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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *
4 * Copyright (C) 2011 Novell Inc.
5 */
6
7#include <linux/kernel.h>
8#include <linux/uuid.h>
9#include <linux/fs.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"
15
16#undef pr_fmt
17#define pr_fmt(fmt) "overlayfs: " fmt
18
19enum ovl_path_type {
20 __OVL_PATH_UPPER = (1 << 0),
21 __OVL_PATH_MERGE = (1 << 1),
22 __OVL_PATH_ORIGIN = (1 << 2),
23};
24
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)
28
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)
34
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)
41
42enum ovl_xattr {
43 OVL_XATTR_OPAQUE,
44 OVL_XATTR_REDIRECT,
45 OVL_XATTR_ORIGIN,
46 OVL_XATTR_IMPURE,
47 OVL_XATTR_NLINK,
48 OVL_XATTR_UPPER,
49 OVL_XATTR_UUID,
50 OVL_XATTR_METACOPY,
51 OVL_XATTR_PROTATTR,
52 OVL_XATTR_XWHITEOUT,
53};
54
55enum ovl_inode_flag {
56 /* Pure upper dir that may contain non pure upper entries */
57 OVL_IMPURE,
58 /* Non-merge dir that may contain whiteout entries */
59 OVL_WHITEOUTS,
60 OVL_INDEX,
61 OVL_UPPERDATA,
62 /* Inode number will remain constant over copy up. */
63 OVL_CONST_INO,
64 OVL_HAS_DIGEST,
65 OVL_VERIFIED_DIGEST,
66};
67
68enum ovl_entry_flag {
69 OVL_E_UPPER_ALIAS,
70 OVL_E_OPAQUE,
71 OVL_E_CONNECTED,
72 /* Lower stack may contain xwhiteout entries */
73 OVL_E_XWHITEOUTS,
74};
75
76enum {
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". */
80 OVL_REDIRECT_ON,
81};
82
83enum {
84 OVL_UUID_OFF,
85 OVL_UUID_NULL,
86 OVL_UUID_AUTO,
87 OVL_UUID_ON,
88};
89
90enum {
91 OVL_XINO_OFF,
92 OVL_XINO_AUTO,
93 OVL_XINO_ON,
94};
95
96enum {
97 OVL_VERITY_OFF,
98 OVL_VERITY_ON,
99 OVL_VERITY_REQUIRE,
100};
101
102/*
103 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
104 * where:
105 * origin.fh - exported file handle of the lower file
106 * origin.uuid - uuid of the lower filesystem
107 */
108#define OVL_FH_VERSION 0
109#define OVL_FH_MAGIC 0xfb
110
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)
116
117#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
118 OVL_FH_FLAG_PATH_UPPER)
119
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
124#else
125#error Endianness not defined
126#endif
127
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
132
133/* On-disk format for "origin" file handle */
134struct ovl_fb {
135 u8 version; /* 0 */
136 u8 magic; /* 0xfb */
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 */
142} __packed;
143
144/* In-memory and on-wire format for overlay file handle */
145struct ovl_fh {
146 u8 padding[3]; /* make sure fb.fid is 32bit aligned */
147 union {
148 struct ovl_fb fb;
149 DECLARE_FLEX_ARRAY(u8, buf);
150 };
151} __packed;
152
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))
157
158/* On-disk format for "metacopy" xattr (if non-zero size) */
159struct ovl_metacopy {
160 u8 version; /* 0 */
161 u8 len; /* size of this header + used digest bytes */
162 u8 flags;
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 */
165} __packed;
166
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 }
170
171static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy)
172{
173 if (metacopy->len < OVL_METACOPY_MIN_SIZE)
174 return 0;
175 return (int)metacopy->len - OVL_METACOPY_MIN_SIZE;
176}
177
178/* No atime modification on underlying */
179#define OVL_OPEN_FLAGS (O_NOATIME)
180
181extern const char *const ovl_xattr_table[][2];
182static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox)
183{
184 return ovl_xattr_table[ox][ofs->config.userxattr];
185}
186
187/*
188 * When changing ownership of an upper object map the intended ownership
189 * according to the upper layer's idmapping. When an upper mount idmaps files
190 * that are stored on-disk as owned by id 1001 to id 1000 this means stat on
191 * this object will report it as being owned by id 1000 when calling stat via
192 * the upper mount.
193 * In order to change ownership of an object so stat reports id 1000 when
194 * called on an idmapped upper mount the value written to disk - i.e., the
195 * value stored in ia_*id - must 1001. The mount mapping helper will thus take
196 * care to map 1000 to 1001.
197 * The mnt idmapping helpers are nops if the upper layer isn't idmapped.
198 */
199static inline int ovl_do_notify_change(struct ovl_fs *ofs,
200 struct dentry *upperdentry,
201 struct iattr *attr)
202{
203 return notify_change(ovl_upper_mnt_idmap(ofs), upperdentry, attr, NULL);
204}
205
206static inline int ovl_do_rmdir(struct ovl_fs *ofs,
207 struct inode *dir, struct dentry *dentry)
208{
209 int err = vfs_rmdir(ovl_upper_mnt_idmap(ofs), dir, dentry);
210
211 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
212 return err;
213}
214
215static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir,
216 struct dentry *dentry)
217{
218 int err = vfs_unlink(ovl_upper_mnt_idmap(ofs), dir, dentry, NULL);
219
220 pr_debug("unlink(%pd2) = %i\n", dentry, err);
221 return err;
222}
223
224static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry,
225 struct inode *dir, struct dentry *new_dentry)
226{
227 int err = vfs_link(old_dentry, ovl_upper_mnt_idmap(ofs), dir,
228 new_dentry, NULL);
229
230 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
231 return err;
232}
233
234static inline int ovl_do_create(struct ovl_fs *ofs,
235 struct inode *dir, struct dentry *dentry,
236 umode_t mode)
237{
238 int err = vfs_create(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, true);
239
240 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
241 return err;
242}
243
244static inline int ovl_do_mkdir(struct ovl_fs *ofs,
245 struct inode *dir, struct dentry *dentry,
246 umode_t mode)
247{
248 int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
249 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
250 return err;
251}
252
253static inline int ovl_do_mknod(struct ovl_fs *ofs,
254 struct inode *dir, struct dentry *dentry,
255 umode_t mode, dev_t dev)
256{
257 int err = vfs_mknod(ovl_upper_mnt_idmap(ofs), dir, dentry, mode, dev);
258
259 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
260 return err;
261}
262
263static inline int ovl_do_symlink(struct ovl_fs *ofs,
264 struct inode *dir, struct dentry *dentry,
265 const char *oldname)
266{
267 int err = vfs_symlink(ovl_upper_mnt_idmap(ofs), dir, dentry, oldname);
268
269 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
270 return err;
271}
272
273static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name,
274 void *value, size_t size)
275{
276 int err, len;
277
278 WARN_ON(path->dentry->d_sb != path->mnt->mnt_sb);
279
280 err = vfs_getxattr(mnt_idmap(path->mnt), path->dentry,
281 name, value, size);
282 len = (value && err > 0) ? err : 0;
283
284 pr_debug("getxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
285 path->dentry, name, min(len, 48), value, size, err);
286 return err;
287}
288
289static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs,
290 struct dentry *upperdentry,
291 enum ovl_xattr ox, void *value,
292 size_t size)
293{
294 struct path upperpath = {
295 .dentry = upperdentry,
296 .mnt = ovl_upper_mnt(ofs),
297 };
298
299 return ovl_do_getxattr(&upperpath, ovl_xattr(ofs, ox), value, size);
300}
301
302static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs,
303 const struct path *path,
304 enum ovl_xattr ox, void *value,
305 size_t size)
306{
307 return ovl_do_getxattr(path, ovl_xattr(ofs, ox), value, size);
308}
309
310static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
311 const char *name, const void *value,
312 size_t size, int flags)
313{
314 int err = vfs_setxattr(ovl_upper_mnt_idmap(ofs), dentry, name,
315 value, size, flags);
316
317 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, %d) = %i\n",
318 dentry, name, min((int)size, 48), value, size, flags, err);
319 return err;
320}
321
322static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
323 enum ovl_xattr ox, const void *value,
324 size_t size)
325{
326 return ovl_do_setxattr(ofs, dentry, ovl_xattr(ofs, ox), value, size, 0);
327}
328
329static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
330 const char *name)
331{
332 int err = vfs_removexattr(ovl_upper_mnt_idmap(ofs), dentry, name);
333 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
334 return err;
335}
336
337static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
338 enum ovl_xattr ox)
339{
340 return ovl_do_removexattr(ofs, dentry, ovl_xattr(ofs, ox));
341}
342
343static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry,
344 const char *acl_name, struct posix_acl *acl)
345{
346 return vfs_set_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name, acl);
347}
348
349static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry,
350 const char *acl_name)
351{
352 return vfs_remove_acl(ovl_upper_mnt_idmap(ofs), dentry, acl_name);
353}
354
355static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir,
356 struct dentry *olddentry, struct inode *newdir,
357 struct dentry *newdentry, unsigned int flags)
358{
359 int err;
360 struct renamedata rd = {
361 .old_mnt_idmap = ovl_upper_mnt_idmap(ofs),
362 .old_dir = olddir,
363 .old_dentry = olddentry,
364 .new_mnt_idmap = ovl_upper_mnt_idmap(ofs),
365 .new_dir = newdir,
366 .new_dentry = newdentry,
367 .flags = flags,
368 };
369
370 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
371 err = vfs_rename(&rd);
372 if (err) {
373 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
374 olddentry, newdentry, err);
375 }
376 return err;
377}
378
379static inline int ovl_do_whiteout(struct ovl_fs *ofs,
380 struct inode *dir, struct dentry *dentry)
381{
382 int err = vfs_whiteout(ovl_upper_mnt_idmap(ofs), dir, dentry);
383 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
384 return err;
385}
386
387static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
388 struct dentry *dentry, umode_t mode)
389{
390 struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
391 struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path,
392 mode, O_LARGEFILE | O_WRONLY,
393 current_cred());
394 int err = PTR_ERR_OR_ZERO(file);
395
396 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
397 return file;
398}
399
400static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,
401 const char *name,
402 struct dentry *base, int len)
403{
404 return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len);
405}
406
407static inline bool ovl_open_flags_need_copy_up(int flags)
408{
409 if (!flags)
410 return false;
411
412 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
413}
414
415/* util.c */
416int ovl_get_write_access(struct dentry *dentry);
417void ovl_put_write_access(struct dentry *dentry);
418void ovl_start_write(struct dentry *dentry);
419void ovl_end_write(struct dentry *dentry);
420int ovl_want_write(struct dentry *dentry);
421void ovl_drop_write(struct dentry *dentry);
422struct dentry *ovl_workdir(struct dentry *dentry);
423const struct cred *ovl_override_creds(struct super_block *sb);
424void ovl_revert_creds(const struct cred *old_cred);
425
426static inline const struct cred *ovl_creds(struct super_block *sb)
427{
428 return OVL_FS(sb)->creator_cred;
429}
430
431int ovl_can_decode_fh(struct super_block *sb);
432struct dentry *ovl_indexdir(struct super_block *sb);
433bool ovl_index_all(struct super_block *sb);
434bool ovl_verify_lower(struct super_block *sb);
435struct ovl_path *ovl_stack_alloc(unsigned int n);
436void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n);
437void ovl_stack_put(struct ovl_path *stack, unsigned int n);
438void ovl_stack_free(struct ovl_path *stack, unsigned int n);
439struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
440void ovl_free_entry(struct ovl_entry *oe);
441bool ovl_dentry_remote(struct dentry *dentry);
442void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry);
443void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry,
444 struct ovl_entry *oe);
445void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry,
446 struct ovl_entry *oe, unsigned int mask);
447bool ovl_dentry_weird(struct dentry *dentry);
448enum ovl_path_type ovl_path_type(struct dentry *dentry);
449void ovl_path_upper(struct dentry *dentry, struct path *path);
450void ovl_path_lower(struct dentry *dentry, struct path *path);
451void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
452struct inode *ovl_i_path_real(struct inode *inode, struct path *path);
453enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
454enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path);
455struct dentry *ovl_dentry_upper(struct dentry *dentry);
456struct dentry *ovl_dentry_lower(struct dentry *dentry);
457struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
458int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath);
459const struct ovl_layer *ovl_i_layer_lower(struct inode *inode);
460const struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
461struct dentry *ovl_dentry_real(struct dentry *dentry);
462struct dentry *ovl_i_dentry_upper(struct inode *inode);
463struct inode *ovl_inode_upper(struct inode *inode);
464struct inode *ovl_inode_lower(struct inode *inode);
465struct inode *ovl_inode_lowerdata(struct inode *inode);
466struct inode *ovl_inode_real(struct inode *inode);
467struct inode *ovl_inode_realdata(struct inode *inode);
468const char *ovl_lowerdata_redirect(struct inode *inode);
469struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
470void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
471void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
472void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
473bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
474bool ovl_dentry_is_opaque(struct dentry *dentry);
475bool ovl_dentry_is_whiteout(struct dentry *dentry);
476void ovl_dentry_set_opaque(struct dentry *dentry);
477bool ovl_dentry_has_xwhiteouts(struct dentry *dentry);
478void ovl_dentry_set_xwhiteouts(struct dentry *dentry);
479void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs,
480 const struct ovl_layer *layer);
481bool ovl_dentry_has_upper_alias(struct dentry *dentry);
482void ovl_dentry_set_upper_alias(struct dentry *dentry);
483bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
484bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
485bool ovl_has_upperdata(struct inode *inode);
486void ovl_set_upperdata(struct inode *inode);
487const char *ovl_dentry_get_redirect(struct dentry *dentry);
488void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
489void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
490void ovl_dir_modified(struct dentry *dentry, bool impurity);
491u64 ovl_inode_version_get(struct inode *inode);
492bool ovl_is_whiteout(struct dentry *dentry);
493bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path);
494struct file *ovl_path_open(const struct path *path, int flags);
495int ovl_copy_up_start(struct dentry *dentry, int flags);
496void ovl_copy_up_end(struct dentry *dentry);
497bool ovl_already_copied_up(struct dentry *dentry, int flags);
498char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path,
499 enum ovl_xattr ox);
500bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path);
501bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path);
502bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs,
503 const struct path *upperpath);
504
505static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs,
506 struct dentry *upperdentry)
507{
508 struct path upperpath = {
509 .dentry = upperdentry,
510 .mnt = ovl_upper_mnt(ofs),
511 };
512 return ovl_path_is_whiteout(ofs, &upperpath);
513}
514
515static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs,
516 struct dentry *upperdentry)
517{
518 struct path upperpath = {
519 .dentry = upperdentry,
520 .mnt = ovl_upper_mnt(ofs),
521 };
522 return ovl_path_check_origin_xattr(ofs, &upperpath);
523}
524
525int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
526 enum ovl_xattr ox, const void *value, size_t size,
527 int xerr);
528int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
529bool ovl_inuse_trylock(struct dentry *dentry);
530void ovl_inuse_unlock(struct dentry *dentry);
531bool ovl_is_inuse(struct dentry *dentry);
532bool ovl_need_index(struct dentry *dentry);
533int ovl_nlink_start(struct dentry *dentry);
534void ovl_nlink_end(struct dentry *dentry);
535int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
536int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path,
537 struct ovl_metacopy *data);
538int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d,
539 struct ovl_metacopy *metacopy);
540bool ovl_is_metacopy_dentry(struct dentry *dentry);
541char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding);
542int ovl_ensure_verity_loaded(struct path *path);
543int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path,
544 u8 *digest_buf, int *buf_length);
545int ovl_validate_verity(struct ovl_fs *ofs,
546 struct path *metapath,
547 struct path *datapath);
548int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src,
549 struct ovl_metacopy *metacopy);
550int ovl_sync_status(struct ovl_fs *ofs);
551
552static inline void ovl_set_flag(unsigned long flag, struct inode *inode)
553{
554 set_bit(flag, &OVL_I(inode)->flags);
555}
556
557static inline void ovl_clear_flag(unsigned long flag, struct inode *inode)
558{
559 clear_bit(flag, &OVL_I(inode)->flags);
560}
561
562static inline bool ovl_test_flag(unsigned long flag, struct inode *inode)
563{
564 return test_bit(flag, &OVL_I(inode)->flags);
565}
566
567static inline bool ovl_is_impuredir(struct super_block *sb,
568 struct dentry *upperdentry)
569{
570 struct ovl_fs *ofs = OVL_FS(sb);
571 struct path upperpath = {
572 .dentry = upperdentry,
573 .mnt = ovl_upper_mnt(ofs),
574 };
575
576 return ovl_get_dir_xattr_val(ofs, &upperpath, OVL_XATTR_IMPURE) == 'y';
577}
578
579static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs,
580 const struct path *path)
581{
582 return ovl_get_dir_xattr_val(ofs, path, OVL_XATTR_OPAQUE);
583}
584
585static inline bool ovl_redirect_follow(struct ovl_fs *ofs)
586{
587 return ofs->config.redirect_mode != OVL_REDIRECT_NOFOLLOW;
588}
589
590static inline bool ovl_redirect_dir(struct ovl_fs *ofs)
591{
592 return ofs->config.redirect_mode == OVL_REDIRECT_ON;
593}
594
595static inline bool ovl_origin_uuid(struct ovl_fs *ofs)
596{
597 return ofs->config.uuid != OVL_UUID_OFF;
598}
599
600static inline bool ovl_has_fsid(struct ovl_fs *ofs)
601{
602 return ofs->config.uuid == OVL_UUID_ON ||
603 ofs->config.uuid == OVL_UUID_AUTO;
604}
605
606/*
607 * With xino=auto, we do best effort to keep all inodes on same st_dev and
608 * d_ino consistent with st_ino.
609 * With xino=on, we do the same effort but we warn if we failed.
610 */
611static inline bool ovl_xino_warn(struct ovl_fs *ofs)
612{
613 return ofs->config.xino == OVL_XINO_ON;
614}
615
616/*
617 * To avoid regressions in existing setups with overlay lower offline changes,
618 * we allow lower changes only if none of the new features are used.
619 */
620static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs)
621{
622 return (!ofs->config.index && !ofs->config.metacopy &&
623 !ovl_redirect_dir(ofs) && !ovl_xino_warn(ofs));
624}
625
626/* All layers on same fs? */
627static inline bool ovl_same_fs(struct ovl_fs *ofs)
628{
629 return ofs->xino_mode == 0;
630}
631
632/* All overlay inodes have same st_dev? */
633static inline bool ovl_same_dev(struct ovl_fs *ofs)
634{
635 return ofs->xino_mode >= 0;
636}
637
638static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs)
639{
640 return ovl_same_dev(ofs) ? ofs->xino_mode : 0;
641}
642
643static inline void ovl_inode_lock(struct inode *inode)
644{
645 mutex_lock(&OVL_I(inode)->lock);
646}
647
648static inline int ovl_inode_lock_interruptible(struct inode *inode)
649{
650 return mutex_lock_interruptible(&OVL_I(inode)->lock);
651}
652
653static inline void ovl_inode_unlock(struct inode *inode)
654{
655 mutex_unlock(&OVL_I(inode)->lock);
656}
657
658
659/* namei.c */
660int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
661
662static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
663{
664 if (fh_len < sizeof(struct ovl_fh))
665 return -EINVAL;
666
667 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
668}
669
670struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
671 struct vfsmount *mnt, bool connected);
672int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
673 struct dentry *upperdentry, struct ovl_path **stackp);
674int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
675 enum ovl_xattr ox, const struct ovl_fh *fh,
676 bool is_upper, bool set);
677int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry,
678 enum ovl_xattr ox, struct dentry *real,
679 bool is_upper, bool set);
680struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index,
681 bool connected);
682int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
683int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name);
684int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin,
685 struct qstr *name);
686struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
687struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
688 struct dentry *origin, bool verify);
689int ovl_path_next(int idx, struct dentry *dentry, struct path *path,
690 const struct ovl_layer **layer);
691int ovl_verify_lowerdata(struct dentry *dentry);
692struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
693 unsigned int flags);
694bool ovl_lower_positive(struct dentry *dentry);
695
696static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper,
697 const struct ovl_fh *fh, bool set)
698{
699 return ovl_verify_set_fh(ofs, upper, OVL_XATTR_ORIGIN, fh, false, set);
700}
701
702static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper,
703 struct dentry *origin, bool set)
704{
705 return ovl_verify_origin_xattr(ofs, upper, OVL_XATTR_ORIGIN, origin,
706 false, set);
707}
708
709static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
710 struct dentry *upper, bool set)
711{
712 return ovl_verify_origin_xattr(ofs, index, OVL_XATTR_UPPER, upper,
713 true, set);
714}
715
716/* readdir.c */
717extern const struct file_operations ovl_dir_operations;
718struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
719int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
720void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper,
721 struct list_head *list);
722void ovl_cache_free(struct list_head *list);
723void ovl_dir_cache_free(struct inode *inode);
724int ovl_check_d_type_supported(const struct path *realpath);
725int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir,
726 struct vfsmount *mnt, struct dentry *dentry, int level);
727int ovl_indexdir_cleanup(struct ovl_fs *ofs);
728
729/*
730 * Can we iterate real dir directly?
731 *
732 * Non-merge dir may contain whiteouts from a time it was a merge upper, before
733 * lower dir was removed under it and possibly before it was rotated from upper
734 * to lower layer.
735 */
736static inline bool ovl_dir_is_real(struct inode *dir)
737{
738 return !ovl_test_flag(OVL_WHITEOUTS, dir);
739}
740
741/* inode.c */
742int ovl_set_nlink_upper(struct dentry *dentry);
743int ovl_set_nlink_lower(struct dentry *dentry);
744unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry,
745 struct dentry *upperdentry,
746 unsigned int fallback);
747int ovl_permission(struct mnt_idmap *idmap, struct inode *inode,
748 int mask);
749
750#ifdef CONFIG_FS_POSIX_ACL
751struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap,
752 struct inode *inode, int type,
753 bool rcu, bool noperm);
754static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type,
755 bool rcu)
756{
757 return do_ovl_get_acl(&nop_mnt_idmap, inode, type, rcu, true);
758}
759static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap,
760 struct dentry *dentry, int type)
761{
762 return do_ovl_get_acl(idmap, d_inode(dentry), type, false, false);
763}
764int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
765 struct posix_acl *acl, int type);
766struct posix_acl *ovl_get_acl_path(const struct path *path,
767 const char *acl_name, bool noperm);
768#else
769#define ovl_get_inode_acl NULL
770#define ovl_get_acl NULL
771#define ovl_set_acl NULL
772static inline struct posix_acl *ovl_get_acl_path(const struct path *path,
773 const char *acl_name,
774 bool noperm)
775{
776 return NULL;
777}
778#endif
779
780int ovl_update_time(struct inode *inode, int flags);
781bool ovl_is_private_xattr(struct super_block *sb, const char *name);
782
783struct ovl_inode_params {
784 struct inode *newinode;
785 struct dentry *upperdentry;
786 struct ovl_entry *oe;
787 bool index;
788 char *redirect;
789 char *lowerdata_redirect;
790};
791void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
792 unsigned long ino, int fsid);
793struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
794struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
795 bool is_upper);
796bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
797struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
798struct inode *ovl_get_inode(struct super_block *sb,
799 struct ovl_inode_params *oip);
800void ovl_copyattr(struct inode *to);
801
802/* vfs inode flags copied from real to ovl inode */
803#define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE)
804/* vfs inode flags read from overlay.protattr xattr to ovl inode */
805#define OVL_PROT_I_FLAGS_MASK (S_APPEND | S_IMMUTABLE)
806
807/*
808 * fileattr flags copied from lower to upper inode on copy up.
809 * We cannot copy up immutable/append-only flags, because that would prevent
810 * linking temp inode to upper dir, so we store them in xattr instead.
811 */
812#define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL)
813#define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME)
814#define OVL_PROT_FS_FLAGS_MASK (FS_APPEND_FL | FS_IMMUTABLE_FL)
815#define OVL_PROT_FSX_FLAGS_MASK (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE)
816
817void ovl_check_protattr(struct inode *inode, struct dentry *upper);
818int ovl_set_protattr(struct inode *inode, struct dentry *upper,
819 struct fileattr *fa);
820
821static inline void ovl_copyflags(struct inode *from, struct inode *to)
822{
823 unsigned int mask = OVL_COPY_I_FLAGS_MASK;
824
825 inode_set_flags(to, from->i_flags & mask, mask);
826}
827
828/* dir.c */
829extern const struct inode_operations ovl_dir_inode_operations;
830int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
831 struct dentry *dentry);
832struct ovl_cattr {
833 dev_t rdev;
834 umode_t mode;
835 const char *link;
836 struct dentry *hardlink;
837};
838
839#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
840
841int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
842 struct dentry **newdentry, umode_t mode);
843struct dentry *ovl_create_real(struct ovl_fs *ofs,
844 struct inode *dir, struct dentry *newdentry,
845 struct ovl_cattr *attr);
846int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry);
847struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir);
848struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir,
849 struct ovl_cattr *attr);
850
851/* file.c */
852extern const struct file_operations ovl_file_operations;
853int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa);
854int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa);
855int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
856int ovl_fileattr_set(struct mnt_idmap *idmap,
857 struct dentry *dentry, struct fileattr *fa);
858struct ovl_file;
859struct ovl_file *ovl_file_alloc(struct file *realfile);
860void ovl_file_free(struct ovl_file *of);
861
862/* copy_up.c */
863int ovl_copy_up(struct dentry *dentry);
864int ovl_copy_up_with_data(struct dentry *dentry);
865int ovl_maybe_copy_up(struct dentry *dentry, int flags);
866int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new);
867int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat);
868struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct inode *realinode,
869 bool is_upper);
870struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin);
871int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh,
872 struct dentry *upper);
873
874/* export.c */
875extern const struct export_operations ovl_export_operations;
876extern const struct export_operations ovl_export_fid_operations;
877
878/* super.c */
879int ovl_fill_super(struct super_block *sb, struct fs_context *fc);
880
881/* Will this overlay be forced to mount/remount ro? */
882static inline bool ovl_force_readonly(struct ovl_fs *ofs)
883{
884 return (!ovl_upper_mnt(ofs) || !ofs->workdir);
885}
886
887/* xattr.c */
888
889const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs);
890int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
891 struct iattr *attr);
892int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
893 struct kstat *stat, u32 request_mask, unsigned int flags);
894ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
1/*
2 *
3 * Copyright (C) 2011 Novell Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 */
9
10#include <linux/kernel.h>
11#include <linux/uuid.h>
12#include "ovl_entry.h"
13
14enum ovl_path_type {
15 __OVL_PATH_UPPER = (1 << 0),
16 __OVL_PATH_MERGE = (1 << 1),
17 __OVL_PATH_ORIGIN = (1 << 2),
18};
19
20#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
21#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
22#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
23
24#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
25#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
26#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
27#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
28#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
29#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
30#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
31
32enum ovl_inode_flag {
33 /* Pure upper dir that may contain non pure upper entries */
34 OVL_IMPURE,
35 /* Non-merge dir that may contain whiteout entries */
36 OVL_WHITEOUTS,
37 OVL_INDEX,
38};
39
40enum ovl_entry_flag {
41 OVL_E_UPPER_ALIAS,
42 OVL_E_OPAQUE,
43 OVL_E_CONNECTED,
44};
45
46/*
47 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
48 * where:
49 * origin.fh - exported file handle of the lower file
50 * origin.uuid - uuid of the lower filesystem
51 */
52#define OVL_FH_VERSION 0
53#define OVL_FH_MAGIC 0xfb
54
55/* CPU byte order required for fid decoding: */
56#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
57#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
58/* Is the real inode encoded in fid an upper inode? */
59#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
60
61#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
62 OVL_FH_FLAG_PATH_UPPER)
63
64#if defined(__LITTLE_ENDIAN)
65#define OVL_FH_FLAG_CPU_ENDIAN 0
66#elif defined(__BIG_ENDIAN)
67#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
68#else
69#error Endianness not defined
70#endif
71
72/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
73#define OVL_FILEID 0xfb
74
75/* On-disk and in-memeory format for redirect by file handle */
76struct ovl_fh {
77 u8 version; /* 0 */
78 u8 magic; /* 0xfb */
79 u8 len; /* size of this header + size of fid */
80 u8 flags; /* OVL_FH_FLAG_* */
81 u8 type; /* fid_type of fid */
82 uuid_t uuid; /* uuid of filesystem */
83 u8 fid[0]; /* file identifier */
84} __packed;
85
86static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
87{
88 int err = vfs_rmdir(dir, dentry);
89 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
90 return err;
91}
92
93static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
94{
95 int err = vfs_unlink(dir, dentry, NULL);
96 pr_debug("unlink(%pd2) = %i\n", dentry, err);
97 return err;
98}
99
100static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
101 struct dentry *new_dentry, bool debug)
102{
103 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
104 if (debug) {
105 pr_debug("link(%pd2, %pd2) = %i\n",
106 old_dentry, new_dentry, err);
107 }
108 return err;
109}
110
111static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
112 umode_t mode, bool debug)
113{
114 int err = vfs_create(dir, dentry, mode, true);
115 if (debug)
116 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
117 return err;
118}
119
120static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
121 umode_t mode, bool debug)
122{
123 int err = vfs_mkdir(dir, dentry, mode);
124 if (debug)
125 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
126 return err;
127}
128
129static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
130 umode_t mode, dev_t dev, bool debug)
131{
132 int err = vfs_mknod(dir, dentry, mode, dev);
133 if (debug) {
134 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
135 dentry, mode, dev, err);
136 }
137 return err;
138}
139
140static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
141 const char *oldname, bool debug)
142{
143 int err = vfs_symlink(dir, dentry, oldname);
144 if (debug)
145 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
146 return err;
147}
148
149static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
150 const void *value, size_t size, int flags)
151{
152 int err = vfs_setxattr(dentry, name, value, size, flags);
153 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
154 dentry, name, (int) size, (char *) value, flags, err);
155 return err;
156}
157
158static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
159{
160 int err = vfs_removexattr(dentry, name);
161 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
162 return err;
163}
164
165static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
166 struct inode *newdir, struct dentry *newdentry,
167 unsigned int flags)
168{
169 int err;
170
171 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
172 olddentry, newdentry, flags);
173
174 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
175
176 if (err) {
177 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
178 olddentry, newdentry, err);
179 }
180 return err;
181}
182
183static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
184{
185 int err = vfs_whiteout(dir, dentry);
186 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
187 return err;
188}
189
190static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
191{
192 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
193 int err = PTR_ERR_OR_ZERO(ret);
194
195 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
196 return ret;
197}
198
199/* util.c */
200int ovl_want_write(struct dentry *dentry);
201void ovl_drop_write(struct dentry *dentry);
202struct dentry *ovl_workdir(struct dentry *dentry);
203const struct cred *ovl_override_creds(struct super_block *sb);
204struct super_block *ovl_same_sb(struct super_block *sb);
205int ovl_can_decode_fh(struct super_block *sb);
206struct dentry *ovl_indexdir(struct super_block *sb);
207bool ovl_index_all(struct super_block *sb);
208bool ovl_verify_lower(struct super_block *sb);
209struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
210bool ovl_dentry_remote(struct dentry *dentry);
211bool ovl_dentry_weird(struct dentry *dentry);
212enum ovl_path_type ovl_path_type(struct dentry *dentry);
213void ovl_path_upper(struct dentry *dentry, struct path *path);
214void ovl_path_lower(struct dentry *dentry, struct path *path);
215enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
216struct dentry *ovl_dentry_upper(struct dentry *dentry);
217struct dentry *ovl_dentry_lower(struct dentry *dentry);
218struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
219struct dentry *ovl_dentry_real(struct dentry *dentry);
220struct dentry *ovl_i_dentry_upper(struct inode *inode);
221struct inode *ovl_inode_upper(struct inode *inode);
222struct inode *ovl_inode_lower(struct inode *inode);
223struct inode *ovl_inode_real(struct inode *inode);
224struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
225void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
226void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
227void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
228bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
229bool ovl_dentry_is_opaque(struct dentry *dentry);
230bool ovl_dentry_is_whiteout(struct dentry *dentry);
231void ovl_dentry_set_opaque(struct dentry *dentry);
232bool ovl_dentry_has_upper_alias(struct dentry *dentry);
233void ovl_dentry_set_upper_alias(struct dentry *dentry);
234bool ovl_redirect_dir(struct super_block *sb);
235const char *ovl_dentry_get_redirect(struct dentry *dentry);
236void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
237void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
238 struct dentry *lowerdentry);
239void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
240void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
241u64 ovl_dentry_version_get(struct dentry *dentry);
242bool ovl_is_whiteout(struct dentry *dentry);
243struct file *ovl_path_open(struct path *path, int flags);
244int ovl_copy_up_start(struct dentry *dentry);
245void ovl_copy_up_end(struct dentry *dentry);
246bool ovl_check_origin_xattr(struct dentry *dentry);
247bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
248int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
249 const char *name, const void *value, size_t size,
250 int xerr);
251int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
252void ovl_set_flag(unsigned long flag, struct inode *inode);
253void ovl_clear_flag(unsigned long flag, struct inode *inode);
254bool ovl_test_flag(unsigned long flag, struct inode *inode);
255bool ovl_inuse_trylock(struct dentry *dentry);
256void ovl_inuse_unlock(struct dentry *dentry);
257bool ovl_need_index(struct dentry *dentry);
258int ovl_nlink_start(struct dentry *dentry, bool *locked);
259void ovl_nlink_end(struct dentry *dentry, bool locked);
260int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
261
262static inline bool ovl_is_impuredir(struct dentry *dentry)
263{
264 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
265}
266
267static inline unsigned int ovl_xino_bits(struct super_block *sb)
268{
269 struct ovl_fs *ofs = sb->s_fs_info;
270
271 return ofs->xino_bits;
272}
273
274
275/* namei.c */
276int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
277struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
278 bool connected);
279int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
280 struct dentry *upperdentry, struct ovl_path **stackp);
281int ovl_verify_set_fh(struct dentry *dentry, const char *name,
282 struct dentry *real, bool is_upper, bool set);
283struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
284int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
285int ovl_get_index_name(struct dentry *origin, struct qstr *name);
286struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
287struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
288 struct dentry *origin, bool verify);
289int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
290struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
291 unsigned int flags);
292bool ovl_lower_positive(struct dentry *dentry);
293
294static inline int ovl_verify_origin(struct dentry *upper,
295 struct dentry *origin, bool set)
296{
297 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
298}
299
300static inline int ovl_verify_upper(struct dentry *index,
301 struct dentry *upper, bool set)
302{
303 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
304}
305
306/* readdir.c */
307extern const struct file_operations ovl_dir_operations;
308int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
309void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
310void ovl_cache_free(struct list_head *list);
311void ovl_dir_cache_free(struct inode *inode);
312int ovl_check_d_type_supported(struct path *realpath);
313void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
314 struct dentry *dentry, int level);
315int ovl_indexdir_cleanup(struct ovl_fs *ofs);
316
317/* inode.c */
318int ovl_set_nlink_upper(struct dentry *dentry);
319int ovl_set_nlink_lower(struct dentry *dentry);
320unsigned int ovl_get_nlink(struct dentry *lowerdentry,
321 struct dentry *upperdentry,
322 unsigned int fallback);
323int ovl_setattr(struct dentry *dentry, struct iattr *attr);
324int ovl_getattr(const struct path *path, struct kstat *stat,
325 u32 request_mask, unsigned int flags);
326int ovl_permission(struct inode *inode, int mask);
327int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
328 const void *value, size_t size, int flags);
329int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
330 void *value, size_t size);
331ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
332struct posix_acl *ovl_get_acl(struct inode *inode, int type);
333int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
334int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
335bool ovl_is_private_xattr(const char *name);
336
337struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
338struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
339 bool is_upper);
340struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
341 struct ovl_path *lowerpath, struct dentry *index,
342 unsigned int numlower);
343static inline void ovl_copyattr(struct inode *from, struct inode *to)
344{
345 to->i_uid = from->i_uid;
346 to->i_gid = from->i_gid;
347 to->i_mode = from->i_mode;
348 to->i_atime = from->i_atime;
349 to->i_mtime = from->i_mtime;
350 to->i_ctime = from->i_ctime;
351}
352
353/* dir.c */
354extern const struct inode_operations ovl_dir_inode_operations;
355struct dentry *ovl_lookup_temp(struct dentry *workdir);
356int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
357 struct dentry *dentry);
358struct cattr {
359 dev_t rdev;
360 umode_t mode;
361 const char *link;
362};
363int ovl_create_real(struct inode *dir, struct dentry *newdentry,
364 struct cattr *attr,
365 struct dentry *hardlink, bool debug);
366int ovl_cleanup(struct inode *dir, struct dentry *dentry);
367
368/* copy_up.c */
369int ovl_copy_up(struct dentry *dentry);
370int ovl_copy_up_flags(struct dentry *dentry, int flags);
371int ovl_copy_xattr(struct dentry *old, struct dentry *new);
372int ovl_set_attr(struct dentry *upper, struct kstat *stat);
373struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
374int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
375 struct dentry *upper);
376
377/* export.c */
378extern const struct export_operations ovl_export_operations;