ext4: clean up error return for convert_initialized_extent()

PATCH Applied Eric Whitney 2 participants 2 messages Feb 18, 2020 – Mar 6, 2020 ext4 file system

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Eric Whitney

author

2020-02-18 20:27 UTC #0 lore raw

PATCH 1/1 ext4: clean up error return for convert_initialized_extent()

Although convert_initialized_extent() can potentially return an error code with a negative value, its returned value is assigned to an unsigned variable containing a block count in ext4_ext_map_blocks() and then returned to that function's caller. The code currently works, though the way this happens is obscure. The code would be more readable if it followed the error handling convention used elsewhere in ext4_ext_map_blocks().

This patch does not address any known test failure or bug report - it's simply a cleanup. It also addresses a nearby coding standard issue.

Signed-off-by Eric Whitney <[email protected]>

---
 fs/ext4/extents.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

fs/ext4/extents.c +9 -9

index 954013d6076b..71820d879a80 100644
@@ -3931,7 +3931,7 @@ static int
 convert_initialized_extent(handle_t *handle, struct inode *inode,
 			   struct ext4_map_blocks *map,
 			   struct ext4_ext_path **ppath,
-			   unsigned int allocated)
+			   unsigned int *allocated)
 {
 	struct ext4_ext_path *path = *ppath;
 	struct ext4_extent *ex;

@@ -3995,10 +3995,10 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
 	if (err)
 		return err;
 	map->m_flags |= EXT4_MAP_UNWRITTEN;
-	if (allocated > map->m_len)
-		allocated = map->m_len;
-	map->m_len = allocated;
-	return allocated;
+	if (*allocated > map->m_len)
+		*allocated = map->m_len;
+	map->m_len = *allocated;
+	return 0;
 }
 
 static int

@@ -4308,12 +4308,12 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 			 */
 			if ((!ext4_ext_is_unwritten(ex)) &&
 			    (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
-				allocated = convert_initialized_extent(
-						handle, inode, map, &path,
-						allocated);
+				err = convert_initialized_extent(handle,
+					inode, map, &path, &allocated);
 				goto out2;
-			} else if (!ext4_ext_is_unwritten(ex))
+			} else if (!ext4_ext_is_unwritten(ex)) {
 				goto out;
+			}
 
 			ret = ext4_ext_handle_unwritten_extents(
 				handle, inode, map, &path, flags,

Signature · 1 line

2.11.0

Theodore Y. Ts'o

maintainer Applied

2020-03-06 01:29 UTC #1 lore raw

Quoted 8 lines · Eric Whitney

Although convert_initialized_extent() can potentially return an error code with a negative value, its returned value is assigned to an unsigned variable containing a block count in ext4_ext_map_blocks() and then returned to that function's caller. The code currently works, though the way this happens is obscure. The code would be more readable if it followed the error handling convention used elsewhere in ext4_ext_map_blocks().

Quoted 4 lines

This patch does not address any known test failure or bug report - it's simply a cleanup. It also addresses a nearby coding standard issue.
Signed-off-by Eric Whitney <[email protected]>

Thanks, applied.

- Ted