Btrfs-progs: restore can now recover file xattrs

This change adds a new option to the restore command, named -x,
that makes it restore file extented attributes too. This is an
optional behaviour and it's disabled by default.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/cmds-restore.c b/cmds-restore.c
index 712b672..d2870d7 100644 (file)
--- a/cmds-restore.c
+++ b/cmds-restore.c
@@ -33,6 +33,8 @@
 #include <zlib.h>
 #include <regex.h>
 #include <getopt.h>
+#include <sys/types.h>
+#include <attr/xattr.h>
 
 #include "ctree.h"
 #include "disk-io.h"
@@ -50,6 +52,7 @@ static int get_snaps = 0;
 static int verbose = 0;
 static int ignore_errors = 0;
 static int overwrite = 0;
+static int get_xattrs = 0;
 
 #define LZO_LEN 4
 #define PAGE_CACHE_SIZE 4096
@@ -415,6 +418,114 @@ again:
 }
 
 
+static int set_file_xattrs(struct btrfs_root *root, u64 inode,
+                          int fd, const char *file_name)
+{
+       struct btrfs_key key;
+       struct btrfs_path *path;
+       struct extent_buffer *leaf;
+       struct btrfs_dir_item *di;
+       u32 name_len = 0;
+       u32 data_len = 0;
+       u32 len = 0;
+       u32 cur, total_len;
+       char *name = NULL;
+       char *data = NULL;
+       int ret = 0;
+
+       key.objectid = inode;
+       key.type = BTRFS_XATTR_ITEM_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];
+       while (1) {
+               if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+                       do {
+                               ret = next_leaf(root, path);
+                               if (ret < 0) {
+                                       fprintf(stderr,
+                                               "Error searching for extended attributes: %d\n",
+                                               ret);
+                                       goto out;
+                               } else if (ret) {
+                                       /* No more leaves to search */
+                                       ret = 0;
+                                       goto out;
+                               }
+                               leaf = path->nodes[0];
+                       } while (!leaf);
+                       continue;
+               }
+
+               btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+               if (key.type != BTRFS_XATTR_ITEM_KEY || key.objectid != inode)
+                       break;
+               cur = 0;
+               total_len = btrfs_item_size_nr(leaf, path->slots[0]);
+               di = btrfs_item_ptr(leaf, path->slots[0],
+                                   struct btrfs_dir_item);
+
+               while (cur < total_len) {
+                       len = btrfs_dir_name_len(leaf, di);
+                       if (len > name_len) {
+                               free(name);
+                               name = (char *) malloc(len + 1);
+                               if (!name) {
+                                       ret = -ENOMEM;
+                                       goto out;
+                               }
+                       }
+                       read_extent_buffer(leaf, name,
+                                          (unsigned long)(di + 1), len);
+                       name[len] = '\0';
+                       name_len = len;
+
+                       len = btrfs_dir_data_len(leaf, di);
+                       if (len > data_len) {
+                               free(data);
+                               data = (char *) malloc(len);
+                               if (!data) {
+                                       ret = -ENOMEM;
+                                       goto out;
+                               }
+                       }
+                       read_extent_buffer(leaf, data,
+                                          (unsigned long)(di + 1) + name_len,
+                                          len);
+                       data_len = len;
+
+                       if (fsetxattr(fd, name, data, data_len, 0)) {
+                               int err = errno;
+
+                               fprintf(stderr,
+                                       "Error setting extended attribute %s on file %s: %s\n",
+                                       name, file_name, strerror(err));
+                       }
+
+                       len = sizeof(*di) + name_len + data_len;
+                       cur += len;
+                       di = (struct btrfs_dir_item *)((char *)di + len);
+               }
+               path->slots[0]++;
+       }
+       ret = 0;
+out:
+       btrfs_free_path(path);
+       free(name);
+       free(data);
+
+       return ret;
+}
+
+
 static int copy_file(struct btrfs_root *root, int fd, struct btrfs_key *key,
                     const char *file)
 {
@@ -538,6 +649,11 @@ set_size:
                if (ret)
                        return ret;
        }
+       if (get_xattrs) {
+               ret = set_file_xattrs(root, key->objectid, fd, file);
+               if (ret)
+                       return ret;
+       }
        return 0;
 }
 
@@ -978,6 +1094,7 @@ const char * const cmd_restore_usage[] = {
        "Try to restore files from a damaged filesystem (unmounted)",
        "",
        "-s              get snapshots",
+       "-x              get extended attributes",
        "-v              verbose",
        "-i              ignore errors",
        "-o              overwrite",
@@ -1013,7 +1130,7 @@ int cmd_restore(int argc, char **argv)
        regex_t match_reg, *mreg = NULL;
        char reg_err[256];
 
-       while ((opt = getopt_long(argc, argv, "sviot:u:df:r:lc", long_options,
+       while ((opt = getopt_long(argc, argv, "sxviot:u:df:r:lc", long_options,
                                        &option_index)) != -1) {
 
                switch (opt) {
@@ -1076,6 +1193,9 @@ int cmd_restore(int argc, char **argv)
                        case 256:
                                match_regstr = optarg;
                                break;
+                       case 'x':
+                               get_xattrs = 1;
+                               break;
                        default:
                                usage(cmd_restore_usage);
                }