Commit c3b0e880 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

iomap: support REQ_OP_ZONE_APPEND 



A ZONE_APPEND bio must follow hardware restrictions (e.g. not exceeding
max_zone_append_sectors) not to be split. bio_iov_iter_get_pages builds
such restricted bio using __bio_iov_append_get_pages if bio_op(bio) ==
REQ_OP_ZONE_APPEND.

To utilize it, we need to set the bio_op before calling
bio_iov_iter_get_pages(). This commit introduces IOMAP_F_ZONE_APPEND, so
that iomap user can set the flag to indicate they want REQ_OP_ZONE_APPEND
and restricted bio.

Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent ae29333f

fs/iomap/direct-io.c

+37 −6
Original line number Diff line number Diff line
@@ -201,6 +201,34 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos, 
	iomap_dio_submit_bio(dio, iomap, bio, pos);

}



/*

 * Figure out the bio's operation flags from the dio request, the

 * mapping, and whether or not we want FUA.  Note that we can end up

 * clearing the WRITE_FUA flag in the dio request.

 */

static inline unsigned int

iomap_dio_bio_opflags(struct iomap_dio *dio, struct iomap *iomap, bool use_fua)

{

	unsigned int opflags = REQ_SYNC | REQ_IDLE;



	if (!(dio->flags & IOMAP_DIO_WRITE)) {

		WARN_ON_ONCE(iomap->flags & IOMAP_F_ZONE_APPEND);

		return REQ_OP_READ;

	}



	if (iomap->flags & IOMAP_F_ZONE_APPEND)

		opflags |= REQ_OP_ZONE_APPEND;

	else

		opflags |= REQ_OP_WRITE;



	if (use_fua)

		opflags |= REQ_FUA;

	else

		dio->flags &= ~IOMAP_DIO_WRITE_FUA;



	return opflags;

}



static loff_t

iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,

		struct iomap_dio *dio, struct iomap *iomap)
@@ -208,6 +236,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, 
	unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));

	unsigned int fs_block_size = i_blocksize(inode), pad;

	unsigned int align = iov_iter_alignment(dio->submit.iter);

	unsigned int bio_opf;

	struct bio *bio;

	bool need_zeroout = false;

	bool use_fua = false;
@@ -263,6 +292,13 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, 
			iomap_dio_zero(dio, iomap, pos - pad, pad);

	}



	/*

	 * Set the operation flags early so that bio_iov_iter_get_pages

	 * can set up the page vector appropriately for a ZONE_APPEND

	 * operation.

	 */

	bio_opf = iomap_dio_bio_opflags(dio, iomap, use_fua);



	do {

		size_t n;

		if (dio->error) {
@@ -278,6 +314,7 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, 
		bio->bi_ioprio = dio->iocb->ki_ioprio;

		bio->bi_private = dio;

		bio->bi_end_io = iomap_dio_bio_end_io;

		bio->bi_opf = bio_opf;



		ret = bio_iov_iter_get_pages(bio, dio->submit.iter);

		if (unlikely(ret)) {
@@ -293,14 +330,8 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length, 


		n = bio->bi_iter.bi_size;

		if (dio->flags & IOMAP_DIO_WRITE) {

			bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;

			if (use_fua)

				bio->bi_opf |= REQ_FUA;

			else

				dio->flags &= ~IOMAP_DIO_WRITE_FUA;

			task_io_account_write(n);

		} else {

			bio->bi_opf = REQ_OP_READ;

			if (dio->flags & IOMAP_DIO_DIRTY)

				bio_set_pages_dirty(bio);

		}

include/linux/iomap.h

+1 −0
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ struct vm_fault; 
#define IOMAP_F_SHARED		0x04

#define IOMAP_F_MERGED		0x08

#define IOMAP_F_BUFFER_HEAD	0x10

#define IOMAP_F_ZONE_APPEND	0x20



/*

 * Flags set by the core iomap code during operations: