Add options to btrfs-find-root to control generation and level

Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/btrfs-find-root.c b/btrfs-find-root.c
index f2cc1bf..9b3d7df 100644 (file)
--- a/btrfs-find-root.c
+++ b/btrfs-find-root.c
@@ -37,10 +37,13 @@
 
 static u16 csum_size = 0;
 static u64 search_objectid = BTRFS_ROOT_TREE_OBJECTID;
+static u64 search_generation = 0;
+static unsigned long search_level = 0;
 
 static void usage()
 {
-       fprintf(stderr, "Usage: find-roots [-o search_objectid] <device>\n");
+       fprintf(stderr, "Usage: find-roots [-o search_objectid] "
+               "[ -g search_generation ] [ -l search_level ] <device>\n");
 }
 
 int csum_block(void *buf, u32 len)
@@ -126,10 +129,10 @@ out:
 static int search_iobuf(struct btrfs_root *root, void *iobuf,
                        size_t iobuf_size, off_t offset)
 {
-       u64 gen = btrfs_super_generation(root->fs_info->super_copy);
+       u64 gen = search_generation;
        u64 objectid = search_objectid;
        u32 size = btrfs_super_nodesize(root->fs_info->super_copy);
-       u8 level = root->fs_info->super_copy->root_level;
+       u8 level = search_level;
        size_t block_off = 0;
 
        while (block_off < iobuf_size) {
@@ -147,8 +150,9 @@ static int search_iobuf(struct btrfs_root *root, void *iobuf,
                        goto next;
                if (h_byte != (offset + block_off))
                        goto next;
-               if (h_level != level)
+               if (h_level < level)
                        goto next;
+               level = h_level;
                if (csum_block(block, size)) {
                        fprintf(stderr, "Well block %Lu seems good, "
                                "but the csum doesn't match\n",
@@ -158,11 +162,12 @@ static int search_iobuf(struct btrfs_root *root, void *iobuf,
                if (h_gen != gen) {
                        fprintf(stderr, "Well block %Lu seems great, "
                                "but generation doesn't match, "
-                               "have=%Lu, want=%Lu\n", h_byte, h_gen,
-                               gen);
+                               "have=%Lu, want=%Lu level %Lu\n", h_byte,
+                               h_gen, gen, h_level);
                        goto next;
                }
-               printf("Found tree root at %Lu\n", h_byte);
+               printf("Found tree root at %Lu gen %Lu level %Lu\n", h_byte,
+                      h_gen, h_level);
                return 0;
 next:
                block_off += size;
@@ -281,10 +286,10 @@ int main(int argc, char **argv)
        int opt;
        int ret;
 
-       while ((opt = getopt(argc, argv, "o:")) != -1) {
+       while ((opt = getopt(argc, argv, "l:o:g:")) != -1) {
                switch(opt) {
+                       errno = 0;
                        case 'o':
-                               errno = 0;
                                search_objectid = (u64)strtoll(optarg, NULL,
                                                               10);
                                if (errno) {
@@ -293,6 +298,23 @@ int main(int argc, char **argv)
                                        exit(1);
                                }
                                break;
+                       case 'g':
+                               search_generation = (u64)strtoll(optarg, NULL,
+                                                              10);
+                               if (errno) {
+                                       fprintf(stderr, "Error parsing "
+                                               "generation\n");
+                                       exit(1);
+                               }
+                               break;
+                       case 'l':
+                               search_level = strtol(optarg, NULL, 10);
+                               if (errno) {
+                                       fprintf(stderr, "Error parsing "
+                                               "level\n");
+                                       exit(1);
+                               }
+                               break;
                        default:
                                usage();
                                exit(1);
@@ -318,6 +340,9 @@ int main(int argc, char **argv)
                exit(1);
        }
 
+       if (search_generation == 0)
+               search_generation = btrfs_super_generation(root->fs_info->super_copy);
+
        csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
        ret = find_root(root);
        close_ctree(root);