f2fs: handle failed bio allocation

As the below comment of bio_alloc_bioset, f2fs can allocate multiple bios at the
same time. So, we can't guarantee that bio is allocated all the time.

"
 *   When @bs is not NULL, if %__GFP_WAIT is set then bio_alloc will always be
 *   able to allocate a bio. This is due to the mempool guarantees. To make this
 *   work, callers must never allocate more than 1 bio at a time from this pool.
 *   Callers that need to allocate more than 1 bio must always submit the
 *   previously allocated bio for IO before attempting to allocate a new one.
 *   Failure to do so can cause deadlocks under memory pressure.
"

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 1b4265639f07..6273e2cde93e 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -330,10 +330,12 @@ repeat:
 		return 0;
 
 	if (!llist_empty(&fcc->issue_list)) {
-		struct bio *bio = bio_alloc(GFP_NOIO, 0);
+		struct bio *bio;
 		struct flush_cmd *cmd, *next;
 		int ret;
 
+		bio = f2fs_bio_alloc(0);
+
 		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
 
@@ -365,8 +367,15 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
 	if (test_opt(sbi, NOBARRIER))
 		return 0;
 
-	if (!test_opt(sbi, FLUSH_MERGE))
-		return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
+	if (!test_opt(sbi, FLUSH_MERGE)) {
+		struct bio *bio = f2fs_bio_alloc(0);
+		int ret;
+
+		bio->bi_bdev = sbi->sb->s_bdev;
+		ret = submit_bio_wait(WRITE_FLUSH, bio);
+		bio_put(bio);
+		return ret;
+	}
 
 	init_completion(&cmd.wait);