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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>
e9be9d5e 12
e9be9d5e 13enum ovl_path_type {
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14 __OVL_PATH_UPPER = (1 << 0),
15 __OVL_PATH_MERGE = (1 << 1),
59548503 16 __OVL_PATH_ORIGIN = (1 << 2),
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17};
18
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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
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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"
5f8415d6 28#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
3a1e819b 29
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30enum ovl_flag {
31 OVL_IMPURE,
359f392c 32 OVL_INDEX,
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33};
34
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35/*
36 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
37 * where:
38 * origin.fh - exported file handle of the lower file
39 * origin.uuid - uuid of the lower filesystem
40 */
41#define OVL_FH_VERSION 0
42#define OVL_FH_MAGIC 0xfb
43
44/* CPU byte order required for fid decoding: */
45#define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
46#define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
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47/* Is the real inode encoded in fid an upper inode? */
48#define OVL_FH_FLAG_PATH_UPPER (1 << 2)
3a1e819b 49
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50#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
51 OVL_FH_FLAG_PATH_UPPER)
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52
53#if defined(__LITTLE_ENDIAN)
54#define OVL_FH_FLAG_CPU_ENDIAN 0
55#elif defined(__BIG_ENDIAN)
56#define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
57#else
58#error Endianness not defined
59#endif
60
61/* On-disk and in-memeory format for redirect by file handle */
62struct ovl_fh {
63 u8 version; /* 0 */
64 u8 magic; /* 0xfb */
65 u8 len; /* size of this header + size of fid */
66 u8 flags; /* OVL_FH_FLAG_* */
67 u8 type; /* fid_type of fid */
01633fd2 68 uuid_t uuid; /* uuid of filesystem */
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69 u8 fid[0]; /* file identifier */
70} __packed;
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71
72static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
73{
74 int err = vfs_rmdir(dir, dentry);
75 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
76 return err;
77}
78
79static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
80{
81 int err = vfs_unlink(dir, dentry, NULL);
82 pr_debug("unlink(%pd2) = %i\n", dentry, err);
83 return err;
84}
85
86static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
87 struct dentry *new_dentry, bool debug)
88{
89 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
90 if (debug) {
91 pr_debug("link(%pd2, %pd2) = %i\n",
92 old_dentry, new_dentry, err);
93 }
94 return err;
95}
96
97static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
98 umode_t mode, bool debug)
99{
100 int err = vfs_create(dir, dentry, mode, true);
101 if (debug)
102 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
103 return err;
104}
105
106static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
107 umode_t mode, bool debug)
108{
109 int err = vfs_mkdir(dir, dentry, mode);
110 if (debug)
111 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
112 return err;
113}
114
115static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
116 umode_t mode, dev_t dev, bool debug)
117{
118 int err = vfs_mknod(dir, dentry, mode, dev);
119 if (debug) {
120 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
121 dentry, mode, dev, err);
122 }
123 return err;
124}
125
126static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
127 const char *oldname, bool debug)
128{
129 int err = vfs_symlink(dir, dentry, oldname);
130 if (debug)
131 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
132 return err;
133}
134
135static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
136 const void *value, size_t size, int flags)
137{
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138 struct inode *inode = dentry->d_inode;
139 int err;
140
141 inode_lock(inode);
142 err = __vfs_setxattr_noperm(dentry, name, value, size, flags);
143 inode_unlock(inode);
144
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145 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
146 dentry, name, (int) size, (char *) value, flags, err);
147 return err;
148}
149
150static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
151{
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152 struct inode *inode = dentry->d_inode;
153 int err;
154
155 inode_lock(inode);
156 err = __vfs_removexattr_noperm(dentry, name);
157 inode_unlock(inode);
158
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159 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
160 return err;
161}
162
163static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
164 struct inode *newdir, struct dentry *newdentry,
165 unsigned int flags)
166{
167 int err;
168
2773bf00 169 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
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170 olddentry, newdentry, flags);
171
172 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
173
174 if (err) {
2773bf00 175 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
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176 olddentry, newdentry, err);
177 }
178 return err;
179}
180
181static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
182{
183 int err = vfs_whiteout(dir, dentry);
184 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
185 return err;
186}
187
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188static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
189{
190 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
191 int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;
192
193 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
194 return ret;
195}
196
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197/* util.c */
198int ovl_want_write(struct dentry *dentry);
199void ovl_drop_write(struct dentry *dentry);
200struct dentry *ovl_workdir(struct dentry *dentry);
201const struct cred *ovl_override_creds(struct super_block *sb);
7bcd74b9 202struct super_block *ovl_same_sb(struct super_block *sb);
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203bool ovl_can_decode_fh(struct super_block *sb);
204struct dentry *ovl_indexdir(struct super_block *sb);
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205struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
206bool ovl_dentry_remote(struct dentry *dentry);
207bool ovl_dentry_weird(struct dentry *dentry);
e9be9d5e 208enum ovl_path_type ovl_path_type(struct dentry *dentry);
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209void ovl_path_upper(struct dentry *dentry, struct path *path);
210void ovl_path_lower(struct dentry *dentry, struct path *path);
211enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
212struct dentry *ovl_dentry_upper(struct dentry *dentry);
213struct dentry *ovl_dentry_lower(struct dentry *dentry);
214struct dentry *ovl_dentry_real(struct dentry *dentry);
1d88f183 215struct dentry *ovl_i_dentry_upper(struct inode *inode);
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216struct inode *ovl_inode_upper(struct inode *inode);
217struct inode *ovl_inode_lower(struct inode *inode);
218struct inode *ovl_inode_real(struct inode *inode);
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219struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
220void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
e9be9d5e 221bool ovl_dentry_is_opaque(struct dentry *dentry);
c412ce49 222bool ovl_dentry_is_whiteout(struct dentry *dentry);
5cf5b477 223void ovl_dentry_set_opaque(struct dentry *dentry);
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224bool ovl_dentry_has_upper_alias(struct dentry *dentry);
225void ovl_dentry_set_upper_alias(struct dentry *dentry);
a6c60655 226bool ovl_redirect_dir(struct super_block *sb);
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227const char *ovl_dentry_get_redirect(struct dentry *dentry);
228void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
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229void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
230 struct dentry *lowerdentry);
231void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
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232void ovl_dentry_version_inc(struct dentry *dentry);
233u64 ovl_dentry_version_get(struct dentry *dentry);
234bool ovl_is_whiteout(struct dentry *dentry);
e9be9d5e 235struct file *ovl_path_open(struct path *path, int flags);
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236int ovl_copy_up_start(struct dentry *dentry);
237void ovl_copy_up_end(struct dentry *dentry);
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238bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
239int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
240 const char *name, const void *value, size_t size,
241 int xerr);
242int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
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243void ovl_set_flag(unsigned long flag, struct inode *inode);
244bool ovl_test_flag(unsigned long flag, struct inode *inode);
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245bool ovl_inuse_trylock(struct dentry *dentry);
246void ovl_inuse_unlock(struct dentry *dentry);
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247int ovl_nlink_start(struct dentry *dentry, bool *locked);
248void ovl_nlink_end(struct dentry *dentry, bool locked);
e62595ed 249int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
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250
251static inline bool ovl_is_impuredir(struct dentry *dentry)
252{
253 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
254}
255
e9be9d5e 256
bbb1e54d 257/* namei.c */
8b88a2e6 258int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt,
54fb347e 259 struct dentry *origin, bool is_upper, bool set);
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260int ovl_verify_index(struct dentry *index, struct path *lowerstack,
261 unsigned int numlower);
359f392c 262int ovl_get_index_name(struct dentry *origin, struct qstr *name);
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263int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
264struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
265bool ovl_lower_positive(struct dentry *dentry);
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266
267/* readdir.c */
268extern const struct file_operations ovl_dir_operations;
269int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
270void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
271void ovl_cache_free(struct list_head *list);
45aebeaf 272int ovl_check_d_type_supported(struct path *realpath);
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273void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
274 struct dentry *dentry, int level);
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275int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
276 struct path *lowerstack, unsigned int numlower);
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277
278/* inode.c */
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279int ovl_set_nlink_upper(struct dentry *dentry);
280int ovl_set_nlink_lower(struct dentry *dentry);
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281unsigned int ovl_get_nlink(struct dentry *lowerdentry,
282 struct dentry *upperdentry,
283 unsigned int fallback);
e9be9d5e 284int ovl_setattr(struct dentry *dentry, struct iattr *attr);
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285int ovl_getattr(const struct path *path, struct kstat *stat,
286 u32 request_mask, unsigned int flags);
e9be9d5e 287int ovl_permission(struct inode *inode, int mask);
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288int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
289 const void *value, size_t size, int flags);
290int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
0eb45fc3 291 void *value, size_t size);
e9be9d5e 292ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
39a25b2b 293struct posix_acl *ovl_get_acl(struct inode *inode, int type);
2d902671 294int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
d719e8f2 295int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
0956254a 296bool ovl_is_private_xattr(const char *name);
e9be9d5e 297
ca4c8a3a 298struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
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299struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry,
300 struct dentry *index);
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301static inline void ovl_copyattr(struct inode *from, struct inode *to)
302{
303 to->i_uid = from->i_uid;
304 to->i_gid = from->i_gid;
07a2daab 305 to->i_mode = from->i_mode;
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306 to->i_atime = from->i_atime;
307 to->i_mtime = from->i_mtime;
308 to->i_ctime = from->i_ctime;
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309}
310
311/* dir.c */
312extern const struct inode_operations ovl_dir_inode_operations;
3d27573c 313struct dentry *ovl_lookup_temp(struct dentry *workdir);
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314struct cattr {
315 dev_t rdev;
316 umode_t mode;
317 const char *link;
318};
e9be9d5e 319int ovl_create_real(struct inode *dir, struct dentry *newdentry,
32a3d848 320 struct cattr *attr,
e9be9d5e 321 struct dentry *hardlink, bool debug);
415543d5 322int ovl_cleanup(struct inode *dir, struct dentry *dentry);
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323
324/* copy_up.c */
325int ovl_copy_up(struct dentry *dentry);
9aba6521 326int ovl_copy_up_flags(struct dentry *dentry, int flags);
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327int ovl_copy_xattr(struct dentry *old, struct dentry *new);
328int ovl_set_attr(struct dentry *upper, struct kstat *stat);
54fb347e 329struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper);