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;
76 static const struct fs_parameter_spec afs_param_specs[] = {
77 fsparam_flag ("autocell", Opt_autocell),
78 fsparam_string("cell", Opt_cell),
79 fsparam_flag ("dyn", Opt_dyn),
80 fsparam_flag ("rwpath", Opt_rwpath),
81 fsparam_string("source", Opt_source),
82 fsparam_string("vol", Opt_vol),
86 static const struct fs_parameter_description afs_fs_parameters = {
88 .specs = afs_param_specs,
92 * initialise the filesystem
94 int __init afs_fs_init(void)
100 /* create ourselves an inode cache */
101 atomic_set(&afs_count_active_inodes, 0);
104 afs_inode_cachep = kmem_cache_create("afs_inode_cache",
105 sizeof(struct afs_vnode),
107 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
109 if (!afs_inode_cachep) {
110 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
114 /* now export our filesystem to lesser mortals */
115 ret = register_filesystem(&afs_fs_type);
117 kmem_cache_destroy(afs_inode_cachep);
118 _leave(" = %d", ret);
127 * clean up the filesystem
129 void afs_fs_exit(void)
133 afs_mntpt_kill_timer();
134 unregister_filesystem(&afs_fs_type);
136 if (atomic_read(&afs_count_active_inodes) != 0) {
137 printk("kAFS: %d active inode objects still present\n",
138 atomic_read(&afs_count_active_inodes));
143 * Make sure all delayed rcu free inodes are flushed before we
147 kmem_cache_destroy(afs_inode_cachep);
152 * Display the mount device name in /proc/mounts.
154 static int afs_show_devname(struct seq_file *m, struct dentry *root)
156 struct afs_super_info *as = AFS_FS_S(root->d_sb);
157 struct afs_volume *volume = as->volume;
158 struct afs_cell *cell = as->cell;
159 const char *suf = "";
167 switch (volume->type) {
172 if (volume->type_force)
181 seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
186 * Display the mount options in /proc/mounts.
188 static int afs_show_options(struct seq_file *m, struct dentry *root)
190 struct afs_super_info *as = AFS_FS_S(root->d_sb);
194 if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
195 seq_puts(m, ",autocell");
200 * Parse the source name to get cell name, volume name, volume type and R/W
203 * This can be one of the following:
204 * "%[cell:]volume[.]" R/W volume
205 * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
206 * or R/W (rwpath=1) volume
207 * "%[cell:]volume.readonly" R/O volume
208 * "#[cell:]volume.readonly" R/O volume
209 * "%[cell:]volume.backup" Backup volume
210 * "#[cell:]volume.backup" Backup volume
212 static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
214 struct afs_fs_context *ctx = fc->fs_private;
215 struct afs_cell *cell;
216 const char *cellname, *suffix, *name = param->string;
222 printk(KERN_ERR "kAFS: no volume name specified\n");
226 if ((name[0] != '%' && name[0] != '#') || !name[1]) {
227 /* To use dynroot, we don't want to have to provide a source */
228 if (strcmp(name, "none") == 0) {
232 printk(KERN_ERR "kAFS: unparsable volume name\n");
236 /* determine the type of volume we're looking for */
237 ctx->type = AFSVL_ROVOL;
239 if (ctx->rwpath || name[0] == '%') {
240 ctx->type = AFSVL_RWVOL;
245 /* split the cell name out if there is one */
246 ctx->volname = strchr(name, ':');
249 cellnamesz = ctx->volname - name;
257 /* the volume type is further affected by a possible suffix */
258 suffix = strrchr(ctx->volname, '.');
260 if (strcmp(suffix, ".readonly") == 0) {
261 ctx->type = AFSVL_ROVOL;
263 } else if (strcmp(suffix, ".backup") == 0) {
264 ctx->type = AFSVL_BACKVOL;
266 } else if (suffix[1] == 0) {
272 ctx->volnamesz = suffix ?
273 suffix - ctx->volname : strlen(ctx->volname);
275 _debug("cell %*.*s [%p]",
276 cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
278 /* lookup the cell record */
280 cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
283 pr_err("kAFS: unable to lookup cell '%*.*s'\n",
284 cellnamesz, cellnamesz, cellname ?: "");
285 return PTR_ERR(cell);
287 afs_put_cell(ctx->net, ctx->cell);
291 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
292 ctx->cell->name, ctx->cell,
293 ctx->volnamesz, ctx->volnamesz, ctx->volname,
294 suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
296 fc->source = param->string;
297 param->string = NULL;
302 * Parse a single mount parameter.
304 static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
306 struct fs_parse_result result;
307 struct afs_fs_context *ctx = fc->fs_private;
308 struct afs_cell *cell;
311 opt = fs_parse(fc, &afs_fs_parameters, param, &result);
317 if (param->size <= 0)
319 if (param->size > AFS_MAXCELLNAME)
320 return -ENAMETOOLONG;
323 cell = afs_lookup_cell_rcu(ctx->net, param->string, param->size);
326 return PTR_ERR(cell);
327 afs_put_cell(ctx->net, ctx->cell);
332 return afs_parse_source(fc, param);
335 ctx->autocell = true;
339 ctx->dyn_root = true;
347 return invalf(fc, "'vol' param is obsolete");
358 * Validate the options, get the cell key and look up the volume.
360 static int afs_validate_fc(struct fs_context *fc)
362 struct afs_fs_context *ctx = fc->fs_private;
363 struct afs_volume *volume;
366 if (!ctx->dyn_root) {
368 pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
373 pr_warn("kAFS: No cell specified\n");
374 return -EDESTADDRREQ;
377 /* We try to do the mount securely. */
378 key = afs_request_key(ctx->cell);
385 afs_put_volume(ctx->cell, ctx->volume);
389 volume = afs_create_volume(ctx);
391 return PTR_ERR(volume);
393 ctx->volume = volume;
400 * check a superblock to see if it's the one we're looking for
402 static int afs_test_super(struct super_block *sb, struct fs_context *fc)
404 struct afs_fs_context *ctx = fc->fs_private;
405 struct afs_super_info *as = AFS_FS_S(sb);
407 return (as->net_ns == fc->net_ns &&
409 as->volume->vid == ctx->volume->vid &&
413 static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
415 struct afs_super_info *as = AFS_FS_S(sb);
417 return (as->net_ns == fc->net_ns &&
421 static int afs_set_super(struct super_block *sb, struct fs_context *fc)
423 return set_anon_super(sb, NULL);
427 * fill in the superblock
429 static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
431 struct afs_super_info *as = AFS_FS_S(sb);
433 struct inode *inode = NULL;
438 /* fill in the superblock */
439 sb->s_blocksize = PAGE_SIZE;
440 sb->s_blocksize_bits = PAGE_SHIFT;
441 sb->s_magic = AFS_FS_MAGIC;
442 sb->s_op = &afs_super_ops;
444 sb->s_xattr = afs_xattr_handlers;
445 ret = super_setup_bdi(sb);
448 sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
450 /* allocate the root inode and dentry */
452 inode = afs_iget_pseudo_dir(sb, true);
453 sb->s_flags |= SB_RDONLY;
455 sprintf(sb->s_id, "%llu", as->volume->vid);
456 afs_activate_volume(as->volume);
457 fid.vid = as->volume->vid;
461 inode = afs_iget(sb, ctx->key, &fid, NULL, NULL, NULL);
465 return PTR_ERR(inode);
467 if (ctx->autocell || as->dyn_root)
468 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
471 sb->s_root = d_make_root(inode);
476 sb->s_d_op = &afs_dynroot_dentry_operations;
477 ret = afs_dynroot_populate(sb);
481 sb->s_d_op = &afs_fs_dentry_operations;
488 _leave(" = %d", ret);
492 static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
494 struct afs_fs_context *ctx = fc->fs_private;
495 struct afs_super_info *as;
497 as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
499 as->net_ns = get_net(fc->net_ns);
503 as->cell = afs_get_cell(ctx->cell);
504 as->volume = __afs_get_volume(ctx->volume);
510 static void afs_destroy_sbi(struct afs_super_info *as)
513 afs_put_volume(as->cell, as->volume);
514 afs_put_cell(afs_net(as->net_ns), as->cell);
520 static void afs_kill_super(struct super_block *sb)
522 struct afs_super_info *as = AFS_FS_S(sb);
523 struct afs_net *net = afs_net(as->net_ns);
526 afs_dynroot_depopulate(sb);
528 /* Clear the callback interests (which will do ilookup5) before
529 * deactivating the superblock.
532 afs_clear_callback_interests(net, as->volume->servers);
535 afs_deactivate_volume(as->volume);
540 * Get an AFS superblock and root directory.
542 static int afs_get_tree(struct fs_context *fc)
544 struct afs_fs_context *ctx = fc->fs_private;
545 struct super_block *sb;
546 struct afs_super_info *as;
549 ret = afs_validate_fc(fc);
555 /* allocate a superblock info record */
557 as = afs_alloc_sbi(fc);
562 /* allocate a deviceless superblock */
564 as->dyn_root ? afs_dynroot_test_super : afs_test_super,
572 /* initial superblock/root creation */
574 ret = afs_fill_super(sb, ctx);
577 sb->s_flags |= SB_ACTIVE;
580 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
583 fc->root = dget(sb->s_root);
584 _leave(" = 0 [%p]", sb);
588 deactivate_locked_super(sb);
590 _leave(" = %d", ret);
594 static void afs_free_fc(struct fs_context *fc)
596 struct afs_fs_context *ctx = fc->fs_private;
598 afs_destroy_sbi(fc->s_fs_info);
599 afs_put_volume(ctx->cell, ctx->volume);
600 afs_put_cell(ctx->net, ctx->cell);
605 static const struct fs_context_operations afs_context_ops = {
607 .parse_param = afs_parse_param,
608 .get_tree = afs_get_tree,
612 * Set up the filesystem mount context.
614 static int afs_init_fs_context(struct fs_context *fc)
616 struct afs_fs_context *ctx;
617 struct afs_cell *cell;
619 if (current->nsproxy->net_ns != &init_net)
622 ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
626 ctx->type = AFSVL_ROVOL;
627 ctx->net = afs_net(fc->net_ns);
629 /* Default to the workstation cell. */
631 cell = afs_lookup_cell_rcu(ctx->net, NULL, 0);
637 fc->fs_private = ctx;
638 fc->ops = &afs_context_ops;
643 * Initialise an inode cache slab element prior to any use. Note that
644 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
647 static void afs_i_init_once(void *_vnode)
649 struct afs_vnode *vnode = _vnode;
651 memset(vnode, 0, sizeof(*vnode));
652 inode_init_once(&vnode->vfs_inode);
653 mutex_init(&vnode->io_lock);
654 init_rwsem(&vnode->validate_lock);
655 spin_lock_init(&vnode->wb_lock);
656 spin_lock_init(&vnode->lock);
657 INIT_LIST_HEAD(&vnode->wb_keys);
658 INIT_LIST_HEAD(&vnode->pending_locks);
659 INIT_LIST_HEAD(&vnode->granted_locks);
660 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
661 seqlock_init(&vnode->cb_lock);
665 * allocate an AFS inode struct from our slab cache
667 static struct inode *afs_alloc_inode(struct super_block *sb)
669 struct afs_vnode *vnode;
671 vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
675 atomic_inc(&afs_count_active_inodes);
677 /* Reset anything that shouldn't leak from one inode to the next. */
678 memset(&vnode->fid, 0, sizeof(vnode->fid));
679 memset(&vnode->status, 0, sizeof(vnode->status));
681 vnode->volume = NULL;
682 vnode->lock_key = NULL;
683 vnode->permit_cache = NULL;
684 vnode->cb_interest = NULL;
685 #ifdef CONFIG_AFS_FSCACHE
689 vnode->flags = 1 << AFS_VNODE_UNSET;
691 vnode->lock_state = AFS_VNODE_LOCK_NONE;
693 _leave(" = %p", &vnode->vfs_inode);
694 return &vnode->vfs_inode;
697 static void afs_i_callback(struct rcu_head *head)
699 struct inode *inode = container_of(head, struct inode, i_rcu);
700 struct afs_vnode *vnode = AFS_FS_I(inode);
701 kmem_cache_free(afs_inode_cachep, vnode);
705 * destroy an AFS inode struct
707 static void afs_destroy_inode(struct inode *inode)
709 struct afs_vnode *vnode = AFS_FS_I(inode);
711 _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
713 _debug("DESTROY INODE %p", inode);
715 ASSERTCMP(vnode->cb_interest, ==, NULL);
717 call_rcu(&inode->i_rcu, afs_i_callback);
718 atomic_dec(&afs_count_active_inodes);
722 * return information about an AFS volume
724 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
726 struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
727 struct afs_fs_cursor fc;
728 struct afs_volume_status vs;
729 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
733 buf->f_type = dentry->d_sb->s_magic;
734 buf->f_bsize = AFS_BLOCK_SIZE;
735 buf->f_namelen = AFSNAMEMAX - 1;
744 key = afs_request_key(vnode->volume->cell);
749 if (afs_begin_vnode_operation(&fc, vnode, key)) {
750 fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
751 while (afs_select_fileserver(&fc)) {
752 fc.cb_break = afs_calc_vnode_cb_break(vnode);
753 afs_fs_get_volume_status(&fc, &vs);
756 afs_check_for_remote_deletion(&fc, fc.vnode);
757 afs_vnode_commit_status(&fc, vnode, fc.cb_break);
758 ret = afs_end_vnode_operation(&fc);
764 if (vs.max_quota == 0)
765 buf->f_blocks = vs.part_max_blocks;
767 buf->f_blocks = vs.max_quota;
768 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;