Btrfs: make tree checker detect checksum items with overlapping ranges

[sfrench/cifs-2.6.git] / fs / btrfs / tree-checker.c

diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 092b8ece36d72811a8f79bb236a26a3890548676..97f3520b8d98d29b61abc27a6751979854f1c349 100644 (file)
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -332,7 +332,7 @@ static int check_extent_data_item(struct extent_buffer *leaf,
 }
 
 static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
-                          int slot)
+                          int slot, struct btrfs_key *prev_key)
 {
        struct btrfs_fs_info *fs_info = leaf->fs_info;
        u32 sectorsize = fs_info->sectorsize;
@@ -356,6 +356,20 @@ static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
                        btrfs_item_size_nr(leaf, slot), csumsize);
                return -EUCLEAN;
        }
+       if (slot > 0 && prev_key->type == BTRFS_EXTENT_CSUM_KEY) {
+               u64 prev_csum_end;
+               u32 prev_item_size;
+
+               prev_item_size = btrfs_item_size_nr(leaf, slot - 1);
+               prev_csum_end = (prev_item_size / csumsize) * sectorsize;
+               prev_csum_end += prev_key->offset;
+               if (prev_csum_end > key->offset) {
+                       generic_err(leaf, slot - 1,
+"csum end range (%llu) goes beyond the start range (%llu) of the next csum item",
+                                   prev_csum_end, key->offset);
+                       return -EUCLEAN;
+               }
+       }
        return 0;
 }
 
@@ -1355,7 +1369,7 @@ static int check_leaf_item(struct extent_buffer *leaf,
                ret = check_extent_data_item(leaf, key, slot, prev_key);
                break;
        case BTRFS_EXTENT_CSUM_KEY:
-               ret = check_csum_item(leaf, key, slot);
+               ret = check_csum_item(leaf, key, slot, prev_key);
                break;
        case BTRFS_DIR_ITEM_KEY:
        case BTRFS_DIR_INDEX_KEY: