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1/*
2 *
3 * Copyright (C) 2011 Novell Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 */
9
10#include <linux/module.h>
11#include <linux/fs.h>
12#include <linux/slab.h>
13#include <linux/file.h>
14#include <linux/splice.h>
15#include <linux/xattr.h>
16#include <linux/security.h>
17#include <linux/uaccess.h>
18#include <linux/sched/signal.h>
19#include <linux/cred.h>
20#include <linux/namei.h>
21#include <linux/fdtable.h>
22#include <linux/ratelimit.h>
23#include <linux/exportfs.h>
24#include "overlayfs.h"
25
26#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
27
28static int ovl_ccup_set(const char *buf, const struct kernel_param *param)
29{
30 pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n");
31 return 0;
32}
33
34static int ovl_ccup_get(char *buf, const struct kernel_param *param)
35{
36 return sprintf(buf, "N\n");
37}
38
39module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644);
40MODULE_PARM_DESC(ovl_check_copy_up, "Obsolete; does nothing");
41
42int ovl_copy_xattr(struct dentry *old, struct dentry *new)
43{
44 ssize_t list_size, size, value_size = 0;
45 char *buf, *name, *value = NULL;
46 int uninitialized_var(error);
47 size_t slen;
48
49 if (!(old->d_inode->i_opflags & IOP_XATTR) ||
50 !(new->d_inode->i_opflags & IOP_XATTR))
51 return 0;
52
53 list_size = vfs_listxattr(old, NULL, 0);
54 if (list_size <= 0) {
55 if (list_size == -EOPNOTSUPP)
56 return 0;
57 return list_size;
58 }
59
60 buf = kzalloc(list_size, GFP_KERNEL);
61 if (!buf)
62 return -ENOMEM;
63
64 list_size = vfs_listxattr(old, buf, list_size);
65 if (list_size <= 0) {
66 error = list_size;
67 goto out;
68 }
69
70 for (name = buf; list_size; name += slen) {
71 slen = strnlen(name, list_size) + 1;
72
73 /* underlying fs providing us with an broken xattr list? */
74 if (WARN_ON(slen > list_size)) {
75 error = -EIO;
76 break;
77 }
78 list_size -= slen;
79
80 if (ovl_is_private_xattr(name))
81 continue;
82retry:
83 size = vfs_getxattr(old, name, value, value_size);
84 if (size == -ERANGE)
85 size = vfs_getxattr(old, name, NULL, 0);
86
87 if (size < 0) {
88 error = size;
89 break;
90 }
91
92 if (size > value_size) {
93 void *new;
94
95 new = krealloc(value, size, GFP_KERNEL);
96 if (!new) {
97 error = -ENOMEM;
98 break;
99 }
100 value = new;
101 value_size = size;
102 goto retry;
103 }
104
105 error = security_inode_copy_up_xattr(name);
106 if (error < 0 && error != -EOPNOTSUPP)
107 break;
108 if (error == 1) {
109 error = 0;
110 continue; /* Discard */
111 }
112 error = vfs_setxattr(new, name, value, size, 0);
113 if (error)
114 break;
115 }
116 kfree(value);
117out:
118 kfree(buf);
119 return error;
120}
121
122static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
123{
124 struct file *old_file;
125 struct file *new_file;
126 loff_t old_pos = 0;
127 loff_t new_pos = 0;
128 int error = 0;
129
130 if (len == 0)
131 return 0;
132
133 old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY);
134 if (IS_ERR(old_file))
135 return PTR_ERR(old_file);
136
137 new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY);
138 if (IS_ERR(new_file)) {
139 error = PTR_ERR(new_file);
140 goto out_fput;
141 }
142
143 /* Try to use clone_file_range to clone up within the same fs */
144 error = vfs_clone_file_range(old_file, 0, new_file, 0, len);
145 if (!error)
146 goto out;
147 /* Couldn't clone, so now we try to copy the data */
148 error = 0;
149
150 /* FIXME: copy up sparse files efficiently */
151 while (len) {
152 size_t this_len = OVL_COPY_UP_CHUNK_SIZE;
153 long bytes;
154
155 if (len < this_len)
156 this_len = len;
157
158 if (signal_pending_state(TASK_KILLABLE, current)) {
159 error = -EINTR;
160 break;
161 }
162
163 bytes = do_splice_direct(old_file, &old_pos,
164 new_file, &new_pos,
165 this_len, SPLICE_F_MOVE);
166 if (bytes <= 0) {
167 error = bytes;
168 break;
169 }
170 WARN_ON(old_pos != new_pos);
171
172 len -= bytes;
173 }
174out:
175 if (!error)
176 error = vfs_fsync(new_file, 0);
177 fput(new_file);
178out_fput:
179 fput(old_file);
180 return error;
181}
182
183static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat)
184{
185 struct iattr attr = {
186 .ia_valid = ATTR_SIZE,
187 .ia_size = stat->size,
188 };
189
190 return notify_change(upperdentry, &attr, NULL);
191}
192
193static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
194{
195 struct iattr attr = {
196 .ia_valid =
197 ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET,
198 .ia_atime = stat->atime,
199 .ia_mtime = stat->mtime,
200 };
201
202 return notify_change(upperdentry, &attr, NULL);
203}
204
205int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
206{
207 int err = 0;
208
209 if (!S_ISLNK(stat->mode)) {
210 struct iattr attr = {
211 .ia_valid = ATTR_MODE,
212 .ia_mode = stat->mode,
213 };
214 err = notify_change(upperdentry, &attr, NULL);
215 }
216 if (!err) {
217 struct iattr attr = {
218 .ia_valid = ATTR_UID | ATTR_GID,
219 .ia_uid = stat->uid,
220 .ia_gid = stat->gid,
221 };
222 err = notify_change(upperdentry, &attr, NULL);
223 }
224 if (!err)
225 ovl_set_timestamps(upperdentry, stat);
226
227 return err;
228}
229
230struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper)
231{
232 struct ovl_fh *fh;
233 int fh_type, fh_len, dwords;
234 void *buf;
235 int buflen = MAX_HANDLE_SZ;
236 uuid_t *uuid = &real->d_sb->s_uuid;
237
238 buf = kmalloc(buflen, GFP_KERNEL);
239 if (!buf)
240 return ERR_PTR(-ENOMEM);
241
242 /*
243 * We encode a non-connectable file handle for non-dir, because we
244 * only need to find the lower inode number and we don't want to pay
245 * the price or reconnecting the dentry.
246 */
247 dwords = buflen >> 2;
248 fh_type = exportfs_encode_fh(real, buf, &dwords, 0);
249 buflen = (dwords << 2);
250
251 fh = ERR_PTR(-EIO);
252 if (WARN_ON(fh_type < 0) ||
253 WARN_ON(buflen > MAX_HANDLE_SZ) ||
254 WARN_ON(fh_type == FILEID_INVALID))
255 goto out;
256
257 BUILD_BUG_ON(MAX_HANDLE_SZ + offsetof(struct ovl_fh, fid) > 255);
258 fh_len = offsetof(struct ovl_fh, fid) + buflen;
259 fh = kmalloc(fh_len, GFP_KERNEL);
260 if (!fh) {
261 fh = ERR_PTR(-ENOMEM);
262 goto out;
263 }
264
265 fh->version = OVL_FH_VERSION;
266 fh->magic = OVL_FH_MAGIC;
267 fh->type = fh_type;
268 fh->flags = OVL_FH_FLAG_CPU_ENDIAN;
269 /*
270 * When we will want to decode an overlay dentry from this handle
271 * and all layers are on the same fs, if we get a disconncted real
272 * dentry when we decode fid, the only way to tell if we should assign
273 * it to upperdentry or to lowerstack is by checking this flag.
274 */
275 if (is_upper)
276 fh->flags |= OVL_FH_FLAG_PATH_UPPER;
277 fh->len = fh_len;
278 fh->uuid = *uuid;
279 memcpy(fh->fid, buf, buflen);
280
281out:
282 kfree(buf);
283 return fh;
284}
285
286int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
287 struct dentry *upper)
288{
289 const struct ovl_fh *fh = NULL;
290 int err;
291
292 /*
293 * When lower layer doesn't support export operations store a 'null' fh,
294 * so we can use the overlay.origin xattr to distignuish between a copy
295 * up and a pure upper inode.
296 */
297 if (ovl_can_decode_fh(lower->d_sb)) {
298 fh = ovl_encode_real_fh(lower, false);
299 if (IS_ERR(fh))
300 return PTR_ERR(fh);
301 }
302
303 /*
304 * Do not fail when upper doesn't support xattrs.
305 */
306 err = ovl_check_setxattr(dentry, upper, OVL_XATTR_ORIGIN, fh,
307 fh ? fh->len : 0, 0);
308 kfree(fh);
309
310 return err;
311}
312
313/* Store file handle of @upper dir in @index dir entry */
314static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index)
315{
316 const struct ovl_fh *fh;
317 int err;
318
319 fh = ovl_encode_real_fh(upper, true);
320 if (IS_ERR(fh))
321 return PTR_ERR(fh);
322
323 err = ovl_do_setxattr(index, OVL_XATTR_UPPER, fh, fh->len, 0);
324
325 kfree(fh);
326 return err;
327}
328
329/*
330 * Create and install index entry.
331 *
332 * Caller must hold i_mutex on indexdir.
333 */
334static int ovl_create_index(struct dentry *dentry, struct dentry *origin,
335 struct dentry *upper)
336{
337 struct dentry *indexdir = ovl_indexdir(dentry->d_sb);
338 struct inode *dir = d_inode(indexdir);
339 struct dentry *index = NULL;
340 struct dentry *temp = NULL;
341 struct qstr name = { };
342 int err;
343
344 /*
345 * For now this is only used for creating index entry for directories,
346 * because non-dir are copied up directly to index and then hardlinked
347 * to upper dir.
348 *
349 * TODO: implement create index for non-dir, so we can call it when
350 * encoding file handle for non-dir in case index does not exist.
351 */
352 if (WARN_ON(!d_is_dir(dentry)))
353 return -EIO;
354
355 /* Directory not expected to be indexed before copy up */
356 if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry))))
357 return -EIO;
358
359 err = ovl_get_index_name(origin, &name);
360 if (err)
361 return err;
362
363 temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0));
364 err = PTR_ERR(temp);
365 if (IS_ERR(temp))
366 goto free_name;
367
368 err = ovl_set_upper_fh(upper, temp);
369 if (err)
370 goto out;
371
372 index = lookup_one_len(name.name, indexdir, name.len);
373 if (IS_ERR(index)) {
374 err = PTR_ERR(index);
375 } else {
376 err = ovl_do_rename(dir, temp, dir, index, 0);
377 dput(index);
378 }
379out:
380 if (err)
381 ovl_cleanup(dir, temp);
382 dput(temp);
383free_name:
384 kfree(name.name);
385 return err;
386}
387
388struct ovl_copy_up_ctx {
389 struct dentry *parent;
390 struct dentry *dentry;
391 struct path lowerpath;
392 struct kstat stat;
393 struct kstat pstat;
394 const char *link;
395 struct dentry *destdir;
396 struct qstr destname;
397 struct dentry *workdir;
398 bool tmpfile;
399 bool origin;
400 bool indexed;
401 bool metacopy;
402};
403
404static int ovl_link_up(struct ovl_copy_up_ctx *c)
405{
406 int err;
407 struct dentry *upper;
408 struct dentry *upperdir = ovl_dentry_upper(c->parent);
409 struct inode *udir = d_inode(upperdir);
410
411 /* Mark parent "impure" because it may now contain non-pure upper */
412 err = ovl_set_impure(c->parent, upperdir);
413 if (err)
414 return err;
415
416 err = ovl_set_nlink_lower(c->dentry);
417 if (err)
418 return err;
419
420 inode_lock_nested(udir, I_MUTEX_PARENT);
421 upper = lookup_one_len(c->dentry->d_name.name, upperdir,
422 c->dentry->d_name.len);
423 err = PTR_ERR(upper);
424 if (!IS_ERR(upper)) {
425 err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper);
426 dput(upper);
427
428 if (!err) {
429 /* Restore timestamps on parent (best effort) */
430 ovl_set_timestamps(upperdir, &c->pstat);
431 ovl_dentry_set_upper_alias(c->dentry);
432 }
433 }
434 inode_unlock(udir);
435 if (err)
436 return err;
437
438 err = ovl_set_nlink_upper(c->dentry);
439
440 return err;
441}
442
443static int ovl_install_temp(struct ovl_copy_up_ctx *c, struct dentry *temp,
444 struct dentry **newdentry)
445{
446 int err;
447 struct dentry *upper;
448 struct inode *udir = d_inode(c->destdir);
449
450 upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len);
451 if (IS_ERR(upper))
452 return PTR_ERR(upper);
453
454 if (c->tmpfile)
455 err = ovl_do_link(temp, udir, upper);
456 else
457 err = ovl_do_rename(d_inode(c->workdir), temp, udir, upper, 0);
458
459 if (!err)
460 *newdentry = dget(c->tmpfile ? upper : temp);
461 dput(upper);
462
463 return err;
464}
465
466static struct dentry *ovl_get_tmpfile(struct ovl_copy_up_ctx *c)
467{
468 int err;
469 struct dentry *temp;
470 const struct cred *old_creds = NULL;
471 struct cred *new_creds = NULL;
472 struct ovl_cattr cattr = {
473 /* Can't properly set mode on creation because of the umask */
474 .mode = c->stat.mode & S_IFMT,
475 .rdev = c->stat.rdev,
476 .link = c->link
477 };
478
479 err = security_inode_copy_up(c->dentry, &new_creds);
480 temp = ERR_PTR(err);
481 if (err < 0)
482 goto out;
483
484 if (new_creds)
485 old_creds = override_creds(new_creds);
486
487 if (c->tmpfile)
488 temp = ovl_do_tmpfile(c->workdir, c->stat.mode);
489 else
490 temp = ovl_create_temp(c->workdir, &cattr);
491out:
492 if (new_creds) {
493 revert_creds(old_creds);
494 put_cred(new_creds);
495 }
496
497 return temp;
498}
499
500static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
501{
502 int err;
503
504 err = ovl_copy_xattr(c->lowerpath.dentry, temp);
505 if (err)
506 return err;
507
508 /*
509 * Store identifier of lower inode in upper inode xattr to
510 * allow lookup of the copy up origin inode.
511 *
512 * Don't set origin when we are breaking the association with a lower
513 * hard link.
514 */
515 if (c->origin) {
516 err = ovl_set_origin(c->dentry, c->lowerpath.dentry, temp);
517 if (err)
518 return err;
519 }
520
521 if (S_ISREG(c->stat.mode) && !c->metacopy) {
522 struct path upperpath, datapath;
523
524 ovl_path_upper(c->dentry, &upperpath);
525 BUG_ON(upperpath.dentry != NULL);
526 upperpath.dentry = temp;
527
528 ovl_path_lowerdata(c->dentry, &datapath);
529 err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size);
530 if (err)
531 return err;
532 }
533
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
541 inode_lock(temp->d_inode);
542 if (c->metacopy)
543 err = ovl_set_size(temp, &c->stat);
544 if (!err)
545 err = ovl_set_attr(temp, &c->stat);
546 inode_unlock(temp->d_inode);
547
548 return err;
549}
550
551static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c)
552{
553 struct inode *udir = c->destdir->d_inode;
554 struct inode *inode;
555 struct dentry *newdentry = NULL;
556 struct dentry *temp;
557 int err;
558
559 temp = ovl_get_tmpfile(c);
560 if (IS_ERR(temp))
561 return PTR_ERR(temp);
562
563 err = ovl_copy_up_inode(c, temp);
564 if (err)
565 goto out;
566
567 if (S_ISDIR(c->stat.mode) && c->indexed) {
568 err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp);
569 if (err)
570 goto out;
571 }
572
573 if (c->tmpfile) {
574 inode_lock_nested(udir, I_MUTEX_PARENT);
575 err = ovl_install_temp(c, temp, &newdentry);
576 inode_unlock(udir);
577 } else {
578 err = ovl_install_temp(c, temp, &newdentry);
579 }
580 if (err)
581 goto out;
582
583 if (!c->metacopy)
584 ovl_set_upperdata(d_inode(c->dentry));
585 inode = d_inode(c->dentry);
586 ovl_inode_update(inode, newdentry);
587 if (S_ISDIR(inode->i_mode))
588 ovl_set_flag(OVL_WHITEOUTS, inode);
589
590out:
591 if (err && !c->tmpfile)
592 ovl_cleanup(d_inode(c->workdir), temp);
593 dput(temp);
594 return err;
595
596}
597
598/*
599 * Copy up a single dentry
600 *
601 * All renames start with copy up of source if necessary. The actual
602 * rename will only proceed once the copy up was successful. Copy up uses
603 * upper parent i_mutex for exclusion. Since rename can change d_parent it
604 * is possible that the copy up will lock the old parent. At that point
605 * the file will have already been copied up anyway.
606 */
607static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
608{
609 int err;
610 struct ovl_fs *ofs = c->dentry->d_sb->s_fs_info;
611 bool to_index = false;
612
613 /*
614 * Indexed non-dir is copied up directly to the index entry and then
615 * hardlinked to upper dir. Indexed dir is copied up to indexdir,
616 * then index entry is created and then copied up dir installed.
617 * Copying dir up to indexdir instead of workdir simplifies locking.
618 */
619 if (ovl_need_index(c->dentry)) {
620 c->indexed = true;
621 if (S_ISDIR(c->stat.mode))
622 c->workdir = ovl_indexdir(c->dentry->d_sb);
623 else
624 to_index = true;
625 }
626
627 if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index)
628 c->origin = true;
629
630 if (to_index) {
631 c->destdir = ovl_indexdir(c->dentry->d_sb);
632 err = ovl_get_index_name(c->lowerpath.dentry, &c->destname);
633 if (err)
634 return err;
635 } else if (WARN_ON(!c->parent)) {
636 /* Disconnected dentry must be copied up to index dir */
637 return -EIO;
638 } else {
639 /*
640 * Mark parent "impure" because it may now contain non-pure
641 * upper
642 */
643 err = ovl_set_impure(c->parent, c->destdir);
644 if (err)
645 return err;
646 }
647
648 /* Should we copyup with O_TMPFILE or with workdir? */
649 if (S_ISREG(c->stat.mode) && ofs->tmpfile) {
650 c->tmpfile = true;
651 err = ovl_copy_up_locked(c);
652 } else {
653 err = ovl_lock_rename_workdir(c->workdir, c->destdir);
654 if (!err) {
655 err = ovl_copy_up_locked(c);
656 unlock_rename(c->workdir, c->destdir);
657 }
658 }
659
660
661 if (err)
662 goto out;
663
664 if (c->indexed)
665 ovl_set_flag(OVL_INDEX, d_inode(c->dentry));
666
667 if (to_index) {
668 /* Initialize nlink for copy up of disconnected dentry */
669 err = ovl_set_nlink_upper(c->dentry);
670 } else {
671 struct inode *udir = d_inode(c->destdir);
672
673 /* Restore timestamps on parent (best effort) */
674 inode_lock(udir);
675 ovl_set_timestamps(c->destdir, &c->pstat);
676 inode_unlock(udir);
677
678 ovl_dentry_set_upper_alias(c->dentry);
679 }
680
681out:
682 if (to_index)
683 kfree(c->destname.name);
684 return err;
685}
686
687static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode,
688 int flags)
689{
690 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
691
692 /* TODO: Will enable metacopy in last patch of series */
693 return false;
694
695 if (!ofs->config.metacopy)
696 return false;
697
698 if (!S_ISREG(mode))
699 return false;
700
701 if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)))
702 return false;
703
704 return true;
705}
706
707/* Copy up data of an inode which was copied up metadata only in the past. */
708static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c)
709{
710 struct path upperpath, datapath;
711 int err;
712
713 ovl_path_upper(c->dentry, &upperpath);
714 if (WARN_ON(upperpath.dentry == NULL))
715 return -EIO;
716
717 ovl_path_lowerdata(c->dentry, &datapath);
718 if (WARN_ON(datapath.dentry == NULL))
719 return -EIO;
720
721 err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size);
722 if (err)
723 return err;
724
725 err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);
726 if (err)
727 return err;
728
729 ovl_set_upperdata(d_inode(c->dentry));
730 return err;
731}
732
733static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
734 int flags)
735{
736 int err;
737 DEFINE_DELAYED_CALL(done);
738 struct path parentpath;
739 struct ovl_copy_up_ctx ctx = {
740 .parent = parent,
741 .dentry = dentry,
742 .workdir = ovl_workdir(dentry),
743 };
744
745 if (WARN_ON(!ctx.workdir))
746 return -EROFS;
747
748 ovl_path_lower(dentry, &ctx.lowerpath);
749 err = vfs_getattr(&ctx.lowerpath, &ctx.stat,
750 STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
751 if (err)
752 return err;
753
754 ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags);
755
756 if (parent) {
757 ovl_path_upper(parent, &parentpath);
758 ctx.destdir = parentpath.dentry;
759 ctx.destname = dentry->d_name;
760
761 err = vfs_getattr(&parentpath, &ctx.pstat,
762 STATX_ATIME | STATX_MTIME,
763 AT_STATX_SYNC_AS_STAT);
764 if (err)
765 return err;
766 }
767
768 /* maybe truncate regular file. this has no effect on dirs */
769 if (flags & O_TRUNC)
770 ctx.stat.size = 0;
771
772 if (S_ISLNK(ctx.stat.mode)) {
773 ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done);
774 if (IS_ERR(ctx.link))
775 return PTR_ERR(ctx.link);
776 }
777
778 err = ovl_copy_up_start(dentry, flags);
779 /* err < 0: interrupted, err > 0: raced with another copy-up */
780 if (unlikely(err)) {
781 if (err > 0)
782 err = 0;
783 } else {
784 if (!ovl_dentry_upper(dentry))
785 err = ovl_do_copy_up(&ctx);
786 if (!err && parent && !ovl_dentry_has_upper_alias(dentry))
787 err = ovl_link_up(&ctx);
788 if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags))
789 err = ovl_copy_up_meta_inode_data(&ctx);
790 ovl_copy_up_end(dentry);
791 }
792 do_delayed_call(&done);
793
794 return err;
795}
796
797int ovl_copy_up_flags(struct dentry *dentry, int flags)
798{
799 int err = 0;
800 const struct cred *old_cred = ovl_override_creds(dentry->d_sb);
801 bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED);
802
803 /*
804 * With NFS export, copy up can get called for a disconnected non-dir.
805 * In this case, we will copy up lower inode to index dir without
806 * linking it to upper dir.
807 */
808 if (WARN_ON(disconnected && d_is_dir(dentry)))
809 return -EIO;
810
811 while (!err) {
812 struct dentry *next;
813 struct dentry *parent = NULL;
814
815 if (ovl_already_copied_up(dentry, flags))
816 break;
817
818 next = dget(dentry);
819 /* find the topmost dentry not yet copied up */
820 for (; !disconnected;) {
821 parent = dget_parent(next);
822
823 if (ovl_dentry_upper(parent))
824 break;
825
826 dput(next);
827 next = parent;
828 }
829
830 err = ovl_copy_up_one(parent, next, flags);
831
832 dput(parent);
833 dput(next);
834 }
835 revert_creds(old_cred);
836
837 return err;
838}
839
840static bool ovl_open_need_copy_up(struct dentry *dentry, int flags)
841{
842 /* Copy up of disconnected dentry does not set upper alias */
843 if (ovl_already_copied_up(dentry, flags))
844 return false;
845
846 if (special_file(d_inode(dentry)->i_mode))
847 return false;
848
849 if (!ovl_open_flags_need_copy_up(flags))
850 return false;
851
852 return true;
853}
854
855int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
856{
857 int err = 0;
858
859 if (ovl_open_need_copy_up(dentry, file_flags)) {
860 err = ovl_want_write(dentry);
861 if (!err) {
862 err = ovl_copy_up_flags(dentry, file_flags);
863 ovl_drop_write(dentry);
864 }
865 }
866
867 return err;
868}
869
870int ovl_copy_up(struct dentry *dentry)
871{
872 return ovl_copy_up_flags(dentry, 0);
873}