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ovl: allocate anon bdev per unique lower fs
[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>
ee023c30 12#include "ovl_entry.h"
e9be9d5e 13
e9be9d5e 14enum ovl_path_type {
38e813db
MS		 15 __OVL_PATH_UPPER = (1 << 0),
16 __OVL_PATH_MERGE = (1 << 1),
59548503 17 __OVL_PATH_ORIGIN = (1 << 2),
e9be9d5e
MS		 18};
19
1afaba1e
MS		 20#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
21#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
59548503 22#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
d837a49b 23
fe2b7595
AG		 24#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
25#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
02b69b28 26#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
3a1e819b 27#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
ee1d6d37 28#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
5f8415d6 29#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
ad1d615c 30#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
3a1e819b 31
c62520a8 32enum ovl_inode_flag {
b79e05aa 33 /* Pure upper dir that may contain non pure upper entries */
13c72075 34 OVL_IMPURE,
b79e05aa
AG		 35 /* Non-merge dir that may contain whiteout entries */
36 OVL_WHITEOUTS,
359f392c 37 OVL_INDEX,
13c72075
MS		 38};
39
c62520a8
AG		 40enum ovl_entry_flag {
41 OVL_E_UPPER_ALIAS,
42 OVL_E_OPAQUE,
2ca3c148 43 OVL_E_CONNECTED,
c62520a8
AG		 44};
45
3a1e819b
AG		 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)
54fb347e
AG		 58/* Is the real inode encoded in fid an upper inode? */
59#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
3a1e819b 60
961af647
AG		 61#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
62 OVL_FH_FLAG_PATH_UPPER)
3a1e819b
AG		 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
8ed5eec9
AG		 72/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
73#define OVL_FILEID 0xfb
74
3a1e819b
AG		 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 */
01633fd2 82 uuid_t uuid; /* uuid of filesystem */
3a1e819b
AG		 83 u8 fid[0]; /* file identifier */
84} __packed;
e9be9d5e
MS		 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
2773bf00 171 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
e9be9d5e
MS		 172 olddentry, newdentry, flags);
173
174 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
175
176 if (err) {
2773bf00 177 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
e9be9d5e
MS		 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
e7f52429
AG		 190static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
191{
192 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
7879cb43 193 int err = PTR_ERR_OR_ZERO(ret);
e7f52429
AG		 194
195 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
196 return ret;
197}
198
bbb1e54d
MS		 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);
7bcd74b9 204struct super_block *ovl_same_sb(struct super_block *sb);
02bcd157
AG		 205bool ovl_can_decode_fh(struct super_block *sb);
206struct dentry *ovl_indexdir(struct super_block *sb);
f168f109
AG		 207bool ovl_index_all(struct super_block *sb);
208bool ovl_verify_lower(struct super_block *sb);
bbb1e54d
MS		 209struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
210bool ovl_dentry_remote(struct dentry *dentry);
211bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e 212enum ovl_path_type ovl_path_type(struct dentry *dentry);
e9be9d5e
MS		 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);
da309e8c 218struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
e9be9d5e 219struct dentry *ovl_dentry_real(struct dentry *dentry);
1d88f183 220struct dentry *ovl_i_dentry_upper(struct inode *inode);
09d8b586
MS		 221struct inode *ovl_inode_upper(struct inode *inode);
222struct inode *ovl_inode_lower(struct inode *inode);
223struct inode *ovl_inode_real(struct inode *inode);
4edb83bb
MS		 224struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
225void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
c62520a8
AG		 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);
e9be9d5e 229bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49 230bool ovl_dentry_is_whiteout(struct dentry *dentry);
5cf5b477 231void ovl_dentry_set_opaque(struct dentry *dentry);
55acc661
MS		 232bool ovl_dentry_has_upper_alias(struct dentry *dentry);
233void ovl_dentry_set_upper_alias(struct dentry *dentry);
a6c60655 234bool ovl_redirect_dir(struct super_block *sb);
a6c60655
MS		 235const char *ovl_dentry_get_redirect(struct dentry *dentry);
236void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
09d8b586
MS		 237void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
238 struct dentry *lowerdentry);
239void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
4edb83bb 240void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
bbb1e54d
MS		 241u64 ovl_dentry_version_get(struct dentry *dentry);
242bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e 243struct file *ovl_path_open(struct path *path, int flags);
39d3d60a
AG		 244int ovl_copy_up_start(struct dentry *dentry);
245void ovl_copy_up_end(struct dentry *dentry);
b79e05aa 246bool ovl_check_origin_xattr(struct dentry *dentry);
f3a15685
AG		 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);
13c72075 252void ovl_set_flag(unsigned long flag, struct inode *inode);
4edb83bb 253void ovl_clear_flag(unsigned long flag, struct inode *inode);
13c72075 254bool ovl_test_flag(unsigned long flag, struct inode *inode);
ad0af710
AG		 255bool ovl_inuse_trylock(struct dentry *dentry);
256void ovl_inuse_unlock(struct dentry *dentry);
24b33ee1 257bool ovl_need_index(struct dentry *dentry);
5f8415d6
AG		 258int ovl_nlink_start(struct dentry *dentry, bool *locked);
259void ovl_nlink_end(struct dentry *dentry, bool locked);
5820dc08 260int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
f3a15685
AG		 261
262static inline bool ovl_is_impuredir(struct dentry *dentry)
263{
264 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
265}
266
e9be9d5e 267
bbb1e54d 268/* namei.c */
8556a420 269int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
8a22efa1
AG		 270struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
271 bool connected);
272int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
f941866f 273 struct dentry *upperdentry, struct ovl_path **stackp);
05122443
AG		 274int ovl_verify_set_fh(struct dentry *dentry, const char *name,
275 struct dentry *real, bool is_upper, bool set);
3b0bfc6e 276struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
1eff1a1d 277int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
359f392c 278int ovl_get_index_name(struct dentry *origin, struct qstr *name);
91ffe7be 279struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
06170154
AG		 280struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
281 struct dentry *origin, bool verify);
bbb1e54d 282int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
1eff1a1d
AG		 283struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
284 unsigned int flags);
bbb1e54d 285bool ovl_lower_positive(struct dentry *dentry);
e9be9d5e 286
05122443
AG		 287static inline int ovl_verify_origin(struct dentry *upper,
288 struct dentry *origin, bool set)
289{
290 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
291}
292
ad1d615c
AG		 293static inline int ovl_verify_upper(struct dentry *index,
294 struct dentry *upper, bool set)
295{
296 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
297}
298
e9be9d5e
MS		 299/* readdir.c */
300extern const struct file_operations ovl_dir_operations;
301int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
302void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
303void ovl_cache_free(struct list_head *list);
4edb83bb 304void ovl_dir_cache_free(struct inode *inode);
45aebeaf 305int ovl_check_d_type_supported(struct path *realpath);
eea2fb48
MS		 306void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
307 struct dentry *dentry, int level);
1eff1a1d 308int ovl_indexdir_cleanup(struct ovl_fs *ofs);
e9be9d5e
MS		 309
310/* inode.c */
5f8415d6
AG		 311int ovl_set_nlink_upper(struct dentry *dentry);
312int ovl_set_nlink_lower(struct dentry *dentry);
caf70cb2
AG		 313unsigned int ovl_get_nlink(struct dentry *lowerdentry,
314 struct dentry *upperdentry,
315 unsigned int fallback);
e9be9d5e 316int ovl_setattr(struct dentry *dentry, struct iattr *attr);
5b712091
MS		 317int ovl_getattr(const struct path *path, struct kstat *stat,
318 u32 request_mask, unsigned int flags);
e9be9d5e 319int ovl_permission(struct inode *inode, int mask);
1d88f183
MS		 320int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
321 const void *value, size_t size, int flags);
322int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
0eb45fc3 323 void *value, size_t size);
e9be9d5e 324ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
39a25b2b 325struct posix_acl *ovl_get_acl(struct inode *inode, int type);
2d902671 326int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
d719e8f2 327int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
0956254a 328bool ovl_is_private_xattr(const char *name);
e9be9d5e 329
ca4c8a3a 330struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
4b91c30a
AG		 331struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
332 bool is_upper);
0aceb53e
AG		 333struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
334 struct dentry *lowerdentry, struct dentry *index,
335 unsigned int numlower);
e9be9d5e
MS		 336static inline void ovl_copyattr(struct inode *from, struct inode *to)
337{
338 to->i_uid = from->i_uid;
339 to->i_gid = from->i_gid;
07a2daab 340 to->i_mode = from->i_mode;
d719e8f2
MS		 341 to->i_atime = from->i_atime;
342 to->i_mtime = from->i_mtime;
343 to->i_ctime = from->i_ctime;
e9be9d5e
MS		 344}
345
346/* dir.c */
347extern const struct inode_operations ovl_dir_inode_operations;
3d27573c 348struct dentry *ovl_lookup_temp(struct dentry *workdir);
e7dd0e71
AG		 349int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
350 struct dentry *dentry);
32a3d848
AV		 351struct cattr {
352 dev_t rdev;
353 umode_t mode;
354 const char *link;
355};
e9be9d5e 356int ovl_create_real(struct inode *dir, struct dentry *newdentry,
32a3d848 357 struct cattr *attr,
e9be9d5e 358 struct dentry *hardlink, bool debug);
415543d5 359int ovl_cleanup(struct inode *dir, struct dentry *dentry);
e9be9d5e
MS		 360
361/* copy_up.c */
362int ovl_copy_up(struct dentry *dentry);
9aba6521 363int ovl_copy_up_flags(struct dentry *dentry, int flags);
e9be9d5e
MS		 364int ovl_copy_xattr(struct dentry *old, struct dentry *new);
365int ovl_set_attr(struct dentry *upper, struct kstat *stat);
5b2cccd3 366struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
9678e630
AG		 367int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
368 struct dentry *upper);
8ed5eec9
AG		 369
370/* export.c */
371extern const struct export_operations ovl_export_operations;
Linux 6.x block layer and io_uring tree(s)