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1bd0a3ae | 27 | pr_warn("\"check_copy_up\" module option is obsolete\n"); |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