ext4: Fix hueristic which avoids group preallocation for closed files
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>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index e9c6189..c73d439 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4189,7 +4189,6 @@
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) &&
@@ -4199,6 +4198,7 @@
}
/* 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;