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@redhat.com>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/slab.h>
22 #include <linux/pagemap.h>
23 #include <linux/parser.h>
24 #include <linux/statfs.h>
25 #include <linux/sched.h>
28 #define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
30 static void afs_i_init_once(void *foo
, struct kmem_cache
*cachep
,
32 static int afs_get_sb(struct file_system_type
*fs_type
,
33 int flags
, const char *dev_name
,
34 void *data
, struct vfsmount
*mnt
);
35 static struct inode
*afs_alloc_inode(struct super_block
*sb
);
36 static void afs_put_super(struct super_block
*sb
);
37 static void afs_destroy_inode(struct inode
*inode
);
38 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
);
40 struct file_system_type afs_fs_type
= {
44 .kill_sb
= kill_anon_super
,
48 static const struct super_operations afs_super_ops
= {
50 .alloc_inode
= afs_alloc_inode
,
51 .write_inode
= afs_write_inode
,
52 .destroy_inode
= afs_destroy_inode
,
53 .clear_inode
= afs_clear_inode
,
54 .umount_begin
= afs_umount_begin
,
55 .put_super
= afs_put_super
,
58 static struct kmem_cache
*afs_inode_cachep
;
59 static atomic_t afs_count_active_inodes
;
68 static match_table_t afs_options_list
= {
69 { afs_opt_cell
, "cell=%s" },
70 { afs_opt_rwpath
, "rwpath" },
71 { afs_opt_vol
, "vol=%s" },
76 * initialise the filesystem
78 int __init
afs_fs_init(void)
84 /* create ourselves an inode cache */
85 atomic_set(&afs_count_active_inodes
, 0);
88 afs_inode_cachep
= kmem_cache_create("afs_inode_cache",
89 sizeof(struct afs_vnode
),
93 if (!afs_inode_cachep
) {
94 printk(KERN_NOTICE
"kAFS: Failed to allocate inode cache\n");
98 /* now export our filesystem to lesser mortals */
99 ret
= register_filesystem(&afs_fs_type
);
101 kmem_cache_destroy(afs_inode_cachep
);
102 _leave(" = %d", ret
);
111 * clean up the filesystem
113 void __exit
afs_fs_exit(void)
117 afs_mntpt_kill_timer();
118 unregister_filesystem(&afs_fs_type
);
120 if (atomic_read(&afs_count_active_inodes
) != 0) {
121 printk("kAFS: %d active inode objects still present\n",
122 atomic_read(&afs_count_active_inodes
));
126 kmem_cache_destroy(afs_inode_cachep
);
131 * parse the mount options
132 * - this function has been shamelessly adapted from the ext3 fs which
133 * shamelessly adapted it from the msdos fs
135 static int afs_parse_options(struct afs_mount_params
*params
,
136 char *options
, const char **devname
)
138 struct afs_cell
*cell
;
139 substring_t args
[MAX_OPT_ARGS
];
143 _enter("%s", options
);
145 options
[PAGE_SIZE
- 1] = 0;
147 while ((p
= strsep(&options
, ","))) {
151 token
= match_token(p
, afs_options_list
, args
);
154 cell
= afs_cell_lookup(args
[0].from
,
155 args
[0].to
- args
[0].from
);
157 return PTR_ERR(cell
);
158 afs_put_cell(params
->cell
);
167 *devname
= args
[0].from
;
171 printk(KERN_ERR
"kAFS:"
172 " Unknown or invalid mount option: '%s'\n", p
);
182 * parse a device name to get cell name, volume name, volume type and R/W
184 * - this can be one of the following:
185 * "%[cell:]volume[.]" R/W volume
186 * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
187 * or R/W (rwpath=1) volume
188 * "%[cell:]volume.readonly" R/O volume
189 * "#[cell:]volume.readonly" R/O volume
190 * "%[cell:]volume.backup" Backup volume
191 * "#[cell:]volume.backup" Backup volume
193 static int afs_parse_device_name(struct afs_mount_params
*params
,
196 struct afs_cell
*cell
;
197 const char *cellname
, *suffix
;
203 printk(KERN_ERR
"kAFS: no volume name specified\n");
207 if ((name
[0] != '%' && name
[0] != '#') || !name
[1]) {
208 printk(KERN_ERR
"kAFS: unparsable volume name\n");
212 /* determine the type of volume we're looking for */
213 params
->type
= AFSVL_ROVOL
;
214 params
->force
= false;
215 if (params
->rwpath
|| name
[0] == '%') {
216 params
->type
= AFSVL_RWVOL
;
217 params
->force
= true;
221 /* split the cell name out if there is one */
222 params
->volname
= strchr(name
, ':');
223 if (params
->volname
) {
225 cellnamesz
= params
->volname
- name
;
228 params
->volname
= name
;
233 /* the volume type is further affected by a possible suffix */
234 suffix
= strrchr(params
->volname
, '.');
236 if (strcmp(suffix
, ".readonly") == 0) {
237 params
->type
= AFSVL_ROVOL
;
238 params
->force
= true;
239 } else if (strcmp(suffix
, ".backup") == 0) {
240 params
->type
= AFSVL_BACKVOL
;
241 params
->force
= true;
242 } else if (suffix
[1] == 0) {
248 params
->volnamesz
= suffix
?
249 suffix
- params
->volname
: strlen(params
->volname
);
251 _debug("cell %*.*s [%p]",
252 cellnamesz
, cellnamesz
, cellname
?: "", params
->cell
);
254 /* lookup the cell record */
255 if (cellname
|| !params
->cell
) {
256 cell
= afs_cell_lookup(cellname
, cellnamesz
);
258 printk(KERN_ERR
"kAFS: unable to lookup cell '%s'\n",
260 return PTR_ERR(cell
);
262 afs_put_cell(params
->cell
);
266 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
267 params
->cell
->name
, params
->cell
,
268 params
->volnamesz
, params
->volnamesz
, params
->volname
,
269 suffix
?: "-", params
->type
, params
->force
? " FORCE" : "");
275 * check a superblock to see if it's the one we're looking for
277 static int afs_test_super(struct super_block
*sb
, void *data
)
279 struct afs_mount_params
*params
= data
;
280 struct afs_super_info
*as
= sb
->s_fs_info
;
282 return as
->volume
== params
->volume
;
286 * fill in the superblock
288 static int afs_fill_super(struct super_block
*sb
, void *data
)
290 struct afs_mount_params
*params
= data
;
291 struct afs_super_info
*as
= NULL
;
293 struct dentry
*root
= NULL
;
294 struct inode
*inode
= NULL
;
299 /* allocate a superblock info record */
300 as
= kzalloc(sizeof(struct afs_super_info
), GFP_KERNEL
);
302 _leave(" = -ENOMEM");
306 afs_get_volume(params
->volume
);
307 as
->volume
= params
->volume
;
309 /* fill in the superblock */
310 sb
->s_blocksize
= PAGE_CACHE_SIZE
;
311 sb
->s_blocksize_bits
= PAGE_CACHE_SHIFT
;
312 sb
->s_magic
= AFS_FS_MAGIC
;
313 sb
->s_op
= &afs_super_ops
;
316 /* allocate the root inode and dentry */
317 fid
.vid
= as
->volume
->vid
;
320 inode
= afs_iget(sb
, params
->key
, &fid
, NULL
, NULL
);
325 root
= d_alloc_root(inode
);
335 ret
= PTR_ERR(inode
);
339 afs_put_volume(as
->volume
);
342 sb
->s_fs_info
= NULL
;
344 _leave(" = %d", ret
);
349 * get an AFS superblock
351 static int afs_get_sb(struct file_system_type
*fs_type
,
353 const char *dev_name
,
355 struct vfsmount
*mnt
)
357 struct afs_mount_params params
;
358 struct super_block
*sb
;
359 struct afs_volume
*vol
;
363 _enter(",,%s,%p", dev_name
, options
);
365 memset(¶ms
, 0, sizeof(params
));
367 /* parse the options and device name */
369 ret
= afs_parse_options(¶ms
, options
, &dev_name
);
374 ret
= afs_parse_device_name(¶ms
, dev_name
);
378 /* try and do the mount securely */
379 key
= afs_request_key(params
.cell
);
381 _leave(" = %ld [key]", PTR_ERR(key
));
387 /* parse the device name */
388 vol
= afs_volume_lookup(¶ms
);
395 /* allocate a deviceless superblock */
396 sb
= sget(fs_type
, afs_test_super
, set_anon_super
, ¶ms
);
403 /* initial superblock/root creation */
406 ret
= afs_fill_super(sb
, ¶ms
);
408 up_write(&sb
->s_umount
);
409 deactivate_super(sb
);
412 sb
->s_flags
|= MS_ACTIVE
;
415 ASSERTCMP(sb
->s_flags
, &, MS_ACTIVE
);
418 simple_set_mnt(mnt
, sb
);
419 afs_put_volume(params
.volume
);
420 afs_put_cell(params
.cell
);
421 _leave(" = 0 [%p]", sb
);
425 afs_put_volume(params
.volume
);
426 afs_put_cell(params
.cell
);
428 _leave(" = %d", ret
);
433 * finish the unmounting process on the superblock
435 static void afs_put_super(struct super_block
*sb
)
437 struct afs_super_info
*as
= sb
->s_fs_info
;
441 afs_put_volume(as
->volume
);
447 * initialise an inode cache slab element prior to any use
449 static void afs_i_init_once(void *_vnode
, struct kmem_cache
*cachep
,
452 struct afs_vnode
*vnode
= _vnode
;
454 memset(vnode
, 0, sizeof(*vnode
));
455 inode_init_once(&vnode
->vfs_inode
);
456 init_waitqueue_head(&vnode
->update_waitq
);
457 mutex_init(&vnode
->permits_lock
);
458 mutex_init(&vnode
->validate_lock
);
459 spin_lock_init(&vnode
->writeback_lock
);
460 spin_lock_init(&vnode
->lock
);
461 INIT_LIST_HEAD(&vnode
->writebacks
);
462 INIT_LIST_HEAD(&vnode
->pending_locks
);
463 INIT_LIST_HEAD(&vnode
->granted_locks
);
464 INIT_DELAYED_WORK(&vnode
->lock_work
, afs_lock_work
);
465 INIT_WORK(&vnode
->cb_broken_work
, afs_broken_callback_work
);
469 * allocate an AFS inode struct from our slab cache
471 static struct inode
*afs_alloc_inode(struct super_block
*sb
)
473 struct afs_vnode
*vnode
;
475 vnode
= kmem_cache_alloc(afs_inode_cachep
, GFP_KERNEL
);
479 atomic_inc(&afs_count_active_inodes
);
481 memset(&vnode
->fid
, 0, sizeof(vnode
->fid
));
482 memset(&vnode
->status
, 0, sizeof(vnode
->status
));
484 vnode
->volume
= NULL
;
485 vnode
->update_cnt
= 0;
486 vnode
->flags
= 1 << AFS_VNODE_UNSET
;
487 vnode
->cb_promised
= false;
489 _leave(" = %p", &vnode
->vfs_inode
);
490 return &vnode
->vfs_inode
;
494 * destroy an AFS inode struct
496 static void afs_destroy_inode(struct inode
*inode
)
498 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
500 _enter("%p{%x:%u}", inode
, vnode
->fid
.vid
, vnode
->fid
.vnode
);
502 _debug("DESTROY INODE %p", inode
);
504 ASSERTCMP(vnode
->server
, ==, NULL
);
506 kmem_cache_free(afs_inode_cachep
, vnode
);
507 atomic_dec(&afs_count_active_inodes
);
511 * return information about an AFS volume
513 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
515 struct afs_volume_status vs
;
516 struct afs_vnode
*vnode
= AFS_FS_I(dentry
->d_inode
);
520 key
= afs_request_key(vnode
->volume
->cell
);
524 ret
= afs_vnode_get_volume_status(vnode
, key
, &vs
);
527 _leave(" = %d", ret
);
531 buf
->f_type
= dentry
->d_sb
->s_magic
;
532 buf
->f_bsize
= AFS_BLOCK_SIZE
;
533 buf
->f_namelen
= AFSNAMEMAX
- 1;
535 if (vs
.max_quota
== 0)
536 buf
->f_blocks
= vs
.part_max_blocks
;
538 buf
->f_blocks
= vs
.max_quota
;
539 buf
->f_bavail
= buf
->f_bfree
= buf
->f_blocks
- vs
.blocks_in_use
;