f2fs: prepare a waiter before entering io_schedule
This is to avoid sleep() in the waiter thread.
[ 20.157753] ------------[ cut here ]------------
[ 20.158393] do not call blocking ops when !TASK_RUNNING; state=2 set at [<0000000096354225>] prepare_to_wait+0xcd/0x430
[ 20.159858] WARNING: CPU: 1 PID: 1152 at kernel/sched/core.c:7142 __might_sleep+0x149/0x1a0
...
[ 20.176110] __submit_merged_write_cond+0x191/0x310
[ 20.176739] f2fs_submit_merged_write+0x18/0x20
[ 20.177323] f2fs_wait_on_all_pages+0x269/0x2d0
[ 20.177899] ? block_operations+0x980/0x980
[ 20.178441] ? __kasan_check_read+0x11/0x20
[ 20.178975] ? finish_wait+0x260/0x260
[ 20.179488] ? percpu_counter_set+0x147/0x230
[ 20.180049] do_checkpoint+0x1757/0x2a50
[ 20.180558] f2fs_write_checkpoint+0x840/0xaf0
[ 20.181126] f2fs_sync_fs+0x287/0x4a0
Reported-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 99c8061..ff807e1 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1258,8 +1258,6 @@ void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type)
DEFINE_WAIT(wait);
for (;;) {
- prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
-
if (!get_pages(sbi, type))
break;
@@ -1271,6 +1269,8 @@ void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type)
FS_CP_META_IO);
else if (type == F2FS_WB_CP_DATA)
f2fs_submit_merged_write(sbi, DATA);
+
+ prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
io_schedule_timeout(DEFAULT_IO_TIMEOUT);
}
finish_wait(&sbi->cp_wait, &wait);