1 /* SPDX-License-Identifier: GPL-2.0-only */
4 * Copyright (C) 2011 Novell Inc.
7 #include <linux/kernel.h>
8 #include <linux/uuid.h>
10 #include "ovl_entry.h"
13 __OVL_PATH_UPPER = (1 << 0),
14 __OVL_PATH_MERGE = (1 << 1),
15 __OVL_PATH_ORIGIN = (1 << 2),
18 #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
19 #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
20 #define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
22 #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
23 #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
24 #define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
25 #define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
26 #define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
27 #define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
28 #define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
29 #define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
32 /* Pure upper dir that may contain non pure upper entries */
34 /* Non-merge dir that may contain whiteout entries */
38 /* Inode number will remain constant over copy up. */
49 * The tuple (fh,uuid) is a universal unique identifier for a copy up origin,
51 * origin.fh - exported file handle of the lower file
52 * origin.uuid - uuid of the lower filesystem
54 #define OVL_FH_VERSION 0
55 #define OVL_FH_MAGIC 0xfb
57 /* CPU byte order required for fid decoding: */
58 #define OVL_FH_FLAG_BIG_ENDIAN (1 << 0)
59 #define OVL_FH_FLAG_ANY_ENDIAN (1 << 1)
60 /* Is the real inode encoded in fid an upper inode? */
61 #define OVL_FH_FLAG_PATH_UPPER (1 << 2)
63 #define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \
64 OVL_FH_FLAG_PATH_UPPER)
66 #if defined(__LITTLE_ENDIAN)
67 #define OVL_FH_FLAG_CPU_ENDIAN 0
68 #elif defined(__BIG_ENDIAN)
69 #define OVL_FH_FLAG_CPU_ENDIAN OVL_FH_FLAG_BIG_ENDIAN
71 #error Endianness not defined
74 /* The type used to be returned by overlay exportfs for misaligned fid */
75 #define OVL_FILEID_V0 0xfb
76 /* The type returned by overlay exportfs for 32bit aligned fid */
77 #define OVL_FILEID_V1 0xf8
79 /* On-disk format for "origin" file handle */
83 u8 len; /* size of this header + size of fid */
84 u8 flags; /* OVL_FH_FLAG_* */
85 u8 type; /* fid_type of fid */
86 uuid_t uuid; /* uuid of filesystem */
87 u32 fid[0]; /* file identifier should be 32bit aligned in-memory */
90 /* In-memory and on-wire format for overlay file handle */
92 u8 padding[3]; /* make sure fb.fid is 32bit aligned */
99 #define OVL_FH_WIRE_OFFSET offsetof(struct ovl_fh, fb)
100 #define OVL_FH_LEN(fh) (OVL_FH_WIRE_OFFSET + (fh)->fb.len)
101 #define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
102 offsetof(struct ovl_fb, fid))
104 static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
106 int err = vfs_rmdir(dir, dentry);
108 pr_debug("rmdir(%pd2) = %i\n", dentry, err);
112 static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
114 int err = vfs_unlink(dir, dentry, NULL);
116 pr_debug("unlink(%pd2) = %i\n", dentry, err);
120 static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
121 struct dentry *new_dentry)
123 int err = vfs_link(old_dentry, dir, new_dentry, NULL);
125 pr_debug("link(%pd2, %pd2) = %i\n", old_dentry, new_dentry, err);
129 static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
132 int err = vfs_create(dir, dentry, mode, true);
134 pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
138 static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
141 int err = vfs_mkdir(dir, dentry, mode);
142 pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
146 static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
147 umode_t mode, dev_t dev)
149 int err = vfs_mknod(dir, dentry, mode, dev);
151 pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n", dentry, mode, dev, err);
155 static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
158 int err = vfs_symlink(dir, dentry, oldname);
160 pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
164 static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
165 const void *value, size_t size, int flags)
167 int err = vfs_setxattr(dentry, name, value, size, flags);
168 pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0x%x) = %i\n",
169 dentry, name, min((int)size, 48), value, size, flags, err);
173 static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
175 int err = vfs_removexattr(dentry, name);
176 pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
180 static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
181 struct inode *newdir, struct dentry *newdentry,
186 pr_debug("rename(%pd2, %pd2, 0x%x)\n", olddentry, newdentry, flags);
187 err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
189 pr_debug("...rename(%pd2, %pd2, ...) = %i\n",
190 olddentry, newdentry, err);
195 static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
197 int err = vfs_whiteout(dir, dentry);
198 pr_debug("whiteout(%pd2) = %i\n", dentry, err);
202 static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
204 struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
205 int err = PTR_ERR_OR_ZERO(ret);
207 pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
211 static inline bool ovl_open_flags_need_copy_up(int flags)
216 return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
220 int ovl_want_write(struct dentry *dentry);
221 void ovl_drop_write(struct dentry *dentry);
222 struct dentry *ovl_workdir(struct dentry *dentry);
223 const struct cred *ovl_override_creds(struct super_block *sb);
224 struct super_block *ovl_same_sb(struct super_block *sb);
225 int ovl_can_decode_fh(struct super_block *sb);
226 struct dentry *ovl_indexdir(struct super_block *sb);
227 bool ovl_index_all(struct super_block *sb);
228 bool ovl_verify_lower(struct super_block *sb);
229 struct ovl_entry *ovl_alloc_entry(unsigned int numlower);
230 bool ovl_dentry_remote(struct dentry *dentry);
231 bool ovl_dentry_weird(struct dentry *dentry);
232 enum ovl_path_type ovl_path_type(struct dentry *dentry);
233 void ovl_path_upper(struct dentry *dentry, struct path *path);
234 void ovl_path_lower(struct dentry *dentry, struct path *path);
235 void ovl_path_lowerdata(struct dentry *dentry, struct path *path);
236 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
237 struct dentry *ovl_dentry_upper(struct dentry *dentry);
238 struct dentry *ovl_dentry_lower(struct dentry *dentry);
239 struct dentry *ovl_dentry_lowerdata(struct dentry *dentry);
240 struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
241 struct dentry *ovl_dentry_real(struct dentry *dentry);
242 struct dentry *ovl_i_dentry_upper(struct inode *inode);
243 struct inode *ovl_inode_upper(struct inode *inode);
244 struct inode *ovl_inode_lower(struct inode *inode);
245 struct inode *ovl_inode_lowerdata(struct inode *inode);
246 struct inode *ovl_inode_real(struct inode *inode);
247 struct inode *ovl_inode_realdata(struct inode *inode);
248 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
249 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
250 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
251 void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry);
252 bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry);
253 bool ovl_dentry_is_opaque(struct dentry *dentry);
254 bool ovl_dentry_is_whiteout(struct dentry *dentry);
255 void ovl_dentry_set_opaque(struct dentry *dentry);
256 bool ovl_dentry_has_upper_alias(struct dentry *dentry);
257 void ovl_dentry_set_upper_alias(struct dentry *dentry);
258 bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags);
259 bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags);
260 bool ovl_has_upperdata(struct inode *inode);
261 void ovl_set_upperdata(struct inode *inode);
262 bool ovl_redirect_dir(struct super_block *sb);
263 const char *ovl_dentry_get_redirect(struct dentry *dentry);
264 void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
265 void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
266 struct dentry *lowerdentry, struct dentry *lowerdata);
267 void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
268 void ovl_dir_modified(struct dentry *dentry, bool impurity);
269 u64 ovl_dentry_version_get(struct dentry *dentry);
270 bool ovl_is_whiteout(struct dentry *dentry);
271 struct file *ovl_path_open(struct path *path, int flags);
272 int ovl_copy_up_start(struct dentry *dentry, int flags);
273 void ovl_copy_up_end(struct dentry *dentry);
274 bool ovl_already_copied_up(struct dentry *dentry, int flags);
275 bool ovl_check_origin_xattr(struct dentry *dentry);
276 bool ovl_check_dir_xattr(struct dentry *dentry, const char *name);
277 int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
278 const char *name, const void *value, size_t size,
280 int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
281 void ovl_set_flag(unsigned long flag, struct inode *inode);
282 void ovl_clear_flag(unsigned long flag, struct inode *inode);
283 bool ovl_test_flag(unsigned long flag, struct inode *inode);
284 bool ovl_inuse_trylock(struct dentry *dentry);
285 void ovl_inuse_unlock(struct dentry *dentry);
286 bool ovl_is_inuse(struct dentry *dentry);
287 bool ovl_need_index(struct dentry *dentry);
288 int ovl_nlink_start(struct dentry *dentry);
289 void ovl_nlink_end(struct dentry *dentry);
290 int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
291 int ovl_check_metacopy_xattr(struct dentry *dentry);
292 bool ovl_is_metacopy_dentry(struct dentry *dentry);
293 char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
294 ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
297 static inline bool ovl_is_impuredir(struct dentry *dentry)
299 return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
302 static inline unsigned int ovl_xino_bits(struct super_block *sb)
304 struct ovl_fs *ofs = sb->s_fs_info;
306 return ofs->xino_bits;
309 static inline int ovl_inode_lock(struct inode *inode)
311 return mutex_lock_interruptible(&OVL_I(inode)->lock);
314 static inline void ovl_inode_unlock(struct inode *inode)
316 mutex_unlock(&OVL_I(inode)->lock);
321 int ovl_check_fb_len(struct ovl_fb *fb, int fb_len);
323 static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len)
325 return ovl_check_fb_len(&fh->fb, fh_len - OVL_FH_WIRE_OFFSET);
328 struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
330 int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
331 struct dentry *upperdentry, struct ovl_path **stackp);
332 int ovl_verify_set_fh(struct dentry *dentry, const char *name,
333 struct dentry *real, bool is_upper, bool set);
334 struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
335 int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
336 int ovl_get_index_name(struct dentry *origin, struct qstr *name);
337 struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);
338 struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
339 struct dentry *origin, bool verify);
340 int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
341 struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
343 bool ovl_lower_positive(struct dentry *dentry);
345 static inline int ovl_verify_origin(struct dentry *upper,
346 struct dentry *origin, bool set)
348 return ovl_verify_set_fh(upper, OVL_XATTR_ORIGIN, origin, false, set);
351 static inline int ovl_verify_upper(struct dentry *index,
352 struct dentry *upper, bool set)
354 return ovl_verify_set_fh(index, OVL_XATTR_UPPER, upper, true, set);
358 extern const struct file_operations ovl_dir_operations;
359 int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
360 void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
361 void ovl_cache_free(struct list_head *list);
362 void ovl_dir_cache_free(struct inode *inode);
363 int ovl_check_d_type_supported(struct path *realpath);
364 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
365 struct dentry *dentry, int level);
366 int ovl_indexdir_cleanup(struct ovl_fs *ofs);
369 int ovl_set_nlink_upper(struct dentry *dentry);
370 int ovl_set_nlink_lower(struct dentry *dentry);
371 unsigned int ovl_get_nlink(struct dentry *lowerdentry,
372 struct dentry *upperdentry,
373 unsigned int fallback);
374 int ovl_setattr(struct dentry *dentry, struct iattr *attr);
375 int ovl_getattr(const struct path *path, struct kstat *stat,
376 u32 request_mask, unsigned int flags);
377 int ovl_permission(struct inode *inode, int mask);
378 int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
379 const void *value, size_t size, int flags);
380 int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
381 void *value, size_t size);
382 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
383 struct posix_acl *ovl_get_acl(struct inode *inode, int type);
384 int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
385 bool ovl_is_private_xattr(const char *name);
387 struct ovl_inode_params {
388 struct inode *newinode;
389 struct dentry *upperdentry;
390 struct ovl_path *lowerpath;
391 struct dentry *index;
392 unsigned int numlower;
394 struct dentry *lowerdata;
396 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
397 struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
399 bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir);
400 struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir);
401 struct inode *ovl_get_inode(struct super_block *sb,
402 struct ovl_inode_params *oip);
403 static inline void ovl_copyattr(struct inode *from, struct inode *to)
405 to->i_uid = from->i_uid;
406 to->i_gid = from->i_gid;
407 to->i_mode = from->i_mode;
408 to->i_atime = from->i_atime;
409 to->i_mtime = from->i_mtime;
410 to->i_ctime = from->i_ctime;
411 i_size_write(to, i_size_read(from));
414 static inline void ovl_copyflags(struct inode *from, struct inode *to)
416 unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
418 inode_set_flags(to, from->i_flags & mask, mask);
422 extern const struct inode_operations ovl_dir_inode_operations;
423 int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir,
424 struct dentry *dentry);
429 struct dentry *hardlink;
432 #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
434 struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry,
435 struct ovl_cattr *attr);
436 int ovl_cleanup(struct inode *dir, struct dentry *dentry);
437 struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
440 extern const struct file_operations ovl_file_operations;
443 int ovl_copy_up(struct dentry *dentry);
444 int ovl_copy_up_with_data(struct dentry *dentry);
445 int ovl_copy_up_flags(struct dentry *dentry, int flags);
446 int ovl_maybe_copy_up(struct dentry *dentry, int flags);
447 int ovl_copy_xattr(struct dentry *old, struct dentry *new);
448 int ovl_set_attr(struct dentry *upper, struct kstat *stat);
449 struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
450 int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
451 struct dentry *upper);
454 extern const struct export_operations ovl_export_operations;