Commit 80175539 authored by Stefan Roesch's avatar Stefan Roesch Committed by Jens Axboe
Browse files

fs: add a FMODE_BUF_WASYNC flags for f_mode 



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: default avatarStefan Roesch <shr@fb.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-8-shr@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 18e419f6

fs/read_write.c

+3 −1
Original line number Diff line number Diff line
@@ -1660,7 +1660,9 @@ 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);

include/linux/fs.h

+3 −0
Original line number Diff line number Diff line
@@ -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!