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
,
48 MODULE_ALIAS_FS("afs");
50 static const struct super_operations afs_super_ops
= {
52 .alloc_inode
= afs_alloc_inode
,
53 .drop_inode
= afs_drop_inode
,
54 .destroy_inode
= afs_destroy_inode
,
55 .evict_inode
= afs_evict_inode
,
56 .show_options
= generic_show_options
,
59 static struct kmem_cache
*afs_inode_cachep
;
60 static atomic_t afs_count_active_inodes
;
70 static const match_table_t afs_options_list
= {
71 { afs_opt_cell
, "cell=%s" },
72 { afs_opt_rwpath
, "rwpath" },
73 { afs_opt_vol
, "vol=%s" },
74 { afs_opt_autocell
, "autocell" },
79 * initialise the filesystem
81 int __init
afs_fs_init(void)
87 /* create ourselves an inode cache */
88 atomic_set(&afs_count_active_inodes
, 0);
91 afs_inode_cachep
= kmem_cache_create("afs_inode_cache",
92 sizeof(struct afs_vnode
),
94 SLAB_HWCACHE_ALIGN
|SLAB_ACCOUNT
,
96 if (!afs_inode_cachep
) {
97 printk(KERN_NOTICE
"kAFS: Failed to allocate inode cache\n");
101 /* now export our filesystem to lesser mortals */
102 ret
= register_filesystem(&afs_fs_type
);
104 kmem_cache_destroy(afs_inode_cachep
);
105 _leave(" = %d", ret
);
114 * clean up the filesystem
116 void __exit
afs_fs_exit(void)
120 afs_mntpt_kill_timer();
121 unregister_filesystem(&afs_fs_type
);
123 if (atomic_read(&afs_count_active_inodes
) != 0) {
124 printk("kAFS: %d active inode objects still present\n",
125 atomic_read(&afs_count_active_inodes
));
130 * Make sure all delayed rcu free inodes are flushed before we
134 kmem_cache_destroy(afs_inode_cachep
);
139 * parse the mount options
140 * - this function has been shamelessly adapted from the ext3 fs which
141 * shamelessly adapted it from the msdos fs
143 static int afs_parse_options(struct afs_mount_params
*params
,
144 char *options
, const char **devname
)
146 struct afs_cell
*cell
;
147 substring_t args
[MAX_OPT_ARGS
];
151 _enter("%s", options
);
153 options
[PAGE_SIZE
- 1] = 0;
155 while ((p
= strsep(&options
, ","))) {
159 token
= match_token(p
, afs_options_list
, args
);
162 cell
= afs_cell_lookup(args
[0].from
,
163 args
[0].to
- args
[0].from
,
166 return PTR_ERR(cell
);
167 afs_put_cell(params
->cell
);
176 *devname
= args
[0].from
;
179 case afs_opt_autocell
:
180 params
->autocell
= 1;
184 printk(KERN_ERR
"kAFS:"
185 " Unknown or invalid mount option: '%s'\n", p
);
195 * parse a device name to get cell name, volume name, volume type and R/W
197 * - this can be one of the following:
198 * "%[cell:]volume[.]" R/W volume
199 * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
200 * or R/W (rwpath=1) volume
201 * "%[cell:]volume.readonly" R/O volume
202 * "#[cell:]volume.readonly" R/O volume
203 * "%[cell:]volume.backup" Backup volume
204 * "#[cell:]volume.backup" Backup volume
206 static int afs_parse_device_name(struct afs_mount_params
*params
,
209 struct afs_cell
*cell
;
210 const char *cellname
, *suffix
;
216 printk(KERN_ERR
"kAFS: no volume name specified\n");
220 if ((name
[0] != '%' && name
[0] != '#') || !name
[1]) {
221 printk(KERN_ERR
"kAFS: unparsable volume name\n");
225 /* determine the type of volume we're looking for */
226 params
->type
= AFSVL_ROVOL
;
227 params
->force
= false;
228 if (params
->rwpath
|| name
[0] == '%') {
229 params
->type
= AFSVL_RWVOL
;
230 params
->force
= true;
234 /* split the cell name out if there is one */
235 params
->volname
= strchr(name
, ':');
236 if (params
->volname
) {
238 cellnamesz
= params
->volname
- name
;
241 params
->volname
= name
;
246 /* the volume type is further affected by a possible suffix */
247 suffix
= strrchr(params
->volname
, '.');
249 if (strcmp(suffix
, ".readonly") == 0) {
250 params
->type
= AFSVL_ROVOL
;
251 params
->force
= true;
252 } else if (strcmp(suffix
, ".backup") == 0) {
253 params
->type
= AFSVL_BACKVOL
;
254 params
->force
= true;
255 } else if (suffix
[1] == 0) {
261 params
->volnamesz
= suffix
?
262 suffix
- params
->volname
: strlen(params
->volname
);
264 _debug("cell %*.*s [%p]",
265 cellnamesz
, cellnamesz
, cellname
?: "", params
->cell
);
267 /* lookup the cell record */
268 if (cellname
|| !params
->cell
) {
269 cell
= afs_cell_lookup(cellname
, cellnamesz
, true);
271 printk(KERN_ERR
"kAFS: unable to lookup cell '%*.*s'\n",
272 cellnamesz
, cellnamesz
, cellname
?: "");
273 return PTR_ERR(cell
);
275 afs_put_cell(params
->cell
);
279 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
280 params
->cell
->name
, params
->cell
,
281 params
->volnamesz
, params
->volnamesz
, params
->volname
,
282 suffix
?: "-", params
->type
, params
->force
? " FORCE" : "");
288 * check a superblock to see if it's the one we're looking for
290 static int afs_test_super(struct super_block
*sb
, void *data
)
292 struct afs_super_info
*as1
= data
;
293 struct afs_super_info
*as
= sb
->s_fs_info
;
295 return as
->volume
== as1
->volume
;
298 static int afs_set_super(struct super_block
*sb
, void *data
)
300 sb
->s_fs_info
= data
;
301 return set_anon_super(sb
, NULL
);
305 * fill in the superblock
307 static int afs_fill_super(struct super_block
*sb
,
308 struct afs_mount_params
*params
)
310 struct afs_super_info
*as
= sb
->s_fs_info
;
312 struct inode
*inode
= NULL
;
317 /* fill in the superblock */
318 sb
->s_blocksize
= PAGE_SIZE
;
319 sb
->s_blocksize_bits
= PAGE_SHIFT
;
320 sb
->s_magic
= AFS_FS_MAGIC
;
321 sb
->s_op
= &afs_super_ops
;
322 ret
= super_setup_bdi(sb
);
325 sb
->s_bdi
->ra_pages
= VM_MAX_READAHEAD
* 1024 / PAGE_SIZE
;
326 strlcpy(sb
->s_id
, as
->volume
->vlocation
->vldb
.name
, sizeof(sb
->s_id
));
328 /* allocate the root inode and dentry */
329 fid
.vid
= as
->volume
->vid
;
332 inode
= afs_iget(sb
, params
->key
, &fid
, NULL
, NULL
);
334 return PTR_ERR(inode
);
336 if (params
->autocell
)
337 set_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(inode
)->flags
);
340 sb
->s_root
= d_make_root(inode
);
344 sb
->s_d_op
= &afs_fs_dentry_operations
;
350 _leave(" = %d", ret
);
355 * get an AFS superblock
357 static struct dentry
*afs_mount(struct file_system_type
*fs_type
,
358 int flags
, const char *dev_name
, void *options
)
360 struct afs_mount_params params
;
361 struct super_block
*sb
;
362 struct afs_volume
*vol
;
364 char *new_opts
= kstrdup(options
, GFP_KERNEL
);
365 struct afs_super_info
*as
;
368 _enter(",,%s,%p", dev_name
, options
);
370 memset(¶ms
, 0, sizeof(params
));
373 if (current
->nsproxy
->net_ns
!= &init_net
)
376 /* parse the options and device name */
378 ret
= afs_parse_options(¶ms
, options
, &dev_name
);
383 ret
= afs_parse_device_name(¶ms
, dev_name
);
387 /* try and do the mount securely */
388 key
= afs_request_key(params
.cell
);
390 _leave(" = %ld [key]", PTR_ERR(key
));
396 /* parse the device name */
397 vol
= afs_volume_lookup(¶ms
);
403 /* allocate a superblock info record */
404 as
= kzalloc(sizeof(struct afs_super_info
), GFP_KERNEL
);
412 /* allocate a deviceless superblock */
413 sb
= sget(fs_type
, afs_test_super
, afs_set_super
, flags
, as
);
422 /* initial superblock/root creation */
424 ret
= afs_fill_super(sb
, ¶ms
);
426 deactivate_locked_super(sb
);
429 save_mount_options(sb
, new_opts
);
430 sb
->s_flags
|= MS_ACTIVE
;
433 ASSERTCMP(sb
->s_flags
, &, MS_ACTIVE
);
438 afs_put_cell(params
.cell
);
440 _leave(" = 0 [%p]", sb
);
441 return dget(sb
->s_root
);
444 afs_put_cell(params
.cell
);
447 _leave(" = %d", ret
);
451 static void afs_kill_super(struct super_block
*sb
)
453 struct afs_super_info
*as
= sb
->s_fs_info
;
455 afs_put_volume(as
->volume
);
460 * initialise an inode cache slab element prior to any use
462 static void afs_i_init_once(void *_vnode
)
464 struct afs_vnode
*vnode
= _vnode
;
466 memset(vnode
, 0, sizeof(*vnode
));
467 inode_init_once(&vnode
->vfs_inode
);
468 init_waitqueue_head(&vnode
->update_waitq
);
469 mutex_init(&vnode
->permits_lock
);
470 mutex_init(&vnode
->validate_lock
);
471 spin_lock_init(&vnode
->writeback_lock
);
472 spin_lock_init(&vnode
->lock
);
473 INIT_LIST_HEAD(&vnode
->writebacks
);
474 INIT_LIST_HEAD(&vnode
->pending_locks
);
475 INIT_LIST_HEAD(&vnode
->granted_locks
);
476 INIT_DELAYED_WORK(&vnode
->lock_work
, afs_lock_work
);
477 INIT_WORK(&vnode
->cb_broken_work
, afs_broken_callback_work
);
481 * allocate an AFS inode struct from our slab cache
483 static struct inode
*afs_alloc_inode(struct super_block
*sb
)
485 struct afs_vnode
*vnode
;
487 vnode
= kmem_cache_alloc(afs_inode_cachep
, GFP_KERNEL
);
491 atomic_inc(&afs_count_active_inodes
);
493 memset(&vnode
->fid
, 0, sizeof(vnode
->fid
));
494 memset(&vnode
->status
, 0, sizeof(vnode
->status
));
496 vnode
->volume
= NULL
;
497 vnode
->update_cnt
= 0;
498 vnode
->flags
= 1 << AFS_VNODE_UNSET
;
499 vnode
->cb_promised
= false;
501 _leave(" = %p", &vnode
->vfs_inode
);
502 return &vnode
->vfs_inode
;
505 static void afs_i_callback(struct rcu_head
*head
)
507 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
508 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
509 kmem_cache_free(afs_inode_cachep
, vnode
);
513 * destroy an AFS inode struct
515 static void afs_destroy_inode(struct inode
*inode
)
517 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
519 _enter("%p{%x:%u}", inode
, vnode
->fid
.vid
, vnode
->fid
.vnode
);
521 _debug("DESTROY INODE %p", inode
);
523 ASSERTCMP(vnode
->server
, ==, NULL
);
525 call_rcu(&inode
->i_rcu
, afs_i_callback
);
526 atomic_dec(&afs_count_active_inodes
);
530 * return information about an AFS volume
532 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
534 struct afs_volume_status vs
;
535 struct afs_vnode
*vnode
= AFS_FS_I(d_inode(dentry
));
539 key
= afs_request_key(vnode
->volume
->cell
);
543 ret
= afs_vnode_get_volume_status(vnode
, key
, &vs
);
546 _leave(" = %d", ret
);
550 buf
->f_type
= dentry
->d_sb
->s_magic
;
551 buf
->f_bsize
= AFS_BLOCK_SIZE
;
552 buf
->f_namelen
= AFSNAMEMAX
- 1;
554 if (vs
.max_quota
== 0)
555 buf
->f_blocks
= vs
.part_max_blocks
;
557 buf
->f_blocks
= vs
.max_quota
;
558 buf
->f_bavail
= buf
->f_bfree
= buf
->f_blocks
- vs
.blocks_in_use
;