diff mbox series

[RESEND,v9,07/14] fs: Add check for async buffered writes to generic_write_checks

Message ID 20220623175157.1715274-8-shr@fb.com (mailing list archive)
State New
Headers show
Series io-uring/xfs: support async buffered writes | expand

Commit Message

Stefan Roesch June 23, 2022, 5:51 p.m. UTC 
This introduces the flag FMODE_BUF_WASYNC. If devices support async
buffered writes, this flag can be set. It also modifies the check in
generic_write_checks to take async buffered writes into consideration.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
---
 fs/read_write.c    | 4 +++-
 include/linux/fs.h | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

Comments

Christoph Hellwig June 24, 2022, 5:21 a.m. UTC | #1 
FYI, I think a subject like

"fs: add a FMODE_BUF_WASYNC flags for f_mode"

might be a more descriptive.  As the new flag here really is the
interesting part, not that we check it.
Jens Axboe June 24, 2022, 2:48 p.m. UTC | #2 
On 6/23/22 11:21 PM, Christoph Hellwig wrote:
> FYI, I think a subject like
> 
> "fs: add a FMODE_BUF_WASYNC flags for f_mode"
> 
> might be a more descriptive.  As the new flag here really is the
> interesting part, not that we check it.

Agree on that - if others do too, I can just make that edit.
Jens Axboe June 24, 2022, 5:06 p.m. UTC | #3 
On 6/23/22 11:21 PM, Christoph Hellwig wrote:
> FYI, I think a subject like
> 
> "fs: add a FMODE_BUF_WASYNC flags for f_mode"
> 
> might be a more descriptive.  As the new flag here really is the
> interesting part, not that we check it.

I made that edit.
diff mbox series

Patch

diff --git a/fs/read_write.c b/fs/read_write.c
index b1b1cdfee9d3..a1f4d45c2406 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1649,7 +1649,9 @@  int generic_write_checks_count(struct kiocb *iocb, loff_t *count)
 	if (iocb->ki_flags & IOCB_APPEND)
 		iocb->ki_pos = i_size_read(inode);
 
-	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
+	if ((iocb->ki_flags & IOCB_NOWAIT) &&
+	    !((iocb->ki_flags & IOCB_DIRECT) ||
+	      (file->f_mode & FMODE_BUF_WASYNC)))
 		return -EINVAL;
 
 	return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9ad5e3520fae..bc84847c201e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -180,6 +180,9 @@  typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 /* File supports async buffered reads */
 #define FMODE_BUF_RASYNC	((__force fmode_t)0x40000000)
 
+/* File supports async nowait buffered writes */
+#define FMODE_BUF_WASYNC	((__force fmode_t)0x80000000)
+
 /*
  * Attribute flags.  These should be or-ed together to figure out what
  * has been changed!