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;