diff options
authorPavel Begunkov <>2021-01-16 05:32:30 +0000
committerJens Axboe <>2021-01-16 12:14:02 -0700
commit4325cb498cb743dacaa3edbec398c5255f476ef6 (patch)
parent6b393a1ff1746a1c91bd95cbb2d79b104d8f15ac (diff)
io_uring: fix uring_flush in exit_files() warning
WARNING: CPU: 1 PID: 11100 at fs/io_uring.c:9096 io_uring_flush+0x326/0x3a0 fs/io_uring.c:9096 RIP: 0010:io_uring_flush+0x326/0x3a0 fs/io_uring.c:9096 Call Trace: filp_close+0xb4/0x170 fs/open.c:1280 close_files fs/file.c:401 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1cc/0x350 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:433 do_exit+0xc22/0x2ae0 kernel/exit.c:820 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x3e9/0x20a0 kernel/signal.c:2770 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 An SQPOLL ring creator task may have gotten rid of its file note during exit and called io_disable_sqo_submit(), but the io_uring is still left referenced through fdtable, which will be put during close_files() and cause a false positive warning. First split the warning into two for more clarity when is hit, and the add sqo_dead check to handle the described case. Reported-by: Signed-off-by: Pavel Begunkov <> Signed-off-by: Jens Axboe <>
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 616c5f732a26..d494c4269fc5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -9131,7 +9131,10 @@ static int io_uring_flush(struct file *file, void *data)
if (ctx->flags & IORING_SETUP_SQPOLL) {
/* there is only one file note, which is owned by sqo_task */
- WARN_ON_ONCE((ctx->sqo_task == current) ==
+ WARN_ON_ONCE(ctx->sqo_task != current &&
+ xa_load(&tctx->xa, (unsigned long)file));
+ /* sqo_dead check is for when this happens after cancellation */
+ WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead &&
!xa_load(&tctx->xa, (unsigned long)file));