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ovl: Copy up meta inode data from lowest data inode
[linux-block.git] / fs / overlayfs / overlayfs.h
CommitLineData
e9be9d5e
MS		 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>
3a1e819b 11#include <linux/uuid.h>
46e5d0a3 12#include <linux/fs.h>
ee023c30 13#include "ovl_entry.h"
e9be9d5e 14
e9be9d5e 15enum ovl_path_type {
38e813db
MS		 16 __OVL_PATH_UPPER = (1 << 0),
17 __OVL_PATH_MERGE = (1 << 1),
59548503 18 __OVL_PATH_ORIGIN = (1 << 2),
e9be9d5e
MS		 19};
20
1afaba1e
MS		 21#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
22#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
59548503 23#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
d837a49b 24
fe2b7595
AG		 25#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
26#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
02b69b28 27#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
3a1e819b 28#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
ee1d6d37 29#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
5f8415d6 30#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
ad1d615c 31#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
0c288874 32#define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
3a1e819b 33
c62520a8 34enum ovl_inode_flag {
b79e05aa 35 /* Pure upper dir that may contain non pure upper entries */
13c72075 36 OVL_IMPURE,
b79e05aa
AG		 37 /* Non-merge dir that may contain whiteout entries */
38 OVL_WHITEOUTS,
359f392c 39 OVL_INDEX,
0c288874 40 OVL_UPPERDATA,
13c72075
MS		 41};
42
c62520a8
AG		 43enum ovl_entry_flag {
44 OVL_E_UPPER_ALIAS,
45 OVL_E_OPAQUE,
2ca3c148 46 OVL_E_CONNECTED,
c62520a8
AG		 47};
48
3a1e819b
AG		 49/*
50 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
51 * where:
52 * origin.fh - exported file handle of the lower file
53 * origin.uuid - uuid of the lower filesystem
54 */
55#define OVL_FH_VERSION 0
56#define OVL_FH_MAGIC 0xfb
57
58/* CPU byte order required for fid decoding: */
59#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
60#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
54fb347e
AG		 61/* Is the real inode encoded in fid an upper inode? */
62#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
3a1e819b 63
961af647
AG		 64#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
65 OVL_FH_FLAG_PATH_UPPER)
3a1e819b
AG		 66
67#if defined(__LITTLE_ENDIAN)
68#define OVL_FH_FLAG_CPU_ENDIAN 0
69#elif defined(__BIG_ENDIAN)
70#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
71#else
72#error Endianness not defined
73#endif
74
8ed5eec9
AG		 75/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
76#define OVL_FILEID 0xfb
77
3a1e819b
AG		 78/* On-disk and in-memeory format for redirect by file handle */
79struct ovl_fh {
80 u8 version; /* 0 */
81 u8 magic; /* 0xfb */
82 u8 len; /* size of this header + size of fid */
83 u8 flags; /* OVL_FH_FLAG_* */
84 u8 type; /* fid_type of fid */
01633fd2 85 uuid_t uuid; /* uuid of filesystem */
3a1e819b
AG		 86 u8 fid[0]; /* file identifier */
87} __packed;
e9be9d5e
MS		 88
89static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
90{
91 int err = vfs_rmdir(dir, dentry);
6cf00764 92
e9be9d5e
MS		 93 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
94 return err;
95}
96
97static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
98{
99 int err = vfs_unlink(dir, dentry, NULL);
6cf00764 100
e9be9d5e
MS		 101 pr_debug("unlink(%pd2) = %i\n", dentry, err);
102 return err;
103}
104
105static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
6cf00764 106 struct dentry *new_dentry)
e9be9d5e
MS		 107{
108 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
6cf00764
AG		 109
110 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
e9be9d5e
MS		 111 return err;
112}
113
114static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
6cf00764 115 umode_t mode)
e9be9d5e
MS		 116{
117 int err = vfs_create(dir, dentry, mode, true);
6cf00764
AG		 118
119 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
e9be9d5e
MS		 120 return err;
121}
122
123static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
6cf00764 124 umode_t mode)
e9be9d5e
MS		 125{
126 int err = vfs_mkdir(dir, dentry, mode);
6cf00764 127 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
e9be9d5e
MS		 128 return err;
129}
130
131static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
6cf00764 132 umode_t mode, dev_t dev)
e9be9d5e
MS		 133{
134 int err = vfs_mknod(dir, dentry, mode, dev);
6cf00764
AG		 135
136 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
e9be9d5e
MS		 137 return err;
138}
139
140static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
6cf00764 141 const char *oldname)
e9be9d5e
MS		 142{
143 int err = vfs_symlink(dir, dentry, oldname);
6cf00764
AG		 144
145 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
e9be9d5e
MS		 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
6cf00764 171 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
e9be9d5e 172 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
e9be9d5e 173 if (err) {
2773bf00 174 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
e9be9d5e
MS		 175 olddentry, newdentry, err);
176 }
177 return err;
178}
179
180static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
181{
182 int err = vfs_whiteout(dir, dentry);
183 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
184 return err;
185}
186
e7f52429
AG		 187static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
188{
189 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
7879cb43 190 int err = PTR_ERR_OR_ZERO(ret);
e7f52429
AG		 191
192 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
193 return ret;
194}
195
0c288874
VG		 196static inline bool ovl_open_flags_need_copy_up(int flags)
197{
198 if (!flags)
199 return false;
200
201 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
202}
203
bbb1e54d
MS		 204/* util.c */
205int ovl_want_write(struct dentry *dentry);
206void ovl_drop_write(struct dentry *dentry);
207struct dentry *ovl_workdir(struct dentry *dentry);
208const struct cred *ovl_override_creds(struct super_block *sb);
7bcd74b9 209struct super_block *ovl_same_sb(struct super_block *sb);
e487d889 210int ovl_can_decode_fh(struct super_block *sb);
02bcd157 211struct dentry *ovl_indexdir(struct super_block *sb);
f168f109
AG		 212bool ovl_index_all(struct super_block *sb);
213bool ovl_verify_lower(struct super_block *sb);
bbb1e54d
MS		 214struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
215bool ovl_dentry_remote(struct dentry *dentry);
216bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e 217enum ovl_path_type ovl_path_type(struct dentry *dentry);
e9be9d5e
MS		 218void ovl_path_upper(struct dentry *dentry, struct path *path);
219void ovl_path_lower(struct dentry *dentry, struct path *path);
4f93b426 220void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
e9be9d5e
MS		 221enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
222struct dentry *ovl_dentry_upper(struct dentry *dentry);
223struct dentry *ovl_dentry_lower(struct dentry *dentry);
da309e8c 224struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
e9be9d5e 225struct dentry *ovl_dentry_real(struct dentry *dentry);
1d88f183 226struct dentry *ovl_i_dentry_upper(struct inode *inode);
09d8b586
MS		 227struct inode *ovl_inode_upper(struct inode *inode);
228struct inode *ovl_inode_lower(struct inode *inode);
229struct inode *ovl_inode_real(struct inode *inode);
4edb83bb
MS		 230struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
231void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
c62520a8
AG		 232void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
233void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
234bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
e9be9d5e 235bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49 236bool ovl_dentry_is_whiteout(struct dentry *dentry);
5cf5b477 237void ovl_dentry_set_opaque(struct dentry *dentry);
55acc661
MS		 238bool ovl_dentry_has_upper_alias(struct dentry *dentry);
239void ovl_dentry_set_upper_alias(struct dentry *dentry);
0c288874
VG		 240bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
241bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
242bool ovl_has_upperdata(struct inode *inode);
243void ovl_set_upperdata(struct inode *inode);
a6c60655 244bool ovl_redirect_dir(struct super_block *sb);
a6c60655
MS		 245const char *ovl_dentry_get_redirect(struct dentry *dentry);
246void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
09d8b586
MS		 247void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
248 struct dentry *lowerdentry);
249void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
d9854c87 250void ovl_dir_modified(struct dentry *dentry, bool impurity);
bbb1e54d
MS		 251u64 ovl_dentry_version_get(struct dentry *dentry);
252bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e 253struct file *ovl_path_open(struct path *path, int flags);
0c288874 254int ovl_copy_up_start(struct dentry *dentry, int flags);
39d3d60a 255void ovl_copy_up_end(struct dentry *dentry);
0c288874 256bool ovl_already_copied_up(struct dentry *dentry, int flags);
b79e05aa 257bool ovl_check_origin_xattr(struct dentry *dentry);
f3a15685
AG		 258bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
259int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
260 const char *name, const void *value, size_t size,
261 int xerr);
262int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
13c72075 263void ovl_set_flag(unsigned long flag, struct inode *inode);
4edb83bb 264void ovl_clear_flag(unsigned long flag, struct inode *inode);
13c72075 265bool ovl_test_flag(unsigned long flag, struct inode *inode);
ad0af710
AG		 266bool ovl_inuse_trylock(struct dentry *dentry);
267void ovl_inuse_unlock(struct dentry *dentry);
24b33ee1 268bool ovl_need_index(struct dentry *dentry);
5f8415d6
AG		 269int ovl_nlink_start(struct dentry *dentry, bool *locked);
270void ovl_nlink_end(struct dentry *dentry, bool locked);
5820dc08 271int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
9d3dfea3 272int ovl_check_metacopy_xattr(struct dentry *dentry);
f3a15685
AG		 273
274static inline bool ovl_is_impuredir(struct dentry *dentry)
275{
276 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
277}
278
e487d889
AG		 279static inline unsigned int ovl_xino_bits(struct super_block *sb)
280{
281 struct ovl_fs *ofs = sb->s_fs_info;
282
283 return ofs->xino_bits;
284}
285
e9be9d5e 286
bbb1e54d 287/* namei.c */
8556a420 288int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
8a22efa1
AG		 289struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
290 bool connected);
291int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
f941866f 292 struct dentry *upperdentry, struct ovl_path **stackp);
05122443
AG		 293int ovl_verify_set_fh(struct dentry *dentry, const char *name,
294 struct dentry *real, bool is_upper, bool set);
3b0bfc6e 295struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
1eff1a1d 296int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
359f392c 297int ovl_get_index_name(struct dentry *origin, struct qstr *name);
91ffe7be 298struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
06170154
AG		 299struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
300 struct dentry *origin, bool verify);
bbb1e54d 301int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
1eff1a1d
AG		 302struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
303 unsigned int flags);
bbb1e54d 304bool ovl_lower_positive(struct dentry *dentry);
e9be9d5e 305
05122443
AG		 306static inline int ovl_verify_origin(struct dentry *upper,
307 struct dentry *origin, bool set)
308{
309 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
310}
311
ad1d615c
AG		 312static inline int ovl_verify_upper(struct dentry *index,
313 struct dentry *upper, bool set)
314{
315 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
316}
317
e9be9d5e
MS		 318/* readdir.c */
319extern const struct file_operations ovl_dir_operations;
320int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
321void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
322void ovl_cache_free(struct list_head *list);
4edb83bb 323void ovl_dir_cache_free(struct inode *inode);
45aebeaf 324int ovl_check_d_type_supported(struct path *realpath);
eea2fb48
MS		 325void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
326 struct dentry *dentry, int level);
1eff1a1d 327int ovl_indexdir_cleanup(struct ovl_fs *ofs);
e9be9d5e
MS		 328
329/* inode.c */
5f8415d6
AG		 330int ovl_set_nlink_upper(struct dentry *dentry);
331int ovl_set_nlink_lower(struct dentry *dentry);
caf70cb2
AG		 332unsigned int ovl_get_nlink(struct dentry *lowerdentry,
333 struct dentry *upperdentry,
334 unsigned int fallback);
e9be9d5e 335int ovl_setattr(struct dentry *dentry, struct iattr *attr);
5b712091
MS		 336int ovl_getattr(const struct path *path, struct kstat *stat,
337 u32 request_mask, unsigned int flags);
e9be9d5e 338int ovl_permission(struct inode *inode, int mask);
1d88f183
MS		 339int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
340 const void *value, size_t size, int flags);
341int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
0eb45fc3 342 void *value, size_t size);
e9be9d5e 343ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
39a25b2b 344struct posix_acl *ovl_get_acl(struct inode *inode, int type);
95582b00 345int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
0956254a 346bool ovl_is_private_xattr(const char *name);
e9be9d5e 347
ac6a52eb 348struct ovl_inode_params {
01b39dcc 349 struct inode *newinode;
ac6a52eb
VG		 350 struct dentry *upperdentry;
351 struct ovl_path *lowerpath;
352 struct dentry *index;
353 unsigned int numlower;
9cec54c8 354 char *redirect;
ac6a52eb 355};
ca4c8a3a 356struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
4b91c30a
AG		 357struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
358 bool is_upper);
ac6a52eb
VG		 359struct inode *ovl_get_inode(struct super_block *sb,
360 struct ovl_inode_params *oip);
e9be9d5e
MS		 361static inline void ovl_copyattr(struct inode *from, struct inode *to)
362{
363 to->i_uid = from->i_uid;
364 to->i_gid = from->i_gid;
07a2daab 365 to->i_mode = from->i_mode;
d719e8f2
MS		 366 to->i_atime = from->i_atime;
367 to->i_mtime = from->i_mtime;
368 to->i_ctime = from->i_ctime;
46e5d0a3 369 i_size_write(to, i_size_read(from));
e9be9d5e
MS		 370}
371
4f357295
MS		 372static inline void ovl_copyflags(struct inode *from, struct inode *to)
373{
374 unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
375
376 inode_set_flags(to, from->i_flags & mask, mask);
377}
378
e9be9d5e
MS		 379/* dir.c */
380extern const struct inode_operations ovl_dir_inode_operations;
e7dd0e71
AG		 381int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
382 struct dentry *dentry);
471ec5dc 383struct ovl_cattr {
32a3d848
AV		 384 dev_t rdev;
385 umode_t mode;
386 const char *link;
471ec5dc 387 struct dentry *hardlink;
32a3d848 388};
471ec5dc
AG		 389
390#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
391
95a1c815
MS		 392struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
393 struct ovl_cattr *attr);
415543d5 394int ovl_cleanup(struct inode *dir, struct dentry *dentry);
137ec526 395struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
e9be9d5e 396
d1d04ef8
MS		 397/* file.c */
398extern const struct file_operations ovl_file_operations;
399
e9be9d5e
MS		 400/* copy_up.c */
401int ovl_copy_up(struct dentry *dentry);
9aba6521 402int ovl_copy_up_flags(struct dentry *dentry, int flags);
d6eac039 403int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
e9be9d5e
MS		 404int ovl_copy_xattr(struct dentry *old, struct dentry *new);
405int ovl_set_attr(struct dentry *upper, struct kstat *stat);
5b2cccd3 406struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
9678e630
AG		 407int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
408 struct dentry *upper);
8ed5eec9
AG		 409
410/* export.c */
411extern const struct export_operations ovl_export_operations;
Linux 6.x block layer and io_uring tree(s)