btrfs-progs: corrupt btrfs items in btrfs-corrup-block

For testing fsck against completely broken btrfs_items.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c
index 75dca6eb2e1693b0f8e8198b69bf887f6b4bb778..15f1082a104ea66689148f7f51f58f92fa86d5fe 100644 (file)
--- a/btrfs-corrupt-block.c
+++ b/btrfs-corrupt-block.c
@@ -108,6 +108,8 @@ static void print_usage(void)
        fprintf(stderr, "\t-K The key to corrupt in the format "
                "<num>,<num>,<num> (must also specify -f for the field)\n");
        fprintf(stderr, "\t-f The field in the item to corrupt\n");
+       fprintf(stderr, "\t-I An item to corrupt (must also specify the field "
+               "to corrupt and a root+key for the item)\n");
        fprintf(stderr, "\t-D Corrupt a dir item, must specify key and field\n");
        exit(1);
 }
@@ -313,6 +315,11 @@ enum btrfs_metadata_block_field {
        BTRFS_METADATA_BLOCK_BAD,
 };
 
+enum btrfs_item_field {
+       BTRFS_ITEM_OFFSET,
+       BTRFS_ITEM_BAD,
+};
+
 enum btrfs_key_field {
        BTRFS_KEY_OBJECTID,
        BTRFS_KEY_TYPE,
@@ -353,6 +360,13 @@ static enum btrfs_key_field convert_key_field(char *field)
        return BTRFS_KEY_BAD;
 }
 
+static enum btrfs_item_field convert_item_field(char *field)
+{
+       if (!strncmp(field, "offset", FIELD_BUF_LEN))
+               return BTRFS_ITEM_OFFSET;
+       return BTRFS_ITEM_BAD;
+}
+
 static enum btrfs_dir_item_field convert_dir_item_field(char *field)
 {
        if (!strncmp(field, "name", FIELD_BUF_LEN))
@@ -371,6 +385,15 @@ static u64 generate_u64(u64 orig)
        return ret;
 }
 
+static u32 generate_u32(u32 orig)
+{
+       u32 ret;
+       do {
+               ret = rand();
+       } while (ret == orig);
+       return ret;
+}
+
 static u8 generate_u8(u8 orig)
 {
        u8 ret;
@@ -709,6 +732,58 @@ out:
        return ret;
 }
 
+static int corrupt_btrfs_item(struct btrfs_root *root, struct btrfs_key *key,
+                             char *field)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_path *path;
+       enum btrfs_item_field corrupt_field;
+       u32 orig, bogus;
+       int ret;
+
+       corrupt_field = convert_item_field(field);
+       if (corrupt_field == BTRFS_ITEM_BAD) {
+               fprintf(stderr, "Invalid field %s\n", field);
+               return -EINVAL;
+       }
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       trans = btrfs_start_transaction(root, 1);
+       if (IS_ERR(trans)) {
+               btrfs_free_path(path);
+               fprintf(stderr, "Couldn't start transaction %ld\n",
+                       PTR_ERR(trans));
+               return PTR_ERR(trans);
+       }
+
+       ret = btrfs_search_slot(trans, root, key, path, 0, 1);
+       if (ret != 0) {
+               fprintf(stderr, "Error searching to node %d\n", ret);
+               goto out;
+       }
+
+       ret = 0;
+       switch (corrupt_field) {
+       case BTRFS_ITEM_OFFSET:
+               orig = btrfs_item_offset_nr(path->nodes[0], path->slots[0]);
+               bogus = generate_u32(orig);
+               btrfs_set_item_offset(path->nodes[0],
+                                     btrfs_item_nr(path->slots[0]), bogus);
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+       btrfs_commit_transaction(trans, root);
+       btrfs_free_path(path);
+       return ret;
+}
+
 static struct option long_options[] = {
        /* { "byte-count", 1, NULL, 'b' }, */
        { "logical", 1, NULL, 'l' },
@@ -724,6 +799,7 @@ static struct option long_options[] = {
        { "metadata-block", 1, NULL, 'm'},
        { "field", 1, NULL, 'f'},
        { "key", 1, NULL, 'K'},
+       { "item", 0, NULL, 'I'},
        { "dir-item", 0, NULL, 'D'},
        { 0, 0, 0, 0}
 };
@@ -888,6 +964,7 @@ int main(int ac, char **av)
        int corrupt_block_keys = 0;
        int chunk_rec = 0;
        int chunk_tree = 0;
+       int corrupt_item = 0;
        int corrupt_di = 0;
        u64 metadata_block = 0;
        u64 inode = 0;
@@ -900,7 +977,7 @@ int main(int ac, char **av)
 
        while(1) {
                int c;
-               c = getopt_long(ac, av, "l:c:b:eEkuUi:f:x:m:K:D", long_options,
+               c = getopt_long(ac, av, "l:c:b:eEkuUi:f:x:m:K:ID", long_options,
                                &option_index);
                if (c < 0)
                        break;
@@ -954,6 +1031,9 @@ int main(int ac, char **av)
                        case 'D':
                                corrupt_di = 1;
                                break;
+                       case 'I':
+                               corrupt_item = 1;
+                               break;
                        default:
                                print_usage();
                }
@@ -1056,6 +1136,12 @@ int main(int ac, char **av)
                ret = corrupt_dir_item(root, &key, field);
                goto out_close;
        }
+       if (corrupt_item) {
+               if (!key.objectid)
+                       print_usage();
+               ret = corrupt_btrfs_item(root, &key, field);
+               goto out_close;
+       }
        if (key.objectid || key.offset || key.type) {
                if (!strlen(field))
                        print_usage();