ocfs2: lighten up allocate transaction
The issue scenario is as following:
When fallocating a very large disk space for a small file,
__ocfs2_extend_allocation attempts to get a very large transaction. For
some journal sizes, there may be not enough room for this transaction,
and the fallocate will fail.
The patch below extends & restarts the transaction as necessary while
allocating space, and should work with even the smallest journal. This
patch refers ext4 resize.
Test:
# mkfs.ocfs2 -b 4K -C 32K -T datafiles /dev/sdc
...(jounral size is 32M)
# mount.ocfs2 /dev/sdc /mnt/ocfs2/
# touch /mnt/ocfs2/1.log
# fallocate -o 0 -l 400G /mnt/ocfs2/1.log
fallocate: /mnt/ocfs2/1.log: fallocate failed: Cannot allocate memory
# tail -f /var/log/messages
[ 7372.278591] JBD: fallocate wants too many credits (2051 > 2048)
[ 7372.278597] (fallocate,6438,0):__ocfs2_extend_allocation:709 ERROR: status = -12
[ 7372.278603] (fallocate,6438,0):ocfs2_allocate_unwritten_extents:1504 ERROR: status = -12
[ 7372.278607] (fallocate,6438,0):__ocfs2_change_file_space:1955 ERROR: status = -12
^C
With this patch, the test works well.
Signed-off-by: Younger Liu <younger.liu@huawei.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 3261d71..409c549 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -671,11 +671,7 @@
} else {
BUG_ON(why != RESTART_TRANS);
- /* TODO: This can be more intelligent. */
- credits = ocfs2_calc_extend_credits(osb->sb,
- &fe->id2.i_list,
- clusters_to_add);
- status = ocfs2_extend_trans(handle, credits);
+ status = ocfs2_allocate_extend_trans(handle, 1);
if (status < 0) {
/* handle still has to be committed at
* this point. */