL);
361 struct afs_super_info *as;
364 _enter(",,%s,%p", dev_name, options);
366 memset(¶ms, 0, sizeof(params));
369 if (current->nsproxy->net_ns != &init_net)
372 /* parse the options and device name */
374 ret = afs_parse_options(¶ms, options, &dev_name);
379 ret = afs_parse_device_name(¶ms, dev_name);
383 /* try and do the mount securely */
384 key = afs_request_key(params.cell);
386 _leave(" = %ld [key]", PTR_ERR(key));
392 /* parse the device name */
393 vol = afs_volume_lookup(¶ms);
399 /* allocate a superblock info record */
400 as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
408 /* allocate a deviceless superblock */
409 sb = sget(fs_type, afs_test_super, afs_set_super, flags, as);
418 /* initial superblock/root creation */
420 ret = afs_fill_super(sb, ¶ms);
422 deactivate_locked_super(sb);
425 save_mount_options(sb, new_opts);
426 sb->s_flags |= MS_ACTIVE;
429 ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
434 afs_put_cell(params.cell);
436 _leave(" = 0 [%p]", sb);
437 return dget(sb->s_root);
440 afs_put_cell(params.cell);
443 _leave(" = %d", ret);
447 static void afs_kill_super(struct super_block *sb)
449 struct afs_super_info *as = sb->s_fs_info;
451 afs_put_volume(as->volume);
456 * initialise an inode cache slab element prior to any use
458 static void afs_i_init_once(void *_vnode)
460 struct afs_vnode *vnode = _vnode;
462 memset(vnode, 0, sizeof(*vnode));
463 inode_init_once(&vnode->vfs_inode);
464 init_waitqueue_head(&vnode->update_waitq);
465 mutex_init(&vnode->permits_lock);
466 mutex_init(&vnode->validate_lock);
467 spin_lock_init(&vnode->writeback_lock);
468 spin_lock_init(&vnode->lock);
469 INIT_LIST_HEAD(&vnode->writebacks);
470 INIT_LIST_HEAD(&vnode->pending_locks);
471 INIT_LIST_HEAD(&vnode->granted_locks);
472 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
473 INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
477 * allocate an AFS inode struct from our slab cache
479 static struct inode *afs_alloc_inode(struct super_block *sb)
481 struct afs_vnode *vnode;
483 vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
487 atomic_inc(&afs_count_active_inodes);
489 memset(&vnode->fid, 0, sizeof(vnode->fid));
490 memset(&vnode->status, 0, sizeof(vnode->status));
492 vnode->volume = NULL;
493 vnode->update_cnt = 0;
494 vnode->flags = 1 << AFS_VNODE_UNSET;
495 vnode->cb_promised = false;
497 _leave(" = %p", &vnode->vfs_inode);
498 return &vnode->vfs_inode;
501 static void afs_i_callback(struct rcu_head *head)
503 struct inode *inode = container_of(head, struct inode, i_rcu);
504 struct afs_vnode *vnode = AFS_FS_I(inode);
505 kmem_cache_free(afs_inode_cachep, vnode);
509 * destroy an AFS inode struct
511 static void afs_destroy_inode(struct inode *inode)
513 struct afs_vnode *vnode = AFS_FS_I(inode);
515 _enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
517 _debug("DESTROY INODE %p", inode);
519 ASSERTCMP(vnode->server, ==, NULL);
521 call_rcu(&inode->i_rcu, afs_i_callback);
522 atomic_dec(&afs_count_active_inodes);
526 * return information about an AFS volume
528 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
530 struct afs_volume_status vs;
531 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
535 key = afs_request_key(vnode->volume->cell);
539 ret = afs_vnode_get_volume_status(vnode, key, &vs);
542 _leave(" = %d", ret);
546 buf->f_type = dentry->d_sb->s_magic;
547 buf->f_bsize = AFS_BLOCK_SIZE;
548 buf->f_namelen = AFSNAMEMAX - 1;
550 if (vs.max_quota == 0)
551 buf->f_blocks = vs.part_max_blocks;
553 buf->f_blocks = vs.max_quota;
554 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;