ovl: whiteout orphan index entries on mount
[linux-block.git] / fs / overlayfs / overlayfs.h
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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 {
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15 __OVL_PATH_UPPER = (1 << 0),
16 __OVL_PATH_MERGE = (1 << 1),
59548503 17 __OVL_PATH_ORIGIN = (1 << 2),
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18};
19
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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
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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
13c72075 32enum ovl_flag {
b79e05aa 33 /* Pure upper dir that may contain non pure upper entries */
13c72075 34 OVL_IMPURE,
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35 /* Non-merge dir that may contain whiteout entries */
36 OVL_WHITEOUTS,
359f392c 37 OVL_INDEX,
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38};
39
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40/*
41 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
42 * where:
43 * origin.fh - exported file handle of the lower file
44 * origin.uuid - uuid of the lower filesystem
45 */
46#define OVL_FH_VERSION 0
47#define OVL_FH_MAGIC 0xfb
48
49/* CPU byte order required for fid decoding: */
50#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
51#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
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52/* Is the real inode encoded in fid an upper inode? */
53#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
3a1e819b 54
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55#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
56 OVL_FH_FLAG_PATH_UPPER)
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57
58#if defined(__LITTLE_ENDIAN)
59#define OVL_FH_FLAG_CPU_ENDIAN 0
60#elif defined(__BIG_ENDIAN)
61#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
62#else
63#error Endianness not defined
64#endif
65
66/* On-disk and in-memeory format for redirect by file handle */
67struct ovl_fh {
68 u8 version; /* 0 */
69 u8 magic; /* 0xfb */
70 u8 len; /* size of this header + size of fid */
71 u8 flags; /* OVL_FH_FLAG_* */
72 u8 type; /* fid_type of fid */
01633fd2 73 uuid_t uuid; /* uuid of filesystem */
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74 u8 fid[0]; /* file identifier */
75} __packed;
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76
77static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
78{
79 int err = vfs_rmdir(dir, dentry);
80 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
81 return err;
82}
83
84static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
85{
86 int err = vfs_unlink(dir, dentry, NULL);
87 pr_debug("unlink(%pd2) = %i\n", dentry, err);
88 return err;
89}
90
91static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
92 struct dentry *new_dentry, bool debug)
93{
94 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
95 if (debug) {
96 pr_debug("link(%pd2, %pd2) = %i\n",
97 old_dentry, new_dentry, err);
98 }
99 return err;
100}
101
102static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
103 umode_t mode, bool debug)
104{
105 int err = vfs_create(dir, dentry, mode, true);
106 if (debug)
107 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
108 return err;
109}
110
111static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
112 umode_t mode, bool debug)
113{
114 int err = vfs_mkdir(dir, dentry, mode);
115 if (debug)
116 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
117 return err;
118}
119
120static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
121 umode_t mode, dev_t dev, bool debug)
122{
123 int err = vfs_mknod(dir, dentry, mode, dev);
124 if (debug) {
125 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
126 dentry, mode, dev, err);
127 }
128 return err;
129}
130
131static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
132 const char *oldname, bool debug)
133{
134 int err = vfs_symlink(dir, dentry, oldname);
135 if (debug)
136 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
137 return err;
138}
139
140static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
141 const void *value, size_t size, int flags)
142{
143 int err = vfs_setxattr(dentry, name, value, size, flags);
144 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
145 dentry, name, (int) size, (char *) value, flags, err);
146 return err;
147}
148
149static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
150{
151 int err = vfs_removexattr(dentry, name);
152 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
153 return err;
154}
155
156static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
157 struct inode *newdir, struct dentry *newdentry,
158 unsigned int flags)
159{
160 int err;
161
2773bf00 162 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
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163 olddentry, newdentry, flags);
164
165 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
166
167 if (err) {
2773bf00 168 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
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169 olddentry, newdentry, err);
170 }
171 return err;
172}
173
174static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
175{
176 int err = vfs_whiteout(dir, dentry);
177 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
178 return err;
179}
180
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181static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
182{
183 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
7879cb43 184 int err = PTR_ERR_OR_ZERO(ret);
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185
186 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
187 return ret;
188}
189
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190/* util.c */
191int ovl_want_write(struct dentry *dentry);
192void ovl_drop_write(struct dentry *dentry);
193struct dentry *ovl_workdir(struct dentry *dentry);
194const struct cred *ovl_override_creds(struct super_block *sb);
7bcd74b9 195struct super_block *ovl_same_sb(struct super_block *sb);
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196bool ovl_can_decode_fh(struct super_block *sb);
197struct dentry *ovl_indexdir(struct super_block *sb);
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198bool ovl_index_all(struct super_block *sb);
199bool ovl_verify_lower(struct super_block *sb);
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200struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
201bool ovl_dentry_remote(struct dentry *dentry);
202bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e 203enum ovl_path_type ovl_path_type(struct dentry *dentry);
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204void ovl_path_upper(struct dentry *dentry, struct path *path);
205void ovl_path_lower(struct dentry *dentry, struct path *path);
206enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
207struct dentry *ovl_dentry_upper(struct dentry *dentry);
208struct dentry *ovl_dentry_lower(struct dentry *dentry);
209struct dentry *ovl_dentry_real(struct dentry *dentry);
1d88f183 210struct dentry *ovl_i_dentry_upper(struct inode *inode);
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211struct inode *ovl_inode_upper(struct inode *inode);
212struct inode *ovl_inode_lower(struct inode *inode);
213struct inode *ovl_inode_real(struct inode *inode);
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214struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
215void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
e9be9d5e 216bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49 217bool ovl_dentry_is_whiteout(struct dentry *dentry);
5cf5b477 218void ovl_dentry_set_opaque(struct dentry *dentry);
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219bool ovl_dentry_has_upper_alias(struct dentry *dentry);
220void ovl_dentry_set_upper_alias(struct dentry *dentry);
a6c60655 221bool ovl_redirect_dir(struct super_block *sb);
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222const char *ovl_dentry_get_redirect(struct dentry *dentry);
223void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
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224void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
225 struct dentry *lowerdentry);
226void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
4edb83bb 227void ovl_dentry_version_inc(struct dentry *dentry, bool impurity);
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228u64 ovl_dentry_version_get(struct dentry *dentry);
229bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e 230struct file *ovl_path_open(struct path *path, int flags);
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231int ovl_copy_up_start(struct dentry *dentry);
232void ovl_copy_up_end(struct dentry *dentry);
b79e05aa 233bool ovl_check_origin_xattr(struct dentry *dentry);
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234bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
235int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
236 const char *name, const void *value, size_t size,
237 int xerr);
238int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
13c72075 239void ovl_set_flag(unsigned long flag, struct inode *inode);
4edb83bb 240void ovl_clear_flag(unsigned long flag, struct inode *inode);
13c72075 241bool ovl_test_flag(unsigned long flag, struct inode *inode);
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242bool ovl_inuse_trylock(struct dentry *dentry);
243void ovl_inuse_unlock(struct dentry *dentry);
24b33ee1 244bool ovl_need_index(struct dentry *dentry);
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245int ovl_nlink_start(struct dentry *dentry, bool *locked);
246void ovl_nlink_end(struct dentry *dentry, bool locked);
5820dc08 247int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
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248
249static inline bool ovl_is_impuredir(struct dentry *dentry)
250{
251 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
252}
253
e9be9d5e 254
bbb1e54d 255/* namei.c */
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256int ovl_verify_set_fh(struct dentry *dentry, const char *name,
257 struct dentry *real, bool is_upper, bool set);
1eff1a1d 258int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
359f392c 259int ovl_get_index_name(struct dentry *origin, struct qstr *name);
bbb1e54d 260int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
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261struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
262 unsigned int flags);
bbb1e54d 263bool ovl_lower_positive(struct dentry *dentry);
e9be9d5e 264
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265static inline int ovl_verify_origin(struct dentry *upper,
266 struct dentry *origin, bool set)
267{
268 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
269}
270
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271static inline int ovl_verify_upper(struct dentry *index,
272 struct dentry *upper, bool set)
273{
274 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
275}
276
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277/* readdir.c */
278extern const struct file_operations ovl_dir_operations;
279int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
280void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
281void ovl_cache_free(struct list_head *list);
4edb83bb 282void ovl_dir_cache_free(struct inode *inode);
45aebeaf 283int ovl_check_d_type_supported(struct path *realpath);
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284void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
285 struct dentry *dentry, int level);
1eff1a1d 286int ovl_indexdir_cleanup(struct ovl_fs *ofs);
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287
288/* inode.c */
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289int ovl_set_nlink_upper(struct dentry *dentry);
290int ovl_set_nlink_lower(struct dentry *dentry);
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291unsigned int ovl_get_nlink(struct dentry *lowerdentry,
292 struct dentry *upperdentry,
293 unsigned int fallback);
e9be9d5e 294int ovl_setattr(struct dentry *dentry, struct iattr *attr);
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295int ovl_getattr(const struct path *path, struct kstat *stat,
296 u32 request_mask, unsigned int flags);
e9be9d5e 297int ovl_permission(struct inode *inode, int mask);
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298int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
299 const void *value, size_t size, int flags);
300int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
0eb45fc3 301 void *value, size_t size);
e9be9d5e 302ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
39a25b2b 303struct posix_acl *ovl_get_acl(struct inode *inode, int type);
2d902671 304int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
d719e8f2 305int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
0956254a 306bool ovl_is_private_xattr(const char *name);
e9be9d5e 307
ca4c8a3a 308struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
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309struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry,
310 struct dentry *index);
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311static inline void ovl_copyattr(struct inode *from, struct inode *to)
312{
313 to->i_uid = from->i_uid;
314 to->i_gid = from->i_gid;
07a2daab 315 to->i_mode = from->i_mode;
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316 to->i_atime = from->i_atime;
317 to->i_mtime = from->i_mtime;
318 to->i_ctime = from->i_ctime;
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319}
320
321/* dir.c */
322extern const struct inode_operations ovl_dir_inode_operations;
3d27573c 323struct dentry *ovl_lookup_temp(struct dentry *workdir);
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324int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
325 struct dentry *dentry);
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326struct cattr {
327 dev_t rdev;
328 umode_t mode;
329 const char *link;
330};
e9be9d5e 331int ovl_create_real(struct inode *dir, struct dentry *newdentry,
32a3d848 332 struct cattr *attr,
e9be9d5e 333 struct dentry *hardlink, bool debug);
415543d5 334int ovl_cleanup(struct inode *dir, struct dentry *dentry);
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335
336/* copy_up.c */
337int ovl_copy_up(struct dentry *dentry);
9aba6521 338int ovl_copy_up_flags(struct dentry *dentry, int flags);
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339int ovl_copy_xattr(struct dentry *old, struct dentry *new);
340int ovl_set_attr(struct dentry *upper, struct kstat *stat);
05122443 341struct ovl_fh *ovl_encode_fh(struct dentry *real, bool is_upper);
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342int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
343 struct dentry *upper);