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 int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
);
37 static int afs_show_devname(struct seq_file
*m
, struct dentry
*root
);
38 static int afs_show_options(struct seq_file
*m
, struct dentry
*root
);
39 static int afs_init_fs_context(struct fs_context
*fc
);
40 static const struct fs_parameter_description afs_fs_parameters
;
42 struct file_system_type afs_fs_type
= {
45 .init_fs_context
= afs_init_fs_context
,
46 .parameters
= &afs_fs_parameters
,
47 .kill_sb
= afs_kill_super
,
50 MODULE_ALIAS_FS("afs");
54 static const struct super_operations afs_super_ops
= {
56 .alloc_inode
= afs_alloc_inode
,
57 .drop_inode
= afs_drop_inode
,
58 .destroy_inode
= afs_destroy_inode
,
59 .evict_inode
= afs_evict_inode
,
60 .show_devname
= afs_show_devname
,
61 .show_options
= afs_show_options
,
64 static struct kmem_cache
*afs_inode_cachep
;
65 static atomic_t afs_count_active_inodes
;
73 static const struct fs_parameter_spec afs_param_specs
[] = {
74 fsparam_flag ("autocell", Opt_autocell
),
75 fsparam_flag ("dyn", Opt_dyn
),
76 fsparam_string("source", Opt_source
),
80 static const struct fs_parameter_description afs_fs_parameters
= {
82 .specs
= afs_param_specs
,
86 * initialise the filesystem
88 int __init
afs_fs_init(void)
94 /* create ourselves an inode cache */
95 atomic_set(&afs_count_active_inodes
, 0);
98 afs_inode_cachep
= kmem_cache_create("afs_inode_cache",
99 sizeof(struct afs_vnode
),
101 SLAB_HWCACHE_ALIGN
|SLAB_ACCOUNT
,
103 if (!afs_inode_cachep
) {
104 printk(KERN_NOTICE
"kAFS: Failed to allocate inode cache\n");
108 /* now export our filesystem to lesser mortals */
109 ret
= register_filesystem(&afs_fs_type
);
111 kmem_cache_destroy(afs_inode_cachep
);
112 _leave(" = %d", ret
);
121 * clean up the filesystem
123 void afs_fs_exit(void)
127 afs_mntpt_kill_timer();
128 unregister_filesystem(&afs_fs_type
);
130 if (atomic_read(&afs_count_active_inodes
) != 0) {
131 printk("kAFS: %d active inode objects still present\n",
132 atomic_read(&afs_count_active_inodes
));
137 * Make sure all delayed rcu free inodes are flushed before we
141 kmem_cache_destroy(afs_inode_cachep
);
146 * Display the mount device name in /proc/mounts.
148 static int afs_show_devname(struct seq_file
*m
, struct dentry
*root
)
150 struct afs_super_info
*as
= AFS_FS_S(root
->d_sb
);
151 struct afs_volume
*volume
= as
->volume
;
152 struct afs_cell
*cell
= as
->cell
;
153 const char *suf
= "";
161 switch (volume
->type
) {
166 if (volume
->type_force
)
175 seq_printf(m
, "%c%s:%s%s", pref
, cell
->name
, volume
->name
, suf
);
180 * Display the mount options in /proc/mounts.
182 static int afs_show_options(struct seq_file
*m
, struct dentry
*root
)
184 struct afs_super_info
*as
= AFS_FS_S(root
->d_sb
);
188 if (test_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(d_inode(root
))->flags
))
189 seq_puts(m
, ",autocell");
194 * Parse the source 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 (R/O parent),
200 * or R/W (R/W parent) 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_source(struct fs_context
*fc
, struct fs_parameter
*param
)
208 struct afs_fs_context
*ctx
= fc
->fs_private
;
209 struct afs_cell
*cell
;
210 const char *cellname
, *suffix
, *name
= param
->string
;
216 printk(KERN_ERR
"kAFS: no volume name specified\n");
220 if ((name
[0] != '%' && name
[0] != '#') || !name
[1]) {
221 /* To use dynroot, we don't want to have to provide a source */
222 if (strcmp(name
, "none") == 0) {
226 printk(KERN_ERR
"kAFS: unparsable volume name\n");
230 /* determine the type of volume we're looking for */
231 if (name
[0] == '%') {
232 ctx
->type
= AFSVL_RWVOL
;
237 /* split the cell name out if there is one */
238 ctx
->volname
= strchr(name
, ':');
241 cellnamesz
= ctx
->volname
- name
;
249 /* the volume type is further affected by a possible suffix */
250 suffix
= strrchr(ctx
->volname
, '.');
252 if (strcmp(suffix
, ".readonly") == 0) {
253 ctx
->type
= AFSVL_ROVOL
;
255 } else if (strcmp(suffix
, ".backup") == 0) {
256 ctx
->type
= AFSVL_BACKVOL
;
258 } else if (suffix
[1] == 0) {
264 ctx
->volnamesz
= suffix
?
265 suffix
- ctx
->volname
: strlen(ctx
->volname
);
267 _debug("cell %*.*s [%p]",
268 cellnamesz
, cellnamesz
, cellname
?: "", ctx
->cell
);
270 /* lookup the cell record */
272 cell
= afs_lookup_cell(ctx
->net
, cellname
, cellnamesz
,
275 pr_err("kAFS: unable to lookup cell '%*.*s'\n",
276 cellnamesz
, cellnamesz
, cellname
?: "");
277 return PTR_ERR(cell
);
279 afs_put_cell(ctx
->net
, ctx
->cell
);
283 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
284 ctx
->cell
->name
, ctx
->cell
,
285 ctx
->volnamesz
, ctx
->volnamesz
, ctx
->volname
,
286 suffix
?: "-", ctx
->type
, ctx
->force
? " FORCE" : "");
288 fc
->source
= param
->string
;
289 param
->string
= NULL
;
294 * Parse a single mount parameter.
296 static int afs_parse_param(struct fs_context
*fc
, struct fs_parameter
*param
)
298 struct fs_parse_result result
;
299 struct afs_fs_context
*ctx
= fc
->fs_private
;
302 opt
= fs_parse(fc
, &afs_fs_parameters
, param
, &result
);
308 return afs_parse_source(fc
, param
);
311 ctx
->autocell
= true;
315 ctx
->dyn_root
= true;
327 * Validate the options, get the cell key and look up the volume.
329 static int afs_validate_fc(struct fs_context
*fc
)
331 struct afs_fs_context
*ctx
= fc
->fs_private
;
332 struct afs_volume
*volume
;
335 if (!ctx
->dyn_root
) {
337 pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
342 pr_warn("kAFS: No cell specified\n");
343 return -EDESTADDRREQ
;
346 /* We try to do the mount securely. */
347 key
= afs_request_key(ctx
->cell
);
354 afs_put_volume(ctx
->cell
, ctx
->volume
);
358 volume
= afs_create_volume(ctx
);
360 return PTR_ERR(volume
);
362 ctx
->volume
= volume
;
369 * check a superblock to see if it's the one we're looking for
371 static int afs_test_super(struct super_block
*sb
, struct fs_context
*fc
)
373 struct afs_fs_context
*ctx
= fc
->fs_private
;
374 struct afs_super_info
*as
= AFS_FS_S(sb
);
376 return (as
->net_ns
== fc
->net_ns
&&
378 as
->volume
->vid
== ctx
->volume
->vid
&&
382 static int afs_dynroot_test_super(struct super_block
*sb
, struct fs_context
*fc
)
384 struct afs_super_info
*as
= AFS_FS_S(sb
);
386 return (as
->net_ns
== fc
->net_ns
&&
390 static int afs_set_super(struct super_block
*sb
, struct fs_context
*fc
)
392 return set_anon_super(sb
, NULL
);
396 * fill in the superblock
398 static int afs_fill_super(struct super_block
*sb
, struct afs_fs_context
*ctx
)
400 struct afs_super_info
*as
= AFS_FS_S(sb
);
402 struct inode
*inode
= NULL
;
407 /* fill in the superblock */
408 sb
->s_blocksize
= PAGE_SIZE
;
409 sb
->s_blocksize_bits
= PAGE_SHIFT
;
410 sb
->s_magic
= AFS_FS_MAGIC
;
411 sb
->s_op
= &afs_super_ops
;
413 sb
->s_xattr
= afs_xattr_handlers
;
414 ret
= super_setup_bdi(sb
);
417 sb
->s_bdi
->ra_pages
= VM_READAHEAD_PAGES
;
419 /* allocate the root inode and dentry */
421 inode
= afs_iget_pseudo_dir(sb
, true);
422 sb
->s_flags
|= SB_RDONLY
;
424 sprintf(sb
->s_id
, "%llu", as
->volume
->vid
);
425 afs_activate_volume(as
->volume
);
426 fid
.vid
= as
->volume
->vid
;
430 inode
= afs_iget(sb
, ctx
->key
, &fid
, NULL
, NULL
, NULL
);
434 return PTR_ERR(inode
);
436 if (ctx
->autocell
|| as
->dyn_root
)
437 set_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(inode
)->flags
);
440 sb
->s_root
= d_make_root(inode
);
445 sb
->s_d_op
= &afs_dynroot_dentry_operations
;
446 ret
= afs_dynroot_populate(sb
);
450 sb
->s_d_op
= &afs_fs_dentry_operations
;
457 _leave(" = %d", ret
);
461 static struct afs_super_info
*afs_alloc_sbi(struct fs_context
*fc
)
463 struct afs_fs_context
*ctx
= fc
->fs_private
;
464 struct afs_super_info
*as
;
466 as
= kzalloc(sizeof(struct afs_super_info
), GFP_KERNEL
);
468 as
->net_ns
= get_net(fc
->net_ns
);
472 as
->cell
= afs_get_cell(ctx
->cell
);
473 as
->volume
= __afs_get_volume(ctx
->volume
);
479 static void afs_destroy_sbi(struct afs_super_info
*as
)
482 afs_put_volume(as
->cell
, as
->volume
);
483 afs_put_cell(afs_net(as
->net_ns
), as
->cell
);
489 static void afs_kill_super(struct super_block
*sb
)
491 struct afs_super_info
*as
= AFS_FS_S(sb
);
492 struct afs_net
*net
= afs_net(as
->net_ns
);
495 afs_dynroot_depopulate(sb
);
497 /* Clear the callback interests (which will do ilookup5) before
498 * deactivating the superblock.
501 afs_clear_callback_interests(net
, as
->volume
->servers
);
504 afs_deactivate_volume(as
->volume
);
509 * Get an AFS superblock and root directory.
511 static int afs_get_tree(struct fs_context
*fc
)
513 struct afs_fs_context
*ctx
= fc
->fs_private
;
514 struct super_block
*sb
;
515 struct afs_super_info
*as
;
518 ret
= afs_validate_fc(fc
);
524 /* allocate a superblock info record */
526 as
= afs_alloc_sbi(fc
);
531 /* allocate a deviceless superblock */
533 as
->dyn_root
? afs_dynroot_test_super
: afs_test_super
,
541 /* initial superblock/root creation */
543 ret
= afs_fill_super(sb
, ctx
);
546 sb
->s_flags
|= SB_ACTIVE
;
549 ASSERTCMP(sb
->s_flags
, &, SB_ACTIVE
);
552 fc
->root
= dget(sb
->s_root
);
553 _leave(" = 0 [%p]", sb
);
557 deactivate_locked_super(sb
);
559 _leave(" = %d", ret
);
563 static void afs_free_fc(struct fs_context
*fc
)
565 struct afs_fs_context
*ctx
= fc
->fs_private
;
567 afs_destroy_sbi(fc
->s_fs_info
);
568 afs_put_volume(ctx
->cell
, ctx
->volume
);
569 afs_put_cell(ctx
->net
, ctx
->cell
);
574 static const struct fs_context_operations afs_context_ops
= {
576 .parse_param
= afs_parse_param
,
577 .get_tree
= afs_get_tree
,
581 * Set up the filesystem mount context.
583 static int afs_init_fs_context(struct fs_context
*fc
)
585 struct afs_fs_context
*ctx
;
586 struct afs_cell
*cell
;
588 ctx
= kzalloc(sizeof(struct afs_fs_context
), GFP_KERNEL
);
592 ctx
->type
= AFSVL_ROVOL
;
593 ctx
->net
= afs_net(fc
->net_ns
);
595 /* Default to the workstation cell. */
597 cell
= afs_lookup_cell_rcu(ctx
->net
, NULL
, 0);
603 fc
->fs_private
= ctx
;
604 fc
->ops
= &afs_context_ops
;
609 * Initialise an inode cache slab element prior to any use. Note that
610 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
613 static void afs_i_init_once(void *_vnode
)
615 struct afs_vnode
*vnode
= _vnode
;
617 memset(vnode
, 0, sizeof(*vnode
));
618 inode_init_once(&vnode
->vfs_inode
);
619 mutex_init(&vnode
->io_lock
);
620 init_rwsem(&vnode
->validate_lock
);
621 spin_lock_init(&vnode
->wb_lock
);
622 spin_lock_init(&vnode
->lock
);
623 INIT_LIST_HEAD(&vnode
->wb_keys
);
624 INIT_LIST_HEAD(&vnode
->pending_locks
);
625 INIT_LIST_HEAD(&vnode
->granted_locks
);
626 INIT_DELAYED_WORK(&vnode
->lock_work
, afs_lock_work
);
627 seqlock_init(&vnode
->cb_lock
);
631 * allocate an AFS inode struct from our slab cache
633 static struct inode
*afs_alloc_inode(struct super_block
*sb
)
635 struct afs_vnode
*vnode
;
637 vnode
= kmem_cache_alloc(afs_inode_cachep
, GFP_KERNEL
);
641 atomic_inc(&afs_count_active_inodes
);
643 /* Reset anything that shouldn't leak from one inode to the next. */
644 memset(&vnode
->fid
, 0, sizeof(vnode
->fid
));
645 memset(&vnode
->status
, 0, sizeof(vnode
->status
));
647 vnode
->volume
= NULL
;
648 vnode
->lock_key
= NULL
;
649 vnode
->permit_cache
= NULL
;
650 vnode
->cb_interest
= NULL
;
651 #ifdef CONFIG_AFS_FSCACHE
655 vnode
->flags
= 1 << AFS_VNODE_UNSET
;
657 vnode
->lock_state
= AFS_VNODE_LOCK_NONE
;
659 _leave(" = %p", &vnode
->vfs_inode
);
660 return &vnode
->vfs_inode
;
663 static void afs_i_callback(struct rcu_head
*head
)
665 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
666 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
667 kmem_cache_free(afs_inode_cachep
, vnode
);
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 call_rcu(&inode
->i_rcu
, afs_i_callback
);
684 atomic_dec(&afs_count_active_inodes
);
688 * return information about an AFS volume
690 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
692 struct afs_super_info
*as
= AFS_FS_S(dentry
->d_sb
);
693 struct afs_fs_cursor fc
;
694 struct afs_volume_status vs
;
695 struct afs_vnode
*vnode
= AFS_FS_I(d_inode(dentry
));
699 buf
->f_type
= dentry
->d_sb
->s_magic
;
700 buf
->f_bsize
= AFS_BLOCK_SIZE
;
701 buf
->f_namelen
= AFSNAMEMAX
- 1;
710 key
= afs_request_key(vnode
->volume
->cell
);
715 if (afs_begin_vnode_operation(&fc
, vnode
, key
)) {
716 fc
.flags
|= AFS_FS_CURSOR_NO_VSLEEP
;
717 while (afs_select_fileserver(&fc
)) {
718 fc
.cb_break
= afs_calc_vnode_cb_break(vnode
);
719 afs_fs_get_volume_status(&fc
, &vs
);
722 afs_check_for_remote_deletion(&fc
, fc
.vnode
);
723 afs_vnode_commit_status(&fc
, vnode
, fc
.cb_break
);
724 ret
= afs_end_vnode_operation(&fc
);
730 if (vs
.max_quota
== 0)
731 buf
->f_blocks
= vs
.part_max_blocks
;
733 buf
->f_blocks
= vs
.max_quota
;
734 buf
->f_bavail
= buf
->f_bfree
= buf
->f_blocks
- vs
.blocks_in_use
;