ext4: get rid of ppath in ext4_force_split_extent_at()

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

To get rid of the ppath in ext4_force_split_extent_at(), the following is
done here:

 * Free the extents path when an error is encountered.

No functional changes.

Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Ojaswin Mujoo <[email protected]>
Tested-by: Ojaswin Mujoo <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

Author: LiBaokun96

fs/ext4/extents.c

@@ -328,27 +328,20 @@ static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
 	return size;
 }
 
-static inline int
+static inline struct ext4_ext_path *
 ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
-			   struct ext4_ext_path **ppath, ext4_lblk_t lblk,
+			   struct ext4_ext_path *path, ext4_lblk_t lblk,
 			   int nofail)
 {
-	struct ext4_ext_path *path = *ppath;
 	int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
 	int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO;
 
 	if (nofail)
 		flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
 
-	path = ext4_split_extent_at(handle, inode, path, lblk, unwritten ?
+	return ext4_split_extent_at(handle, inode, path, lblk, unwritten ?
 			EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
 			flags);
-	if (IS_ERR(path)) {
-		*ppath = NULL;
-		return PTR_ERR(path);
-	}
-	*ppath = path;
-	return 0;
 }
 
 static int
@@ -2907,11 +2900,12 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 			 * fail removing space due to ENOSPC so try to use
 			 * reserved block if that happens.
 			 */
-			err = ext4_force_split_extent_at(handle, inode, &path,
-							 end + 1, 1);
-			if (err < 0)
+			path = ext4_force_split_extent_at(handle, inode, path,
+							  end + 1, 1);
+			if (IS_ERR(path)) {
+				err = PTR_ERR(path);
 				goto out;
-
+			}
 		} else if (sbi->s_cluster_ratio > 1 && end >= ex_end &&
 			   partial.state == initial) {
 			/*
@@ -5728,17 +5722,21 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
 		/* Prepare left boundary */
 		if (e1_blk < lblk1) {
 			split = 1;
-			*erp = ext4_force_split_extent_at(handle, inode1,
-						&path1, lblk1, 0);
-			if (unlikely(*erp))
+			path1 = ext4_force_split_extent_at(handle, inode1,
+							   path1, lblk1, 0);
+			if (IS_ERR(path1)) {
+				*erp = PTR_ERR(path1);
 				goto finish;
+			}
 		}
 		if (e2_blk < lblk2) {
 			split = 1;
-			*erp = ext4_force_split_extent_at(handle, inode2,
-						&path2,  lblk2, 0);
-			if (unlikely(*erp))
+			path2 = ext4_force_split_extent_at(handle, inode2,
+							   path2, lblk2, 0);
+			if (IS_ERR(path2)) {
+				*erp = PTR_ERR(path2);
 				goto finish;
+			}
 		}
 		/* ext4_split_extent_at() may result in leaf extent split,
 		 * path must to be revalidated. */
@@ -5754,17 +5752,21 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
 
 		if (len != e1_len) {
 			split = 1;
-			*erp = ext4_force_split_extent_at(handle, inode1,
-						&path1, lblk1 + len, 0);
-			if (unlikely(*erp))
+			path1 = ext4_force_split_extent_at(handle, inode1,
+							path1, lblk1 + len, 0);
+			if (IS_ERR(path1)) {
+				*erp = PTR_ERR(path1);
 				goto finish;
+			}
 		}
 		if (len != e2_len) {
 			split = 1;
-			*erp = ext4_force_split_extent_at(handle, inode2,
-						&path2, lblk2 + len, 0);
-			if (*erp)
+			path2 = ext4_force_split_extent_at(handle, inode2,
+							path2, lblk2 + len, 0);
+			if (IS_ERR(path2)) {
+				*erp = PTR_ERR(path2);
 				goto finish;
+			}
 		}
 		/* ext4_split_extent_at() may result in leaf extent split,
 		 * path must to be revalidated. */
@@ -5930,24 +5932,29 @@ int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
 		ext4_ext_get_actual_len(ex) != len) {
 		/* We need to split this extent to match our extent first */
 		down_write(&EXT4_I(inode)->i_data_sem);
-		ret = ext4_force_split_extent_at(NULL, inode, &path, start, 1);
+		path = ext4_force_split_extent_at(NULL, inode, path, start, 1);
 		up_write(&EXT4_I(inode)->i_data_sem);
-		if (ret)
+		if (IS_ERR(path)) {
+			ret = PTR_ERR(path);
 			goto out;
+		}
 
 		path = ext4_find_extent(inode, start, path, 0);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
+
 		ex = path[path->p_depth].p_ext;
 		WARN_ON(le32_to_cpu(ex->ee_block) != start);
 
 		if (ext4_ext_get_actual_len(ex) != len) {
 			down_write(&EXT4_I(inode)->i_data_sem);
-			ret = ext4_force_split_extent_at(NULL, inode, &path,
-							 start + len, 1);
+			path = ext4_force_split_extent_at(NULL, inode, path,
+							  start + len, 1);
 			up_write(&EXT4_I(inode)->i_data_sem);
-			if (ret)
+			if (IS_ERR(path)) {
+				ret = PTR_ERR(path);
 				goto out;
+			}
 
 			path = ext4_find_extent(inode, start, path, 0);
 			if (IS_ERR(path))