3 * Copyright (C) 2011 Novell Inc.
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.
10 #include <linux/kernel.h>
11 #include <linux/uuid.h>
14 __OVL_PATH_UPPER = (1 << 0),
15 __OVL_PATH_MERGE = (1 << 1),
16 __OVL_PATH_ORIGIN = (1 << 2),
19 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
20 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
21 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
23 #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
24 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
25 #define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
26 #define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
29 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
31 * origin.fh - exported file handle of the lower file
32 * origin.uuid - uuid of the lower filesystem
34 #define OVL_FH_VERSION 0
35 #define OVL_FH_MAGIC 0xfb
37 /* CPU byte order required for fid decoding: */
38 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
39 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
41 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN)
43 #if defined(__LITTLE_ENDIAN)
44 #define OVL_FH_FLAG_CPU_ENDIAN 0
45 #elif defined(__BIG_ENDIAN)
46 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
48 #error Endianness not defined
51 /* On-disk and in-memeory format for redirect by file handle */
55 u8 len; /* size of this header + size of fid */
56 u8 flags; /* OVL_FH_FLAG_* */
57 u8 type; /* fid_type of fid */
58 uuid_be uuid; /* uuid of filesystem */
59 u8 fid[0]; /* file identifier */
62 #define OVL_ISUPPER_MASK 1UL
64 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
66 int err = vfs_rmdir(dir, dentry);
67 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
71 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
73 int err = vfs_unlink(dir, dentry, NULL);
74 pr_debug("unlink(%pd2) = %i\n", dentry, err);
78 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
79 struct dentry *new_dentry, bool debug)
81 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
83 pr_debug("link(%pd2, %pd2) = %i\n",
84 old_dentry, new_dentry, err);
89 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
90 umode_t mode, bool debug)
92 int err = vfs_create(dir, dentry, mode, true);
94 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
98 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
99 umode_t mode, bool debug)
101 int err = vfs_mkdir(dir, dentry, mode);
103 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
107 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
108 umode_t mode, dev_t dev, bool debug)
110 int err = vfs_mknod(dir, dentry, mode, dev);
112 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
113 dentry, mode, dev, err);
118 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
119 const char *oldname, bool debug)
121 int err = vfs_symlink(dir, dentry, oldname);
123 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
127 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
128 const void *value, size_t size, int flags)
130 int err = vfs_setxattr(dentry, name, value, size, flags);
131 pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
132 dentry, name, (int) size, (char *) value, flags, err);
136 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
138 int err = vfs_removexattr(dentry, name);
139 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
143 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
144 struct inode *newdir, struct dentry *newdentry,
149 pr_debug("rename(%pd2, %pd2, 0x%x)\n",
150 olddentry, newdentry, flags);
152 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
155 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
156 olddentry, newdentry, err);
161 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
163 int err = vfs_whiteout(dir, dentry);
164 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
168 static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
170 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
171 int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;
173 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
177 static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)
179 unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
182 *is_upper = x & OVL_ISUPPER_MASK;
184 return (struct inode *) (x & ~OVL_ISUPPER_MASK);
188 int ovl_want_write(struct dentry *dentry);
189 void ovl_drop_write(struct dentry *dentry);
190 struct dentry *ovl_workdir(struct dentry *dentry);
191 const struct cred *ovl_override_creds(struct super_block *sb);
192 struct super_block *ovl_same_sb(struct super_block *sb);
193 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
194 bool ovl_dentry_remote(struct dentry *dentry);
195 bool ovl_dentry_weird(struct dentry *dentry);
196 enum ovl_path_type ovl_path_type(struct dentry *dentry);
197 void ovl_path_upper(struct dentry *dentry, struct path *path);
198 void ovl_path_lower(struct dentry *dentry, struct path *path);
199 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
200 struct dentry *ovl_dentry_upper(struct dentry *dentry);
201 struct dentry *ovl_dentry_lower(struct dentry *dentry);
202 struct dentry *ovl_dentry_real(struct dentry *dentry);
203 struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
204 void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
205 bool ovl_dentry_is_opaque(struct dentry *dentry);
206 bool ovl_dentry_is_whiteout(struct dentry *dentry);
207 void ovl_dentry_set_opaque(struct dentry *dentry);
208 bool ovl_redirect_dir(struct super_block *sb);
209 void ovl_clear_redirect_dir(struct super_block *sb);
210 const char *ovl_dentry_get_redirect(struct dentry *dentry);
211 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
212 void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
213 void ovl_inode_init(struct inode *inode, struct inode *realinode,
215 void ovl_inode_update(struct inode *inode, struct inode *upperinode);
216 void ovl_dentry_version_inc(struct dentry *dentry);
217 u64 ovl_dentry_version_get(struct dentry *dentry);
218 bool ovl_is_whiteout(struct dentry *dentry);
219 struct file *ovl_path_open(struct path *path, int flags);
220 int ovl_copy_up_start(struct dentry *dentry);
221 void ovl_copy_up_end(struct dentry *dentry);
224 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
225 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
226 bool ovl_lower_positive(struct dentry *dentry);
229 extern const struct file_operations ovl_dir_operations;
230 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
231 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
232 void ovl_cache_free(struct list_head *list);
233 int ovl_check_d_type_supported(struct path *realpath);
234 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
235 struct dentry *dentry, int level);
238 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
239 int ovl_getattr(const struct path *path, struct kstat *stat,
240 u32 request_mask, unsigned int flags);
241 int ovl_permission(struct inode *inode, int mask);
242 int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
243 size_t size, int flags);
244 int ovl_xattr_get(struct dentry *dentry, const char *name,
245 void *value, size_t size);
246 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
247 struct posix_acl *ovl_get_acl(struct inode *inode, int type);
248 int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
249 int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
250 bool ovl_is_private_xattr(const char *name);
252 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
253 struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode);
254 static inline void ovl_copyattr(struct inode *from, struct inode *to)
256 to->i_uid = from->i_uid;
257 to->i_gid = from->i_gid;
258 to->i_mode = from->i_mode;
259 to->i_atime = from->i_atime;
260 to->i_mtime = from->i_mtime;
261 to->i_ctime = from->i_ctime;
265 extern const struct inode_operations ovl_dir_inode_operations;
266 struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
272 int ovl_create_real(struct inode *dir, struct dentry *newdentry,
274 struct dentry *hardlink, bool debug);
275 void ovl_cleanup(struct inode *dir, struct dentry *dentry);
278 int ovl_copy_up(struct dentry *dentry);
279 int ovl_copy_up_flags(struct dentry *dentry, int flags);
280 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
281 int ovl_set_attr(struct dentry *upper, struct kstat *stat);