Btrfs-progs: try other mirrors on read failure

If we hit a bad disk and the read doesn't work, try other mirrors in case we have other disks with good copies. Thanks, Signed-off-by: Josef Bacik <[email protected]>
talakad · Mar 18, 2013 · 23bfbf0 · 23bfbf0
1 parent 9969ea4
commit 23bfbf0
Showing 1 changed file with 10 additions and 3 deletions.
diff --git a/cmds-restore.c b/cmds-restore.c
@@ -245,9 +245,16 @@ static int copy_one_extent(struct btrfs_root *root, int fd,
 
 	done = pread(dev_fd, inbuf+count, length, dev_bytenr);
 	if (done < length) {
-		ret = -1;
-		fprintf(stderr, "Short read %d\n", errno);
-		goto out;
+		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
+					      bytenr, length);
+		mirror_num++;
+		if (mirror_num >= num_copies) {
+			ret = -1;
+			fprintf(stderr, "Exhausted mirrors trying to read\n");
+			goto out;
+		}
+		fprintf(stderr, "Trying another mirror\n");
+		goto again;
 	}
 
 	count += length;