1 // SPDX-License-Identifier: GPL-2.0-only
4 * Copyright (C) 2011 Novell Inc.
7 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/file.h>
11 #include <linux/fileattr.h>
12 #include <linux/splice.h>
13 #include <linux/xattr.h>
14 #include <linux/security.h>
15 #include <linux/uaccess.h>
16 #include <linux/sched/signal.h>
17 #include <linux/cred.h>
18 #include <linux/namei.h>
19 #include <linux/fdtable.h>
20 #include <linux/ratelimit.h>
21 #include <linux/exportfs.h>
22 #include "overlayfs.h"
24 #define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
26 static int ovl_ccup_set(const char *buf, const struct kernel_param *param)
28 pr_warn("\"check_copy_up\" module option is obsolete\n");
32 static int ovl_ccup_get(char *buf, const struct kernel_param *param)
34 return sprintf(buf, "N\n");
37 module_param_call(check_copy_up, ovl_ccup_set, ovl_ccup_get, NULL, 0644);
38 MODULE_PARM_DESC(check_copy_up, "Obsolete; does nothing");
40 static bool ovl_must_copy_xattr(const char *name)
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);
47 int ovl_copy_xattr(struct super_block *sb, struct dentry *old,
50 ssize_t list_size, size, value_size = 0;
51 char *buf, *name, *value = NULL;
55 if (!(old->d_inode->i_opflags & IOP_XATTR) ||
56 !(new->d_inode->i_opflags & IOP_XATTR))
59 list_size = vfs_listxattr(old, NULL, 0);
61 if (list_size == -EOPNOTSUPP)
66 buf = kvzalloc(list_size, GFP_KERNEL);
70 list_size = vfs_listxattr(old, buf, list_size);
76 for (name = buf; list_size; name += slen) {
77 slen = strnlen(name, list_size) + 1;
79 /* underlying fs providing us with an broken xattr list? */
80 if (WARN_ON(slen > list_size)) {
86 if (ovl_is_private_xattr(sb, name))
89 error = security_inode_copy_up_xattr(name);
90 if (error < 0 && error != -EOPNOTSUPP)
94 continue; /* Discard */
97 size = vfs_getxattr(&init_user_ns, old, name, value, value_size);
99 size = vfs_getxattr(&init_user_ns, old, name, NULL, 0);
106 if (size > value_size) {
109 new = kvmalloc(size, GFP_KERNEL);
120 error = vfs_setxattr(&init_user_ns, new, name, value, size, 0);
122 if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name))
125 /* Ignore failure to copy unknown xattrs */
135 static int ovl_copy_fileattr(struct inode *inode, struct path *old,
138 struct fileattr oldfa = { .flags_valid = true };
139 struct fileattr newfa = { .flags_valid = true };
142 err = ovl_real_fileattr_get(old, &oldfa);
144 /* Ntfs-3g returns -EINVAL for "no fileattr support" */
145 if (err == -ENOTTY || err == -EINVAL)
147 pr_warn("failed to retrieve lower fileattr (%pd2, err=%i)\n",
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.
158 if (oldfa.flags & OVL_PROT_FS_FLAGS_MASK) {
159 err = ovl_set_protattr(inode, new->dentry, &oldfa);
161 pr_warn_once("copying fileattr: no xattr on upper\n");
166 /* Don't bother copying flags if none are set */
167 if (!(oldfa.flags & OVL_COPY_FS_FLAGS_MASK))
170 err = ovl_real_fileattr_get(new, &newfa);
173 * Returning an error if upper doesn't support fileattr will
174 * result in a regression, so revert to the old behavior.
176 if (err == -ENOTTY || err == -EINVAL) {
177 pr_warn_once("copying fileattr: no support on upper\n");
180 pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n",
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);
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);
193 return ovl_real_fileattr_set(new, &newfa);
196 static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old,
197 struct path *new, loff_t len)
199 struct file *old_file;
200 struct file *new_file;
204 loff_t data_pos = -1;
206 bool skip_hole = false;
212 old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY);
213 if (IS_ERR(old_file))
214 return PTR_ERR(old_file);
216 new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY);
217 if (IS_ERR(new_file)) {
218 error = PTR_ERR(new_file);
222 /* Try to use clone_file_range to clone up within the same fs */
223 cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0);
226 /* Couldn't clone, so now we try to copy the data */
228 /* Check if lower fs supports seek operation */
229 if (old_file->f_mode & FMODE_LSEEK &&
230 old_file->f_op->llseek)
234 size_t this_len = OVL_COPY_UP_CHUNK_SIZE;
240 if (signal_pending_state(TASK_KILLABLE, current)) {
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.
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.
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;
266 old_pos = new_pos = data_pos;
268 } else if (data_pos == -ENXIO) {
270 } else if (data_pos < 0) {
275 bytes = do_splice_direct(old_file, &old_pos,
277 this_len, SPLICE_F_MOVE);
282 WARN_ON(old_pos != new_pos);
287 if (!error && ovl_should_sync(ofs))
288 error = vfs_fsync(new_file, 0);
295 static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat)
297 struct iattr attr = {
298 .ia_valid = ATTR_SIZE,
299 .ia_size = stat->size,
302 return notify_change(&init_user_ns, upperdentry, &attr, NULL);
305 static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
307 struct iattr attr = {
309 ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET,
310 .ia_atime = stat->atime,
311 .ia_mtime = stat->mtime,
314 return notify_change(&init_user_ns, upperdentry, &attr, NULL);
317 int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
321 if (!S_ISLNK(stat->mode)) {
322 struct iattr attr = {
323 .ia_valid = ATTR_MODE,
324 .ia_mode = stat->mode,
326 err = notify_change(&init_user_ns, upperdentry, &attr, NULL);
329 struct iattr attr = {
330 .ia_valid = ATTR_UID | ATTR_GID,
334 err = notify_change(&init_user_ns, upperdentry, &attr, NULL);
337 ovl_set_timestamps(upperdentry, stat);
342 struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real,
347 int buflen = MAX_HANDLE_SZ;
348 uuid_t *uuid = &real->d_sb->s_uuid;
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);
355 fh = kzalloc(buflen + OVL_FH_FID_OFFSET, GFP_KERNEL);
357 return ERR_PTR(-ENOMEM);
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.
364 dwords = buflen >> 2;
365 fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0);
366 buflen = (dwords << 2);
369 if (WARN_ON(fh_type < 0) ||
370 WARN_ON(buflen > MAX_HANDLE_SZ) ||
371 WARN_ON(fh_type == FILEID_INVALID))
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;
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.
385 fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER;
386 fh->fb.len = sizeof(fh->fb) + buflen;
387 if (ofs->config.uuid)
397 int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower,
398 struct dentry *upper)
400 const struct ovl_fh *fh = NULL;
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.
408 if (ovl_can_decode_fh(lower->d_sb)) {
409 fh = ovl_encode_real_fh(ofs, lower, false);
415 * Do not fail when upper doesn't support xattrs.
417 err = ovl_check_setxattr(ofs, upper, OVL_XATTR_ORIGIN, fh->buf,
418 fh ? fh->fb.len : 0, 0);
421 /* Ignore -EPERM from setting "user.*" on symlink/special */
422 return err == -EPERM ? 0 : err;
425 /* Store file handle of @upper dir in @index dir entry */
426 static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper,
427 struct dentry *index)
429 const struct ovl_fh *fh;
432 fh = ovl_encode_real_fh(ofs, upper, true);
436 err = ovl_do_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len);
443 * Create and install index entry.
445 * Caller must hold i_mutex on indexdir.
447 static int ovl_create_index(struct dentry *dentry, struct dentry *origin,
448 struct dentry *upper)
450 struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
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 = { };
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
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.
466 if (WARN_ON(!d_is_dir(dentry)))
469 /* Directory not expected to be indexed before copy up */
470 if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry))))
473 err = ovl_get_index_name(ofs, origin, &name);
477 temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0));
482 err = ovl_set_upper_fh(ofs, upper, temp);
486 index = lookup_one_len(name.name, indexdir, name.len);
488 err = PTR_ERR(index);
490 err = ovl_do_rename(dir, temp, dir, index, 0);
495 ovl_cleanup(dir, temp);
502 struct ovl_copy_up_ctx {
503 struct dentry *parent;
504 struct dentry *dentry;
505 struct path lowerpath;
509 struct dentry *destdir;
510 struct qstr destname;
511 struct dentry *workdir;
517 static int ovl_link_up(struct ovl_copy_up_ctx *c)
520 struct dentry *upper;
521 struct dentry *upperdir = ovl_dentry_upper(c->parent);
522 struct inode *udir = d_inode(upperdir);
524 /* Mark parent "impure" because it may now contain non-pure upper */
525 err = ovl_set_impure(c->parent, upperdir);
529 err = ovl_set_nlink_lower(c->dentry);
533 inode_lock_nested(udir, I_MUTEX_PARENT);
534 upper = lookup_one_len(c->dentry->d_name.name, upperdir,
535 c->dentry->d_name.len);
536 err = PTR_ERR(upper);
537 if (!IS_ERR(upper)) {
538 err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper);
542 /* Restore timestamps on parent (best effort) */
543 ovl_set_timestamps(upperdir, &c->pstat);
544 ovl_dentry_set_upper_alias(c->dentry);
551 err = ovl_set_nlink_upper(c->dentry);
556 static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
558 struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
559 struct inode *inode = d_inode(c->dentry);
560 struct path upperpath, datapath;
563 ovl_path_upper(c->dentry, &upperpath);
564 if (WARN_ON(upperpath.dentry != NULL))
567 upperpath.dentry = temp;
570 * Copy up data first and then xattrs. Writing data after
571 * xattrs will remove security.capability xattr automatically.
573 if (S_ISREG(c->stat.mode) && !c->metacopy) {
574 ovl_path_lowerdata(c->dentry, &datapath);
575 err = ovl_copy_up_data(ofs, &datapath, &upperpath,
581 err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp);
585 if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) {
587 * Copy the fileattr inode flags that are the source of already
590 err = ovl_copy_fileattr(inode, &c->lowerpath, &upperpath);
596 * Store identifier of lower inode in upper inode xattr to
597 * allow lookup of the copy up origin inode.
599 * Don't set origin when we are breaking the association with a lower
603 err = ovl_set_origin(ofs, c->lowerpath.dentry, temp);
609 err = ovl_check_setxattr(ofs, temp, OVL_XATTR_METACOPY,
610 NULL, 0, -EOPNOTSUPP);
615 inode_lock(temp->d_inode);
616 if (S_ISREG(c->stat.mode))
617 err = ovl_set_size(temp, &c->stat);
619 err = ovl_set_attr(temp, &c->stat);
620 inode_unlock(temp->d_inode);
625 struct ovl_cu_creds {
626 const struct cred *old;
630 static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc)
634 cc->old = cc->new = NULL;
635 err = security_inode_copy_up(dentry, &cc->new);
640 cc->old = override_creds(cc->new);
645 static void ovl_revert_cu_creds(struct ovl_cu_creds *cc)
648 revert_creds(cc->old);
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.
657 static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
660 struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir);
661 struct dentry *temp, *upper;
662 struct ovl_cu_creds cc;
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,
671 /* workdir and destdir could be the same when copying up to indexdir */
673 if (lock_rename(c->workdir, c->destdir) != NULL)
676 err = ovl_prep_cu_creds(c->dentry, &cc);
680 temp = ovl_create_temp(c->workdir, &cattr);
681 ovl_revert_cu_creds(&cc);
687 err = ovl_copy_up_inode(c, temp);
691 if (S_ISDIR(c->stat.mode) && c->indexed) {
692 err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp);
697 upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len);
698 err = PTR_ERR(upper);
702 err = ovl_do_rename(wdir, temp, udir, upper, 0);
708 ovl_set_upperdata(d_inode(c->dentry));
709 inode = d_inode(c->dentry);
710 ovl_inode_update(inode, temp);
711 if (S_ISDIR(inode->i_mode))
712 ovl_set_flag(OVL_WHITEOUTS, inode);
714 unlock_rename(c->workdir, c->destdir);
719 ovl_cleanup(wdir, temp);
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)
727 struct inode *udir = d_inode(c->destdir);
728 struct dentry *temp, *upper;
729 struct ovl_cu_creds cc;
732 err = ovl_prep_cu_creds(c->dentry, &cc);
736 temp = ovl_do_tmpfile(c->workdir, c->stat.mode);
737 ovl_revert_cu_creds(&cc);
740 return PTR_ERR(temp);
742 err = ovl_copy_up_inode(c, temp);
746 inode_lock_nested(udir, I_MUTEX_PARENT);
748 upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len);
749 err = PTR_ERR(upper);
750 if (!IS_ERR(upper)) {
751 err = ovl_do_link(temp, udir, upper);
760 ovl_set_upperdata(d_inode(c->dentry));
761 ovl_inode_update(d_inode(c->dentry), temp);
771 * Copy up a single dentry
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.
779 static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
782 struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
783 bool to_index = false;
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.
791 if (ovl_need_index(c->dentry)) {
793 if (S_ISDIR(c->stat.mode))
794 c->workdir = ovl_indexdir(c->dentry->d_sb);
799 if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index)
803 c->destdir = ovl_indexdir(c->dentry->d_sb);
804 err = ovl_get_index_name(ofs, c->lowerpath.dentry, &c->destname);
807 } else if (WARN_ON(!c->parent)) {
808 /* Disconnected dentry must be copied up to index dir */
812 * Mark parent "impure" because it may now contain non-pure
815 err = ovl_set_impure(c->parent, c->destdir);
820 /* Should we copyup with O_TMPFILE or with workdir? */
821 if (S_ISREG(c->stat.mode) && ofs->tmpfile)
822 err = ovl_copy_up_tmpfile(c);
824 err = ovl_copy_up_workdir(c);
829 ovl_set_flag(OVL_INDEX, d_inode(c->dentry));
832 /* Initialize nlink for copy up of disconnected dentry */
833 err = ovl_set_nlink_upper(c->dentry);
835 struct inode *udir = d_inode(c->destdir);
837 /* Restore timestamps on parent (best effort) */
839 ovl_set_timestamps(c->destdir, &c->pstat);
842 ovl_dentry_set_upper_alias(c->dentry);
847 kfree(c->destname.name);
851 static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode,
854 struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
856 if (!ofs->config.metacopy)
862 if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC)))
868 static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value)
873 res = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
874 if (res == -ENODATA || res == -EOPNOTSUPP)
878 buf = kzalloc(res, GFP_KERNEL);
882 res = vfs_getxattr(&init_user_ns, dentry, name, buf, res);
891 /* Copy up data of an inode which was copied up metadata only in the past. */
892 static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c)
894 struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
895 struct path upperpath, datapath;
897 char *capability = NULL;
900 ovl_path_upper(c->dentry, &upperpath);
901 if (WARN_ON(upperpath.dentry == NULL))
904 ovl_path_lowerdata(c->dentry, &datapath);
905 if (WARN_ON(datapath.dentry == NULL))
909 err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS,
915 err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size);
920 * Writing to upper file will clear security.capability xattr. We
921 * don't want that to happen for normal copy-up operation.
924 err = vfs_setxattr(&init_user_ns, upperpath.dentry,
925 XATTR_NAME_CAPS, capability, cap_size, 0);
931 err = ovl_do_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY);
935 ovl_set_upperdata(d_inode(c->dentry));
942 static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
946 DEFINE_DELAYED_CALL(done);
947 struct path parentpath;
948 struct ovl_copy_up_ctx ctx = {
951 .workdir = ovl_workdir(dentry),
954 if (WARN_ON(!ctx.workdir))
957 ovl_path_lower(dentry, &ctx.lowerpath);
958 err = vfs_getattr(&ctx.lowerpath, &ctx.stat,
959 STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
963 ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags);
966 ovl_path_upper(parent, &parentpath);
967 ctx.destdir = parentpath.dentry;
968 ctx.destname = dentry->d_name;
970 err = vfs_getattr(&parentpath, &ctx.pstat,
971 STATX_ATIME | STATX_MTIME,
972 AT_STATX_SYNC_AS_STAT);
977 /* maybe truncate regular file. this has no effect on dirs */
981 if (S_ISLNK(ctx.stat.mode)) {
982 ctx.link = vfs_get_link(ctx.lowerpath.dentry, &done);
983 if (IS_ERR(ctx.link))
984 return PTR_ERR(ctx.link);
987 err = ovl_copy_up_start(dentry, flags);
988 /* err < 0: interrupted, err > 0: raced with another copy-up */
993 if (!ovl_dentry_upper(dentry))
994 err = ovl_do_copy_up(&ctx);
995 if (!err && parent && !ovl_dentry_has_upper_alias(dentry))
996 err = ovl_link_up(&ctx);
997 if (!err && ovl_dentry_needs_data_copy_up_locked(dentry, flags))
998 err = ovl_copy_up_meta_inode_data(&ctx);
999 ovl_copy_up_end(dentry);
1001 do_delayed_call(&done);
1006 static int ovl_copy_up_flags(struct dentry *dentry, int flags)
1009 const struct cred *old_cred;
1010 bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED);
1013 * With NFS export, copy up can get called for a disconnected non-dir.
1014 * In this case, we will copy up lower inode to index dir without
1015 * linking it to upper dir.
1017 if (WARN_ON(disconnected && d_is_dir(dentry)))
1020 old_cred = ovl_override_creds(dentry->d_sb);
1022 struct dentry *next;
1023 struct dentry *parent = NULL;
1025 if (ovl_already_copied_up(dentry, flags))
1028 next = dget(dentry);
1029 /* find the topmost dentry not yet copied up */
1030 for (; !disconnected;) {
1031 parent = dget_parent(next);
1033 if (ovl_dentry_upper(parent))
1040 err = ovl_copy_up_one(parent, next, flags);
1045 revert_creds(old_cred);
1050 static bool ovl_open_need_copy_up(struct dentry *dentry, int flags)
1052 /* Copy up of disconnected dentry does not set upper alias */
1053 if (ovl_already_copied_up(dentry, flags))
1056 if (special_file(d_inode(dentry)->i_mode))
1059 if (!ovl_open_flags_need_copy_up(flags))
1065 int ovl_maybe_copy_up(struct dentry *dentry, int flags)
1069 if (ovl_open_need_copy_up(dentry, flags)) {
1070 err = ovl_want_write(dentry);
1072 err = ovl_copy_up_flags(dentry, flags);
1073 ovl_drop_write(dentry);
1080 int ovl_copy_up_with_data(struct dentry *dentry)
1082 return ovl_copy_up_flags(dentry, O_WRONLY);
1085 int ovl_copy_up(struct dentry *dentry)
1087 return ovl_copy_up_flags(dentry, 0);