1 /* SPDX-License-Identifier: GPL-2.0-only */
4 * Copyright (C) 2011 Novell Inc.
7 #include <linux/kernel.h>
8 #include <linux/uuid.h>
10 #include <linux/fsverity.h>
11 #include <linux/namei.h>
12 #include <linux/posix_acl.h>
13 #include <linux/posix_acl_xattr.h>
14 #include "ovl_entry.h"
17 #define pr_fmt(fmt) "overlayfs: " fmt
20 __OVL_PATH_UPPER = (1 << 0),
21 __OVL_PATH_MERGE = (1 << 1),
22 __OVL_PATH_ORIGIN = (1 << 2),
25 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
26 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
27 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
29 #define OVL_XATTR_NAMESPACE "overlay."
30 #define OVL_XATTR_TRUSTED_PREFIX XATTR_TRUSTED_PREFIX OVL_XATTR_NAMESPACE
31 #define OVL_XATTR_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_TRUSTED_PREFIX) - 1)
32 #define OVL_XATTR_USER_PREFIX XATTR_USER_PREFIX OVL_XATTR_NAMESPACE
33 #define OVL_XATTR_USER_PREFIX_LEN (sizeof(OVL_XATTR_USER_PREFIX) - 1)
35 #define OVL_XATTR_ESCAPE_PREFIX OVL_XATTR_NAMESPACE
36 #define OVL_XATTR_ESCAPE_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_PREFIX) - 1)
37 #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX OVL_XATTR_TRUSTED_PREFIX OVL_XATTR_ESCAPE_PREFIX
38 #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_TRUSTED_PREFIX) - 1)
39 #define OVL_XATTR_ESCAPE_USER_PREFIX OVL_XATTR_USER_PREFIX OVL_XATTR_ESCAPE_PREFIX
40 #define OVL_XATTR_ESCAPE_USER_PREFIX_LEN (sizeof(OVL_XATTR_ESCAPE_USER_PREFIX) - 1)
56 /* Pure upper dir that may contain non pure upper entries */
58 /* Non-merge dir that may contain whiteout entries */
62 /* Inode number will remain constant over copy up. */
72 /* Lower stack may contain xwhiteout entries */
77 OVL_REDIRECT_OFF, /* "off" mode is never used. In effect */
78 OVL_REDIRECT_FOLLOW, /* ...it translates to either "follow" */
79 OVL_REDIRECT_NOFOLLOW, /* ...or "nofollow". */
103 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
105 * origin.fh - exported file handle of the lower file
106 * origin.uuid - uuid of the lower filesystem
108 #define OVL_FH_VERSION 0
109 #define OVL_FH_MAGIC 0xfb
111 /* CPU byte order required for fid decoding: */
112 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
113 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
114 /* Is the real inode encoded in fid an upper inode? */
115 #define OVL_FH_FLAG_PATH_UPPER (1 << 2)
117 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
118 OVL_FH_FLAG_PATH_UPPER)
120 #if defined(__LITTLE_ENDIAN)
121 #define OVL_FH_FLAG_CPU_ENDIAN 0
122 #elif defined(__BIG_ENDIAN)
123 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
125 #error Endianness not defined
128 /* The type used to be returned by overlay exportfs for misaligned fid */
129 #define OVL_FILEID_V0 0xfb
130 /* The type returned by overlay exportfs for 32bit aligned fid */
131 #define OVL_FILEID_V1 0xf8
133 /* On-disk format for "origin" file handle */
137 u8 len; /* size of this header + size of fid */
138 u8 flags; /* OVL_FH_FLAG_* */
139 u8 type; /* fid_type of fid */
140 uuid_t uuid; /* uuid of filesystem */
141 u32 fid[]; /* file identifier should be 32bit aligned in-memory */
144 /* In-memory and on-wire format for overlay file handle */
146 u8 padding[3]; /* make sure fb.fid is 32bit aligned */
149 DECLARE_FLEX_ARRAY(u8, buf);
153 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb)
154 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len)
155 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
156 offsetof(struct ovl_fb, fid))
158 /* On-disk format for "metacopy" xattr (if non-zero size) */
159 struct ovl_metacopy {
161 u8 len; /* size of this header + used digest bytes */
163 u8 digest_algo; /* FS_VERITY_HASH_ALG_* constant, 0 for no digest */
164 u8 digest[FS_VERITY_MAX_DIGEST_SIZE]; /* Only the used part on disk */
167 #define OVL_METACOPY_MAX_SIZE (sizeof(struct ovl_metacopy))
168 #define OVL_METACOPY_MIN_SIZE (OVL_METACOPY_MAX_SIZE - FS_VERITY_MAX_DIGEST_SIZE)
169 #define OVL_METACOPY_INIT { 0, OVL_METACOPY_MIN_SIZE }
171 static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy)
173 if (metacopy->len < OVL_METACOPY_MIN_SIZE)
175 return (int)metacopy->len - OVL_METACOPY_MIN_SIZE;
178 extern const char *const ovl_xattr_table[][2];
179 static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox)
181 return ovl_xattr_table[ox][ofs->config.userxattr];
185 * When changing ownership of an upper object map the intended ownership
186 * according to the upper layer's idmapping. When an upper mount idmaps files
187 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on
188 * this object will report it as being owned by id 1000 when calling stat via
190 * In order to change ownership of an object so stat reports id 1000 when
191 * called on an idmapped upper mount the value written to disk - i.e., the
192 * value stored in ia_*id - must 1001. The mount mapping helper will thus take
193 * care to map 1000 to 1001.
194 * The mnt idmapping helpers are nops if the upper layer isn't idmapped.
196 static inline int ovl_do_notify_change(struct ovl_fs *ofs,
197 struct dentry *upperdentry,
200 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL);
203 static inline int ovl_do_rmdir(struct ovl_fs *ofs,
204 struct inode *dir, struct dentry *dentry)
206 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry);
208 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
212 static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir,
213 struct dentry *dentry)
215 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL);
217 pr_debug("unlink(%pd2) = %i\n", dentry, err);
221 static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry,
222 struct inode *dir, struct dentry *new_dentry)
224 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir,
227 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
231 static inline int ovl_do_create(struct ovl_fs *ofs,
232 struct inode *dir, struct dentry *dentry,
235 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true);
237 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
241 static inline int ovl_do_mkdir(struct ovl_fs *ofs,
242 struct inode *dir, struct dentry *dentry,
245 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
246 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
250 static inline int ovl_do_mknod(struct ovl_fs *ofs,
251 struct inode *dir, struct dentry *dentry,
252 umode_t mode, dev_t dev)
254 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev);
256 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
260 static inline int ovl_do_symlink(struct ovl_fs *ofs,
261 struct inode *dir, struct dentry *dentry,
264 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname);
266 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
270 static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name,
271 void *value, size_t size)
275 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb);
277 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry,
279 len = (value && err > 0) ? err : 0;
281 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
282 path->dentry, name, min(len, 48), value, size, err);
286 static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs,
287 struct dentry *upperdentry,
288 enum ovl_xattr ox, void *value,
291 struct path upperpath = {
292 .dentry = upperdentry,
293 .mnt = ovl_upper_mnt(ofs),
296 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size);
299 static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs,
300 const struct path *path,
301 enum ovl_xattr ox, void *value,
304 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size);
307 static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
308 const char *name, const void *value,
309 size_t size, int flags)
311 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name,
314 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n",
315 dentry, name, min((int)size, 48), value, size, flags, err);
319 static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
320 enum ovl_xattr ox, const void *value,
323 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0);
326 static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
329 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name);
330 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
334 static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
337 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox));
340 static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry,
341 const char *acl_name, struct posix_acl *acl)
343 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl);
346 static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry,
347 const char *acl_name)
349 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name);
352 static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir,
353 struct dentry *olddentry, struct inode *newdir,
354 struct dentry *newdentry, unsigned int flags)
357 struct renamedata rd = {
358 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs),
360 .old_dentry = olddentry,
361 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs),
363 .new_dentry = newdentry,
367 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
368 err = vfs_rename(&rd);
370 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
371 olddentry, newdentry, err);
376 static inline int ovl_do_whiteout(struct ovl_fs *ofs,
377 struct inode *dir, struct dentry *dentry)
379 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry);
380 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
384 static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
385 struct dentry *dentry, umode_t mode)
387 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
388 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path,
389 mode, O_LARGEFILE | O_WRONLY,
391 int err = PTR_ERR_OR_ZERO(file);
393 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
397 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,
399 struct dentry *base, int len)
401 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len);
404 static inline bool ovl_open_flags_need_copy_up(int flags)
409 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
412 static inline int ovl_do_getattr(const struct path *path, struct kstat *stat,
413 u32 request_mask, unsigned int flags)
415 if (flags & AT_GETATTR_NOSEC)
416 return vfs_getattr_nosec(path, stat, request_mask, flags);
417 return vfs_getattr(path, stat, request_mask, flags);
421 int ovl_get_write_access(struct dentry *dentry);
422 void ovl_put_write_access(struct dentry *dentry);
423 void ovl_start_write(struct dentry *dentry);
424 void ovl_end_write(struct dentry *dentry);
425 int ovl_want_write(struct dentry *dentry);
426 void ovl_drop_write(struct dentry *dentry);
427 struct dentry *ovl_workdir(struct dentry *dentry);
428 const struct cred *ovl_override_creds(struct super_block *sb);
430 static inline const struct cred *ovl_creds(struct super_block *sb)
432 return OVL_FS(sb)->creator_cred;
435 int ovl_can_decode_fh(struct super_block *sb);
436 struct dentry *ovl_indexdir(struct super_block *sb);
437 bool ovl_index_all(struct super_block *sb);
438 bool ovl_verify_lower(struct super_block *sb);
439 struct ovl_path *ovl_stack_alloc(unsigned int n);
440 void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n);
441 void ovl_stack_put(struct ovl_path *stack, unsigned int n);
442 void ovl_stack_free(struct ovl_path *stack, unsigned int n);
443 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
444 void ovl_free_entry(struct ovl_entry *oe);
445 bool ovl_dentry_remote(struct dentry *dentry);
446 void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry);
447 void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry,
448 struct ovl_entry *oe);
449 void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry,
450 struct ovl_entry *oe, unsigned int mask);
451 bool ovl_dentry_weird(struct dentry *dentry);
452 enum ovl_path_type ovl_path_type(struct dentry *dentry);
453 void ovl_path_upper(struct dentry *dentry, struct path *path);
454 void ovl_path_lower(struct dentry *dentry, struct path *path);
455 void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
456 struct inode *ovl_i_path_real(struct inode *inode, struct path *path);
457 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
458 enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path);
459 struct dentry *ovl_dentry_upper(struct dentry *dentry);
460 struct dentry *ovl_dentry_lower(struct dentry *dentry);
461 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
462 int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath);
463 const struct ovl_layer *ovl_i_layer_lower(struct inode *inode);
464 const struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
465 struct dentry *ovl_dentry_real(struct dentry *dentry);
466 struct dentry *ovl_i_dentry_upper(struct inode *inode);
467 struct inode *ovl_inode_upper(struct inode *inode);
468 struct inode *ovl_inode_lower(struct inode *inode);
469 struct inode *ovl_inode_lowerdata(struct inode *inode);
470 struct inode *ovl_inode_real(struct inode *inode);
471 struct inode *ovl_inode_realdata(struct inode *inode);
472 const char *ovl_lowerdata_redirect(struct inode *inode);
473 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
474 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
475 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
476 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
477 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
478 bool ovl_dentry_is_opaque(struct dentry *dentry);
479 bool ovl_dentry_is_whiteout(struct dentry *dentry);
480 void ovl_dentry_set_opaque(struct dentry *dentry);
481 bool ovl_dentry_has_xwhiteouts(struct dentry *dentry);
482 void ovl_dentry_set_xwhiteouts(struct dentry *dentry);
483 void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs,
484 const struct ovl_layer *layer);
485 bool ovl_dentry_has_upper_alias(struct dentry *dentry);
486 void ovl_dentry_set_upper_alias(struct dentry *dentry);
487 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
488 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
489 bool ovl_has_upperdata(struct inode *inode);
490 void ovl_set_upperdata(struct inode *inode);
491 const char *ovl_dentry_get_redirect(struct dentry *dentry);
492 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
493 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
494 void ovl_dir_modified(struct dentry *dentry, bool impurity);
495 u64 ovl_inode_version_get(struct inode *inode);
496 bool ovl_is_whiteout(struct dentry *dentry);
497 bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path);
498 struct file *ovl_path_open(const struct path *path, int flags);
499 int ovl_copy_up_start(struct dentry *dentry, int flags);
500 void ovl_copy_up_end(struct dentry *dentry);
501 bool ovl_already_copied_up(struct dentry *dentry, int flags);
502 char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path,
504 bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path);
505 bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path);
506 bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs,
507 const struct path *upperpath);
509 static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs,
510 struct dentry *upperdentry)
512 struct path upperpath = {
513 .dentry = upperdentry,
514 .mnt = ovl_upper_mnt(ofs),
516 return ovl_path_is_whiteout(ofs, &upperpath);
519 static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs,
520 struct dentry *upperdentry)
522 struct path upperpath = {
523 .dentry = upperdentry,
524 .mnt = ovl_upper_mnt(ofs),
526 return ovl_path_check_origin_xattr(ofs, &upperpath);
529 int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
530 enum ovl_xattr ox, const void *value, size_t size,
532 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
533 bool ovl_inuse_trylock(struct dentry *dentry);
534 void ovl_inuse_unlock(struct dentry *dentry);
535 bool ovl_is_inuse(struct dentry *dentry);
536 bool ovl_need_index(struct dentry *dentry);
537 int ovl_nlink_start(struct dentry *dentry);
538 void ovl_nlink_end(struct dentry *dentry);
539 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
540 int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path,
541 struct ovl_metacopy *data);
542 int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d,
543 struct ovl_metacopy *metacopy);
544 bool ovl_is_metacopy_dentry(struct dentry *dentry);
545 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding);
546 int ovl_ensure_verity_loaded(struct path *path);
547 int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path,
548 u8 *digest_buf, int *buf_length);
549 int ovl_validate_verity(struct ovl_fs *ofs,
550 struct path *metapath,
551 struct path *datapath);
552 int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src,
553 struct ovl_metacopy *metacopy);
554 int ovl_sync_status(struct ovl_fs *ofs);
556 static inline void ovl_set_flag(unsigned long flag, struct inode *inode)
558 set_bit(flag, &OVL_I(inode)->flags);
561 static inline void ovl_clear_flag(unsigned long flag, struct inode *inode)
563 clear_bit(flag, &OVL_I(inode)->flags);
566 static inline bool ovl_test_flag(unsigned long flag, struct inode *inode)
568 return test_bit(flag, &OVL_I(inode)->flags);
571 static inline bool ovl_is_impuredir(struct super_block *sb,
572 struct dentry *upperdentry)
574 struct ovl_fs *ofs = OVL_FS(sb);
575 struct path upperpath = {
576 .dentry = upperdentry,
577 .mnt = ovl_upper_mnt(ofs),
580 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y';
583 static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs,
584 const struct path *path)
586 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE);
589 static inline bool ovl_redirect_follow(struct ovl_fs *ofs)
591 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW;
594 static inline bool ovl_redirect_dir(struct ovl_fs *ofs)
596 return ofs->config.redirect_mode == OVL_REDIRECT_ON;
599 static inline bool ovl_origin_uuid(struct ovl_fs *ofs)
601 return ofs->config.uuid != OVL_UUID_OFF;
604 static inline bool ovl_has_fsid(struct ovl_fs *ofs)
606 return ofs->config.uuid == OVL_UUID_ON ||
607 ofs->config.uuid == OVL_UUID_AUTO;
611 * With xino=auto, we do best effort to keep all inodes on same st_dev and
612 * d_ino consistent with st_ino.
613 * With xino=on, we do the same effort but we warn if we failed.
615 static inline bool ovl_xino_warn(struct ovl_fs *ofs)
617 return ofs->config.xino == OVL_XINO_ON;
621 * To avoid regressions in existing setups with overlay lower offline changes,
622 * we allow lower changes only if none of the new features are used.
624 static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs)
626 return (!ofs->config.index && !ofs->config.metacopy &&
627 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs));
630 /* All layers on same fs? */
631 static inline bool ovl_same_fs(struct ovl_fs *ofs)
633 return ofs->xino_mode == 0;
636 /* All overlay inodes have same st_dev? */
637 static inline bool ovl_same_dev(struct ovl_fs *ofs)
639 return ofs->xino_mode >= 0;
642 static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs)
644 return ovl_same_dev(ofs) ? ofs->xino_mode : 0;
647 static inline void ovl_inode_lock(struct inode *inode)
649 mutex_lock(&OVL_I(inode)->lock);
652 static inline int ovl_inode_lock_interruptible(struct inode *inode)
654 return mutex_lock_interruptible(&OVL_I(inode)->lock);
657 static inline void ovl_inode_unlock(struct inode *inode)
659 mutex_unlock(&OVL_I(inode)->lock);
664 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
666 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
668 if (fh_len < sizeof(struct ovl_fh))
671 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
674 struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
675 struct vfsmount *mnt, bool connected);
676 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
677 struct dentry *upperdentry, struct ovl_path **stackp);
678 int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
679 enum ovl_xattr ox, const struct ovl_fh *fh,
680 bool is_upper, bool set);
681 int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry,
682 enum ovl_xattr ox, struct dentry *real,
683 bool is_upper, bool set);
684 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index,
686 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
687 int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name);
688 int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin,
690 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
691 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
692 struct dentry *origin, bool verify);
693 int ovl_path_next(int idx, struct dentry *dentry, struct path *path,
694 const struct ovl_layer **layer);
695 int ovl_verify_lowerdata(struct dentry *dentry);
696 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
698 bool ovl_lower_positive(struct dentry *dentry);
700 static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper,
701 const struct ovl_fh *fh, bool set)
703 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set);
706 static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper,
707 struct dentry *origin, bool set)
709 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin,
713 static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
714 struct dentry *upper, bool set)
716 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper,
721 extern const struct file_operations ovl_dir_operations;
722 struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
723 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
724 void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper,
725 struct list_head *list);
726 void ovl_cache_free(struct list_head *list);
727 void ovl_dir_cache_free(struct inode *inode);
728 int ovl_check_d_type_supported(const struct path *realpath);
729 int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir,
730 struct vfsmount *mnt, struct dentry *dentry, int level);
731 int ovl_indexdir_cleanup(struct ovl_fs *ofs);
734 * Can we iterate real dir directly?
736 * Non-merge dir may contain whiteouts from a time it was a merge upper, before
737 * lower dir was removed under it and possibly before it was rotated from upper
740 static inline bool ovl_dir_is_real(struct inode *dir)
742 return !ovl_test_flag(OVL_WHITEOUTS, dir);
746 int ovl_set_nlink_upper(struct dentry *dentry);
747 int ovl_set_nlink_lower(struct dentry *dentry);
748 unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,
749 struct dentry *upperdentry,
750 unsigned int fallback);
751 int ovl_permission(struct mnt_idmap *idmap, struct inode *inode,
754 #ifdef CONFIG_FS_POSIX_ACL
755 struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap,
756 struct inode *inode, int type,
757 bool rcu, bool noperm);
758 static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type,
761 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true);
763 static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap,
764 struct dentry *dentry, int type)
766 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false);
768 int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
769 struct posix_acl *acl, int type);
770 struct posix_acl *ovl_get_acl_path(const struct path *path,
771 const char *acl_name, bool noperm);
773 #define ovl_get_inode_acl NULL
774 #define ovl_get_acl NULL
775 #define ovl_set_acl NULL
776 static inline struct posix_acl *ovl_get_acl_path(const struct path *path,
777 const char *acl_name,
784 int ovl_update_time(struct inode *inode, int flags);
785 bool ovl_is_private_xattr(struct super_block *sb, const char *name);
787 struct ovl_inode_params {
788 struct inode *newinode;
789 struct dentry *upperdentry;
790 struct ovl_entry *oe;
793 char *lowerdata_redirect;
795 void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
796 unsigned long ino, int fsid);
797 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
798 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
800 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
801 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
802 struct inode *ovl_get_inode(struct super_block *sb,
803 struct ovl_inode_params *oip);
804 void ovl_copyattr(struct inode *to);
806 /* vfs inode flags copied from real to ovl inode */
807 #define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE)
808 /* vfs inode flags read from overlay.protattr xattr to ovl inode */
809 #define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE)
812 * fileattr flags copied from lower to upper inode on copy up.
813 * We cannot copy up immutable/append-only flags, because that would prevent
814 * linking temp inode to upper dir, so we store them in xattr instead.
816 #define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL)
817 #define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME)
818 #define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL)
819 #define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE)
821 void ovl_check_protattr(struct inode *inode, struct dentry *upper);
822 int ovl_set_protattr(struct inode *inode, struct dentry *upper,
823 struct fileattr *fa);
825 static inline void ovl_copyflags(struct inode *from, struct inode *to)
827 unsigned int mask = OVL_COPY_I_FLAGS_MASK;
829 inode_set_flags(to, from->i_flags & mask, mask);
833 extern const struct inode_operations ovl_dir_inode_operations;
834 int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
835 struct dentry *dentry);
840 struct dentry *hardlink;
843 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
845 int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
846 struct dentry **newdentry, umode_t mode);
847 struct dentry *ovl_create_real(struct ovl_fs *ofs,
848 struct inode *dir, struct dentry *newdentry,
849 struct ovl_cattr *attr);
850 int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry);
851 struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir);
852 struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir,
853 struct ovl_cattr *attr);
856 extern const struct file_operations ovl_file_operations;
857 int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa);
858 int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa);
859 int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
860 int ovl_fileattr_set(struct mnt_idmap *idmap,
861 struct dentry *dentry, struct fileattr *fa);
864 int ovl_copy_up(struct dentry *dentry);
865 int ovl_copy_up_with_data(struct dentry *dentry);
866 int ovl_maybe_copy_up(struct dentry *dentry, int flags);
867 int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new);
868 int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat);
869 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real,
871 struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin);
872 int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh,
873 struct dentry *upper);
876 extern const struct export_operations ovl_export_operations;
877 extern const struct export_operations ovl_export_fid_operations;
880 int ovl_fill_super(struct super_block *sb, struct fs_context *fc);
882 /* Will this overlay be forced to mount/remount ro? */
883 static inline bool ovl_force_readonly(struct ovl_fs *ofs)
885 return (!ovl_upper_mnt(ofs) || !ofs->workdir);
890 const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs);
891 int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
893 int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
894 struct kstat *stat, u32 request_mask, unsigned int flags);
895 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);