diff mbox

Btrfs: check items for correctness as we search

Message ID 1300305863-2609-1-git-send-email-josef@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Josef Bacik March 16, 2011, 8:04 p.m. UTC
None
diff mbox

Patch

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b5baff0..73e5300 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -732,122 +732,6 @@  static inline unsigned int leaf_data_end(struct btrfs_root *root,
 	return btrfs_item_offset_nr(leaf, nr - 1);
 }
 
-/*
- * extra debugging checks to make sure all the items in a key are
- * well formed and in the proper order
- */
-static int check_node(struct btrfs_root *root, struct btrfs_path *path,
-		      int level)
-{
-	struct extent_buffer *parent = NULL;
-	struct extent_buffer *node = path->nodes[level];
-	struct btrfs_disk_key parent_key;
-	struct btrfs_disk_key node_key;
-	int parent_slot;
-	int slot;
-	struct btrfs_key cpukey;
-	u32 nritems = btrfs_header_nritems(node);
-
-	if (path->nodes[level + 1])
-		parent = path->nodes[level + 1];
-
-	slot = path->slots[level];
-	BUG_ON(nritems == 0);
-	if (parent) {
-		parent_slot = path->slots[level + 1];
-		btrfs_node_key(parent, &parent_key, parent_slot);
-		btrfs_node_key(node, &node_key, 0);
-		BUG_ON(memcmp(&parent_key, &node_key,
-			      sizeof(struct btrfs_disk_key)));
-		BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
-		       btrfs_header_bytenr(node));
-	}
-	BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
-	if (slot != 0) {
-		btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
-		btrfs_node_key(node, &node_key, slot);
-		BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
-	}
-	if (slot < nritems - 1) {
-		btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
-		btrfs_node_key(node, &node_key, slot);
-		BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
-	}
-	return 0;
-}
-
-/*
- * extra checking to make sure all the items in a leaf are
- * well formed and in the proper order
- */
-static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
-		      int level)
-{
-	struct extent_buffer *leaf = path->nodes[level];
-	struct extent_buffer *parent = NULL;
-	int parent_slot;
-	struct btrfs_key cpukey;
-	struct btrfs_disk_key parent_key;
-	struct btrfs_disk_key leaf_key;
-	int slot = path->slots[0];
-
-	u32 nritems = btrfs_header_nritems(leaf);
-
-	if (path->nodes[level + 1])
-		parent = path->nodes[level + 1];
-
-	if (nritems == 0)
-		return 0;
-
-	if (parent) {
-		parent_slot = path->slots[level + 1];
-		btrfs_node_key(parent, &parent_key, parent_slot);
-		btrfs_item_key(leaf, &leaf_key, 0);
-
-		BUG_ON(memcmp(&parent_key, &leaf_key,
-		       sizeof(struct btrfs_disk_key)));
-		BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
-		       btrfs_header_bytenr(leaf));
-	}
-	if (slot != 0 && slot < nritems - 1) {
-		btrfs_item_key(leaf, &leaf_key, slot);
-		btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
-		if (comp_keys(&leaf_key, &cpukey) <= 0) {
-			btrfs_print_leaf(root, leaf);
-			printk(KERN_CRIT "slot %d offset bad key\n", slot);
-			BUG_ON(1);
-		}
-		if (btrfs_item_offset_nr(leaf, slot - 1) !=
-		       btrfs_item_end_nr(leaf, slot)) {
-			btrfs_print_leaf(root, leaf);
-			printk(KERN_CRIT "slot %d offset bad\n", slot);
-			BUG_ON(1);
-		}
-	}
-	if (slot < nritems - 1) {
-		btrfs_item_key(leaf, &leaf_key, slot);
-		btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
-		BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
-		if (btrfs_item_offset_nr(leaf, slot) !=
-			btrfs_item_end_nr(leaf, slot + 1)) {
-			btrfs_print_leaf(root, leaf);
-			printk(KERN_CRIT "slot %d offset bad\n", slot);
-			BUG_ON(1);
-		}
-	}
-	BUG_ON(btrfs_item_offset_nr(leaf, 0) +
-	       btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
-	return 0;
-}
-
-static noinline int check_block(struct btrfs_root *root,
-				struct btrfs_path *path, int level)
-{
-	return 0;
-	if (level == 0)
-		return check_leaf(root, path, level);
-	return check_node(root, path, level);
-}
 
 /*
  * search for key in the extent_buffer.  The items start at offset p,
@@ -1188,7 +1072,6 @@  static noinline int balance_level(struct btrfs_trans_handle *trans,
 		}
 	}
 	/* double check we haven't messed things up */
-	check_block(root, path, level);
 	if (orig_ptr !=
 	    btrfs_node_blockptr(path->nodes[level], path->slots[level]))
 		BUG();
@@ -1798,12 +1681,6 @@  cow_done:
 		if (!cow)
 			btrfs_unlock_up_safe(p, level + 1);
 
-		ret = check_block(root, p, level);
-		if (ret) {
-			ret = -1;
-			goto done;
-		}
-
 		ret = bin_search(b, key, level, &slot);
 
 		if (level != 0) {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 495b1ac..1694782 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -331,6 +331,14 @@  static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 		    !verify_parent_transid(io_tree, eb, parent_transid))
 			return ret;
 
+		/*
+		 * This buffer's crc is fine, but its contents are corrupted, so
+		 * there is no reason to read the other copies, they won't be
+		 * any less wrong.
+		 */
+		if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
+			return ret;
+
 		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 					      eb->start, eb->len);
 		if (num_copies == 1)
@@ -419,6 +427,76 @@  static int check_tree_block_fsid(struct btrfs_root *root,
 	return ret;
 }
 
+#define CORRUPT(reason, eb, root, slot)				\
+	printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu,"	\
+	       "root=%llu, slot=%d\n", reason,			\
+	       (unsigned long long)btrfs_header_bytenr(eb),	\
+	       (unsigned long long)root->objectid, slot)
+
+/*
+ * extra checking to make sure all the items in a leaf are
+ * well formed and in the proper order
+ */
+static int check_leaf(struct btrfs_root *root,
+		      struct extent_buffer *leaf, int slot)
+{
+	struct btrfs_key key;
+	struct btrfs_key leaf_key;
+	u32 nritems = btrfs_header_nritems(leaf);
+
+	btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
+	if (slot != 0 && slot < nritems - 1) {
+		btrfs_item_key_to_cpu(leaf, &key, slot - 1);
+		if (btrfs_comp_cpu_keys(&leaf_key, &key) <= 0) {
+			CORRUPT("offset bad key", leaf, root, slot);
+			return -EIO;
+		}
+		if (btrfs_item_offset_nr(leaf, slot - 1) !=
+		       btrfs_item_end_nr(leaf, slot)) {
+			CORRUPT("slot offset bad", leaf, root, slot);
+			return -EIO;
+		}
+	}
+	if (slot < nritems - 1) {
+		btrfs_item_key_to_cpu(leaf, &key, slot + 1);
+		if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
+			CORRUPT("offset bad key", leaf, root, slot);
+			return -EIO;
+		}
+		if (btrfs_item_offset_nr(leaf, slot) !=
+			btrfs_item_end_nr(leaf, slot + 1)) {
+			CORRUPT("slot offset bad", leaf, root, slot);
+			return -EIO;
+		}
+	}
+	if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
+	    BTRFS_LEAF_DATA_SIZE(root)) {
+		CORRUPT("invalid offset size pair", leaf, root, slot);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static noinline int check_block(struct btrfs_root *root,
+				struct extent_buffer *eb)
+{
+	u32 nritems = btrfs_header_nritems(eb);
+	int slot;
+	int ret = 0;
+
+	if (nritems == 0)
+		return 0;
+
+	for (slot = 0; slot < nritems; slot++) {
+		ret = check_leaf(root, eb, slot);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void btrfs_set_buffer_lockdep_class(struct extent_buffer *eb, int level)
 {
@@ -485,8 +563,20 @@  static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 	btrfs_set_buffer_lockdep_class(eb, found_level);
 
 	ret = csum_tree_block(root, eb, 1);
-	if (ret)
+	if (ret) {
+		ret = -EIO;
+		goto err;
+	}
+
+	/*
+	 * If this is a leaf block and it is corrupt, set the corrupt bit so
+	 * that we don't try and read the other copies of this block, just
+	 * return -EIO.
+	 */
+	if (found_level == 0 && check_block(root, eb)) {
+		set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
 		ret = -EIO;
+	}
 
 	end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 	end = eb->start + end - 1;
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 9318dfe..f62c544 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -31,6 +31,7 @@ 
 #define EXTENT_BUFFER_UPTODATE 0
 #define EXTENT_BUFFER_BLOCKING 1
 #define EXTENT_BUFFER_DIRTY 2
+#define EXTENT_BUFFER_CORRUPT 3
 
 /* these are flags for extent_clear_unlock_delalloc */
 #define EXTENT_CLEAR_UNLOCK_PAGE 0x1