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_spec 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
,
49 .fs_flags
= FS_RENAME_DOES_D_MOVE
,
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
;
76 static const struct constant_table afs_param_flock
[] = {
77 {"local", afs_flock_mode_local
},
78 {"openafs", afs_flock_mode_openafs
},
79 {"strict", afs_flock_mode_strict
},
80 {"write", afs_flock_mode_write
},
84 static const struct fs_parameter_spec afs_fs_parameters
[] = {
85 fsparam_flag ("autocell", Opt_autocell
),
86 fsparam_flag ("dyn", Opt_dyn
),
87 fsparam_enum ("flock", Opt_flock
, afs_param_flock
),
88 fsparam_string("source", Opt_source
),
93 * initialise the filesystem
95 int __init
afs_fs_init(void)
101 /* create ourselves an inode cache */
102 atomic_set(&afs_count_active_inodes
, 0);
105 afs_inode_cachep
= kmem_cache_create("afs_inode_cache",
106 sizeof(struct afs_vnode
),
108 SLAB_HWCACHE_ALIGN
|SLAB_ACCOUNT
,
110 if (!afs_inode_cachep
) {
111 printk(KERN_NOTICE
"kAFS: Failed to allocate inode cache\n");
115 /* now export our filesystem to lesser mortals */
116 ret
= register_filesystem(&afs_fs_type
);
118 kmem_cache_destroy(afs_inode_cachep
);
119 _leave(" = %d", ret
);
128 * clean up the filesystem
130 void afs_fs_exit(void)
134 afs_mntpt_kill_timer();
135 unregister_filesystem(&afs_fs_type
);
137 if (atomic_read(&afs_count_active_inodes
) != 0) {
138 printk("kAFS: %d active inode objects still present\n",
139 atomic_read(&afs_count_active_inodes
));
144 * Make sure all delayed rcu free inodes are flushed before we
148 kmem_cache_destroy(afs_inode_cachep
);
153 * Display the mount device name in /proc/mounts.
155 static int afs_show_devname(struct seq_file
*m
, struct dentry
*root
)
157 struct afs_super_info
*as
= AFS_FS_S(root
->d_sb
);
158 struct afs_volume
*volume
= as
->volume
;
159 struct afs_cell
*cell
= as
->cell
;
160 const char *suf
= "";
168 switch (volume
->type
) {
173 if (volume
->type_force
)
182 seq_printf(m
, "%c%s:%s%s", pref
, cell
->name
, volume
->name
, suf
);
187 * Display the mount options in /proc/mounts.
189 static int afs_show_options(struct seq_file
*m
, struct dentry
*root
)
191 struct afs_super_info
*as
= AFS_FS_S(root
->d_sb
);
192 const char *p
= NULL
;
196 if (test_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(d_inode(root
))->flags
))
197 seq_puts(m
, ",autocell");
198 switch (as
->flock_mode
) {
199 case afs_flock_mode_unset
: break;
200 case afs_flock_mode_local
: p
= "local"; break;
201 case afs_flock_mode_openafs
: p
= "openafs"; break;
202 case afs_flock_mode_strict
: p
= "strict"; break;
203 case afs_flock_mode_write
: p
= "write"; break;
206 seq_printf(m
, ",flock=%s", p
);
212 * Parse the source name to get cell name, volume name, volume type and R/W
215 * This can be one of the following:
216 * "%[cell:]volume[.]" R/W volume
217 * "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
218 * or R/W (R/W parent) volume
219 * "%[cell:]volume.readonly" R/O volume
220 * "#[cell:]volume.readonly" R/O volume
221 * "%[cell:]volume.backup" Backup volume
222 * "#[cell:]volume.backup" Backup volume
224 static int afs_parse_source(struct fs_context
*fc
, struct fs_parameter
*param
)
226 struct afs_fs_context
*ctx
= fc
->fs_private
;
227 struct afs_cell
*cell
;
228 const char *cellname
, *suffix
, *name
= param
->string
;
234 return invalf(fc
, "kAFS: Multiple sources not supported");
237 printk(KERN_ERR
"kAFS: no volume name specified\n");
241 if ((name
[0] != '%' && name
[0] != '#') || !name
[1]) {
242 /* To use dynroot, we don't want to have to provide a source */
243 if (strcmp(name
, "none") == 0) {
247 printk(KERN_ERR
"kAFS: unparsable volume name\n");
251 /* determine the type of volume we're looking for */
252 if (name
[0] == '%') {
253 ctx
->type
= AFSVL_RWVOL
;
258 /* split the cell name out if there is one */
259 ctx
->volname
= strchr(name
, ':');
262 cellnamesz
= ctx
->volname
- name
;
270 /* the volume type is further affected by a possible suffix */
271 suffix
= strrchr(ctx
->volname
, '.');
273 if (strcmp(suffix
, ".readonly") == 0) {
274 ctx
->type
= AFSVL_ROVOL
;
276 } else if (strcmp(suffix
, ".backup") == 0) {
277 ctx
->type
= AFSVL_BACKVOL
;
279 } else if (suffix
[1] == 0) {
285 ctx
->volnamesz
= suffix
?
286 suffix
- ctx
->volname
: strlen(ctx
->volname
);
288 _debug("cell %*.*s [%p]",
289 cellnamesz
, cellnamesz
, cellname
?: "", ctx
->cell
);
291 /* lookup the cell record */
293 cell
= afs_lookup_cell(ctx
->net
, cellname
, cellnamesz
,
296 pr_err("kAFS: unable to lookup cell '%*.*s'\n",
297 cellnamesz
, cellnamesz
, cellname
?: "");
298 return PTR_ERR(cell
);
300 afs_unuse_cell(ctx
->net
, ctx
->cell
, afs_cell_trace_unuse_parse
);
301 afs_see_cell(cell
, afs_cell_trace_see_source
);
305 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
306 ctx
->cell
->name
, ctx
->cell
,
307 ctx
->volnamesz
, ctx
->volnamesz
, ctx
->volname
,
308 suffix
?: "-", ctx
->type
, ctx
->force
? " FORCE" : "");
310 fc
->source
= param
->string
;
311 param
->string
= NULL
;
316 * Parse a single mount parameter.
318 static int afs_parse_param(struct fs_context
*fc
, struct fs_parameter
*param
)
320 struct fs_parse_result result
;
321 struct afs_fs_context
*ctx
= fc
->fs_private
;
324 opt
= fs_parse(fc
, afs_fs_parameters
, param
, &result
);
330 return afs_parse_source(fc
, param
);
333 ctx
->autocell
= true;
337 ctx
->dyn_root
= true;
341 ctx
->flock_mode
= result
.uint_32
;
353 * Validate the options, get the cell key and look up the volume.
355 static int afs_validate_fc(struct fs_context
*fc
)
357 struct afs_fs_context
*ctx
= fc
->fs_private
;
358 struct afs_volume
*volume
;
359 struct afs_cell
*cell
;
363 if (!ctx
->dyn_root
) {
365 pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
370 pr_warn("kAFS: No cell specified\n");
371 return -EDESTADDRREQ
;
375 /* We try to do the mount securely. */
376 key
= afs_request_key(ctx
->cell
);
383 afs_put_volume(ctx
->net
, ctx
->volume
,
384 afs_volume_trace_put_validate_fc
);
388 if (test_bit(AFS_CELL_FL_CHECK_ALIAS
, &ctx
->cell
->flags
)) {
389 ret
= afs_cell_detect_alias(ctx
->cell
, key
);
393 _debug("switch to alias");
396 cell
= afs_use_cell(ctx
->cell
->alias_of
,
397 afs_cell_trace_use_fc_alias
);
398 afs_unuse_cell(ctx
->net
, ctx
->cell
, afs_cell_trace_unuse_fc
);
404 volume
= afs_create_volume(ctx
);
406 return PTR_ERR(volume
);
408 ctx
->volume
= volume
;
415 * check a superblock to see if it's the one we're looking for
417 static int afs_test_super(struct super_block
*sb
, struct fs_context
*fc
)
419 struct afs_fs_context
*ctx
= fc
->fs_private
;
420 struct afs_super_info
*as
= AFS_FS_S(sb
);
422 return (as
->net_ns
== fc
->net_ns
&&
424 as
->volume
->vid
== ctx
->volume
->vid
&&
425 as
->cell
== ctx
->cell
&&
429 static int afs_dynroot_test_super(struct super_block
*sb
, struct fs_context
*fc
)
431 struct afs_super_info
*as
= AFS_FS_S(sb
);
433 return (as
->net_ns
== fc
->net_ns
&&
437 static int afs_set_super(struct super_block
*sb
, struct fs_context
*fc
)
439 return set_anon_super(sb
, NULL
);
443 * fill in the superblock
445 static int afs_fill_super(struct super_block
*sb
, struct afs_fs_context
*ctx
)
447 struct afs_super_info
*as
= AFS_FS_S(sb
);
448 struct inode
*inode
= NULL
;
453 /* fill in the superblock */
454 sb
->s_blocksize
= PAGE_SIZE
;
455 sb
->s_blocksize_bits
= PAGE_SHIFT
;
456 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
457 sb
->s_magic
= AFS_FS_MAGIC
;
458 sb
->s_op
= &afs_super_ops
;
460 sb
->s_xattr
= afs_xattr_handlers
;
461 ret
= super_setup_bdi(sb
);
465 /* allocate the root inode and dentry */
467 inode
= afs_iget_pseudo_dir(sb
, true);
469 sprintf(sb
->s_id
, "%llu", as
->volume
->vid
);
470 afs_activate_volume(as
->volume
);
471 inode
= afs_root_iget(sb
, ctx
->key
);
475 return PTR_ERR(inode
);
477 if (ctx
->autocell
|| as
->dyn_root
)
478 set_bit(AFS_VNODE_AUTOCELL
, &AFS_FS_I(inode
)->flags
);
481 sb
->s_root
= d_make_root(inode
);
486 sb
->s_d_op
= &afs_dynroot_dentry_operations
;
487 ret
= afs_dynroot_populate(sb
);
491 sb
->s_d_op
= &afs_fs_dentry_operations
;
492 rcu_assign_pointer(as
->volume
->sb
, sb
);
499 _leave(" = %d", ret
);
503 static struct afs_super_info
*afs_alloc_sbi(struct fs_context
*fc
)
505 struct afs_fs_context
*ctx
= fc
->fs_private
;
506 struct afs_super_info
*as
;
508 as
= kzalloc(sizeof(struct afs_super_info
), GFP_KERNEL
);
510 as
->net_ns
= get_net(fc
->net_ns
);
511 as
->flock_mode
= ctx
->flock_mode
;
515 as
->cell
= afs_use_cell(ctx
->cell
, afs_cell_trace_use_sbi
);
516 as
->volume
= afs_get_volume(ctx
->volume
,
517 afs_volume_trace_get_alloc_sbi
);
523 static void afs_destroy_sbi(struct afs_super_info
*as
)
526 struct afs_net
*net
= afs_net(as
->net_ns
);
527 afs_put_volume(net
, as
->volume
, afs_volume_trace_put_destroy_sbi
);
528 afs_unuse_cell(net
, as
->cell
, afs_cell_trace_unuse_sbi
);
534 static void afs_kill_super(struct super_block
*sb
)
536 struct afs_super_info
*as
= AFS_FS_S(sb
);
539 afs_dynroot_depopulate(sb
);
541 /* Clear the callback interests (which will do ilookup5) before
542 * deactivating the superblock.
545 rcu_assign_pointer(as
->volume
->sb
, NULL
);
548 afs_deactivate_volume(as
->volume
);
553 * Get an AFS superblock and root directory.
555 static int afs_get_tree(struct fs_context
*fc
)
557 struct afs_fs_context
*ctx
= fc
->fs_private
;
558 struct super_block
*sb
;
559 struct afs_super_info
*as
;
562 ret
= afs_validate_fc(fc
);
568 /* allocate a superblock info record */
570 as
= afs_alloc_sbi(fc
);
575 /* allocate a deviceless superblock */
577 as
->dyn_root
? afs_dynroot_test_super
: afs_test_super
,
585 /* initial superblock/root creation */
587 ret
= afs_fill_super(sb
, ctx
);
590 sb
->s_flags
|= SB_ACTIVE
;
593 ASSERTCMP(sb
->s_flags
, &, SB_ACTIVE
);
596 fc
->root
= dget(sb
->s_root
);
597 trace_afs_get_tree(as
->cell
, as
->volume
);
598 _leave(" = 0 [%p]", sb
);
602 deactivate_locked_super(sb
);
604 _leave(" = %d", ret
);
608 static void afs_free_fc(struct fs_context
*fc
)
610 struct afs_fs_context
*ctx
= fc
->fs_private
;
612 afs_destroy_sbi(fc
->s_fs_info
);
613 afs_put_volume(ctx
->net
, ctx
->volume
, afs_volume_trace_put_free_fc
);
614 afs_unuse_cell(ctx
->net
, ctx
->cell
, afs_cell_trace_unuse_fc
);
619 static const struct fs_context_operations afs_context_ops
= {
621 .parse_param
= afs_parse_param
,
622 .get_tree
= afs_get_tree
,
626 * Set up the filesystem mount context.
628 static int afs_init_fs_context(struct fs_context
*fc
)
630 struct afs_fs_context
*ctx
;
631 struct afs_cell
*cell
;
633 ctx
= kzalloc(sizeof(struct afs_fs_context
), GFP_KERNEL
);
637 ctx
->type
= AFSVL_ROVOL
;
638 ctx
->net
= afs_net(fc
->net_ns
);
640 /* Default to the workstation cell. */
641 cell
= afs_find_cell(ctx
->net
, NULL
, 0, afs_cell_trace_use_fc
);
646 fc
->fs_private
= ctx
;
647 fc
->ops
= &afs_context_ops
;
652 * Initialise an inode cache slab element prior to any use. Note that
653 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
656 static void afs_i_init_once(void *_vnode
)
658 struct afs_vnode
*vnode
= _vnode
;
660 memset(vnode
, 0, sizeof(*vnode
));
661 inode_init_once(&vnode
->vfs_inode
);
662 mutex_init(&vnode
->io_lock
);
663 init_rwsem(&vnode
->validate_lock
);
664 spin_lock_init(&vnode
->wb_lock
);
665 spin_lock_init(&vnode
->lock
);
666 INIT_LIST_HEAD(&vnode
->wb_keys
);
667 INIT_LIST_HEAD(&vnode
->pending_locks
);
668 INIT_LIST_HEAD(&vnode
->granted_locks
);
669 INIT_DELAYED_WORK(&vnode
->lock_work
, afs_lock_work
);
670 seqlock_init(&vnode
->cb_lock
);
674 * allocate an AFS inode struct from our slab cache
676 static struct inode
*afs_alloc_inode(struct super_block
*sb
)
678 struct afs_vnode
*vnode
;
680 vnode
= kmem_cache_alloc(afs_inode_cachep
, GFP_KERNEL
);
684 atomic_inc(&afs_count_active_inodes
);
686 /* Reset anything that shouldn't leak from one inode to the next. */
687 memset(&vnode
->fid
, 0, sizeof(vnode
->fid
));
688 memset(&vnode
->status
, 0, sizeof(vnode
->status
));
690 vnode
->volume
= NULL
;
691 vnode
->lock_key
= NULL
;
692 vnode
->permit_cache
= NULL
;
693 #ifdef CONFIG_AFS_FSCACHE
697 vnode
->flags
= 1 << AFS_VNODE_UNSET
;
698 vnode
->lock_state
= AFS_VNODE_LOCK_NONE
;
700 init_rwsem(&vnode
->rmdir_lock
);
702 _leave(" = %p", &vnode
->vfs_inode
);
703 return &vnode
->vfs_inode
;
706 static void afs_free_inode(struct inode
*inode
)
708 kmem_cache_free(afs_inode_cachep
, AFS_FS_I(inode
));
712 * destroy an AFS inode struct
714 static void afs_destroy_inode(struct inode
*inode
)
716 struct afs_vnode
*vnode
= AFS_FS_I(inode
);
718 _enter("%p{%llx:%llu}", inode
, vnode
->fid
.vid
, vnode
->fid
.vnode
);
720 _debug("DESTROY INODE %p", inode
);
722 atomic_dec(&afs_count_active_inodes
);
725 static void afs_get_volume_status_success(struct afs_operation
*op
)
727 struct afs_volume_status
*vs
= &op
->volstatus
.vs
;
728 struct kstatfs
*buf
= op
->volstatus
.buf
;
730 if (vs
->max_quota
== 0)
731 buf
->f_blocks
= vs
->part_max_blocks
;
733 buf
->f_blocks
= vs
->max_quota
;
735 if (buf
->f_blocks
> vs
->blocks_in_use
)
736 buf
->f_bavail
= buf
->f_bfree
=
737 buf
->f_blocks
- vs
->blocks_in_use
;
740 static const struct afs_operation_ops afs_get_volume_status_operation
= {
741 .issue_afs_rpc
= afs_fs_get_volume_status
,
742 .issue_yfs_rpc
= yfs_fs_get_volume_status
,
743 .success
= afs_get_volume_status_success
,
747 * return information about an AFS volume
749 static int afs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
751 struct afs_super_info
*as
= AFS_FS_S(dentry
->d_sb
);
752 struct afs_operation
*op
;
753 struct afs_vnode
*vnode
= AFS_FS_I(d_inode(dentry
));
755 buf
->f_type
= dentry
->d_sb
->s_magic
;
756 buf
->f_bsize
= AFS_BLOCK_SIZE
;
757 buf
->f_namelen
= AFSNAMEMAX
- 1;
766 op
= afs_alloc_operation(NULL
, as
->volume
);
770 afs_op_set_vnode(op
, 0, vnode
);
772 op
->volstatus
.buf
= buf
;
773 op
->ops
= &afs_get_volume_status_operation
;
774 return afs_do_sync_operation(op
);