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FAILED: patch "[PATCH] fs/aio: Restrict kiocb_set_cancel_fn() to I/O submitted via" failed to apply to 5.10-stable tree

PATCH New [email protected] 2 participants 2 messages Feb 26, 2024

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#0 lore raw

The patch below does not apply to the 5.10-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 <[email protected]>.

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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x b820de741ae48ccf50dd95e297889c286ff4f760
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024022654-stainless-aground-196f@gregkh' --subject-prefix 'PATCH 5.10.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 <[email protected]>
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.

fs/aio.c +8 -1
index bb2ff48991f3..da18dbcfcb22 100644
@@ -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) {
include/linux/fs.h +2 -0
index ed5966a70495..c2dcc98cb4c8 100644
@@ -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 \
#1 lore raw

PATCH 1/1 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.

Cc Christoph Hellwig <[email protected]>
Cc Avi Kivity <[email protected]>
Cc Sandeep Dhavale <[email protected]>
Cc Jens Axboe <[email protected]>
Cc Greg Kroah-Hartman <[email protected]>
Cc Kent Overstreet <[email protected]>
(cherry picked from commit b820de741ae48ccf50dd95e297889c286ff4f760)
[ bvanassche: resolved merge conflicts ]
---
 fs/aio.c           | 9 ++++++++-
 include/linux/fs.h | 2 ++
 2 files changed, 10 insertions(+), 1 deletion(-)
fs/aio.c +8 -1
index 5934ea84b499..900ed5207540 100644
@@ -569,6 +569,13 @@ 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;
 
@@ -1454,7 +1461,7 @@ 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 = iocb_flags(req->ki_filp);
+	req->ki_flags = iocb_flags(req->ki_filp) | IOCB_AIO_RW;
 	if (iocb->aio_flags & IOCB_FLAG_RESFD)
 		req->ki_flags |= IOCB_EVENTFD;
 	req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp));
include/linux/fs.h +2 -0
index 82316863c71f..6de70634e547 100644
@@ -316,6 +316,8 @@ enum rw_hint {
 /* iocb->ki_waitq is valid */
 #define IOCB_WAITQ		(1 << 19)
 #define IOCB_NOIO		(1 << 20)
+/* kiocb is a read or write operation submitted by fs/aio.c. */
+#define IOCB_AIO_RW		(1 << 23)
 
 struct kiocb {
 	struct file		*ki_filp;