Commit 97be7ebe authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

vfs: add the RWF_HIPRI flag for preadv2/pwritev2 



This adds a flag that tells the file system that this is a high priority
request for which it's worth to poll the hardware.  The flag is purely
advisory and can be ignored if not supported.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarStephen Bates <stephen.bates@pmcs.com>
Tested-by: default avatarStephen Bates <stephen.bates@pmcs.com>
Acked-by: default avatarJeff Moyer <jmoyer@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 4babf2c5

fs/read_write.c

+4 −2
Original line number Diff line number Diff line
@@ -697,10 +697,12 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, 
	struct kiocb kiocb;

	ssize_t ret;



	if (flags)

	if (flags & ~RWF_HIPRI)

		return -EOPNOTSUPP;



	init_sync_kiocb(&kiocb, filp);

	if (flags & RWF_HIPRI)

		kiocb.ki_flags |= IOCB_HIPRI;

	kiocb.ki_pos = *ppos;



	ret = fn(&kiocb, iter);
@@ -715,7 +717,7 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, 
{

	ssize_t ret = 0;



	if (flags)

	if (flags & ~RWF_HIPRI)

		return -EOPNOTSUPP;



	while (iov_iter_count(iter)) {

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -320,6 +320,7 @@ struct writeback_control; 
#define IOCB_EVENTFD		(1 << 0)

#define IOCB_APPEND		(1 << 1)

#define IOCB_DIRECT		(1 << 2)

#define IOCB_HIPRI		(1 << 3)



struct kiocb {

	struct file		*ki_filp;

include/uapi/linux/fs.h

+3 −0
Original line number Diff line number Diff line
@@ -305,4 +305,7 @@ struct fsxattr { 
#define SYNC_FILE_RANGE_WRITE		2

#define SYNC_FILE_RANGE_WAIT_AFTER	4



/* flags for preadv2/pwritev2: */

#define RWF_HIPRI			0x00000001 /* high priority request, poll if possible */



#endif /* _UAPI_LINUX_FS_H */

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