commit
ec22ba8e ext4: disable merging of uninitialized extents
ensured that if either extent under consideration is uninit,
we decline to merge, and ext4_can_extents_be_merged() returns false.
So there is no need for the caller to then test whether the
extent under consideration is unitialized; if it were, we
wouldn't have gotten that far.
The comments were also inaccurate; ext4_can_extents_be_merged()
no longer XORs the states, it fails if *either* is uninit.
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---
Disclaimer: compile-tested only.
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index de6d467..35f65cf 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1715,7 +1715,6 @@ static int ext4_ext_try_to_merge_right(struct inode *inode,
struct ext4_extent_header *eh;
unsigned int depth, len;
int merge_done = 0;
- int uninitialized = 0;
depth = ext_depth(inode);
BUG_ON(path[depth].p_hdr == NULL);
@@ -1725,12 +1724,8 @@ static int ext4_ext_try_to_merge_right(struct inode *inode,
if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
break;
/* merge with next extent! */
- if (ext4_ext_is_uninitialized(ex))
- uninitialized = 1;
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(ex + 1));
- if (uninitialized)
- ext4_ext_mark_uninitialized(ex);
if (ex + 1 < EXT_LAST_EXTENT(eh)) {
len = (EXT_LAST_EXTENT(eh) - ex - 1)
@@ -1885,7 +1880,6 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
struct ext4_ext_path *npath = NULL;
int depth, len, err;
ext4_lblk_t next;
- unsigned uninitialized = 0;
int mb_flags = 0;
if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
@@ -1937,18 +1931,8 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
if (err)
return err;
- /*
- * ext4_can_extents_be_merged should have checked
- * that either both extents are uninitialized, or
- * both aren't. Thus we need to check only one of
- * them here.
- */
- if (ext4_ext_is_uninitialized(ex))
- uninitialized = 1;
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(newext));
- if (uninitialized)
- ext4_ext_mark_uninitialized(ex);
eh = path[depth].p_hdr;
nearex = ex;
goto merge;
@@ -1971,20 +1955,10 @@ prepend:
if (err)
return err;
- /*
- * ext4_can_extents_be_merged should have checked
- * that either both extents are uninitialized, or
- * both aren't. Thus we need to check only one of
- * them here.
- */
- if (ext4_ext_is_uninitialized(ex))
- uninitialized = 1;
ex->ee_block = newext->ee_block;
ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(newext));
- if (uninitialized)
- ext4_ext_mark_uninitialized(ex);
eh = path[depth].p_hdr;
nearex = ex;
goto merge;
--
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