Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix checks in BTRFS_IOC_CLONE_RANGE
  Btrfs: fix CLONE ioctl destination file size expansion to block boundary
  Btrfs: fix split_leaf double split corner case

2 files changed, 126 insertions, 23 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 0d1d966..c3df14c 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2304,12 +2304,17 @@ noinline int btrfs_leaf_free_space(struct btrfs_root *root,
 	return ret;
 }
 
+/*
+ * min slot controls the lowest index we're willing to push to the
+ * right.  We'll push up to and including min_slot, but no lower
+ */
 static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
 				      struct btrfs_root *root,
 				      struct btrfs_path *path,
 				      int data_size, int empty,
 				      struct extent_buffer *right,
-				      int free_space, u32 left_nritems)
+				      int free_space, u32 left_nritems,
+				      u32 min_slot)
 {
 	struct extent_buffer *left = path->nodes[0];
 	struct extent_buffer *upper = path->nodes[1];
@@ -2327,7 +2332,7 @@ static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
 	if (empty)
 		nr = 0;
 	else
-		nr = 1;
+		nr = max_t(u32, 1, min_slot);
 
 	if (path->slots[0] >= left_nritems)
 		push_space += data_size;
@@ -2469,10 +2474,14 @@ out_unlock:
  *
  * returns 1 if the push failed because the other node didn't have enough
  * room, 0 if everything worked out and < 0 if there were major errors.
+ *
+ * this will push starting from min_slot to the end of the leaf.  It won't
+ * push any slot lower than min_slot
  */
 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
-			   *root, struct btrfs_path *path, int data_size,
-			   int empty)
+			   *root, struct btrfs_path *path,
+			   int min_data_size, int data_size,
+			   int empty, u32 min_slot)
 {
 	struct extent_buffer *left = path->nodes[0];
 	struct extent_buffer *right;
@@ -2514,8 +2523,8 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (left_nritems == 0)
 		goto out_unlock;
 
-	return __push_leaf_right(trans, root, path, data_size, empty,
-				right, free_space, left_nritems);
+	return __push_leaf_right(trans, root, path, min_data_size, empty,
+				right, free_space, left_nritems, min_slot);
 out_unlock:
 	btrfs_tree_unlock(right);
 	free_extent_buffer(right);
@@ -2525,12 +2534,17 @@ out_unlock:
 /*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ *
+ * max_slot can put a limit on how far into the leaf we'll push items.  The
+ * item at 'max_slot' won't be touched.  Use (u32)-1 to make us do all the
+ * items
  */
 static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
 				     struct btrfs_path *path, int data_size,
 				     int empty, struct extent_buffer *left,
-				     int free_space, int right_nritems)
+				     int free_space, u32 right_nritems,
+				     u32 max_slot)
 {
 	struct btrfs_disk_key disk_key;
 	struct extent_buffer *right = path->nodes[0];
@@ -2549,9 +2563,9 @@ static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
 	slot = path->slots[1];
 
 	if (empty)
-		nr = right_nritems;
+		nr = min(right_nritems, max_slot);
 	else
-		nr = right_nritems - 1;
+		nr = min(right_nritems - 1, max_slot);
 
 	for (i = 0; i < nr; i++) {
 		item = btrfs_item_nr(right, i);
@@ -2712,10 +2726,14 @@ out:
 /*
  * push some data in the path leaf to the left, trying to free up at
  * least data_size bytes.  returns zero if the push worked, nonzero otherwise
+ *
+ * max_slot can put a limit on how far into the leaf we'll push items.  The
+ * item at 'max_slot' won't be touched.  Use (u32)-1 to make us push all the
+ * items
  */
 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, struct btrfs_path *path, int data_size,
-			  int empty)
+			  *root, struct btrfs_path *path, int min_data_size,
+			  int data_size, int empty, u32 max_slot)
 {
 	struct extent_buffer *right = path->nodes[0];
 	struct extent_buffer *left;
@@ -2761,8 +2779,9 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 		goto out;
 	}
 
-	return __push_leaf_left(trans, root, path, data_size,
-			       empty, left, free_space, right_nritems);
+	return __push_leaf_left(trans, root, path, min_data_size,
+			       empty, left, free_space, right_nritems,
+			       max_slot);
 out:
 	btrfs_tree_unlock(left);
 	free_extent_buffer(left);
@@ -2855,6 +2874,64 @@ static noinline int copy_for_split(struct btrfs_trans_handle *trans,
 }
 
 /*
+ * double splits happen when we need to insert a big item in the middle
+ * of a leaf.  A double split can leave us with 3 mostly empty leaves:
+ * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
+ *          A                 B                 C
+ *
+ * We avoid this by trying to push the items on either side of our target
+ * into the adjacent leaves.  If all goes well we can avoid the double split
+ * completely.
+ */
+static noinline int push_for_double_split(struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  struct btrfs_path *path,
+					  int data_size)
+{
+	int ret;
+	int progress = 0;
+	int slot;
+	u32 nritems;
+
+	slot = path->slots[0];
+
+	/*
+	 * try to push all the items after our slot into the
+	 * right leaf
+	 */
+	ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot);
+	if (ret < 0)
+		return ret;
+
+	if (ret == 0)
+		progress++;
+
+	nritems = btrfs_header_nritems(path->nodes[0]);
+	/*
+	 * our goal is to get our slot at the start or end of a leaf.  If
+	 * we've done so we're done
+	 */
+	if (path->slots[0] == 0 || path->slots[0] == nritems)
+		return 0;
+
+	if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
+		return 0;
+
+	/* try to push all the items before our slot into the next leaf */
+	slot = path->slots[0];
+	ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot);
+	if (ret < 0)
+		return ret;
+
+	if (ret == 0)
+		progress++;
+
+	if (progress)
+		return 0;
+	return 1;
+}
+
+/*
  * split the path's leaf in two, making sure there is at least data_size
  * available for the resulting leaf level of the path.
  *
@@ -2876,6 +2953,7 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
 	int wret;
 	int split;
 	int num_doubles = 0;
+	int tried_avoid_double = 0;
 
 	l = path->nodes[0];
 	slot = path->slots[0];
@@ -2884,12 +2962,14 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
 		return -EOVERFLOW;
 
 	/* first try to make some room by pushing left and right */
-	if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
-		wret = push_leaf_right(trans, root, path, data_size, 0);
+	if (data_size) {
+		wret = push_leaf_right(trans, root, path, data_size,
+				       data_size, 0, 0);
 		if (wret < 0)
 			return wret;
 		if (wret) {
-			wret = push_leaf_left(trans, root, path, data_size, 0);
+			wret = push_leaf_left(trans, root, path, data_size,
+					      data_size, 0, (u32)-1);
 			if (wret < 0)
 				return wret;
 		}
@@ -2923,6 +3003,8 @@ again:
 				if (mid != nritems &&
 				    leaf_space_used(l, mid, nritems - mid) +
 				    data_size > BTRFS_LEAF_DATA_SIZE(root)) {
+					if (data_size && !tried_avoid_double)
+						goto push_for_double;
 					split = 2;
 				}
 			}
@@ -2939,6 +3021,8 @@ again:
 				if (mid != nritems &&
 				    leaf_space_used(l, mid, nritems - mid) +
 				    data_size > BTRFS_LEAF_DATA_SIZE(root)) {
+					if (data_size && !tried_avoid_double)
+						goto push_for_double;
 					split = 2 ;
 				}
 			}
@@ -3019,6 +3103,13 @@ again:
 	}
 
 	return ret;
+
+push_for_double:
+	push_for_double_split(trans, root, path, data_size);
+	tried_avoid_double = 1;
+	if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size)
+		return 0;
+	goto again;
 }
 
 static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
@@ -3915,13 +4006,15 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			extent_buffer_get(leaf);
 
 			btrfs_set_path_blocking(path);
-			wret = push_leaf_left(trans, root, path, 1, 1);
+			wret = push_leaf_left(trans, root, path, 1, 1,
+					      1, (u32)-1);
 			if (wret < 0 && wret != -ENOSPC)
 				ret = wret;
 
 			if (path->nodes[0] == leaf &&
 			    btrfs_header_nritems(leaf)) {
-				wret = push_leaf_right(trans, root, path, 1, 1);
+				wret = push_leaf_right(trans, root, path, 1,
+						       1, 1, 0);
 				if (wret < 0 && wret != -ENOSPC)
 					ret = wret;
 			}
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4dbaf89..9254b3d 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1458,7 +1458,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 	 */
 
 	/* the destination must be opened for writing */
-	if (!(file->f_mode & FMODE_WRITE))
+	if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
 		return -EINVAL;
 
 	ret = mnt_want_write(file->f_path.mnt);
@@ -1511,7 +1511,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 
 	/* determine range to clone */
 	ret = -EINVAL;
-	if (off >= src->i_size || off + len > src->i_size)
+	if (off + len > src->i_size || off + len < off)
 		goto out_unlock;
 	if (len == 0)
 		olen = len = src->i_size - off;
@@ -1578,6 +1578,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 			u64 disko = 0, diskl = 0;
 			u64 datao = 0, datal = 0;
 			u8 comp;
+			u64 endoff;
 
 			size = btrfs_item_size_nr(leaf, slot);
 			read_extent_buffer(leaf, buf,
@@ -1712,9 +1713,18 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
 			btrfs_release_path(root, path);
 
 			inode->i_mtime = inode->i_ctime = CURRENT_TIME;
-			if (new_key.offset + datal > inode->i_size)
-				btrfs_i_size_write(inode,
-						   new_key.offset + datal);
+
+			/*
+			 * we round up to the block size at eof when
+			 * determining which extents to clone above,
+			 * but shouldn't round up the file size
+			 */
+			endoff = new_key.offset + datal;
+			if (endoff > off+olen)
+				endoff = off+olen;
+			if (endoff > inode->i_size)
+				btrfs_i_size_write(inode, endoff);
+
 			BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
 			ret = btrfs_update_inode(trans, root, inode);
 			BUG_ON(ret);