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-rw-r--r--Documentation/btrfs-restore.asciidoc3
-rw-r--r--cmds-restore.c141
2 files changed, 141 insertions, 3 deletions
diff --git a/Documentation/btrfs-restore.asciidoc b/Documentation/btrfs-restore.asciidoc
index f66d7553..5faeb561 100644
--- a/Documentation/btrfs-restore.asciidoc
+++ b/Documentation/btrfs-restore.asciidoc
@@ -32,6 +32,9 @@ get extended attributes.
-m|--metadata::
restore owner, mode and times.
+-S|--symlinks::
+restore symbolic links as well as normal files.
+
-v::
verbose.
diff --git a/cmds-restore.c b/cmds-restore.c
index 40fed5a0..059fbf2c 100644
--- a/cmds-restore.c
+++ b/cmds-restore.c
@@ -45,9 +45,11 @@
static char fs_name[PATH_MAX];
static char path_name[PATH_MAX];
+static char symlink_target[PATH_MAX];
static int get_snaps = 0;
static int verbose = 0;
static int restore_metadata = 0;
+static int restore_symlinks = 0;
static int ignore_errors = 0;
static int overwrite = 0;
static int get_xattrs = 0;
@@ -811,6 +813,126 @@ static int overwrite_ok(const char * path)
return 1;
}
+static int copy_symlink(struct btrfs_root *root, struct btrfs_key *key,
+ const char *file)
+{
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_file_extent_item *extent_item;
+ struct btrfs_inode_item *inode_item;
+ u32 len;
+ u32 name_offset;
+ int ret;
+ struct btrfs_timespec *bts;
+ struct timespec times[2];
+
+ ret = overwrite_ok(path_name);
+ if (ret == 0)
+ return 0; /* skip this file */
+
+ /* symlink() can't overwrite, so unlink first */
+ if (ret == 2) {
+ ret = unlink(path_name);
+ if (ret) {
+ fprintf(stderr, "failed to unlink '%s' for overwrite\n",
+ path_name);
+ return ret;
+ }
+ }
+
+ key->type = BTRFS_EXTENT_DATA_KEY;
+ key->offset = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ leaf = path->nodes[0];
+ if (!leaf) {
+ fprintf(stderr, "Error getting leaf for symlink '%s'\n", file);
+ ret = -1;
+ goto out;
+ }
+
+ extent_item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+
+ len = btrfs_file_extent_inline_item_len(leaf,
+ btrfs_item_nr(path->slots[0]));
+ if (len > PATH_MAX) {
+ fprintf(stderr, "Symlink '%s' target length %d is longer than PATH_MAX\n",
+ fs_name, len);
+ ret = -1;
+ goto out;
+ }
+
+ name_offset = (unsigned long) extent_item
+ + offsetof(struct btrfs_file_extent_item, disk_bytenr);
+ read_extent_buffer(leaf, symlink_target, name_offset, len);
+
+ symlink_target[len] = 0;
+
+ if (!dry_run) {
+ ret = symlink(symlink_target, path_name);
+ if (ret < 0) {
+ fprintf(stderr, "Failed to restore symlink '%s': %s\n",
+ path_name, strerror(errno));
+ goto out;
+ }
+ }
+ printf("SYMLINK: '%s' => '%s'\n", path_name, symlink_target);
+
+ ret = 0;
+ if (!restore_metadata)
+ goto out;
+
+ /*
+ * Symlink metadata operates differently than files/directories, so do
+ * our own work here.
+ */
+ key->type = BTRFS_INODE_ITEM_KEY;
+ key->offset = 0;
+
+ btrfs_release_path(path);
+
+ ret = btrfs_lookup_inode(NULL, root, path, key, 0);
+ if (ret) {
+ fprintf(stderr, "Failed to lookup inode for '%s'\n", file);
+ goto out;
+ }
+
+ inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_inode_item);
+
+ ret = fchownat(-1, file, btrfs_inode_uid(path->nodes[0], inode_item),
+ btrfs_inode_gid(path->nodes[0], inode_item),
+ AT_SYMLINK_NOFOLLOW);
+ if (ret) {
+ fprintf(stderr, "Failed to change owner: %s\n",
+ strerror(errno));
+ goto out;
+ }
+
+ bts = btrfs_inode_atime(inode_item);
+ times[0].tv_sec = btrfs_timespec_sec(path->nodes[0], bts);
+ times[0].tv_nsec = btrfs_timespec_nsec(path->nodes[0], bts);
+
+ bts = btrfs_inode_mtime(inode_item);
+ times[1].tv_sec = btrfs_timespec_sec(path->nodes[0], bts);
+ times[1].tv_nsec = btrfs_timespec_nsec(path->nodes[0], bts);
+
+ ret = utimensat(-1, file, times, AT_SYMLINK_NOFOLLOW);
+ if (ret)
+ fprintf(stderr, "Failed to set times: %s\n", strerror(errno));
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
const char *output_rootdir, const char *in_dir,
const regex_t *mreg)
@@ -925,8 +1047,7 @@ static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
snprintf(path_name, PATH_MAX, "%s%s", output_rootdir, fs_name);
/*
- * At this point we're only going to restore directories and
- * files, no symlinks or anything else.
+ * Restore directories, files, symlinks and metadata.
*/
if (type == BTRFS_FT_REG_FILE) {
if (!overwrite_ok(path_name))
@@ -1033,6 +1154,15 @@ static int search_dir(struct btrfs_root *root, struct btrfs_key *key,
goto next;
goto out;
}
+ } else if (type == BTRFS_FT_SYMLINK) {
+ if (restore_symlinks)
+ ret = copy_symlink(root, &location, path_name);
+ if (ret < 0) {
+ if (ignore_errors)
+ goto next;
+ btrfs_free_path(path);
+ return ret;
+ }
}
next:
path->slots[0]++;
@@ -1259,6 +1389,7 @@ const char * const cmd_restore_usage[] = {
"-s get snapshots",
"-x get extended attributes",
"-m|--metadata restore owner, mode and times",
+ "-S|--symlinks restore symbolic links"
"-v verbose",
"-i ignore errors",
"-o overwrite",
@@ -1301,10 +1432,11 @@ int cmd_restore(int argc, char **argv)
{ "path-regex", required_argument, NULL, 256},
{ "dry-run", no_argument, NULL, 'D'},
{ "metadata", no_argument, NULL, 'm'},
+ { "symlinks", no_argument, NULL, 'S'},
{ NULL, 0, NULL, 0}
};
- opt = getopt_long(argc, argv, "sxviot:u:dmf:r:lDc", long_options,
+ opt = getopt_long(argc, argv, "sSxviot:u:dmf:r:lDc", long_options,
NULL);
if (opt < 0)
break;
@@ -1353,6 +1485,9 @@ int cmd_restore(int argc, char **argv)
case 'm':
restore_metadata = 1;
break;
+ case 'S':
+ restore_symlinks = 1;
+ break;
case 'D':
dry_run = 1;
break;