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ovl: verify index dir matches upper dir
[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>
e9be9d5e 12
e9be9d5e 13enum ovl_path_type {
38e813db
MS		 14 __OVL_PATH_UPPER = (1 << 0),
15 __OVL_PATH_MERGE = (1 << 1),
59548503 16 __OVL_PATH_ORIGIN = (1 << 2),
e9be9d5e
MS		 17};
18
1afaba1e
MS		 19#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
20#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
59548503 21#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
d837a49b 22
fe2b7595
AG		 23#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
24#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
02b69b28 25#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
3a1e819b 26#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
ee1d6d37 27#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
3a1e819b 28
13c72075
MS		 29enum ovl_flag {
30 OVL_IMPURE,
31};
32
3a1e819b
AG		 33/*
34 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
35 * where:
36 * origin.fh - exported file handle of the lower file
37 * origin.uuid - uuid of the lower filesystem
38 */
39#define OVL_FH_VERSION 0
40#define OVL_FH_MAGIC 0xfb
41
42/* CPU byte order required for fid decoding: */
43#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
44#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
54fb347e
AG		 45/* Is the real inode encoded in fid an upper inode? */
46#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
3a1e819b
AG		 47
48#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN)
49
50#if defined(__LITTLE_ENDIAN)
51#define OVL_FH_FLAG_CPU_ENDIAN 0
52#elif defined(__BIG_ENDIAN)
53#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
54#else
55#error Endianness not defined
56#endif
57
58/* On-disk and in-memeory format for redirect by file handle */
59struct ovl_fh {
60 u8 version; /* 0 */
61 u8 magic; /* 0xfb */
62 u8 len; /* size of this header + size of fid */
63 u8 flags; /* OVL_FH_FLAG_* */
64 u8 type; /* fid_type of fid */
01633fd2 65 uuid_t uuid; /* uuid of filesystem */
3a1e819b
AG		 66 u8 fid[0]; /* file identifier */
67} __packed;
e9be9d5e
MS		 68
69static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
70{
71 int err = vfs_rmdir(dir, dentry);
72 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
73 return err;
74}
75
76static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
77{
78 int err = vfs_unlink(dir, dentry, NULL);
79 pr_debug("unlink(%pd2) = %i\n", dentry, err);
80 return err;
81}
82
83static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
84 struct dentry *new_dentry, bool debug)
85{
86 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
87 if (debug) {
88 pr_debug("link(%pd2, %pd2) = %i\n",
89 old_dentry, new_dentry, err);
90 }
91 return err;
92}
93
94static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
95 umode_t mode, bool debug)
96{
97 int err = vfs_create(dir, dentry, mode, true);
98 if (debug)
99 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
100 return err;
101}
102
103static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
104 umode_t mode, bool debug)
105{
106 int err = vfs_mkdir(dir, dentry, mode);
107 if (debug)
108 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
109 return err;
110}
111
112static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
113 umode_t mode, dev_t dev, bool debug)
114{
115 int err = vfs_mknod(dir, dentry, mode, dev);
116 if (debug) {
117 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
118 dentry, mode, dev, err);
119 }
120 return err;
121}
122
123static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
124 const char *oldname, bool debug)
125{
126 int err = vfs_symlink(dir, dentry, oldname);
127 if (debug)
128 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
129 return err;
130}
131
132static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
133 const void *value, size_t size, int flags)
134{
135 int err = vfs_setxattr(dentry, name, value, size, flags);
136 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
137 dentry, name, (int) size, (char *) value, flags, err);
138 return err;
139}
140
141static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
142{
143 int err = vfs_removexattr(dentry, name);
144 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
145 return err;
146}
147
148static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
149 struct inode *newdir, struct dentry *newdentry,
150 unsigned int flags)
151{
152 int err;
153
2773bf00 154 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
e9be9d5e
MS		 155 olddentry, newdentry, flags);
156
157 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
158
159 if (err) {
2773bf00 160 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
e9be9d5e
MS		 161 olddentry, newdentry, err);
162 }
163 return err;
164}
165
166static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
167{
168 int err = vfs_whiteout(dir, dentry);
169 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
170 return err;
171}
172
e7f52429
AG		 173static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
174{
175 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
176 int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;
177
178 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
179 return ret;
180}
181
bbb1e54d
MS		 182/* util.c */
183int ovl_want_write(struct dentry *dentry);
184void ovl_drop_write(struct dentry *dentry);
185struct dentry *ovl_workdir(struct dentry *dentry);
186const struct cred *ovl_override_creds(struct super_block *sb);
7bcd74b9 187struct super_block *ovl_same_sb(struct super_block *sb);
02bcd157
AG		 188bool ovl_can_decode_fh(struct super_block *sb);
189struct dentry *ovl_indexdir(struct super_block *sb);
bbb1e54d
MS		 190struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
191bool ovl_dentry_remote(struct dentry *dentry);
192bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e 193enum ovl_path_type ovl_path_type(struct dentry *dentry);
e9be9d5e
MS		 194void ovl_path_upper(struct dentry *dentry, struct path *path);
195void ovl_path_lower(struct dentry *dentry, struct path *path);
196enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
197struct dentry *ovl_dentry_upper(struct dentry *dentry);
198struct dentry *ovl_dentry_lower(struct dentry *dentry);
199struct dentry *ovl_dentry_real(struct dentry *dentry);
09d8b586
MS		 200struct inode *ovl_inode_upper(struct inode *inode);
201struct inode *ovl_inode_lower(struct inode *inode);
202struct inode *ovl_inode_real(struct inode *inode);
e9be9d5e
MS		 203struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
204void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
e9be9d5e 205bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49 206bool ovl_dentry_is_whiteout(struct dentry *dentry);
5cf5b477 207void ovl_dentry_set_opaque(struct dentry *dentry);
a6c60655 208bool ovl_redirect_dir(struct super_block *sb);
a6c60655
MS		 209const char *ovl_dentry_get_redirect(struct dentry *dentry);
210void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
09d8b586
MS		 211void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
212 struct dentry *lowerdentry);
213void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
bbb1e54d
MS		 214void ovl_dentry_version_inc(struct dentry *dentry);
215u64 ovl_dentry_version_get(struct dentry *dentry);
216bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e 217struct file *ovl_path_open(struct path *path, int flags);
39d3d60a
AG		 218int ovl_copy_up_start(struct dentry *dentry);
219void ovl_copy_up_end(struct dentry *dentry);
f3a15685
AG		 220bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
221int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
222 const char *name, const void *value, size_t size,
223 int xerr);
224int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
13c72075
MS		 225void ovl_set_flag(unsigned long flag, struct inode *inode);
226bool ovl_test_flag(unsigned long flag, struct inode *inode);
ad0af710
AG		 227bool ovl_inuse_trylock(struct dentry *dentry);
228void ovl_inuse_unlock(struct dentry *dentry);
f3a15685
AG		 229
230static inline bool ovl_is_impuredir(struct dentry *dentry)
231{
232 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
233}
234
e9be9d5e 235
bbb1e54d 236/* namei.c */
8b88a2e6 237int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt,
54fb347e 238 struct dentry *origin, bool is_upper, bool set);
bbb1e54d
MS		 239int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
240struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
241bool ovl_lower_positive(struct dentry *dentry);
e9be9d5e
MS		 242
243/* readdir.c */
244extern const struct file_operations ovl_dir_operations;
245int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
246void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
247void ovl_cache_free(struct list_head *list);
45aebeaf 248int ovl_check_d_type_supported(struct path *realpath);
eea2fb48
MS		 249void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
250 struct dentry *dentry, int level);
e9be9d5e
MS		 251
252/* inode.c */
253int ovl_setattr(struct dentry *dentry, struct iattr *attr);
5b712091
MS		 254int ovl_getattr(const struct path *path, struct kstat *stat,
255 u32 request_mask, unsigned int flags);
e9be9d5e 256int ovl_permission(struct inode *inode, int mask);
0e585ccc
AG		 257int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
258 size_t size, int flags);
0eb45fc3
AG		 259int ovl_xattr_get(struct dentry *dentry, const char *name,
260 void *value, size_t size);
e9be9d5e 261ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
39a25b2b 262struct posix_acl *ovl_get_acl(struct inode *inode, int type);
2d902671 263int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
d719e8f2 264int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
0956254a 265bool ovl_is_private_xattr(const char *name);
e9be9d5e 266
ca4c8a3a 267struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
09d8b586 268struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry);
e9be9d5e
MS		 269static inline void ovl_copyattr(struct inode *from, struct inode *to)
270{
271 to->i_uid = from->i_uid;
272 to->i_gid = from->i_gid;
07a2daab 273 to->i_mode = from->i_mode;
d719e8f2
MS		 274 to->i_atime = from->i_atime;
275 to->i_mtime = from->i_mtime;
276 to->i_ctime = from->i_ctime;
e9be9d5e
MS		 277}
278
279/* dir.c */
280extern const struct inode_operations ovl_dir_inode_operations;
3d27573c 281struct dentry *ovl_lookup_temp(struct dentry *workdir);
32a3d848
AV		 282struct cattr {
283 dev_t rdev;
284 umode_t mode;
285 const char *link;
286};
e9be9d5e 287int ovl_create_real(struct inode *dir, struct dentry *newdentry,
32a3d848 288 struct cattr *attr,
e9be9d5e
MS		 289 struct dentry *hardlink, bool debug);
290void ovl_cleanup(struct inode *dir, struct dentry *dentry);
291
292/* copy_up.c */
293int ovl_copy_up(struct dentry *dentry);
9aba6521 294int ovl_copy_up_flags(struct dentry *dentry, int flags);
e9be9d5e
MS		 295int ovl_copy_xattr(struct dentry *old, struct dentry *new);
296int ovl_set_attr(struct dentry *upper, struct kstat *stat);
54fb347e 297struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper);
Linux 6.x block layer and io_uring tree(s)