FAILED: patch "[PATCH] io_uring: allow retry for O_NONBLOCK if async is supported" failed to apply to 5.14-stable tree
The patch below does not apply to the 5.14-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.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5d329e1286b0a040264e239b80257c937f6e685f Mon Sep 17 00:00:00 2001
From: Jens Axboe axboe@kernel.dk Date: Tue, 14 Sep 2021 11:08:37 -0600 Subject: [PATCH] io_uring: allow retry for O_NONBLOCK if async is supported
A common complaint is that using O_NONBLOCK files with io_uring can be a bit of a pain. Be a bit nicer and allow normal retry IFF the file does support async behavior. This makes it possible to use io_uring more reliably with O_NONBLOCK files, for use cases where it either isn't possible or feasible to modify the file flags.
Cc: stable@vger.kernel.org Reported-and-tested-by: Dan Melnic dmm@fb.com Signed-off-by: Jens Axboe axboe@kernel.dk
diff --git a/fs/io_uring.c b/fs/io_uring.c index ae489ab275dd..3077f85a2638 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2843,7 +2843,8 @@ static bool io_file_supports_nowait(struct io_kiocb *req, int rw) return __io_file_supports_nowait(req->file, rw); }
-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) +static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, + int rw) { struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw.kiocb; @@ -2865,8 +2866,13 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (unlikely(ret)) return ret;
- /* don't allow async punt for O_NONBLOCK or RWF_NOWAIT */ - if ((kiocb->ki_flags & IOCB_NOWAIT) || (file->f_flags & O_NONBLOCK)) + /* + * If the file is marked O_NONBLOCK, still allow retry for it if it + * supports async. Otherwise it's impossible to use O_NONBLOCK files + * reliably. If not, or it IOCB_NOWAIT is set, don't retry. + */ + if ((kiocb->ki_flags & IOCB_NOWAIT) || + ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw))) req->flags |= REQ_F_NOWAIT;
ioprio = READ_ONCE(sqe->ioprio); @@ -3349,7 +3355,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { if (unlikely(!(req->file->f_mode & FMODE_READ))) return -EBADF; - return io_prep_rw(req, sqe); + return io_prep_rw(req, sqe, READ); }
/* @@ -3542,7 +3548,7 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { if (unlikely(!(req->file->f_mode & FMODE_WRITE))) return -EBADF; - return io_prep_rw(req, sqe); + return io_prep_rw(req, sqe, WRITE); }
static int io_write(struct io_kiocb *req, unsigned int issue_flags)
On 9/18/21 6:34 AM, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.14-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.
Just a trivial fuzz, here's a fixed version.
On Sat, Sep 18, 2021 at 06:44:16AM -0600, Jens Axboe wrote:
On 9/18/21 6:34 AM, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.14-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.
Just a trivial fuzz, here's a fixed version.
Sorry, no, the fuzz was easy, this breaks the build:
fs/io_uring.c: In function ‘io_prep_rw’: fs/io_uring.c:2715:47: error: implicit declaration of function ‘io_file_supports_nowait’; did you mean ‘io_file_supports_async’? [-Werror=implicit-function-declaration] 2715 | ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw))) | ^~~~~~~~~~~~~~~~~~~~~~~ | io_file_supports_async CHK kernel/kheaders_data.tar.xz cc1: some warnings being treated as errors
Any hint as to what that function would be in 5.14.y?
thanks,
greg k-h
On 9/18/21 6:47 AM, Greg KH wrote:
On Sat, Sep 18, 2021 at 06:44:16AM -0600, Jens Axboe wrote:
On 9/18/21 6:34 AM, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.14-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.
Just a trivial fuzz, here's a fixed version.
Sorry, no, the fuzz was easy, this breaks the build:
fs/io_uring.c: In function ‘io_prep_rw’: fs/io_uring.c:2715:47: error: implicit declaration of function ‘io_file_supports_nowait’; did you mean ‘io_file_supports_async’? [-Werror=implicit-function-declaration] 2715 | ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw))) | ^~~~~~~~~~~~~~~~~~~~~~~ | io_file_supports_async CHK kernel/kheaders_data.tar.xz cc1: some warnings being treated as errors
Any hint as to what that function would be in 5.14.y?
Ah sorry I'm an idiot, it should be that io_file_supports_nowait() that also caused the fuzz in applying.
On Sat, Sep 18, 2021 at 06:49:35AM -0600, Jens Axboe wrote:
On 9/18/21 6:47 AM, Greg KH wrote:
On Sat, Sep 18, 2021 at 06:44:16AM -0600, Jens Axboe wrote:
On 9/18/21 6:34 AM, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.14-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.
Just a trivial fuzz, here's a fixed version.
Sorry, no, the fuzz was easy, this breaks the build:
fs/io_uring.c: In function ‘io_prep_rw’: fs/io_uring.c:2715:47: error: implicit declaration of function ‘io_file_supports_nowait’; did you mean ‘io_file_supports_async’? [-Werror=implicit-function-declaration] 2715 | ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw))) | ^~~~~~~~~~~~~~~~~~~~~~~ | io_file_supports_async CHK kernel/kheaders_data.tar.xz cc1: some warnings being treated as errors
Any hint as to what that function would be in 5.14.y?
Ah sorry I'm an idiot, it should be that io_file_supports_nowait() that also caused the fuzz in applying.
This version worked, thanks!
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
gregkh＠linuxfoundation.org
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Jens Axboe