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;