The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x b820de741ae48ccf50dd95e297889c286ff4f760 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024022601-stem-comfort-1bb5@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

b820de741ae4 ("fs/aio: Restrict kiocb_set_cancel_fn() to I/O submitted via libaio") 9cf3516c29e6 ("fs: add IOCB flags related to passing back dio completions") f6c73a11133e ("fs.h: Add TRACE_IOCB_STRINGS for use in trace points") 1da8cf961bb1 ("Merge tag 'io_uring-6.0-2022-08-13' of git://git.kernel.dk/linux-block")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b820de741ae48ccf50dd95e297889c286ff4f760 Mon Sep 17 00:00:00 2001 From: Bart Van Assche bvanassche@acm.org Date: Thu, 15 Feb 2024 12:47:38 -0800 Subject: [PATCH] fs/aio: Restrict kiocb_set_cancel_fn() to I/O submitted via libaio

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@kernel.dk Cc: Christoph Hellwig hch@lst.de Cc: Avi Kivity avi@scylladb.com Cc: Sandeep Dhavale dhavale@google.com Cc: Jens Axboe axboe@kernel.dk Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Kent Overstreet kent.overstreet@linux.dev Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche bvanassche@acm.org Link: https://lore.kernel.org/r/20240215204739.2677806-2-bvanassche@acm.org Signed-off-by: Christian Brauner brauner@kernel.org

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 ed5966a70495..c2dcc98cb4c8 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 \