Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e9be9d5e MS |
2 | /* |
3 | * | |
4 | * Copyright (C) 2011 Novell Inc. | |
e9be9d5e MS |
5 | */ |
6 | ||
fb5bb2c3 | 7 | #include <linux/module.h> |
e9be9d5e MS |
8 | #include <linux/fs.h> |
9 | #include <linux/slab.h> | |
10 | #include <linux/file.h> | |
72db8211 | 11 | #include <linux/fileattr.h> |
e9be9d5e MS |
12 | #include <linux/splice.h> |
13 | #include <linux/xattr.h> | |
14 | #include <linux/security.h> | |
15 | #include <linux/uaccess.h> | |
174cd4b1 | 16 | #include <linux/sched/signal.h> |
5b825c3a | 17 | #include <linux/cred.h> |
e9be9d5e | 18 | #include <linux/namei.h> |
fb5bb2c3 DH |
19 | #include <linux/fdtable.h> |
20 | #include <linux/ratelimit.h> | |
3a1e819b | 21 | #include <linux/exportfs.h> |
e9be9d5e MS |
22 | #include "overlayfs.h" |
23 | ||
24 | #define OVL_COPY_UP_CHUNK_SIZE (1 << 20) | |
25 | ||
670c2324 | 26 | static int ovl_ccup_set(const char *buf, const struct kernel_param *param) |
fb5bb2c3 | 27 | { |
1bd0a3ae | 28 | pr_warn("\"check_copy_up\" module option is obsolete\n"); |
fb5bb2c3 DH |
29 | return 0; |
30 | } | |
31 | ||
670c2324 | 32 | static int ovl_ccup_get(char *buf, const struct kernel_param *param) |
fb5bb2c3 | 33 | { |
670c2324 | 34 | return sprintf(buf, "N\n"); |
fb5bb2c3 DH |
35 | } |
36 | ||
670c2324 | 37 | module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644); |
253e7483 | 38 | MODULE_PARM_DESC(check_copy_up, "Obsolete; does nothing"); |
670c2324 | 39 | |
c61ca557 MS |
40 | static bool ovl_must_copy_xattr(const char *name) |
41 | { | |
42 | return !strcmp(name, XATTR_POSIX_ACL_ACCESS) || | |
43 | !strcmp(name, XATTR_POSIX_ACL_DEFAULT) || | |
44 | !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN); | |
45 | } | |
46 | ||
610afc0b MS |
47 | int ovl_copy_xattr(struct super_block *sb, struct dentry *old, |
48 | struct dentry *new) | |
e9be9d5e | 49 | { |
e4ad29fa VC |
50 | ssize_t list_size, size, value_size = 0; |
51 | char *buf, *name, *value = NULL; | |
520da69d | 52 | int error = 0; |
8b326c61 | 53 | size_t slen; |
e9be9d5e | 54 | |
5d6c3191 AG |
55 | if (!(old->d_inode->i_opflags & IOP_XATTR) || |
56 | !(new->d_inode->i_opflags & IOP_XATTR)) | |
e9be9d5e MS |
57 | return 0; |
58 | ||
59 | list_size = vfs_listxattr(old, NULL, 0); | |
60 | if (list_size <= 0) { | |
61 | if (list_size == -EOPNOTSUPP) | |
62 | return 0; | |
63 | return list_size; | |
64 | } | |
65 | ||
f945ca19 | 66 | buf = kvzalloc(list_size, GFP_KERNEL); |
e9be9d5e MS |
67 | if (!buf) |
68 | return -ENOMEM; | |
69 | ||
e9be9d5e MS |
70 | list_size = vfs_listxattr(old, buf, list_size); |
71 | if (list_size <= 0) { | |
72 | error = list_size; | |
e4ad29fa | 73 | goto out; |
e9be9d5e MS |
74 | } |
75 | ||
8b326c61 MS |
76 | for (name = buf; list_size; name += slen) { |
77 | slen = strnlen(name, list_size) + 1; | |
78 | ||
79 | /* underlying fs providing us with an broken xattr list? */ | |
80 | if (WARN_ON(slen > list_size)) { | |
81 | error = -EIO; | |
82 | break; | |
83 | } | |
84 | list_size -= slen; | |
85 | ||
610afc0b | 86 | if (ovl_is_private_xattr(sb, name)) |
0956254a | 87 | continue; |
03fedf93 AG |
88 | |
89 | error = security_inode_copy_up_xattr(name); | |
90 | if (error < 0 && error != -EOPNOTSUPP) | |
91 | break; | |
92 | if (error == 1) { | |
93 | error = 0; | |
94 | continue; /* Discard */ | |
95 | } | |
e4ad29fa | 96 | retry: |
c7c7a1a1 | 97 | size = vfs_getxattr(&init_user_ns, old, name, value, value_size); |
e4ad29fa | 98 | if (size == -ERANGE) |
c7c7a1a1 | 99 | size = vfs_getxattr(&init_user_ns, old, name, NULL, 0); |
e4ad29fa | 100 | |
97daf8b9 | 101 | if (size < 0) { |
e9be9d5e | 102 | error = size; |
e4ad29fa | 103 | break; |
e9be9d5e | 104 | } |
e4ad29fa VC |
105 | |
106 | if (size > value_size) { | |
107 | void *new; | |
108 | ||
f945ca19 | 109 | new = kvmalloc(size, GFP_KERNEL); |
e4ad29fa VC |
110 | if (!new) { |
111 | error = -ENOMEM; | |
112 | break; | |
113 | } | |
f945ca19 | 114 | kvfree(value); |
e4ad29fa VC |
115 | value = new; |
116 | value_size = size; | |
117 | goto retry; | |
118 | } | |
119 | ||
c914c0e2 | 120 | error = ovl_do_setxattr(OVL_FS(sb), new, name, value, size, 0); |
c61ca557 MS |
121 | if (error) { |
122 | if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name)) | |
123 | break; | |
124 | ||
125 | /* Ignore failure to copy unknown xattrs */ | |
126 | error = 0; | |
127 | } | |
e9be9d5e | 128 | } |
f945ca19 | 129 | kvfree(value); |
e9be9d5e | 130 | out: |
f945ca19 | 131 | kvfree(buf); |
e9be9d5e MS |
132 | return error; |
133 | } | |
134 | ||
096a218a AG |
135 | static int ovl_copy_fileattr(struct inode *inode, struct path *old, |
136 | struct path *new) | |
72db8211 AG |
137 | { |
138 | struct fileattr oldfa = { .flags_valid = true }; | |
139 | struct fileattr newfa = { .flags_valid = true }; | |
140 | int err; | |
141 | ||
142 | err = ovl_real_fileattr_get(old, &oldfa); | |
5b0a414d MS |
143 | if (err) { |
144 | /* Ntfs-3g returns -EINVAL for "no fileattr support" */ | |
145 | if (err == -ENOTTY || err == -EINVAL) | |
146 | return 0; | |
147 | pr_warn("failed to retrieve lower fileattr (%pd2, err=%i)\n", | |
4ee7e4a6 | 148 | old->dentry, err); |
72db8211 | 149 | return err; |
5b0a414d | 150 | } |
72db8211 | 151 | |
096a218a AG |
152 | /* |
153 | * We cannot set immutable and append-only flags on upper inode, | |
154 | * because we would not be able to link upper inode to upper dir | |
155 | * not set overlay private xattr on upper inode. | |
156 | * Store these flags in overlay.protattr xattr instead. | |
157 | */ | |
158 | if (oldfa.flags & OVL_PROT_FS_FLAGS_MASK) { | |
159 | err = ovl_set_protattr(inode, new->dentry, &oldfa); | |
94fd1975 MS |
160 | if (err == -EPERM) |
161 | pr_warn_once("copying fileattr: no xattr on upper\n"); | |
162 | else if (err) | |
096a218a AG |
163 | return err; |
164 | } | |
165 | ||
5b0a414d MS |
166 | /* Don't bother copying flags if none are set */ |
167 | if (!(oldfa.flags & OVL_COPY_FS_FLAGS_MASK)) | |
168 | return 0; | |
169 | ||
170 | err = ovl_real_fileattr_get(new, &newfa); | |
171 | if (err) { | |
94fd1975 MS |
172 | /* |
173 | * Returning an error if upper doesn't support fileattr will | |
174 | * result in a regression, so revert to the old behavior. | |
175 | */ | |
176 | if (err == -ENOTTY || err == -EINVAL) { | |
177 | pr_warn_once("copying fileattr: no support on upper\n"); | |
178 | return 0; | |
179 | } | |
5b0a414d | 180 | pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n", |
4ee7e4a6 | 181 | new->dentry, err); |
5b0a414d MS |
182 | return err; |
183 | } | |
184 | ||
72db8211 AG |
185 | BUILD_BUG_ON(OVL_COPY_FS_FLAGS_MASK & ~FS_COMMON_FL); |
186 | newfa.flags &= ~OVL_COPY_FS_FLAGS_MASK; | |
187 | newfa.flags |= (oldfa.flags & OVL_COPY_FS_FLAGS_MASK); | |
188 | ||
189 | BUILD_BUG_ON(OVL_COPY_FSX_FLAGS_MASK & ~FS_XFLAG_COMMON); | |
190 | newfa.fsx_xflags &= ~OVL_COPY_FSX_FLAGS_MASK; | |
191 | newfa.fsx_xflags |= (oldfa.fsx_xflags & OVL_COPY_FSX_FLAGS_MASK); | |
192 | ||
193 | return ovl_real_fileattr_set(new, &newfa); | |
194 | } | |
195 | ||
c86243b0 VG |
196 | static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, |
197 | struct path *new, loff_t len) | |
e9be9d5e MS |
198 | { |
199 | struct file *old_file; | |
200 | struct file *new_file; | |
201 | loff_t old_pos = 0; | |
202 | loff_t new_pos = 0; | |
42ec3d4c | 203 | loff_t cloned; |
b504c654 CX |
204 | loff_t data_pos = -1; |
205 | loff_t hole_len; | |
206 | bool skip_hole = false; | |
e9be9d5e MS |
207 | int error = 0; |
208 | ||
209 | if (len == 0) | |
210 | return 0; | |
211 | ||
0480334f | 212 | old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); |
e9be9d5e MS |
213 | if (IS_ERR(old_file)) |
214 | return PTR_ERR(old_file); | |
215 | ||
0480334f | 216 | new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); |
e9be9d5e MS |
217 | if (IS_ERR(new_file)) { |
218 | error = PTR_ERR(new_file); | |
219 | goto out_fput; | |
220 | } | |
221 | ||
2ea98466 | 222 | /* Try to use clone_file_range to clone up within the same fs */ |
452ce659 | 223 | cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); |
42ec3d4c | 224 | if (cloned == len) |
2ea98466 AG |
225 | goto out; |
226 | /* Couldn't clone, so now we try to copy the data */ | |
2ea98466 | 227 | |
b504c654 CX |
228 | /* Check if lower fs supports seek operation */ |
229 | if (old_file->f_mode & FMODE_LSEEK && | |
230 | old_file->f_op->llseek) | |
231 | skip_hole = true; | |
232 | ||
e9be9d5e MS |
233 | while (len) { |
234 | size_t this_len = OVL_COPY_UP_CHUNK_SIZE; | |
235 | long bytes; | |
236 | ||
237 | if (len < this_len) | |
238 | this_len = len; | |
239 | ||
240 | if (signal_pending_state(TASK_KILLABLE, current)) { | |
241 | error = -EINTR; | |
242 | break; | |
243 | } | |
244 | ||
b504c654 CX |
245 | /* |
246 | * Fill zero for hole will cost unnecessary disk space | |
247 | * and meanwhile slow down the copy-up speed, so we do | |
248 | * an optimization for hole during copy-up, it relies | |
249 | * on SEEK_DATA implementation in lower fs so if lower | |
250 | * fs does not support it, copy-up will behave as before. | |
251 | * | |
252 | * Detail logic of hole detection as below: | |
253 | * When we detect next data position is larger than current | |
254 | * position we will skip that hole, otherwise we copy | |
255 | * data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, | |
256 | * it may not recognize all kind of holes and sometimes | |
257 | * only skips partial of hole area. However, it will be | |
258 | * enough for most of the use cases. | |
259 | */ | |
260 | ||
261 | if (skip_hole && data_pos < old_pos) { | |
262 | data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); | |
263 | if (data_pos > old_pos) { | |
264 | hole_len = data_pos - old_pos; | |
265 | len -= hole_len; | |
266 | old_pos = new_pos = data_pos; | |
267 | continue; | |
268 | } else if (data_pos == -ENXIO) { | |
269 | break; | |
270 | } else if (data_pos < 0) { | |
271 | skip_hole = false; | |
272 | } | |
273 | } | |
274 | ||
e9be9d5e MS |
275 | bytes = do_splice_direct(old_file, &old_pos, |
276 | new_file, &new_pos, | |
277 | this_len, SPLICE_F_MOVE); | |
278 | if (bytes <= 0) { | |
279 | error = bytes; | |
280 | break; | |
281 | } | |
282 | WARN_ON(old_pos != new_pos); | |
283 | ||
284 | len -= bytes; | |
285 | } | |
2ea98466 | 286 | out: |
c86243b0 | 287 | if (!error && ovl_should_sync(ofs)) |
641089c1 | 288 | error = vfs_fsync(new_file, 0); |
e9be9d5e MS |
289 | fput(new_file); |
290 | out_fput: | |
291 | fput(old_file); | |
292 | return error; | |
293 | } | |
294 | ||
0c288874 VG |
295 | static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) |
296 | { | |
297 | struct iattr attr = { | |
298 | .ia_valid = ATTR_SIZE, | |
299 | .ia_size = stat->size, | |
300 | }; | |
301 | ||
2f221d6f | 302 | return notify_change(&init_user_ns, upperdentry, &attr, NULL); |
0c288874 VG |
303 | } |
304 | ||
e9be9d5e MS |
305 | static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) |
306 | { | |
307 | struct iattr attr = { | |
308 | .ia_valid = | |
309 | ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, | |
310 | .ia_atime = stat->atime, | |
311 | .ia_mtime = stat->mtime, | |
312 | }; | |
313 | ||
2f221d6f | 314 | return notify_change(&init_user_ns, upperdentry, &attr, NULL); |
e9be9d5e MS |
315 | } |
316 | ||
317 | int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) | |
318 | { | |
319 | int err = 0; | |
320 | ||
321 | if (!S_ISLNK(stat->mode)) { | |
322 | struct iattr attr = { | |
323 | .ia_valid = ATTR_MODE, | |
324 | .ia_mode = stat->mode, | |
325 | }; | |
2f221d6f | 326 | err = notify_change(&init_user_ns, upperdentry, &attr, NULL); |
e9be9d5e MS |
327 | } |
328 | if (!err) { | |
329 | struct iattr attr = { | |
330 | .ia_valid = ATTR_UID | ATTR_GID, | |
331 | .ia_uid = stat->uid, | |
332 | .ia_gid = stat->gid, | |
333 | }; | |
2f221d6f | 334 | err = notify_change(&init_user_ns, upperdentry, &attr, NULL); |
e9be9d5e MS |
335 | } |
336 | if (!err) | |
337 | ovl_set_timestamps(upperdentry, stat); | |
338 | ||
339 | return err; | |
e9be9d5e MS |
340 | } |
341 | ||
1cdb0cb6 PT |
342 | struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, |
343 | bool is_upper) | |
3a1e819b AG |
344 | { |
345 | struct ovl_fh *fh; | |
ec7bbb53 | 346 | int fh_type, dwords; |
3a1e819b | 347 | int buflen = MAX_HANDLE_SZ; |
05122443 | 348 | uuid_t *uuid = &real->d_sb->s_uuid; |
ec7bbb53 | 349 | int err; |
3a1e819b | 350 | |
ec7bbb53 AG |
351 | /* Make sure the real fid stays 32bit aligned */ |
352 | BUILD_BUG_ON(OVL_FH_FID_OFFSET % 4); | |
353 | BUILD_BUG_ON(MAX_HANDLE_SZ + OVL_FH_FID_OFFSET > 255); | |
354 | ||
355 | fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL); | |
356 | if (!fh) | |
3a1e819b AG |
357 | return ERR_PTR(-ENOMEM); |
358 | ||
359 | /* | |
360 | * We encode a non-connectable file handle for non-dir, because we | |
361 | * only need to find the lower inode number and we don't want to pay | |
362 | * the price or reconnecting the dentry. | |
363 | */ | |
364 | dwords = buflen >> 2; | |
ec7bbb53 | 365 | fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); |
3a1e819b AG |
366 | buflen = (dwords << 2); |
367 | ||
ec7bbb53 | 368 | err = -EIO; |
3a1e819b AG |
369 | if (WARN_ON(fh_type < 0) || |
370 | WARN_ON(buflen > MAX_HANDLE_SZ) || | |
371 | WARN_ON(fh_type == FILEID_INVALID)) | |
ec7bbb53 | 372 | goto out_err; |
3a1e819b | 373 | |
cbe7fba8 AG |
374 | fh->fb.version = OVL_FH_VERSION; |
375 | fh->fb.magic = OVL_FH_MAGIC; | |
376 | fh->fb.type = fh_type; | |
377 | fh->fb.flags = OVL_FH_FLAG_CPU_ENDIAN; | |
54fb347e AG |
378 | /* |
379 | * When we will want to decode an overlay dentry from this handle | |
380 | * and all layers are on the same fs, if we get a disconncted real | |
381 | * dentry when we decode fid, the only way to tell if we should assign | |
382 | * it to upperdentry or to lowerstack is by checking this flag. | |
383 | */ | |
384 | if (is_upper) | |
cbe7fba8 | 385 | fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; |
ec7bbb53 | 386 | fh->fb.len = sizeof(fh->fb) + buflen; |
5830fb6b PT |
387 | if (ofs->config.uuid) |
388 | fh->fb.uuid = *uuid; | |
3a1e819b | 389 | |
3a1e819b | 390 | return fh; |
ec7bbb53 AG |
391 | |
392 | out_err: | |
393 | kfree(fh); | |
394 | return ERR_PTR(err); | |
3a1e819b AG |
395 | } |
396 | ||
a0c236b1 AG |
397 | int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, |
398 | struct dentry *upper) | |
3a1e819b | 399 | { |
3a1e819b AG |
400 | const struct ovl_fh *fh = NULL; |
401 | int err; | |
402 | ||
403 | /* | |
404 | * When lower layer doesn't support export operations store a 'null' fh, | |
405 | * so we can use the overlay.origin xattr to distignuish between a copy | |
406 | * up and a pure upper inode. | |
407 | */ | |
02bcd157 | 408 | if (ovl_can_decode_fh(lower->d_sb)) { |
1cdb0cb6 | 409 | fh = ovl_encode_real_fh(ofs, lower, false); |
3a1e819b AG |
410 | if (IS_ERR(fh)) |
411 | return PTR_ERR(fh); | |
412 | } | |
413 | ||
6266d465 MS |
414 | /* |
415 | * Do not fail when upper doesn't support xattrs. | |
416 | */ | |
a0c236b1 | 417 | err = ovl_check_setxattr(ofs, upper, OVL_XATTR_ORIGIN, fh->buf, |
cbe7fba8 | 418 | fh ? fh->fb.len : 0, 0); |
3a1e819b AG |
419 | kfree(fh); |
420 | ||
6939f977 MS |
421 | /* Ignore -EPERM from setting "user.*" on symlink/special */ |
422 | return err == -EPERM ? 0 : err; | |
3a1e819b AG |
423 | } |
424 | ||
016b720f | 425 | /* Store file handle of @upper dir in @index dir entry */ |
610afc0b MS |
426 | static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, |
427 | struct dentry *index) | |
016b720f AG |
428 | { |
429 | const struct ovl_fh *fh; | |
430 | int err; | |
431 | ||
1cdb0cb6 | 432 | fh = ovl_encode_real_fh(ofs, upper, true); |
016b720f AG |
433 | if (IS_ERR(fh)) |
434 | return PTR_ERR(fh); | |
435 | ||
c914c0e2 | 436 | err = ovl_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); |
016b720f AG |
437 | |
438 | kfree(fh); | |
439 | return err; | |
440 | } | |
441 | ||
442 | /* | |
443 | * Create and install index entry. | |
444 | * | |
445 | * Caller must hold i_mutex on indexdir. | |
446 | */ | |
447 | static int ovl_create_index(struct dentry *dentry, struct dentry *origin, | |
448 | struct dentry *upper) | |
449 | { | |
1cdb0cb6 | 450 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
016b720f AG |
451 | struct dentry *indexdir = ovl_indexdir(dentry->d_sb); |
452 | struct inode *dir = d_inode(indexdir); | |
453 | struct dentry *index = NULL; | |
454 | struct dentry *temp = NULL; | |
455 | struct qstr name = { }; | |
456 | int err; | |
457 | ||
458 | /* | |
459 | * For now this is only used for creating index entry for directories, | |
460 | * because non-dir are copied up directly to index and then hardlinked | |
461 | * to upper dir. | |
462 | * | |
463 | * TODO: implement create index for non-dir, so we can call it when | |
464 | * encoding file handle for non-dir in case index does not exist. | |
465 | */ | |
466 | if (WARN_ON(!d_is_dir(dentry))) | |
467 | return -EIO; | |
468 | ||
469 | /* Directory not expected to be indexed before copy up */ | |
470 | if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) | |
471 | return -EIO; | |
472 | ||
1cdb0cb6 | 473 | err = ovl_get_index_name(ofs, origin, &name); |
016b720f AG |
474 | if (err) |
475 | return err; | |
476 | ||
137ec526 | 477 | temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); |
b148cba4 | 478 | err = PTR_ERR(temp); |
016b720f | 479 | if (IS_ERR(temp)) |
b148cba4 | 480 | goto free_name; |
016b720f | 481 | |
1cdb0cb6 | 482 | err = ovl_set_upper_fh(ofs, upper, temp); |
016b720f | 483 | if (err) |
b148cba4 | 484 | goto out; |
016b720f AG |
485 | |
486 | index = lookup_one_len(name.name, indexdir, name.len); | |
487 | if (IS_ERR(index)) { | |
488 | err = PTR_ERR(index); | |
489 | } else { | |
490 | err = ovl_do_rename(dir, temp, dir, index, 0); | |
491 | dput(index); | |
492 | } | |
016b720f | 493 | out: |
b148cba4 MS |
494 | if (err) |
495 | ovl_cleanup(dir, temp); | |
016b720f | 496 | dput(temp); |
b148cba4 | 497 | free_name: |
016b720f AG |
498 | kfree(name.name); |
499 | return err; | |
016b720f AG |
500 | } |
501 | ||
f4439de1 AG |
502 | struct ovl_copy_up_ctx { |
503 | struct dentry *parent; | |
504 | struct dentry *dentry; | |
505 | struct path lowerpath; | |
506 | struct kstat stat; | |
507 | struct kstat pstat; | |
508 | const char *link; | |
509 | struct dentry *destdir; | |
510 | struct qstr destname; | |
511 | struct dentry *workdir; | |
f4439de1 | 512 | bool origin; |
016b720f | 513 | bool indexed; |
44d5bf10 | 514 | bool metacopy; |
f4439de1 AG |
515 | }; |
516 | ||
517 | static int ovl_link_up(struct ovl_copy_up_ctx *c) | |
59be0971 AG |
518 | { |
519 | int err; | |
520 | struct dentry *upper; | |
f4439de1 | 521 | struct dentry *upperdir = ovl_dentry_upper(c->parent); |
59be0971 AG |
522 | struct inode *udir = d_inode(upperdir); |
523 | ||
f4439de1 AG |
524 | /* Mark parent "impure" because it may now contain non-pure upper */ |
525 | err = ovl_set_impure(c->parent, upperdir); | |
526 | if (err) | |
527 | return err; | |
528 | ||
529 | err = ovl_set_nlink_lower(c->dentry); | |
5f8415d6 AG |
530 | if (err) |
531 | return err; | |
532 | ||
59be0971 | 533 | inode_lock_nested(udir, I_MUTEX_PARENT); |
f4439de1 AG |
534 | upper = lookup_one_len(c->dentry->d_name.name, upperdir, |
535 | c->dentry->d_name.len); | |
59be0971 AG |
536 | err = PTR_ERR(upper); |
537 | if (!IS_ERR(upper)) { | |
6cf00764 | 538 | err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); |
59be0971 AG |
539 | dput(upper); |
540 | ||
f4439de1 AG |
541 | if (!err) { |
542 | /* Restore timestamps on parent (best effort) */ | |
543 | ovl_set_timestamps(upperdir, &c->pstat); | |
544 | ovl_dentry_set_upper_alias(c->dentry); | |
545 | } | |
59be0971 AG |
546 | } |
547 | inode_unlock(udir); | |
aa3ff3c1 AG |
548 | if (err) |
549 | return err; | |
550 | ||
551 | err = ovl_set_nlink_upper(c->dentry); | |
59be0971 AG |
552 | |
553 | return err; | |
554 | } | |
555 | ||
23f0ab13 | 556 | static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) |
7d90b853 | 557 | { |
c86243b0 | 558 | struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); |
72db8211 AG |
559 | struct inode *inode = d_inode(c->dentry); |
560 | struct path upperpath, datapath; | |
7d90b853 MS |
561 | int err; |
562 | ||
72db8211 AG |
563 | ovl_path_upper(c->dentry, &upperpath); |
564 | if (WARN_ON(upperpath.dentry != NULL)) | |
565 | return -EIO; | |
566 | ||
567 | upperpath.dentry = temp; | |
568 | ||
5f32879e VG |
569 | /* |
570 | * Copy up data first and then xattrs. Writing data after | |
571 | * xattrs will remove security.capability xattr automatically. | |
572 | */ | |
573 | if (S_ISREG(c->stat.mode) && !c->metacopy) { | |
5f32879e | 574 | ovl_path_lowerdata(c->dentry, &datapath); |
c86243b0 VG |
575 | err = ovl_copy_up_data(ofs, &datapath, &upperpath, |
576 | c->stat.size); | |
5f32879e VG |
577 | if (err) |
578 | return err; | |
579 | } | |
580 | ||
610afc0b | 581 | err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp); |
e9be9d5e | 582 | if (err) |
02209d10 | 583 | return err; |
e9be9d5e | 584 | |
72db8211 AG |
585 | if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) { |
586 | /* | |
587 | * Copy the fileattr inode flags that are the source of already | |
588 | * copied i_flags | |
589 | */ | |
096a218a | 590 | err = ovl_copy_fileattr(inode, &c->lowerpath, &upperpath); |
72db8211 AG |
591 | if (err) |
592 | return err; | |
593 | } | |
594 | ||
3a1e819b AG |
595 | /* |
596 | * Store identifier of lower inode in upper inode xattr to | |
597 | * allow lookup of the copy up origin inode. | |
fbaf94ee MS |
598 | * |
599 | * Don't set origin when we are breaking the association with a lower | |
600 | * hard link. | |
3a1e819b | 601 | */ |
59be0971 | 602 | if (c->origin) { |
a0c236b1 | 603 | err = ovl_set_origin(ofs, c->lowerpath.dentry, temp); |
fbaf94ee | 604 | if (err) |
02209d10 | 605 | return err; |
fbaf94ee | 606 | } |
3a1e819b | 607 | |
0c288874 | 608 | if (c->metacopy) { |
a0c236b1 | 609 | err = ovl_check_setxattr(ofs, temp, OVL_XATTR_METACOPY, |
0c288874 VG |
610 | NULL, 0, -EOPNOTSUPP); |
611 | if (err) | |
612 | return err; | |
613 | } | |
614 | ||
bd64e575 | 615 | inode_lock(temp->d_inode); |
b504c654 | 616 | if (S_ISREG(c->stat.mode)) |
0c288874 VG |
617 | err = ovl_set_size(temp, &c->stat); |
618 | if (!err) | |
619 | err = ovl_set_attr(temp, &c->stat); | |
bd64e575 VG |
620 | inode_unlock(temp->d_inode); |
621 | ||
622 | return err; | |
02209d10 AG |
623 | } |
624 | ||
6b52243f MS |
625 | struct ovl_cu_creds { |
626 | const struct cred *old; | |
627 | struct cred *new; | |
628 | }; | |
629 | ||
630 | static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) | |
b10cdcdc AG |
631 | { |
632 | int err; | |
b10cdcdc | 633 | |
6b52243f MS |
634 | cc->old = cc->new = NULL; |
635 | err = security_inode_copy_up(dentry, &cc->new); | |
b10cdcdc | 636 | if (err < 0) |
6b52243f | 637 | return err; |
b10cdcdc | 638 | |
6b52243f MS |
639 | if (cc->new) |
640 | cc->old = override_creds(cc->new); | |
b10cdcdc | 641 | |
6b52243f | 642 | return 0; |
b10cdcdc AG |
643 | } |
644 | ||
6b52243f | 645 | static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) |
b10cdcdc | 646 | { |
6b52243f MS |
647 | if (cc->new) { |
648 | revert_creds(cc->old); | |
649 | put_cred(cc->new); | |
650 | } | |
b10cdcdc AG |
651 | } |
652 | ||
653 | /* | |
654 | * Copyup using workdir to prepare temp file. Used when copying up directories, | |
655 | * special files or when upper fs doesn't support O_TMPFILE. | |
656 | */ | |
657 | static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) | |
02209d10 | 658 | { |
b79e05aa | 659 | struct inode *inode; |
6b52243f MS |
660 | struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); |
661 | struct dentry *temp, *upper; | |
662 | struct ovl_cu_creds cc; | |
02209d10 | 663 | int err; |
6b52243f MS |
664 | struct ovl_cattr cattr = { |
665 | /* Can't properly set mode on creation because of the umask */ | |
666 | .mode = c->stat.mode & S_IFMT, | |
667 | .rdev = c->stat.rdev, | |
668 | .link = c->link | |
669 | }; | |
02209d10 | 670 | |
773cb4c5 AG |
671 | /* workdir and destdir could be the same when copying up to indexdir */ |
672 | err = -EIO; | |
673 | if (lock_rename(c->workdir, c->destdir) != NULL) | |
674 | goto unlock; | |
b10cdcdc | 675 | |
6b52243f MS |
676 | err = ovl_prep_cu_creds(c->dentry, &cc); |
677 | if (err) | |
678 | goto unlock; | |
679 | ||
680 | temp = ovl_create_temp(c->workdir, &cattr); | |
681 | ovl_revert_cu_creds(&cc); | |
682 | ||
b10cdcdc | 683 | err = PTR_ERR(temp); |
b148cba4 | 684 | if (IS_ERR(temp)) |
b10cdcdc | 685 | goto unlock; |
02209d10 | 686 | |
23f0ab13 | 687 | err = ovl_copy_up_inode(c, temp); |
02209d10 | 688 | if (err) |
b10cdcdc | 689 | goto cleanup; |
02209d10 | 690 | |
016b720f AG |
691 | if (S_ISDIR(c->stat.mode) && c->indexed) { |
692 | err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); | |
693 | if (err) | |
b10cdcdc | 694 | goto cleanup; |
016b720f AG |
695 | } |
696 | ||
6b52243f MS |
697 | upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); |
698 | err = PTR_ERR(upper); | |
699 | if (IS_ERR(upper)) | |
700 | goto cleanup; | |
701 | ||
702 | err = ovl_do_rename(wdir, temp, udir, upper, 0); | |
703 | dput(upper); | |
e9be9d5e | 704 | if (err) |
b10cdcdc | 705 | goto cleanup; |
e9be9d5e | 706 | |
0c288874 VG |
707 | if (!c->metacopy) |
708 | ovl_set_upperdata(d_inode(c->dentry)); | |
b79e05aa | 709 | inode = d_inode(c->dentry); |
6b52243f | 710 | ovl_inode_update(inode, temp); |
b79e05aa AG |
711 | if (S_ISDIR(inode->i_mode)) |
712 | ovl_set_flag(OVL_WHITEOUTS, inode); | |
b10cdcdc AG |
713 | unlock: |
714 | unlock_rename(c->workdir, c->destdir); | |
715 | ||
716 | return err; | |
717 | ||
718 | cleanup: | |
6b52243f MS |
719 | ovl_cleanup(wdir, temp); |
720 | dput(temp); | |
721 | goto unlock; | |
b10cdcdc AG |
722 | } |
723 | ||
6b52243f MS |
724 | /* Copyup using O_TMPFILE which does not require cross dir locking */ |
725 | static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) | |
b10cdcdc | 726 | { |
6b52243f MS |
727 | struct inode *udir = d_inode(c->destdir); |
728 | struct dentry *temp, *upper; | |
729 | struct ovl_cu_creds cc; | |
b10cdcdc | 730 | int err; |
b10cdcdc | 731 | |
6b52243f MS |
732 | err = ovl_prep_cu_creds(c->dentry, &cc); |
733 | if (err) | |
734 | return err; | |
b10cdcdc AG |
735 | |
736 | temp = ovl_do_tmpfile(c->workdir, c->stat.mode); | |
6b52243f | 737 | ovl_revert_cu_creds(&cc); |
b10cdcdc | 738 | |
6b52243f MS |
739 | if (IS_ERR(temp)) |
740 | return PTR_ERR(temp); | |
b10cdcdc | 741 | |
6b52243f MS |
742 | err = ovl_copy_up_inode(c, temp); |
743 | if (err) | |
744 | goto out_dput; | |
b10cdcdc AG |
745 | |
746 | inode_lock_nested(udir, I_MUTEX_PARENT); | |
747 | ||
748 | upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); | |
749 | err = PTR_ERR(upper); | |
6b52243f MS |
750 | if (!IS_ERR(upper)) { |
751 | err = ovl_do_link(temp, udir, upper); | |
752 | dput(upper); | |
753 | } | |
b10cdcdc AG |
754 | inode_unlock(udir); |
755 | ||
b10cdcdc | 756 | if (err) |
6b52243f | 757 | goto out_dput; |
b10cdcdc AG |
758 | |
759 | if (!c->metacopy) | |
760 | ovl_set_upperdata(d_inode(c->dentry)); | |
6b52243f | 761 | ovl_inode_update(d_inode(c->dentry), temp); |
b79e05aa | 762 | |
6b52243f MS |
763 | return 0; |
764 | ||
765 | out_dput: | |
42f269b9 | 766 | dput(temp); |
e9be9d5e | 767 | return err; |
e9be9d5e MS |
768 | } |
769 | ||
770 | /* | |
771 | * Copy up a single dentry | |
772 | * | |
a6c60655 MS |
773 | * All renames start with copy up of source if necessary. The actual |
774 | * rename will only proceed once the copy up was successful. Copy up uses | |
775 | * upper parent i_mutex for exclusion. Since rename can change d_parent it | |
776 | * is possible that the copy up will lock the old parent. At that point | |
777 | * the file will have already been copied up anyway. | |
e9be9d5e | 778 | */ |
a6fb235a | 779 | static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) |
e9be9d5e | 780 | { |
e9be9d5e | 781 | int err; |
1cdb0cb6 | 782 | struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); |
016b720f | 783 | bool to_index = false; |
59be0971 | 784 | |
016b720f AG |
785 | /* |
786 | * Indexed non-dir is copied up directly to the index entry and then | |
787 | * hardlinked to upper dir. Indexed dir is copied up to indexdir, | |
788 | * then index entry is created and then copied up dir installed. | |
789 | * Copying dir up to indexdir instead of workdir simplifies locking. | |
790 | */ | |
791 | if (ovl_need_index(c->dentry)) { | |
792 | c->indexed = true; | |
793 | if (S_ISDIR(c->stat.mode)) | |
794 | c->workdir = ovl_indexdir(c->dentry->d_sb); | |
795 | else | |
796 | to_index = true; | |
797 | } | |
798 | ||
799 | if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) | |
59be0971 AG |
800 | c->origin = true; |
801 | ||
016b720f | 802 | if (to_index) { |
59be0971 | 803 | c->destdir = ovl_indexdir(c->dentry->d_sb); |
1cdb0cb6 | 804 | err = ovl_get_index_name(ofs, c->lowerpath.dentry, &c->destname); |
59be0971 AG |
805 | if (err) |
806 | return err; | |
aa3ff3c1 AG |
807 | } else if (WARN_ON(!c->parent)) { |
808 | /* Disconnected dentry must be copied up to index dir */ | |
809 | return -EIO; | |
59be0971 AG |
810 | } else { |
811 | /* | |
812 | * Mark parent "impure" because it may now contain non-pure | |
813 | * upper | |
814 | */ | |
815 | err = ovl_set_impure(c->parent, c->destdir); | |
816 | if (err) | |
817 | return err; | |
818 | } | |
e9be9d5e | 819 | |
01ad3eb8 | 820 | /* Should we copyup with O_TMPFILE or with workdir? */ |
b10cdcdc AG |
821 | if (S_ISREG(c->stat.mode) && ofs->tmpfile) |
822 | err = ovl_copy_up_tmpfile(c); | |
823 | else | |
824 | err = ovl_copy_up_workdir(c); | |
aa3ff3c1 AG |
825 | if (err) |
826 | goto out; | |
827 | ||
828 | if (c->indexed) | |
016b720f AG |
829 | ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); |
830 | ||
831 | if (to_index) { | |
aa3ff3c1 AG |
832 | /* Initialize nlink for copy up of disconnected dentry */ |
833 | err = ovl_set_nlink_upper(c->dentry); | |
834 | } else { | |
59be0971 AG |
835 | struct inode *udir = d_inode(c->destdir); |
836 | ||
837 | /* Restore timestamps on parent (best effort) */ | |
838 | inode_lock(udir); | |
839 | ovl_set_timestamps(c->destdir, &c->pstat); | |
840 | inode_unlock(udir); | |
841 | ||
842 | ovl_dentry_set_upper_alias(c->dentry); | |
e9be9d5e MS |
843 | } |
844 | ||
aa3ff3c1 AG |
845 | out: |
846 | if (to_index) | |
847 | kfree(c->destname.name); | |
a6fb235a MS |
848 | return err; |
849 | } | |
850 | ||
44d5bf10 VG |
851 | static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, |
852 | int flags) | |
853 | { | |
854 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
855 | ||
44d5bf10 VG |
856 | if (!ofs->config.metacopy) |
857 | return false; | |
858 | ||
859 | if (!S_ISREG(mode)) | |
860 | return false; | |
861 | ||
862 | if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) | |
863 | return false; | |
864 | ||
865 | return true; | |
866 | } | |
867 | ||
c914c0e2 AG |
868 | static ssize_t ovl_getxattr_value(struct ovl_fs *ofs, struct dentry *dentry, |
869 | char *name, char **value) | |
fee0f298 MS |
870 | { |
871 | ssize_t res; | |
de7a52c9 | 872 | char *buf; |
fee0f298 | 873 | |
c914c0e2 | 874 | res = ovl_do_getxattr(ofs, dentry, name, NULL, 0); |
de7a52c9 MS |
875 | if (res == -ENODATA || res == -EOPNOTSUPP) |
876 | res = 0; | |
fee0f298 | 877 | |
de7a52c9 MS |
878 | if (res > 0) { |
879 | buf = kzalloc(res, GFP_KERNEL); | |
fee0f298 MS |
880 | if (!buf) |
881 | return -ENOMEM; | |
882 | ||
c914c0e2 | 883 | res = ovl_do_getxattr(ofs, dentry, name, buf, res); |
fee0f298 | 884 | if (res < 0) |
de7a52c9 MS |
885 | kfree(buf); |
886 | else | |
887 | *value = buf; | |
fee0f298 | 888 | } |
fee0f298 MS |
889 | return res; |
890 | } | |
891 | ||
0c288874 VG |
892 | /* Copy up data of an inode which was copied up metadata only in the past. */ |
893 | static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) | |
894 | { | |
c86243b0 | 895 | struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); |
4f93b426 | 896 | struct path upperpath, datapath; |
0c288874 | 897 | int err; |
993a0b2a | 898 | char *capability = NULL; |
3f649ab7 | 899 | ssize_t cap_size; |
0c288874 VG |
900 | |
901 | ovl_path_upper(c->dentry, &upperpath); | |
902 | if (WARN_ON(upperpath.dentry == NULL)) | |
903 | return -EIO; | |
904 | ||
4f93b426 VG |
905 | ovl_path_lowerdata(c->dentry, &datapath); |
906 | if (WARN_ON(datapath.dentry == NULL)) | |
907 | return -EIO; | |
908 | ||
993a0b2a | 909 | if (c->stat.size) { |
c914c0e2 AG |
910 | err = cap_size = ovl_getxattr_value(ofs, upperpath.dentry, |
911 | XATTR_NAME_CAPS, &capability); | |
de7a52c9 | 912 | if (cap_size < 0) |
993a0b2a VG |
913 | goto out; |
914 | } | |
915 | ||
c86243b0 | 916 | err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size); |
0c288874 | 917 | if (err) |
993a0b2a VG |
918 | goto out_free; |
919 | ||
920 | /* | |
921 | * Writing to upper file will clear security.capability xattr. We | |
922 | * don't want that to happen for normal copy-up operation. | |
923 | */ | |
924 | if (capability) { | |
c914c0e2 AG |
925 | err = ovl_do_setxattr(ofs, upperpath.dentry, XATTR_NAME_CAPS, |
926 | capability, cap_size, 0); | |
993a0b2a VG |
927 | if (err) |
928 | goto out_free; | |
929 | } | |
930 | ||
0c288874 | 931 | |
c914c0e2 | 932 | err = ovl_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY); |
0c288874 | 933 | if (err) |
993a0b2a | 934 | goto out_free; |
0c288874 VG |
935 | |
936 | ovl_set_upperdata(d_inode(c->dentry)); | |
993a0b2a VG |
937 | out_free: |
938 | kfree(capability); | |
939 | out: | |
0c288874 VG |
940 | return err; |
941 | } | |
942 | ||
a6fb235a MS |
943 | static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, |
944 | int flags) | |
945 | { | |
946 | int err; | |
947 | DEFINE_DELAYED_CALL(done); | |
948 | struct path parentpath; | |
949 | struct ovl_copy_up_ctx ctx = { | |
950 | .parent = parent, | |
951 | .dentry = dentry, | |
952 | .workdir = ovl_workdir(dentry), | |
953 | }; | |
954 | ||
955 | if (WARN_ON(!ctx.workdir)) | |
956 | return -EROFS; | |
957 | ||
958 | ovl_path_lower(dentry, &ctx.lowerpath); | |
959 | err = vfs_getattr(&ctx.lowerpath, &ctx.stat, | |
960 | STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); | |
961 | if (err) | |
962 | return err; | |
963 | ||
44d5bf10 VG |
964 | ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); |
965 | ||
aa3ff3c1 AG |
966 | if (parent) { |
967 | ovl_path_upper(parent, &parentpath); | |
968 | ctx.destdir = parentpath.dentry; | |
969 | ctx.destname = dentry->d_name; | |
a6fb235a | 970 | |
aa3ff3c1 AG |
971 | err = vfs_getattr(&parentpath, &ctx.pstat, |
972 | STATX_ATIME | STATX_MTIME, | |
973 | AT_STATX_SYNC_AS_STAT); | |
974 | if (err) | |
975 | return err; | |
976 | } | |
a6fb235a MS |
977 | |
978 | /* maybe truncate regular file. this has no effect on dirs */ | |
979 | if (flags & O_TRUNC) | |
980 | ctx.stat.size = 0; | |
981 | ||
982 | if (S_ISLNK(ctx.stat.mode)) { | |
983 | ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done); | |
984 | if (IS_ERR(ctx.link)) | |
985 | return PTR_ERR(ctx.link); | |
986 | } | |
a6fb235a | 987 | |
0c288874 | 988 | err = ovl_copy_up_start(dentry, flags); |
fd210b7d MS |
989 | /* err < 0: interrupted, err > 0: raced with another copy-up */ |
990 | if (unlikely(err)) { | |
991 | if (err > 0) | |
992 | err = 0; | |
993 | } else { | |
59be0971 AG |
994 | if (!ovl_dentry_upper(dentry)) |
995 | err = ovl_do_copy_up(&ctx); | |
aa3ff3c1 | 996 | if (!err && parent && !ovl_dentry_has_upper_alias(dentry)) |
f4439de1 | 997 | err = ovl_link_up(&ctx); |
0c288874 VG |
998 | if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags)) |
999 | err = ovl_copy_up_meta_inode_data(&ctx); | |
fd210b7d MS |
1000 | ovl_copy_up_end(dentry); |
1001 | } | |
7764235b | 1002 | do_delayed_call(&done); |
e9be9d5e MS |
1003 | |
1004 | return err; | |
1005 | } | |
1006 | ||
5ac8e802 | 1007 | static int ovl_copy_up_flags(struct dentry *dentry, int flags) |
e9be9d5e | 1008 | { |
8eac98b8 | 1009 | int err = 0; |
7b279bbf | 1010 | const struct cred *old_cred; |
aa3ff3c1 AG |
1011 | bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); |
1012 | ||
1013 | /* | |
1014 | * With NFS export, copy up can get called for a disconnected non-dir. | |
1015 | * In this case, we will copy up lower inode to index dir without | |
1016 | * linking it to upper dir. | |
1017 | */ | |
1018 | if (WARN_ON(disconnected && d_is_dir(dentry))) | |
1019 | return -EIO; | |
e9be9d5e | 1020 | |
7b279bbf | 1021 | old_cred = ovl_override_creds(dentry->d_sb); |
e9be9d5e MS |
1022 | while (!err) { |
1023 | struct dentry *next; | |
aa3ff3c1 | 1024 | struct dentry *parent = NULL; |
e9be9d5e | 1025 | |
0c288874 | 1026 | if (ovl_already_copied_up(dentry, flags)) |
e9be9d5e MS |
1027 | break; |
1028 | ||
1029 | next = dget(dentry); | |
1030 | /* find the topmost dentry not yet copied up */ | |
aa3ff3c1 | 1031 | for (; !disconnected;) { |
e9be9d5e MS |
1032 | parent = dget_parent(next); |
1033 | ||
59be0971 | 1034 | if (ovl_dentry_upper(parent)) |
e9be9d5e MS |
1035 | break; |
1036 | ||
1037 | dput(next); | |
1038 | next = parent; | |
1039 | } | |
1040 | ||
a6fb235a | 1041 | err = ovl_copy_up_one(parent, next, flags); |
e9be9d5e MS |
1042 | |
1043 | dput(parent); | |
1044 | dput(next); | |
1045 | } | |
8eac98b8 | 1046 | revert_creds(old_cred); |
e9be9d5e MS |
1047 | |
1048 | return err; | |
1049 | } | |
9aba6521 | 1050 | |
d6eac039 VG |
1051 | static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) |
1052 | { | |
1053 | /* Copy up of disconnected dentry does not set upper alias */ | |
0c288874 | 1054 | if (ovl_already_copied_up(dentry, flags)) |
d6eac039 VG |
1055 | return false; |
1056 | ||
1057 | if (special_file(d_inode(dentry)->i_mode)) | |
1058 | return false; | |
1059 | ||
0c288874 | 1060 | if (!ovl_open_flags_need_copy_up(flags)) |
d6eac039 VG |
1061 | return false; |
1062 | ||
1063 | return true; | |
1064 | } | |
1065 | ||
3428030d | 1066 | int ovl_maybe_copy_up(struct dentry *dentry, int flags) |
d6eac039 VG |
1067 | { |
1068 | int err = 0; | |
1069 | ||
3428030d | 1070 | if (ovl_open_need_copy_up(dentry, flags)) { |
d6eac039 VG |
1071 | err = ovl_want_write(dentry); |
1072 | if (!err) { | |
3428030d | 1073 | err = ovl_copy_up_flags(dentry, flags); |
d6eac039 VG |
1074 | ovl_drop_write(dentry); |
1075 | } | |
1076 | } | |
1077 | ||
1078 | return err; | |
1079 | } | |
1080 | ||
d1e6f6a9 VG |
1081 | int ovl_copy_up_with_data(struct dentry *dentry) |
1082 | { | |
1083 | return ovl_copy_up_flags(dentry, O_WRONLY); | |
1084 | } | |
1085 | ||
9aba6521 AG |
1086 | int ovl_copy_up(struct dentry *dentry) |
1087 | { | |
1088 | return ovl_copy_up_flags(dentry, 0); | |
1089 | } |