[39/90] ext4: Fix hueristic which avoids group preallocation for closed files

Greg KH
2009-12-11T04:52:56Z

[-- Attachment #1: 0039-ext4-Fix-hueristic-which-avoids-group-preallocation-.patch --]
[-- Type: text/plain, Size: 1148 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
(cherry picked from commit 71780577306fd1e76c7a92e3b308db624d03adb9)

The hueristic was designed to avoid using locality group preallocation
when writing the last segment of a closed file. Fix it by move
setting size to the maximum of size and isize until after we check
whether size == isize.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/ext4/mballoc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4162,7 +4162,6 @@ static void ext4_mb_group_or_file(struct
size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
>> bsbits;
- size = max(size, isize);

if ((size == isize) &&
!ext4_fs_is_busy(sbi) &&
@@ -4172,6 +4171,7 @@ static void ext4_mb_group_or_file(struct
}

/* don't use group allocation for large files */
+ size = max(size, isize);
if (size >= sbi->s_mb_stream_request) {
ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
return;