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ovl: encode lower file handles
[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,
43};
44
3a1e819b
AG		 45/*
46 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
47 * where:
48 * origin.fh - exported file handle of the lower file
49 * origin.uuid - uuid of the lower filesystem
50 */
51#define OVL_FH_VERSION 0
52#define OVL_FH_MAGIC 0xfb
53
54/* CPU byte order required for fid decoding: */
55#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
56#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
54fb347e
AG		 57/* Is the real inode encoded in fid an upper inode? */
58#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
3a1e819b 59
961af647
AG		 60#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
61 OVL_FH_FLAG_PATH_UPPER)
3a1e819b
AG		 62
63#if defined(__LITTLE_ENDIAN)
64#define OVL_FH_FLAG_CPU_ENDIAN 0
65#elif defined(__BIG_ENDIAN)
66#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
67#else
68#error Endianness not defined
69#endif
70
8ed5eec9
AG		 71/* The type returned by overlay exportfs ops when encoding an ovl_fh handle */
72#define OVL_FILEID 0xfb
73
3a1e819b
AG		 74/* On-disk and in-memeory format for redirect by file handle */
75struct ovl_fh {
76 u8 version; /* 0 */
77 u8 magic; /* 0xfb */
78 u8 len; /* size of this header + size of fid */
79 u8 flags; /* OVL_FH_FLAG_* */
80 u8 type; /* fid_type of fid */
01633fd2 81 uuid_t uuid; /* uuid of filesystem */
3a1e819b
AG		 82 u8 fid[0]; /* file identifier */
83} __packed;
e9be9d5e
MS		 84
85static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
86{
87 int err = vfs_rmdir(dir, dentry);
88 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
89 return err;
90}
91
92static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
93{
94 int err = vfs_unlink(dir, dentry, NULL);
95 pr_debug("unlink(%pd2) = %i\n", dentry, err);
96 return err;
97}
98
99static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
100 struct dentry *new_dentry, bool debug)
101{
102 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
103 if (debug) {
104 pr_debug("link(%pd2, %pd2) = %i\n",
105 old_dentry, new_dentry, err);
106 }
107 return err;
108}
109
110static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
111 umode_t mode, bool debug)
112{
113 int err = vfs_create(dir, dentry, mode, true);
114 if (debug)
115 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
116 return err;
117}
118
119static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
120 umode_t mode, bool debug)
121{
122 int err = vfs_mkdir(dir, dentry, mode);
123 if (debug)
124 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
125 return err;
126}
127
128static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
129 umode_t mode, dev_t dev, bool debug)
130{
131 int err = vfs_mknod(dir, dentry, mode, dev);
132 if (debug) {
133 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
134 dentry, mode, dev, err);
135 }
136 return err;
137}
138
139static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
140 const char *oldname, bool debug)
141{
142 int err = vfs_symlink(dir, dentry, oldname);
143 if (debug)
144 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
145 return err;
146}
147
148static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
149 const void *value, size_t size, int flags)
150{
151 int err = vfs_setxattr(dentry, name, value, size, flags);
152 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
153 dentry, name, (int) size, (char *) value, flags, err);
154 return err;
155}
156
157static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
158{
159 int err = vfs_removexattr(dentry, name);
160 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
161 return err;
162}
163
164static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
165 struct inode *newdir, struct dentry *newdentry,
166 unsigned int flags)
167{
168 int err;
169
2773bf00 170 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
e9be9d5e
MS		 171 olddentry, newdentry, flags);
172
173 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
174
175 if (err) {
2773bf00 176 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
e9be9d5e
MS		 177 olddentry, newdentry, err);
178 }
179 return err;
180}
181
182static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
183{
184 int err = vfs_whiteout(dir, dentry);
185 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
186 return err;
187}
188
e7f52429
AG		 189static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
190{
191 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
7879cb43 192 int err = PTR_ERR_OR_ZERO(ret);
e7f52429
AG		 193
194 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
195 return ret;
196}
197
bbb1e54d
MS		 198/* util.c */
199int ovl_want_write(struct dentry *dentry);
200void ovl_drop_write(struct dentry *dentry);
201struct dentry *ovl_workdir(struct dentry *dentry);
202const struct cred *ovl_override_creds(struct super_block *sb);
7bcd74b9 203struct super_block *ovl_same_sb(struct super_block *sb);
02bcd157
AG		 204bool ovl_can_decode_fh(struct super_block *sb);
205struct dentry *ovl_indexdir(struct super_block *sb);
f168f109
AG		 206bool ovl_index_all(struct super_block *sb);
207bool ovl_verify_lower(struct super_block *sb);
bbb1e54d
MS		 208struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
209bool ovl_dentry_remote(struct dentry *dentry);
210bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e 211enum ovl_path_type ovl_path_type(struct dentry *dentry);
e9be9d5e
MS		 212void ovl_path_upper(struct dentry *dentry, struct path *path);
213void ovl_path_lower(struct dentry *dentry, struct path *path);
214enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
215struct dentry *ovl_dentry_upper(struct dentry *dentry);
216struct dentry *ovl_dentry_lower(struct dentry *dentry);
217struct dentry *ovl_dentry_real(struct dentry *dentry);
1d88f183 218struct dentry *ovl_i_dentry_upper(struct inode *inode);
09d8b586
MS		 219struct inode *ovl_inode_upper(struct inode *inode);
220struct inode *ovl_inode_lower(struct inode *inode);
221struct inode *ovl_inode_real(struct inode *inode);
4edb83bb
MS		 222struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
223void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
c62520a8
AG		 224void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
225void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
226bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
e9be9d5e 227bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49 228bool ovl_dentry_is_whiteout(struct dentry *dentry);
5cf5b477 229void ovl_dentry_set_opaque(struct dentry *dentry);
55acc661
MS		 230bool ovl_dentry_has_upper_alias(struct dentry *dentry);
231void ovl_dentry_set_upper_alias(struct dentry *dentry);
a6c60655 232bool ovl_redirect_dir(struct super_block *sb);
a6c60655
MS		 233const char *ovl_dentry_get_redirect(struct dentry *dentry);
234void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
09d8b586
MS		 235void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
236 struct dentry *lowerdentry);
237void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
4edb83bb 238void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
bbb1e54d
MS		 239u64 ovl_dentry_version_get(struct dentry *dentry);
240bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e 241struct file *ovl_path_open(struct path *path, int flags);
39d3d60a
AG		 242int ovl_copy_up_start(struct dentry *dentry);
243void ovl_copy_up_end(struct dentry *dentry);
b79e05aa 244bool ovl_check_origin_xattr(struct dentry *dentry);
f3a15685
AG		 245bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
246int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
247 const char *name, const void *value, size_t size,
248 int xerr);
249int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
13c72075 250void ovl_set_flag(unsigned long flag, struct inode *inode);
4edb83bb 251void ovl_clear_flag(unsigned long flag, struct inode *inode);
13c72075 252bool ovl_test_flag(unsigned long flag, struct inode *inode);
ad0af710
AG		 253bool ovl_inuse_trylock(struct dentry *dentry);
254void ovl_inuse_unlock(struct dentry *dentry);
24b33ee1 255bool ovl_need_index(struct dentry *dentry);
5f8415d6
AG		 256int ovl_nlink_start(struct dentry *dentry, bool *locked);
257void ovl_nlink_end(struct dentry *dentry, bool locked);
5820dc08 258int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
f3a15685
AG		 259
260static inline bool ovl_is_impuredir(struct dentry *dentry)
261{
262 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
263}
264
e9be9d5e 265
bbb1e54d 266/* namei.c */
8556a420
AG		 267int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
268struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt);
05122443
AG		 269int ovl_verify_set_fh(struct dentry *dentry, const char *name,
270 struct dentry *real, bool is_upper, bool set);
1eff1a1d 271int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
359f392c 272int ovl_get_index_name(struct dentry *origin, struct qstr *name);
91ffe7be 273struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
bbb1e54d 274int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
1eff1a1d
AG		 275struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
276 unsigned int flags);
bbb1e54d 277bool ovl_lower_positive(struct dentry *dentry);
e9be9d5e 278
05122443
AG		 279static inline int ovl_verify_origin(struct dentry *upper,
280 struct dentry *origin, bool set)
281{
282 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
283}
284
ad1d615c
AG		 285static inline int ovl_verify_upper(struct dentry *index,
286 struct dentry *upper, bool set)
287{
288 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
289}
290
e9be9d5e
MS		 291/* readdir.c */
292extern const struct file_operations ovl_dir_operations;
293int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
294void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
295void ovl_cache_free(struct list_head *list);
4edb83bb 296void ovl_dir_cache_free(struct inode *inode);
45aebeaf 297int ovl_check_d_type_supported(struct path *realpath);
eea2fb48
MS		 298void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
299 struct dentry *dentry, int level);
1eff1a1d 300int ovl_indexdir_cleanup(struct ovl_fs *ofs);
e9be9d5e
MS		 301
302/* inode.c */
5f8415d6
AG		 303int ovl_set_nlink_upper(struct dentry *dentry);
304int ovl_set_nlink_lower(struct dentry *dentry);
caf70cb2
AG		 305unsigned int ovl_get_nlink(struct dentry *lowerdentry,
306 struct dentry *upperdentry,
307 unsigned int fallback);
e9be9d5e 308int ovl_setattr(struct dentry *dentry, struct iattr *attr);
5b712091
MS		 309int ovl_getattr(const struct path *path, struct kstat *stat,
310 u32 request_mask, unsigned int flags);
e9be9d5e 311int ovl_permission(struct inode *inode, int mask);
1d88f183
MS		 312int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
313 const void *value, size_t size, int flags);
314int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
0eb45fc3 315 void *value, size_t size);
e9be9d5e 316ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
39a25b2b 317struct posix_acl *ovl_get_acl(struct inode *inode, int type);
2d902671 318int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
d719e8f2 319int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
0956254a 320bool ovl_is_private_xattr(const char *name);
e9be9d5e 321
ca4c8a3a 322struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
0aceb53e
AG		 323struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
324 struct dentry *lowerdentry, struct dentry *index,
325 unsigned int numlower);
e9be9d5e
MS		 326static inline void ovl_copyattr(struct inode *from, struct inode *to)
327{
328 to->i_uid = from->i_uid;
329 to->i_gid = from->i_gid;
07a2daab 330 to->i_mode = from->i_mode;
d719e8f2
MS		 331 to->i_atime = from->i_atime;
332 to->i_mtime = from->i_mtime;
333 to->i_ctime = from->i_ctime;
e9be9d5e
MS		 334}
335
336/* dir.c */
337extern const struct inode_operations ovl_dir_inode_operations;
3d27573c 338struct dentry *ovl_lookup_temp(struct dentry *workdir);
e7dd0e71
AG		 339int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
340 struct dentry *dentry);
32a3d848
AV		 341struct cattr {
342 dev_t rdev;
343 umode_t mode;
344 const char *link;
345};
e9be9d5e 346int ovl_create_real(struct inode *dir, struct dentry *newdentry,
32a3d848 347 struct cattr *attr,
e9be9d5e 348 struct dentry *hardlink, bool debug);
415543d5 349int ovl_cleanup(struct inode *dir, struct dentry *dentry);
e9be9d5e
MS		 350
351/* copy_up.c */
352int ovl_copy_up(struct dentry *dentry);
9aba6521 353int ovl_copy_up_flags(struct dentry *dentry, int flags);
e9be9d5e
MS		 354int ovl_copy_xattr(struct dentry *old, struct dentry *new);
355int ovl_set_attr(struct dentry *upper, struct kstat *stat);
05122443 356struct ovl_fh *ovl_encode_fh(struct dentry *real, bool is_upper);
9678e630
AG		 357int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
358 struct dentry *upper);
8ed5eec9
AG		 359
360/* export.c */
361extern const struct export_operations ovl_export_operations;
Linux 6.x block layer and io_uring tree(s)