Btrfs-progs: allow fsck to take the tree bytenr

Sometimes we have a pretty corrupted fs but have an old tree bytenr that we
could use, add the ability to specify the tree root bytenr.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Tested-by: Ansgar Hockmann-Stolle <ansgar.hockmann-stolle@uni-osnabrueck.de>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/cmds-check.c b/cmds-check.c
index d427405..d57363c 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -7677,6 +7677,7 @@ static struct option long_options[] = {
        { "backup", 0, NULL, 0 },
        { "subvol-extents", 1, NULL, 'E' },
        { "qgroup-report", 0, NULL, 'Q' },
+       { "tree-root", 1, NULL, 'r' },
        { NULL, 0, NULL, 0}
 };
 
@@ -7692,6 +7693,7 @@ const char * const cmd_check_usage[] = {
        "--check-data-csum           verify checkums of data blocks",
        "--qgroup-report             print a report on qgroup consistency",
        "--subvol-extents <subvolid> print subvolume extents and sharing state",
+       "--tree-root <bytenr>        use the given bytenr for the tree root",
        NULL
 };
 
@@ -7702,6 +7704,7 @@ int cmd_check(int argc, char **argv)
        struct btrfs_fs_info *info;
        u64 bytenr = 0;
        u64 subvolid = 0;
+       u64 tree_root_bytenr = 0;
        char uuidbuf[BTRFS_UUID_UNPARSED_SIZE];
        int ret;
        u64 num;
@@ -7712,7 +7715,7 @@ int cmd_check(int argc, char **argv)
 
        while(1) {
                int c;
-               c = getopt_long(argc, argv, "as:b", long_options,
+               c = getopt_long(argc, argv, "as:br:", long_options,
                                &option_index);
                if (c < 0)
                        break;
@@ -7739,6 +7742,9 @@ int cmd_check(int argc, char **argv)
                        case 'E':
                                subvolid = arg_strtou64(optarg);
                                break;
+                       case 'r':
+                               tree_root_bytenr = arg_strtou64(optarg);
+                               break;
                        case '?':
                        case 'h':
                                usage(cmd_check_usage);
@@ -7782,7 +7788,8 @@ int cmd_check(int argc, char **argv)
        if (repair)
                ctree_flags |= OPEN_CTREE_PARTIAL;
 
-       info = open_ctree_fs_info(argv[optind], bytenr, 0, ctree_flags);
+       info = open_ctree_fs_info(argv[optind], bytenr, tree_root_bytenr,
+                                 ctree_flags);
        if (!info) {
                fprintf(stderr, "Couldn't open file system\n");
                ret = -EIO;