1 // SPDX-License-Identifier: GPL-2.0-only
4 * Copyright (C) 2011 Novell Inc.
8 #include <linux/slab.h>
9 #include <linux/namei.h>
10 #include <linux/file.h>
11 #include <linux/xattr.h>
12 #include <linux/rbtree.h>
13 #include <linux/security.h>
14 #include <linux/cred.h>
15 #include <linux/ratelimit.h>
16 #include "overlayfs.h"
18 struct ovl_cache_entry {
23 struct list_head l_node;
25 struct ovl_cache_entry *next_maybe_whiteout;
32 struct ovl_dir_cache {
35 struct list_head entries;
39 struct ovl_readdir_data {
40 struct dir_context ctx;
41 struct dentry *dentry;
44 struct list_head *list;
45 struct list_head middle;
46 struct ovl_cache_entry *first_maybe_whiteout;
50 bool d_type_supported;
51 bool in_xwhiteouts_dir;
57 struct ovl_dir_cache *cache;
58 struct list_head *cursor;
59 struct file *realfile;
60 struct file *upperfile;
63 static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)
65 return rb_entry(n, struct ovl_cache_entry, node);
68 static bool ovl_cache_entry_find_link(const char *name, int len,
69 struct rb_node ***link,
70 struct rb_node **parent)
73 struct rb_node **newp = *link;
75 while (!found && *newp) {
77 struct ovl_cache_entry *tmp;
80 tmp = ovl_cache_entry_from_node(*newp);
81 cmp = strncmp(name, tmp->name, len);
83 newp = &tmp->node.rb_right;
84 else if (cmp < 0 || len < tmp->len)
85 newp = &tmp->node.rb_left;
94 static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
95 const char *name, int len)
97 struct rb_node *node = root->rb_node;
101 struct ovl_cache_entry *p = ovl_cache_entry_from_node(node);
103 cmp = strncmp(name, p->name, len);
105 node = p->node.rb_right;
106 else if (cmp < 0 || len < p->len)
107 node = p->node.rb_left;
115 static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd,
116 struct ovl_cache_entry *p)
118 /* Don't care if not doing ovl_iter() */
122 /* Always recalc d_ino when remapping lower inode numbers */
123 if (ovl_xino_bits(OVL_FS(rdd->dentry->d_sb)))
126 /* Always recalc d_ino for parent */
127 if (strcmp(p->name, "..") == 0)
130 /* If this is lower, then native d_ino will do */
135 * Recalc d_ino for '.' and for all entries if dir is impure (contains
138 if ((p->name[0] == '.' && p->len == 1) ||
139 ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry)))
145 static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
146 const char *name, int len,
147 u64 ino, unsigned int d_type)
149 struct ovl_cache_entry *p;
150 size_t size = offsetof(struct ovl_cache_entry, name[len + 1]);
152 p = kmalloc(size, GFP_KERNEL);
156 memcpy(p->name, name, len);
162 /* Defer setting d_ino for upper entry to ovl_iterate() */
163 if (ovl_calc_d_ino(rdd, p))
165 p->is_upper = rdd->is_upper;
166 p->is_whiteout = false;
167 /* Defer check for overlay.whiteout to ovl_iterate() */
168 p->check_xwhiteout = rdd->in_xwhiteouts_dir && d_type == DT_REG;
170 if (d_type == DT_CHR) {
171 p->next_maybe_whiteout = rdd->first_maybe_whiteout;
172 rdd->first_maybe_whiteout = p;
177 static bool ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
178 const char *name, int len, u64 ino,
181 struct rb_node **newp = &rdd->root->rb_node;
182 struct rb_node *parent = NULL;
183 struct ovl_cache_entry *p;
185 if (ovl_cache_entry_find_link(name, len, &newp, &parent))
188 p = ovl_cache_entry_new(rdd, name, len, ino, d_type);
194 list_add_tail(&p->l_node, rdd->list);
195 rb_link_node(&p->node, parent, newp);
196 rb_insert_color(&p->node, rdd->root);
201 static bool ovl_fill_lowest(struct ovl_readdir_data *rdd,
202 const char *name, int namelen,
203 loff_t offset, u64 ino, unsigned int d_type)
205 struct ovl_cache_entry *p;
207 p = ovl_cache_entry_find(rdd->root, name, namelen);
209 list_move_tail(&p->l_node, &rdd->middle);
211 p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
215 list_add_tail(&p->l_node, &rdd->middle);
218 return rdd->err == 0;
221 void ovl_cache_free(struct list_head *list)
223 struct ovl_cache_entry *p;
224 struct ovl_cache_entry *n;
226 list_for_each_entry_safe(p, n, list, l_node)
229 INIT_LIST_HEAD(list);
232 void ovl_dir_cache_free(struct inode *inode)
234 struct ovl_dir_cache *cache = ovl_dir_cache(inode);
237 ovl_cache_free(&cache->entries);
242 static void ovl_cache_put(struct ovl_dir_file *od, struct inode *inode)
244 struct ovl_dir_cache *cache = od->cache;
246 WARN_ON(cache->refcount <= 0);
248 if (!cache->refcount) {
249 if (ovl_dir_cache(inode) == cache)
250 ovl_set_dir_cache(inode, NULL);
252 ovl_cache_free(&cache->entries);
257 static bool ovl_fill_merge(struct dir_context *ctx, const char *name,
258 int namelen, loff_t offset, u64 ino,
261 struct ovl_readdir_data *rdd =
262 container_of(ctx, struct ovl_readdir_data, ctx);
266 return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);
268 return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type);
271 static int ovl_check_whiteouts(const struct path *path, struct ovl_readdir_data *rdd)
274 struct ovl_cache_entry *p;
275 struct dentry *dentry, *dir = path->dentry;
276 const struct cred *old_cred;
278 old_cred = ovl_override_creds(rdd->dentry->d_sb);
280 err = down_write_killable(&dir->d_inode->i_rwsem);
282 while (rdd->first_maybe_whiteout) {
283 p = rdd->first_maybe_whiteout;
284 rdd->first_maybe_whiteout = p->next_maybe_whiteout;
285 dentry = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len);
286 if (!IS_ERR(dentry)) {
287 p->is_whiteout = ovl_is_whiteout(dentry);
291 inode_unlock(dir->d_inode);
293 revert_creds(old_cred);
298 static inline int ovl_dir_read(const struct path *realpath,
299 struct ovl_readdir_data *rdd)
301 struct file *realfile;
304 realfile = ovl_path_open(realpath, O_RDONLY | O_LARGEFILE);
305 if (IS_ERR(realfile))
306 return PTR_ERR(realfile);
308 rdd->in_xwhiteouts_dir = rdd->dentry &&
309 ovl_path_check_xwhiteouts_xattr(OVL_FS(rdd->dentry->d_sb), realpath);
310 rdd->first_maybe_whiteout = NULL;
315 err = iterate_dir(realfile, &rdd->ctx);
318 } while (!err && rdd->count);
320 if (!err && rdd->first_maybe_whiteout && rdd->dentry)
321 err = ovl_check_whiteouts(realpath, rdd);
328 static void ovl_dir_reset(struct file *file)
330 struct ovl_dir_file *od = file->private_data;
331 struct ovl_dir_cache *cache = od->cache;
332 struct inode *inode = file_inode(file);
335 if (cache && ovl_inode_version_get(inode) != cache->version) {
336 ovl_cache_put(od, inode);
340 is_real = ovl_dir_is_real(inode);
341 if (od->is_real != is_real) {
342 /* is_real can only become false when dir is copied up */
343 if (WARN_ON(is_real))
349 static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
350 struct rb_root *root)
353 struct path realpath;
354 struct ovl_readdir_data rdd = {
355 .ctx.actor = ovl_fill_merge,
363 for (idx = 0; idx != -1; idx = next) {
364 next = ovl_path_next(idx, dentry, &realpath);
365 rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry;
368 err = ovl_dir_read(&realpath, &rdd);
373 * Insert lowest layer entries before upper ones, this
374 * allows offsets to be reasonably constant
376 list_add(&rdd.middle, rdd.list);
377 rdd.is_lowest = true;
378 err = ovl_dir_read(&realpath, &rdd);
379 list_del(&rdd.middle);
385 static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
390 list_for_each(p, &od->cache->entries) {
395 /* Cursor is safe since the cache is stable */
399 static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
402 struct ovl_dir_cache *cache;
403 struct inode *inode = d_inode(dentry);
405 cache = ovl_dir_cache(inode);
406 if (cache && ovl_inode_version_get(inode) == cache->version) {
407 WARN_ON(!cache->refcount);
411 ovl_set_dir_cache(d_inode(dentry), NULL);
413 cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
415 return ERR_PTR(-ENOMEM);
418 INIT_LIST_HEAD(&cache->entries);
419 cache->root = RB_ROOT;
421 res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root);
423 ovl_cache_free(&cache->entries);
428 cache->version = ovl_inode_version_get(inode);
429 ovl_set_dir_cache(inode, cache);
434 /* Map inode number to lower fs unique range */
435 static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid,
436 const char *name, int namelen, bool warn)
438 unsigned int xinoshift = 64 - xinobits;
440 if (unlikely(ino >> xinoshift)) {
442 pr_warn_ratelimited("d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
443 namelen, name, ino, xinobits);
449 * The lowest xinobit is reserved for mapping the non-peresistent inode
450 * numbers range, but this range is only exposed via st_ino, not here.
452 return ino | ((u64)fsid) << (xinoshift + 1);
456 * Set d_ino for upper entries if needed. Non-upper entries should always report
457 * the uppermost real inode ino and should not call this function.
459 * When not all layer are on same fs, report real ino also for upper.
461 * When all layers are on the same fs, and upper has a reference to
462 * copy up origin, call vfs_getattr() on the overlay entry to make
463 * sure that d_ino will be consistent with st_ino from stat(2).
465 * Also checks the overlay.whiteout xattr by doing a full lookup which will return
466 * negative in this case.
468 static int ovl_cache_update(const struct path *path, struct ovl_cache_entry *p, bool update_ino)
471 struct dentry *dir = path->dentry;
472 struct ovl_fs *ofs = OVL_FS(dir->d_sb);
473 struct dentry *this = NULL;
474 enum ovl_path_type type;
475 u64 ino = p->real_ino;
476 int xinobits = ovl_xino_bits(ofs);
479 if (!ovl_same_dev(ofs) && !p->check_xwhiteout)
482 if (p->name[0] == '.') {
487 if (p->len == 2 && p->name[1] == '.') {
488 /* we shall not be moved */
489 this = dget(dir->d_parent);
493 /* This checks also for xwhiteouts */
494 this = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len);
495 if (IS_ERR_OR_NULL(this) || !this->d_inode) {
496 /* Mark a stale entry */
497 p->is_whiteout = true;
507 if (!ovl_same_dev(ofs) || !update_ino)
510 type = ovl_path_type(this);
511 if (OVL_TYPE_ORIGIN(type)) {
513 struct path statpath = *path;
515 statpath.dentry = this;
516 err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
521 * Directory inode is always on overlay st_dev.
522 * Non-dir with ovl_same_dev() could be on pseudo st_dev in case
523 * of xino bits overflow.
525 WARN_ON_ONCE(S_ISDIR(stat.mode) &&
526 dir->d_sb->s_dev != stat.dev);
528 } else if (xinobits && !OVL_TYPE_UPPER(type)) {
529 ino = ovl_remap_lower_ino(ino, xinobits,
530 ovl_layer_lower(this)->fsid,
541 pr_warn_ratelimited("failed to look up (%s) for ino (%i)\n",
546 static bool ovl_fill_plain(struct dir_context *ctx, const char *name,
547 int namelen, loff_t offset, u64 ino,
550 struct ovl_cache_entry *p;
551 struct ovl_readdir_data *rdd =
552 container_of(ctx, struct ovl_readdir_data, ctx);
555 p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
560 list_add_tail(&p->l_node, rdd->list);
565 static int ovl_dir_read_impure(const struct path *path, struct list_head *list,
566 struct rb_root *root)
569 struct path realpath;
570 struct ovl_cache_entry *p, *n;
571 struct ovl_readdir_data rdd = {
572 .ctx.actor = ovl_fill_plain,
577 INIT_LIST_HEAD(list);
579 ovl_path_upper(path->dentry, &realpath);
581 err = ovl_dir_read(&realpath, &rdd);
585 list_for_each_entry_safe(p, n, list, l_node) {
586 if (strcmp(p->name, ".") != 0 &&
587 strcmp(p->name, "..") != 0) {
588 err = ovl_cache_update(path, p, true);
592 if (p->ino == p->real_ino) {
593 list_del(&p->l_node);
596 struct rb_node **newp = &root->rb_node;
597 struct rb_node *parent = NULL;
599 if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len,
603 rb_link_node(&p->node, parent, newp);
604 rb_insert_color(&p->node, root);
610 static struct ovl_dir_cache *ovl_cache_get_impure(const struct path *path)
613 struct dentry *dentry = path->dentry;
614 struct inode *inode = d_inode(dentry);
615 struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
616 struct ovl_dir_cache *cache;
618 cache = ovl_dir_cache(inode);
619 if (cache && ovl_inode_version_get(inode) == cache->version)
622 /* Impure cache is not refcounted, free it here */
623 ovl_dir_cache_free(inode);
624 ovl_set_dir_cache(inode, NULL);
626 cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
628 return ERR_PTR(-ENOMEM);
630 res = ovl_dir_read_impure(path, &cache->entries, &cache->root);
632 ovl_cache_free(&cache->entries);
636 if (list_empty(&cache->entries)) {
638 * A good opportunity to get rid of an unneeded "impure" flag.
639 * Removing the "impure" xattr is best effort.
641 if (!ovl_want_write(dentry)) {
642 ovl_removexattr(ofs, ovl_dentry_upper(dentry),
644 ovl_drop_write(dentry);
646 ovl_clear_flag(OVL_IMPURE, inode);
651 cache->version = ovl_inode_version_get(inode);
652 ovl_set_dir_cache(inode, cache);
657 struct ovl_readdir_translate {
658 struct dir_context *orig_ctx;
659 struct ovl_dir_cache *cache;
660 struct dir_context ctx;
667 static bool ovl_fill_real(struct dir_context *ctx, const char *name,
668 int namelen, loff_t offset, u64 ino,
671 struct ovl_readdir_translate *rdt =
672 container_of(ctx, struct ovl_readdir_translate, ctx);
673 struct dir_context *orig_ctx = rdt->orig_ctx;
675 if (rdt->parent_ino && strcmp(name, "..") == 0) {
676 ino = rdt->parent_ino;
677 } else if (rdt->cache) {
678 struct ovl_cache_entry *p;
680 p = ovl_cache_entry_find(&rdt->cache->root, name, namelen);
683 } else if (rdt->xinobits) {
684 ino = ovl_remap_lower_ino(ino, rdt->xinobits, rdt->fsid,
685 name, namelen, rdt->xinowarn);
688 return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
691 static bool ovl_is_impure_dir(struct file *file)
693 struct ovl_dir_file *od = file->private_data;
694 struct inode *dir = file_inode(file);
697 * Only upper dir can be impure, but if we are in the middle of
698 * iterating a lower real dir, dir could be copied up and marked
699 * impure. We only want the impure cache if we started iterating
700 * a real upper dir to begin with.
702 return od->is_upper && ovl_test_flag(OVL_IMPURE, dir);
706 static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
709 struct ovl_dir_file *od = file->private_data;
710 struct dentry *dir = file->f_path.dentry;
711 struct ovl_fs *ofs = OVL_FS(dir->d_sb);
712 const struct ovl_layer *lower_layer = ovl_layer_lower(dir);
713 struct ovl_readdir_translate rdt = {
714 .ctx.actor = ovl_fill_real,
716 .xinobits = ovl_xino_bits(ofs),
717 .xinowarn = ovl_xino_warn(ofs),
720 if (rdt.xinobits && lower_layer)
721 rdt.fsid = lower_layer->fsid;
723 if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) {
725 struct path statpath = file->f_path;
727 statpath.dentry = dir->d_parent;
728 err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
732 WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
733 rdt.parent_ino = stat.ino;
736 if (ovl_is_impure_dir(file)) {
737 rdt.cache = ovl_cache_get_impure(&file->f_path);
738 if (IS_ERR(rdt.cache))
739 return PTR_ERR(rdt.cache);
742 err = iterate_dir(od->realfile, &rdt.ctx);
743 ctx->pos = rdt.ctx.pos;
749 static int ovl_iterate(struct file *file, struct dir_context *ctx)
751 struct ovl_dir_file *od = file->private_data;
752 struct dentry *dentry = file->f_path.dentry;
753 struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
754 struct ovl_cache_entry *p;
755 const struct cred *old_cred;
758 old_cred = ovl_override_creds(dentry->d_sb);
764 * If parent is merge, then need to adjust d_ino for '..', if
765 * dir is impure then need to adjust d_ino for copied up
768 if (ovl_xino_bits(ofs) ||
770 (ovl_is_impure_dir(file) ||
771 OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
772 err = ovl_iterate_real(file, ctx);
774 err = iterate_dir(od->realfile, ctx);
780 struct ovl_dir_cache *cache;
782 cache = ovl_cache_get(dentry);
783 err = PTR_ERR(cache);
788 ovl_seek_cursor(od, ctx->pos);
791 while (od->cursor != &od->cache->entries) {
792 p = list_entry(od->cursor, struct ovl_cache_entry, l_node);
793 if (!p->is_whiteout) {
794 if (!p->ino || p->check_xwhiteout) {
795 err = ovl_cache_update(&file->f_path, p, !p->ino);
800 /* ovl_cache_update() sets is_whiteout on stale entry */
801 if (!p->is_whiteout) {
802 if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
805 od->cursor = p->l_node.next;
810 revert_creds(old_cred);
814 static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
817 struct ovl_dir_file *od = file->private_data;
819 inode_lock(file_inode(file));
824 res = vfs_llseek(od->realfile, offset, origin);
825 file->f_pos = od->realfile->f_pos;
831 offset += file->f_pos;
841 if (offset != file->f_pos) {
842 file->f_pos = offset;
844 ovl_seek_cursor(od, offset);
849 inode_unlock(file_inode(file));
854 static struct file *ovl_dir_open_realfile(const struct file *file,
855 const struct path *realpath)
858 const struct cred *old_cred;
860 old_cred = ovl_override_creds(file_inode(file)->i_sb);
861 res = ovl_path_open(realpath, O_RDONLY | (file->f_flags & O_LARGEFILE));
862 revert_creds(old_cred);
868 * Like ovl_real_fdget(), returns upperfile if dir was copied up since open.
869 * Unlike ovl_real_fdget(), this caches upperfile in file->private_data.
871 * TODO: use same abstract type for file->private_data of dir and file so
872 * upperfile could also be cached for files as well.
874 struct file *ovl_dir_real_file(const struct file *file, bool want_upper)
877 struct ovl_dir_file *od = file->private_data;
878 struct dentry *dentry = file->f_path.dentry;
879 struct file *old, *realfile = od->realfile;
881 if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
882 return want_upper ? NULL : realfile;
885 * Need to check if we started out being a lower dir, but got copied up
888 realfile = READ_ONCE(od->upperfile);
890 struct path upperpath;
892 ovl_path_upper(dentry, &upperpath);
893 realfile = ovl_dir_open_realfile(file, &upperpath);
894 if (IS_ERR(realfile))
897 old = cmpxchg_release(&od->upperfile, NULL, realfile);
908 static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
911 struct file *realfile;
914 err = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));
918 realfile = ovl_dir_real_file(file, true);
919 err = PTR_ERR_OR_ZERO(realfile);
921 /* Nothing to sync for lower */
922 if (!realfile || err)
925 return vfs_fsync_range(realfile, start, end, datasync);
928 static int ovl_dir_release(struct inode *inode, struct file *file)
930 struct ovl_dir_file *od = file->private_data;
934 ovl_cache_put(od, inode);
945 static int ovl_dir_open(struct inode *inode, struct file *file)
947 struct path realpath;
948 struct file *realfile;
949 struct ovl_dir_file *od;
950 enum ovl_path_type type;
952 od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL);
956 type = ovl_path_real(file->f_path.dentry, &realpath);
957 realfile = ovl_dir_open_realfile(file, &realpath);
958 if (IS_ERR(realfile)) {
960 return PTR_ERR(realfile);
962 od->realfile = realfile;
963 od->is_real = ovl_dir_is_real(inode);
964 od->is_upper = OVL_TYPE_UPPER(type);
965 file->private_data = od;
970 WRAP_DIR_ITER(ovl_iterate) // FIXME!
971 const struct file_operations ovl_dir_operations = {
972 .read = generic_read_dir,
973 .open = ovl_dir_open,
974 .iterate_shared = shared_ovl_iterate,
975 .llseek = ovl_dir_llseek,
976 .fsync = ovl_dir_fsync,
977 .release = ovl_dir_release,
980 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
983 struct ovl_cache_entry *p, *n;
984 struct rb_root root = RB_ROOT;
985 const struct cred *old_cred;
987 old_cred = ovl_override_creds(dentry->d_sb);
988 err = ovl_dir_read_merged(dentry, list, &root);
989 revert_creds(old_cred);
995 list_for_each_entry_safe(p, n, list, l_node) {
997 * Select whiteouts in upperdir, they should
998 * be cleared when deleting this directory.
1000 if (p->is_whiteout) {
1006 if (p->name[0] == '.') {
1009 if (p->len == 2 && p->name[1] == '.')
1016 list_del(&p->l_node);
1023 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper,
1024 struct list_head *list)
1026 struct ovl_cache_entry *p;
1028 inode_lock_nested(upper->d_inode, I_MUTEX_CHILD);
1029 list_for_each_entry(p, list, l_node) {
1030 struct dentry *dentry;
1032 if (WARN_ON(!p->is_whiteout || !p->is_upper))
1035 dentry = ovl_lookup_upper(ofs, p->name, upper, p->len);
1036 if (IS_ERR(dentry)) {
1037 pr_err("lookup '%s/%.*s' failed (%i)\n",
1038 upper->d_name.name, p->len, p->name,
1039 (int) PTR_ERR(dentry));
1042 if (dentry->d_inode)
1043 ovl_cleanup(ofs, upper->d_inode, dentry);
1046 inode_unlock(upper->d_inode);
1049 static bool ovl_check_d_type(struct dir_context *ctx, const char *name,
1050 int namelen, loff_t offset, u64 ino,
1051 unsigned int d_type)
1053 struct ovl_readdir_data *rdd =
1054 container_of(ctx, struct ovl_readdir_data, ctx);
1056 /* Even if d_type is not supported, DT_DIR is returned for . and .. */
1057 if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen))
1060 if (d_type != DT_UNKNOWN)
1061 rdd->d_type_supported = true;
1067 * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values
1068 * if error is encountered.
1070 int ovl_check_d_type_supported(const struct path *realpath)
1073 struct ovl_readdir_data rdd = {
1074 .ctx.actor = ovl_check_d_type,
1075 .d_type_supported = false,
1078 err = ovl_dir_read(realpath, &rdd);
1082 return rdd.d_type_supported;
1085 #define OVL_INCOMPATDIR_NAME "incompat"
1087 static int ovl_workdir_cleanup_recurse(struct ovl_fs *ofs, const struct path *path,
1091 struct inode *dir = path->dentry->d_inode;
1093 struct ovl_cache_entry *p;
1094 struct ovl_readdir_data rdd = {
1095 .ctx.actor = ovl_fill_plain,
1098 bool incompat = false;
1101 * The "work/incompat" directory is treated specially - if it is not
1102 * empty, instead of printing a generic error and mounting read-only,
1103 * we will error about incompat features and fail the mount.
1105 * When called from ovl_indexdir_cleanup(), path->dentry->d_name.name
1109 !strcmp(path->dentry->d_name.name, OVL_INCOMPATDIR_NAME))
1112 err = ovl_dir_read(path, &rdd);
1116 inode_lock_nested(dir, I_MUTEX_PARENT);
1117 list_for_each_entry(p, &list, l_node) {
1118 struct dentry *dentry;
1120 if (p->name[0] == '.') {
1123 if (p->len == 2 && p->name[1] == '.')
1125 } else if (incompat) {
1126 pr_err("overlay with incompat feature '%s' cannot be mounted\n",
1131 dentry = ovl_lookup_upper(ofs, p->name, path->dentry, p->len);
1134 if (dentry->d_inode)
1135 err = ovl_workdir_cleanup(ofs, dir, path->mnt, dentry, level);
1142 ovl_cache_free(&list);
1146 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir,
1147 struct vfsmount *mnt, struct dentry *dentry, int level)
1151 if (!d_is_dir(dentry) || level > 1) {
1152 return ovl_cleanup(ofs, dir, dentry);
1155 err = ovl_do_rmdir(ofs, dir, dentry);
1157 struct path path = { .mnt = mnt, .dentry = dentry };
1160 err = ovl_workdir_cleanup_recurse(ofs, &path, level + 1);
1161 inode_lock_nested(dir, I_MUTEX_PARENT);
1163 err = ovl_cleanup(ofs, dir, dentry);
1169 int ovl_indexdir_cleanup(struct ovl_fs *ofs)
1172 struct dentry *indexdir = ofs->indexdir;
1173 struct dentry *index = NULL;
1174 struct inode *dir = indexdir->d_inode;
1175 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = indexdir };
1177 struct ovl_cache_entry *p;
1178 struct ovl_readdir_data rdd = {
1179 .ctx.actor = ovl_fill_plain,
1183 err = ovl_dir_read(&path, &rdd);
1187 inode_lock_nested(dir, I_MUTEX_PARENT);
1188 list_for_each_entry(p, &list, l_node) {
1189 if (p->name[0] == '.') {
1192 if (p->len == 2 && p->name[1] == '.')
1195 index = ovl_lookup_upper(ofs, p->name, indexdir, p->len);
1196 if (IS_ERR(index)) {
1197 err = PTR_ERR(index);
1201 /* Cleanup leftover from index create/cleanup attempt */
1202 if (index->d_name.name[0] == '#') {
1203 err = ovl_workdir_cleanup(ofs, dir, path.mnt, index, 1);
1208 err = ovl_verify_index(ofs, index);
1211 } else if (err == -ESTALE) {
1212 /* Cleanup stale index entries */
1213 err = ovl_cleanup(ofs, dir, index);
1214 } else if (err != -ENOENT) {
1216 * Abort mount to avoid corrupting the index if
1217 * an incompatible index entry was found or on out
1221 } else if (ofs->config.nfs_export) {
1223 * Whiteout orphan index to block future open by
1224 * handle after overlay nlink dropped to zero.
1226 err = ovl_cleanup_and_whiteout(ofs, dir, index);
1228 /* Cleanup orphan index entries */
1229 err = ovl_cleanup(ofs, dir, index);
1242 ovl_cache_free(&list);
1244 pr_err("failed index dir cleanup (%i)\n", err);