If kiocb_set_cancel_fn() is called for I/O submitted via io_uring, the
following kernel warning appears:
WARNING: CPU: 3 PID: 368 at fs/aio.c:598 kiocb_set_cancel_fn+0x9c/0xa8
Call trace:
kiocb_set_cancel_fn+0x9c/0xa8
ffs_epfile_read_iter+0x144/0x1d0
io_read+0x19c/0x498
io_issue_sqe+0x118/0x27c
io_submit_sqes+0x25c/0x5fc
__arm64_sys_io_uring_enter+0x104/0xab0
invoke_syscall+0x58/0x11c
el0_svc_common+0xb4/0xf4
do_el0_svc+0x2c/0xb0
el0_svc+0x2c/0xa4
el0t_64_sync_handler+0x68/0xb4
el0t_64_sync+0x1a4/0x1a8
Fix this by setting the IOCB_AIO_RW flag for read and write I/O that is
submitted by libaio.
Suggested-by: Jens Axboe <axboe@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Avi Kivity <avi@xxxxxxxxxxxx>
Cc: Sandeep Dhavale <dhavale@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
fs/aio.c | 9 ++++++++-
include/linux/fs.h | 2 ++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/aio.c b/fs/aio.c
index bb2ff48991f3..da18dbcfcb22 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -593,6 +593,13 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
struct kioctx *ctx = req->ki_ctx;
unsigned long flags;
+ /*
+ * kiocb didn't come from aio or is neither a read nor a write, hence
+ * ignore it.
+ */
+ if (!(iocb->ki_flags & IOCB_AIO_RW))
+ return;
+
if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
return;
@@ -1509,7 +1516,7 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
req->ki_complete = aio_complete_rw;
req->private = NULL;
req->ki_pos = iocb->aio_offset;
- req->ki_flags = req->ki_filp->f_iocb_flags;
+ req->ki_flags = req->ki_filp->f_iocb_flags | IOCB_AIO_RW;
if (iocb->aio_flags & IOCB_FLAG_RESFD)
req->ki_flags |= IOCB_EVENTFD;
if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c9deac59c29a..d47306fe1121 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -352,6 +352,8 @@ enum rw_hint {
* unrelated IO (like cache flushing, new IO generation, etc).
*/
#define IOCB_DIO_CALLER_COMP (1 << 22)
+/* kiocb is a read or write operation submitted by fs/aio.c. */
+#define IOCB_AIO_RW (1 << 23)
/* for use in trace events */
#define TRACE_IOCB_STRINGS \
