Btrfs: delete inline extents when we find them during logging

Apparently when we do inline extents we allow the data to overlap the last chunk of the btrfs_file_extent_item, which means that we can possibly have a btrfs_file_extent_item that isn't actually as large as a btrfs_file_extent_item. This messes with us when we try to overwrite the extent when logging new extents since we expect for it to be the right size. To fix this just delete the item and try to do the insert again which will give us the proper sized btrfs_file_extent_item. This fixes a panic where map_private_extent_buffer would blow up because we're trying to write past the end of the leaf. Thanks, Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fusionio.com>

Btrfs: delete inline extents when we find them during logging
Apparently when we do inline extents we allow the data to overlap the last chunk of the btrfs_file_extent_item, which means that we can possibly have a btrfs_file_extent_item that isn't actually as large as a btrfs_file_extent_item. This messes with us when we try to overwrite the extent when logging new extents since we expect for it to be the right size. To fix this just delete the item and try to do the insert again which will give us the proper sized btrfs_file_extent_item. This fixes a panic where map_private_extent_buffer would blow up because we're trying to write past the end of the leaf. Thanks, Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Josef Bacik
1 parent 83c8266acc
Showing 1 changed file with 18 additions and 0 deletions Side-by-side Diff
fs/btrfs/tree-log.c
@@ -3300,6 +3300,7 @@
 	int index = log->log_transid % 2;
 	bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
  
+insert:
 	INIT_LIST_HEAD(&ordered_sums);
 	btrfs_init_map_token(&token);
 	key.objectid = btrfs_ino(inode);
@@ -3315,6 +3316,23 @@
 	leaf = path->nodes[0];
 	fi = btrfs_item_ptr(leaf, path->slots[0],
 			    struct btrfs_file_extent_item);
+
+	/*
+	 * If we are overwriting an inline extent with a real one then we need
+	 * to just delete the inline extent as it may not be large enough to
+	 * have the entire file_extent_item.
+	 */
+	if (ret && btrfs_token_file_extent_type(leaf, fi, &token) ==
+	    BTRFS_FILE_EXTENT_INLINE) {
+		ret = btrfs_del_item(trans, log, path);
+		btrfs_release_path(path);
+		if (ret) {
+			path->really_keep_locks = 0;
+			return ret;
+		}
+		goto insert;
+	}
+
 	btrfs_set_token_file_extent_generation(leaf, fi, em->generation,
 					       &token);
 	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
...	...	@@ -3300,6 +3300,7 @@
3300	3300	int index = log->log_transid % 2;
3301	3301	bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3302	3302
	3303	+insert:
3303	3304	INIT_LIST_HEAD(&ordered_sums);
3304	3305	btrfs_init_map_token(&token);
3305	3306	key.objectid = btrfs_ino(inode);
...	...	@@ -3315,6 +3316,23 @@
3315	3316	leaf = path->nodes[0];
3316	3317	fi = btrfs_item_ptr(leaf, path->slots[0],
3317	3318	struct btrfs_file_extent_item);
	3319	+
	3320	+ /*
	3321	+ * If we are overwriting an inline extent with a real one then we need
	3322	+ * to just delete the inline extent as it may not be large enough to
	3323	+ * have the entire file_extent_item.
	3324	+ */
	3325	+ if (ret && btrfs_token_file_extent_type(leaf, fi, &token) ==
	3326	+ BTRFS_FILE_EXTENT_INLINE) {
	3327	+ ret = btrfs_del_item(trans, log, path);
	3328	+ btrfs_release_path(path);
	3329	+ if (ret) {
	3330	+ path->really_keep_locks = 0;
	3331	+ return ret;
	3332	+ }
	3333	+ goto insert;
	3334	+ }
	3335	+
3318	3336	btrfs_set_token_file_extent_generation(leaf, fi, em->generation,
3319	3337	&token);
3320	3338	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {