From a9b8241594adda0a7a4fb3b87bf29d2dff0d997d Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Thu, 20 Feb 2014 21:17:35 -0500
Subject: [PATCH] ext4: merge uninitialized extents
Allow for merging uninitialized extents.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
fs/ext4/extents.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 9875fd0918e79..ef4b535e0a027 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1691,7 +1691,7 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
* the extent that was written properly split out and conversion to
* initialized is trivial.
*/
- if (ext4_ext_is_uninitialized(ex1) || ext4_ext_is_uninitialized(ex2))
+ if (ext4_ext_is_uninitialized(ex1) != ext4_ext_is_uninitialized(ex2))
return 0;
ext1_ee_len = ext4_ext_get_actual_len(ex1);
@@ -1708,6 +1708,11 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
*/
if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
return 0;
+ if (ext4_ext_is_uninitialized(ex1) &&
+ (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
+ atomic_read(&EXT4_I(inode)->i_unwritten) ||
+ (ext1_ee_len + ext2_ee_len > EXT_UNINIT_MAX_LEN)))
+ return 0;
#ifdef AGGRESSIVE_TEST
if (ext1_ee_len >= 4)
return 0;
@@ -1731,7 +1736,7 @@ 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 merge_done = 0, uninit;
depth = ext_depth(inode);
BUG_ON(path[depth].p_hdr == NULL);
@@ -1741,8 +1746,11 @@ 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! */
+ uninit = ext4_ext_is_uninitialized(ex);
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(ex + 1));
+ if (uninit)
+ ext4_ext_mark_uninitialized(ex);
if (ex + 1 < EXT_LAST_EXTENT(eh)) {
len = (EXT_LAST_EXTENT(eh) - ex - 1)
@@ -1896,7 +1904,7 @@ 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;
- int mb_flags = 0;
+ int mb_flags = 0, uninit;
if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
@@ -1946,9 +1954,11 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
path + depth);
if (err)
return err;
-
+ uninit = ext4_ext_is_uninitialized(ex);
ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+ ext4_ext_get_actual_len(newext));
+ if (uninit)
+ ext4_ext_mark_uninitialized(ex);
eh = path[depth].p_hdr;
nearex = ex;
goto merge;
@@ -1971,10 +1981,13 @@ prepend:
if (err)
return err;
+ uninit = ext4_ext_is_uninitialized(ex);
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 (uninit)
+ ext4_ext_mark_uninitialized(ex);
eh = path[depth].p_hdr;
nearex = ex;
goto merge;
--
2.30.2