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,
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 fs_parameter_spec afs_param_specs[] = {
77 fsparam_flag ("autocell", Opt_autocell),
78 fsparam_flag ("dyn", Opt_dyn),
79 fsparam_enum ("flock", Opt_flock),
80 fsparam_string("source", Opt_source),
84 static const struct fs_parameter_enum afs_param_enums[] = {
85 { Opt_flock, "local", afs_flock_mode_local },
86 { Opt_flock, "openafs", afs_flock_mode_openafs },
87 { Opt_flock, "strict", afs_flock_mode_strict },
88 { Opt_flock, "write", afs_flock_mode_write },
92 static const struct fs_parameter_description afs_fs_parameters = {
94 .specs = afs_param_specs,
95 .enums = afs_param_enums,
99 * initialise the filesystem
101 int __init afs_fs_init(void)
107 /* create ourselves an inode cache */
108 atomic_set(&afs_count_active_inodes, 0);
111 afs_inode_cachep = kmem_cache_create("afs_inode_cache",
112 sizeof(struct afs_vnode),
114 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
116 if (!afs_inode_cachep) {
117 printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
121 /* now export our filesystem to lesser mortals */
122 ret = register_filesystem(&afs_fs_type);
124 kmem_cache_destroy(afs_inode_cachep);
125 _leave(" = %d", ret);
134 * clean up the filesystem
136 void afs_fs_exit(void)
140 afs_mntpt_kill_timer();
141 unregister_filesystem(&afs_fs_type);
143 if (atomic_read(&afs_count_active_inodes) != 0) {
144 printk("kAFS: %d active inode objects still present\n",
145 atomic_read(&afs_count_active_inodes));
150 * Make sure all delayed rcu free inodes are flushed before we
154 kmem_cache_destroy(afs_inode_cachep);
159 * Display the mount device name in /proc/mounts.
161 static int afs_show_devname(struct seq_file *m, struct dentry *root)
163 struct afs_super_info *as = AFS_FS_S(root->d_sb);
164 struct afs_volume *volume = as->volume;
165 struct afs_cell *cell = as->cell;
166 const char *suf = "";
174 switch (volume->type) {
179 if (volume->type_force)
188 seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
193 * Display the mount options in /proc/mounts.
195 static int afs_show_options(struct seq_file *m, struct dentry *root)
197 struct afs_super_info *as = AFS_FS_S(root->d_sb);
198 const char *p = NULL;
202 if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
203 seq_puts(m, ",autocell");
204 switch (as->flock_mode) {
205 case afs_flock_mode_unset: break;
206 case afs_flock_mode_local: p = "local"; break;
207 case afs_flock_mode_openafs: p = "openafs"; break;
208 case afs_flock_mode_strict: p = "strict"; break;
209 case afs_flock_mode_write: p = "write"; break;
212 seq_printf(m, ",flock=%s", p);
218 * Parse the source name to get cell name, volume name, volume type and R/W
221 * This can be one of the following:
222 * "%[cell:]volume[.]" R/W volume
223 * "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
224 * or R/W (R/W parent) volume
225 * "%[cell:]volume.readonly" R/O volume
226 * "#[cell:]volume.readonly" R/O volume
227 * "%[cell:]volume.backup" Backup volume
228 * "#[cell:]volume.backup" Backup volume
230 static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
232 struct afs_fs_context *ctx = fc->fs_private;
233 struct afs_cell *cell;
234 const char *cellname, *suffix, *name = param->string;
240 return invalf(fc, "kAFS: Multiple sources not supported");
243 printk(KERN_ERR "kAFS: no volume name specified\n");
247 if ((name[0] != '%' && name[0] != '#') || !name[1]) {
248 /* To use dynroot, we don't want to have to provide a source */
249 if (strcmp(name, "none") == 0) {
253 printk(KERN_ERR "kAFS: unparsable volume name\n");
257 /* determine the type of volume we're looking for */
258 if (name[0] == '%') {
259 ctx->type = AFSVL_RWVOL;
264 /* split the cell name out if there is one */
265 ctx->volname = strchr(name, ':');
268 cellnamesz = ctx->volname - name;
276 /* the volume type is further affected by a possible suffix */
277 suffix = strrchr(ctx->volname, '.');
279 if (strcmp(suffix, ".readonly") == 0) {
280 ctx->type = AFSVL_ROVOL;
282 } else if (strcmp(suffix, ".backup") == 0) {
283 ctx->type = AFSVL_BACKVOL;
285 } else if (suffix[1] == 0) {
291 ctx->volnamesz = suffix ?
292 suffix - ctx->volname : strlen(ctx->volname);
294 _debug("cell %*.*s [%p]",
295 cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
297 /* lookup the cell record */
299 cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
302 pr_err("kAFS: unable to lookup cell '%*.*s'\n",
303 cellnamesz, cellnamesz, cellname ?: "");
304 return PTR_ERR(cell);
306 afs_put_cell(ctx->net, ctx->cell);
310 _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
311 ctx->cell->name, ctx->cell,
312 ctx->volnamesz, ctx->volnamesz, ctx->volname,
313 suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
315 fc->source = param->string;
316 param->string = NULL;
321 * Parse a single mount parameter.
323 static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
325 struct fs_parse_result result;
326 struct afs_fs_context *ctx = fc->fs_private;
329 opt = fs_parse(fc, &afs_fs_parameters, param, &result);
335 return afs_parse_source(fc, param);
338 ctx->autocell = true;
342 ctx->dyn_root = true;
346 ctx->flock_mode = result.uint_32;
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 &&
410 as->cell == ctx->cell &&
414 static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
416 struct afs_super_info *as = AFS_FS_S(sb);
418 return (as->net_ns == fc->net_ns &&
422 static int afs_set_super(struct super_block *sb, struct fs_context *fc)
424 return set_anon_super(sb, NULL);
428 * fill in the superblock
430 static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
432 struct afs_super_info *as = AFS_FS_S(sb);
433 struct afs_iget_data iget_data;
434 struct inode *inode = NULL;
439 /* fill in the superblock */
440 sb->s_blocksize = PAGE_SIZE;
441 sb->s_blocksize_bits = PAGE_SHIFT;
442 sb->s_maxbytes = MAX_LFS_FILESIZE;
443 sb->s_magic = AFS_FS_MAGIC;
444 sb->s_op = &afs_super_ops;
446 sb->s_xattr = afs_xattr_handlers;
447 ret = super_setup_bdi(sb);
450 sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
452 /* allocate the root inode and dentry */
454 inode = afs_iget_pseudo_dir(sb, true);
456 sprintf(sb->s_id, "%llu", as->volume->vid);
457 afs_activate_volume(as->volume);
458 iget_data.fid.vid = as->volume->vid;
459 iget_data.fid.vnode = 1;
460 iget_data.fid.vnode_hi = 0;
461 iget_data.fid.unique = 1;
462 iget_data.cb_v_break = as->volume->cb_v_break;
463 iget_data.cb_s_break = 0;
464 inode = afs_iget(sb, ctx->key, &iget_data, NULL, NULL, NULL);
468 return PTR_ERR(inode);
470 if (ctx->autocell || as->dyn_root)
471 set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
474 sb->s_root = d_make_root(inode);
479 sb->s_d_op = &afs_dynroot_dentry_operations;
480 ret = afs_dynroot_populate(sb);
484 sb->s_d_op = &afs_fs_dentry_operations;
491 _leave(" = %d", ret);
495 static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
497 struct afs_fs_context *ctx = fc->fs_private;
498 struct afs_super_info *as;
500 as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
502 as->net_ns = get_net(fc->net_ns);
503 as->flock_mode = ctx->flock_mode;
507 as->cell = afs_get_cell(ctx->cell);
508 as->volume = __afs_get_volume(ctx->volume);
514 static void afs_destroy_sbi(struct afs_super_info *as)
517 afs_put_volume(as->cell, as->volume);
518 afs_put_cell(afs_net(as->net_ns), as->cell);
524 static void afs_kill_super(struct super_block *sb)
526 struct afs_super_info *as = AFS_FS_S(sb);
527 struct afs_net *net = afs_net(as->net_ns);
530 afs_dynroot_depopulate(sb);
532 /* Clear the callback interests (which will do ilookup5) before
533 * deactivating the superblock.
536 afs_clear_callback_interests(net, as->volume->servers);
539 afs_deactivate_volume(as->volume);
544 * Get an AFS superblock and root directory.
546 static int afs_get_tree(struct fs_context *fc)
548 struct afs_fs_context *ctx = fc->fs_private;
549 struct super_block *sb;
550 struct afs_super_info *as;
553 ret = afs_validate_fc(fc);
559 /* allocate a superblock info record */
561 as = afs_alloc_sbi(fc);
566 /* allocate a deviceless superblock */
568 as->dyn_root ? afs_dynroot_test_super : afs_test_super,
576 /* initial superblock/root creation */
578 ret = afs_fill_super(sb, ctx);
581 sb->s_flags |= SB_ACTIVE;
584 ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
587 fc->root = dget(sb->s_root);
588 trace_afs_get_tree(as->cell, as->volume);
589 _leave(" = 0 [%p]", sb);
593 deactivate_locked_super(sb);
595 _leave(" = %d", ret);
599 static void afs_free_fc(struct fs_context *fc)
601 struct afs_fs_context *ctx = fc->fs_private;
603 afs_destroy_sbi(fc->s_fs_info);
604 afs_put_volume(ctx->cell, ctx->volume);
605 afs_put_cell(ctx->net, ctx->cell);
610 static const struct fs_context_operations afs_context_ops = {
612 .parse_param = afs_parse_param,
613 .get_tree = afs_get_tree,
617 * Set up the filesystem mount context.
619 static int afs_init_fs_context(struct fs_context *fc)
621 struct afs_fs_context *ctx;
622 struct afs_cell *cell;
624 ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
628 ctx->type = AFSVL_ROVOL;
629 ctx->net = afs_net(fc->net_ns);
631 /* Default to the workstation cell. */
633 cell = afs_lookup_cell_rcu(ctx->net, NULL, 0);
639 fc->fs_private = ctx;
640 fc->ops = &afs_context_ops;
645 * Initialise an inode cache slab element prior to any use. Note that
646 * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
649 static void afs_i_init_once(void *_vnode)
651 struct afs_vnode *vnode = _vnode;
653 memset(vnode, 0, sizeof(*vnode));
654 inode_init_once(&vnode->vfs_inode);
655 mutex_init(&vnode->io_lock);
656 init_rwsem(&vnode->validate_lock);
657 spin_lock_init(&vnode->wb_lock);
658 spin_lock_init(&vnode->lock);
659 INIT_LIST_HEAD(&vnode->wb_keys);
660 INIT_LIST_HEAD(&vnode->pending_locks);
661 INIT_LIST_HEAD(&vnode->granted_locks);
662 INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
663 seqlock_init(&vnode->cb_lock);
667 * allocate an AFS inode struct from our slab cache
669 static struct inode *afs_alloc_inode(struct super_block *sb)
671 struct afs_vnode *vnode;
673 vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
677 atomic_inc(&afs_count_active_inodes);
679 /* Reset anything that shouldn't leak from one inode to the next. */
680 memset(&vnode->fid, 0, sizeof(vnode->fid));
681 memset(&vnode->status, 0, sizeof(vnode->status));
683 vnode->volume = NULL;
684 vnode->lock_key = NULL;
685 vnode->permit_cache = NULL;
686 RCU_INIT_POINTER(vnode->cb_interest, NULL);
687 #ifdef CONFIG_AFS_FSCACHE
691 vnode->flags = 1 << AFS_VNODE_UNSET;
692 vnode->lock_state = AFS_VNODE_LOCK_NONE;
694 init_rwsem(&vnode->rmdir_lock);
696 _leave(" = %p", &vnode->vfs_inode);
697 return &vnode->vfs_inode;
700 static void afs_free_inode(struct inode *inode)
702 kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
706 * destroy an AFS inode struct
708 static void afs_destroy_inode(struct inode *inode)
710 struct afs_vnode *vnode = AFS_FS_I(inode);
712 _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
714 _debug("DESTROY INODE %p", inode);
716 ASSERTCMP(rcu_access_pointer(vnode->cb_interest), ==, NULL);
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, true)) {
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 ret = afs_end_vnode_operation(&fc);
763 if (vs.max_quota == 0)
764 buf->f_blocks = vs.part_max_blocks;
766 buf->f_blocks = vs.max_quota;
767 buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;