1 /* AFS superblock handling
3 * Copyright (c) 2002, 2007, 2018 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/fs_parser.h>
25 #include <linux/statfs.h>
26 #include <linux/sched.h>
27 #include <linux/nsproxy.h>
28 #include <linux/magic.h>
29 #include <net/net_namespace.h>
32 static void afs_i_init_once(void *foo
);
33 static void afs_kill_super(struct super_block
*sb
);
34 static struct inode
*afs_alloc_inode(struct super_block
*sb
);
35 static void afs_destroy_inode(struct inode
*inode
);
36 static void afs_free_inode(struct inode
*inode
);
37 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
);
38 static int afs_show_devname(struct seq_file
*m
, struct dentry
*root
);
39 static int afs_show_options(struct seq_file
*m
, struct dentry
*root
);
40 static int afs_init_fs_context(struct fs_context
*fc
);
41 static const struct fs_parameter_description afs_fs_parameters
;
43 struct file_system_type afs_fs_type
= {
46 .init_fs_context
= afs_init_fs_context
,
47 .parameters
= &afs_fs_parameters
,
48 .kill_sb
= afs_kill_super
,
51 MODULE_ALIAS_FS("afs");
55 static const struct super_operations afs_super_ops
= {
57 .alloc_inode
= afs_alloc_inode
,
58 .drop_inode
= afs_drop_inode
,
59 .destroy_inode
= afs_destroy_inode
,
60 .free_inode
= afs_free_inode
,
61 .evict_inode
= afs_evict_inode
,
62 .show_devname
= afs_show_devname
,
63 .show_options
= afs_show_options
,
66 static struct kmem_cache
*afs_inode_cachep
;
67 static atomic_t afs_count_active_inodes
;
75 static const struct fs_parameter_spec afs_param_specs
[] = {
76 fsparam_flag ("autocell", Opt_autocell
),
77 fsparam_flag ("dyn", Opt_dyn
),
78 fsparam_string("source", Opt_source
),
82 static const struct fs_parameter_description afs_fs_parameters
= {
84 .specs
= afs_param_specs
,
88 * initialise the filesystem
90 int __init
afs_fs_init(void)
96 /* create ourselves an inode cache */
97 atomic_set(&afs_count_active_inodes
, 0);
100 afs_inode_cachep
= kmem_cache_create("afs_inode_cache",
101 sizeof(struct afs_vnode
),
103 SLAB_HWCACHE_ALIGN
|SLAB_ACCOUNT
,
105 if (!afs_inode_cachep
) {
106 printk(KERN_NOTICE
"kAFS: Failed to allocate inode cache\n");
110 /* now export our filesystem to lesser mortals */
111 ret
= register_filesystem(&afs_fs_type
);
113 kmem_cache_destroy(afs_inode_cachep
);
114 _leave(" = %d", ret
);
123 * clean up the filesystem
125 void afs_fs_exit(void)
129 afs_mntpt_kill_timer();
130 unregister_filesystem(&afs_fs_type
);
132 if (atomic_read(&afs_count_active_inodes
) != 0) {
133 printk("kAFS: %d active inode objects still present\n",
134 atomic_read(&afs_count_active_inodes
));
139 * Make sure all delayed rcu free inodes are flushed before we
143 kmem_cache_destroy(afs_inode_cachep
);
148 * Display the mount device name in /proc/mounts.
150 static int afs_show_devname(struct seq_file
*m
, struct dentry
*root
)
152 struct afs_super_info
*as
= AFS_FS_S(root
->d_sb
);
153 struct afs_volume
*volume
= as
->volume
;
154 struct afs_cell
*cell
= as
->cell
;
155 const char *suf
= "";
163 switch (volume
->type
) {
168 if (volume
->type_force
)
177 seq_printf(m
, "%c%s:%s%s", pref
, cell
->name
, volume
->name
, suf
);
182 * Display the mount options in /proc/mounts.
184 static int afs_show_options(struct seq_file
*m
, struct dentry
*root
)
186 struct afs_super_info
*as
= AFS_FS_S(root
->d_sb
);
190 if (test_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(d_inode(root
))->flags
))
191 seq_puts(m
, ",autocell");
196 * Parse the source name to get cell name, volume name, volume type and R/W
199 * This can be one of the following:
200 * "%[cell:]volume[.]" R/W volume
201 * "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
202 * or R/W (R/W parent) volume
203 * "%[cell:]volume.readonly" R/O volume
204 * "#[cell:]volume.readonly" R/O volume
205 * "%[cell:]volume.backup" Backup volume
206 * "#[cell:]volume.backup" Backup volume
208 static int afs_parse_source(struct fs_context
*fc
, struct fs_parameter
*param
)
210 struct afs_fs_context
*ctx
= fc
->fs_private
;
211 struct afs_cell
*cell
;
212 const char *cellname
, *suffix
, *name
= param
->string
;
218 printk(KERN_ERR
"kAFS: no volume name specified\n");
222 if ((name
[0] != '%' && name
[0] != '#') || !name
[1]) {
223 /* To use dynroot, we don't want to have to provide a source */
224 if (strcmp(name
, "none") == 0) {
228 printk(KERN_ERR
"kAFS: unparsable volume name\n");
232 /* determine the type of volume we're looking for */
233 if (name
[0] == '%') {
234 ctx
->type
= AFSVL_RWVOL
;
239 /* split the cell name out if there is one */
240 ctx
->volname
= strchr(name
, ':');
243 cellnamesz
= ctx
->volname
- name
;
251 /* the volume type is further affected by a possible suffix */
252 suffix
= strrchr(ctx
->volname
, '.');
254 if (strcmp(suffix
, ".readonly") == 0) {
255 ctx
->type
= AFSVL_ROVOL
;
257 } else if (strcmp(suffix
, ".backup") == 0) {
258 ctx
->type
= AFSVL_BACKVOL
;
260 } else if (suffix
[1] == 0) {
266 ctx
->volnamesz
= suffix
?
267 suffix
- ctx
->volname
: strlen(ctx
->volname
);
269 _debug("cell %*.*s [%p]",
270 cellnamesz
, cellnamesz
, cellname
?: "", ctx
->cell
);
272 /* lookup the cell record */
274 cell
= afs_lookup_cell(ctx
->net
, cellname
, cellnamesz
,
277 pr_err("kAFS: unable to lookup cell '%*.*s'\n",
278 cellnamesz
, cellnamesz
, cellname
?: "");
279 return PTR_ERR(cell
);
281 afs_put_cell(ctx
->net
, ctx
->cell
);
285 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
286 ctx
->cell
->name
, ctx
->cell
,
287 ctx
->volnamesz
, ctx
->volnamesz
, ctx
->volname
,
288 suffix
?: "-", ctx
->type
, ctx
->force
? " FORCE" : "");
290 fc
->source
= param
->string
;
291 param
->string
= NULL
;
296 * Parse a single mount parameter.
298 static int afs_parse_param(struct fs_context
*fc
, struct fs_parameter
*param
)
300 struct fs_parse_result result
;
301 struct afs_fs_context
*ctx
= fc
->fs_private
;
304 opt
= fs_parse(fc
, &afs_fs_parameters
, param
, &result
);
310 return afs_parse_source(fc
, param
);
313 ctx
->autocell
= true;
317 ctx
->dyn_root
= true;
329 * Validate the options, get the cell key and look up the volume.
331 static int afs_validate_fc(struct fs_context
*fc
)
333 struct afs_fs_context
*ctx
= fc
->fs_private
;
334 struct afs_volume
*volume
;
337 if (!ctx
->dyn_root
) {
339 pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
344 pr_warn("kAFS: No cell specified\n");
345 return -EDESTADDRREQ
;
348 /* We try to do the mount securely. */
349 key
= afs_request_key(ctx
->cell
);
356 afs_put_volume(ctx
->cell
, ctx
->volume
);
360 volume
= afs_create_volume(ctx
);
362 return PTR_ERR(volume
);
364 ctx
->volume
= volume
;
371 * check a superblock to see if it's the one we're looking for
373 static int afs_test_super(struct super_block
*sb
, struct fs_context
*fc
)
375 struct afs_fs_context
*ctx
= fc
->fs_private
;
376 struct afs_super_info
*as
= AFS_FS_S(sb
);
378 return (as
->net_ns
== fc
->net_ns
&&
380 as
->volume
->vid
== ctx
->volume
->vid
&&
384 static int afs_dynroot_test_super(struct super_block
*sb
, struct fs_context
*fc
)
386 struct afs_super_info
*as
= AFS_FS_S(sb
);
388 return (as
->net_ns
== fc
->net_ns
&&
392 static int afs_set_super(struct super_block
*sb
, struct fs_context
*fc
)
394 return set_anon_super(sb
, NULL
);
398 * fill in the superblock
400 static int afs_fill_super(struct super_block
*sb
, struct afs_fs_context
*ctx
)
402 struct afs_super_info
*as
= AFS_FS_S(sb
);
404 struct inode
*inode
= NULL
;
409 /* fill in the superblock */
410 sb
->s_blocksize
= PAGE_SIZE
;
411 sb
->s_blocksize_bits
= PAGE_SHIFT
;
412 sb
->s_magic
= AFS_FS_MAGIC
;
413 sb
->s_op
= &afs_super_ops
;
415 sb
->s_xattr
= afs_xattr_handlers
;
416 ret
= super_setup_bdi(sb
);
419 sb
->s_bdi
->ra_pages
= VM_READAHEAD_PAGES
;
421 /* allocate the root inode and dentry */
423 inode
= afs_iget_pseudo_dir(sb
, true);
424 sb
->s_flags
|= SB_RDONLY
;
426 sprintf(sb
->s_id
, "%llu", as
->volume
->vid
);
427 afs_activate_volume(as
->volume
);
428 fid
.vid
= as
->volume
->vid
;
432 inode
= afs_iget(sb
, ctx
->key
, &fid
, NULL
, NULL
, NULL
);
436 return PTR_ERR(inode
);
438 if (ctx
->autocell
|| as
->dyn_root
)
439 set_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(inode
)->flags
);
442 sb
->s_root
= d_make_root(inode
);
447 sb
->s_d_op
= &afs_dynroot_dentry_operations
;
448 ret
= afs_dynroot_populate(sb
);
452 sb
->s_d_op
= &afs_fs_dentry_operations
;
459 _leave(" = %d", ret
);
463 static struct afs_super_info
*afs_alloc_sbi(struct fs_context
*fc
)
465 struct afs_fs_context
*ctx
= fc
->fs_private
;
466 struct afs_super_info
*as
;
468 as
= kzalloc(sizeof(struct afs_super_info
), GFP_KERNEL
);
470 as
->net_ns
= get_net(fc
->net_ns
);
474 as
->cell
= afs_get_cell(ctx
->cell
);
475 as
->volume
= __afs_get_volume(ctx
->volume
);
481 static void afs_destroy_sbi(struct afs_super_info
*as
)
484 afs_put_volume(as
->cell
, as
->volume
);
485 afs_put_cell(afs_net(as
->net_ns
), as
->cell
);
491 static void afs_kill_super(struct super_block
*sb
)
493 struct afs_super_info
*as
= AFS_FS_S(sb
);
494 struct afs_net
*net
= afs_net(as
->net_ns
);
497 afs_dynroot_depopulate(sb
);
499 /* Clear the callback interests (which will do ilookup5) before
500 * deactivating the superblock.
503 afs_clear_callback_interests(net
, as
->volume
->servers
);
506 afs_deactivate_volume(as
->volume
);
511 * Get an AFS superblock and root directory.
513 static int afs_get_tree(struct fs_context
*fc
)
515 struct afs_fs_context
*ctx
= fc
->fs_private
;
516 struct super_block
*sb
;
517 struct afs_super_info
*as
;
520 ret
= afs_validate_fc(fc
);
526 /* allocate a superblock info record */
528 as
= afs_alloc_sbi(fc
);
533 /* allocate a deviceless superblock */
535 as
->dyn_root
? afs_dynroot_test_super
: afs_test_super
,
543 /* initial superblock/root creation */
545 ret
= afs_fill_super(sb
, ctx
);
548 sb
->s_flags
|= SB_ACTIVE
;
551 ASSERTCMP(sb
->s_flags
, &, SB_ACTIVE
);
554 fc
->root
= dget(sb
->s_root
);
555 _leave(" = 0 [%p]", sb
);
559 deactivate_locked_super(sb
);
561 _leave(" = %d", ret
);
565 static void afs_free_fc(struct fs_context
*fc
)
567 struct afs_fs_context
*ctx
= fc
->fs_private
;
569 afs_destroy_sbi(fc
->s_fs_info
);
570 afs_put_volume(ctx
->cell
, ctx
->volume
);
571 afs_put_cell(ctx
->net
, ctx
->cell
);
576 static const struct fs_context_operations afs_context_ops
= {
578 .parse_param
= afs_parse_param
,
579 .get_tree
= afs_get_tree
,
583 * Set up the filesystem mount context.
585 static int afs_init_fs_context(struct fs_context
*fc
)
587 struct afs_fs_context
*ctx
;
588 struct afs_cell
*cell
;
590 ctx
= kzalloc(sizeof(struct afs_fs_context
), GFP_KERNEL
);
594 ctx
->type
= AFSVL_ROVOL
;
595 ctx
->net
= afs_net(fc
->net_ns
);
597 /* Default to the workstation cell. */
599 cell
= afs_lookup_cell_rcu(ctx
->net
, NULL
, 0);
605 fc
->fs_private
= ctx
;
606 fc
->ops
= &afs_context_ops
;
611 * Initialise an inode cache slab element prior to any use. Note that
612 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
615 static void afs_i_init_once(void *_vnode
)
617 struct afs_vnode
*vnode
= _vnode
;
619 memset(vnode
, 0, sizeof(*vnode
));
620 inode_init_once(&vnode
->vfs_inode
);
621 mutex_init(&vnode
->io_lock
);
622 init_rwsem(&vnode
->validate_lock
);
623 spin_lock_init(&vnode
->wb_lock
);
624 spin_lock_init(&vnode
->lock
);
625 INIT_LIST_HEAD(&vnode
->wb_keys
);
626 INIT_LIST_HEAD(&vnode
->pending_locks
);
627 INIT_LIST_HEAD(&vnode
->granted_locks
);
628 INIT_DELAYED_WORK(&vnode
->lock_work
, afs_lock_work
);
629 seqlock_init(&vnode
->cb_lock
);
633 * allocate an AFS inode struct from our slab cache
635 static struct inode
*afs_alloc_inode(struct super_block
*sb
)
637 struct afs_vnode
*vnode
;
639 vnode
= kmem_cache_alloc(afs_inode_cachep
, GFP_KERNEL
);
643 atomic_inc(&afs_count_active_inodes
);
645 /* Reset anything that shouldn't leak from one inode to the next. */
646 memset(&vnode
->fid
, 0, sizeof(vnode
->fid
));
647 memset(&vnode
->status
, 0, sizeof(vnode
->status
));
649 vnode
->volume
= NULL
;
650 vnode
->lock_key
= NULL
;
651 vnode
->permit_cache
= NULL
;
652 vnode
->cb_interest
= NULL
;
653 #ifdef CONFIG_AFS_FSCACHE
657 vnode
->flags
= 1 << AFS_VNODE_UNSET
;
659 vnode
->lock_state
= AFS_VNODE_LOCK_NONE
;
661 _leave(" = %p", &vnode
->vfs_inode
);
662 return &vnode
->vfs_inode
;
665 static void afs_free_inode(struct inode
*inode
)
667 kmem_cache_free(afs_inode_cachep
, AFS_FS_I(inode
));
671 * destroy an AFS inode struct
673 static void afs_destroy_inode(struct inode
*inode
)
675 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
677 _enter("%p{%llx:%llu}", inode
, vnode
->fid
.vid
, vnode
->fid
.vnode
);
679 _debug("DESTROY INODE %p", inode
);
681 ASSERTCMP(vnode
->cb_interest
, ==, NULL
);
683 atomic_dec(&afs_count_active_inodes
);
687 * return information about an AFS volume
689 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
691 struct afs_super_info
*as
= AFS_FS_S(dentry
->d_sb
);
692 struct afs_fs_cursor fc
;
693 struct afs_volume_status vs
;
694 struct afs_vnode
*vnode
= AFS_FS_I(d_inode(dentry
));
698 buf
->f_type
= dentry
->d_sb
->s_magic
;
699 buf
->f_bsize
= AFS_BLOCK_SIZE
;
700 buf
->f_namelen
= AFSNAMEMAX
- 1;
709 key
= afs_request_key(vnode
->volume
->cell
);
714 if (afs_begin_vnode_operation(&fc
, vnode
, key
)) {
715 fc
.flags
|= AFS_FS_CURSOR_NO_VSLEEP
;
716 while (afs_select_fileserver(&fc
)) {
717 fc
.cb_break
= afs_calc_vnode_cb_break(vnode
);
718 afs_fs_get_volume_status(&fc
, &vs
);
721 afs_check_for_remote_deletion(&fc
, fc
.vnode
);
722 afs_vnode_commit_status(&fc
, vnode
, fc
.cb_break
);
723 ret
= afs_end_vnode_operation(&fc
);
729 if (vs
.max_quota
== 0)
730 buf
->f_blocks
= vs
.part_max_blocks
;
732 buf
->f_blocks
= vs
.max_quota
;
733 buf
->f_bavail
= buf
->f_bfree
= buf
->f_blocks
- vs
.blocks_in_use
;