Commit 487c607d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: use iomap for writes to block devices 



Use iomap in buffer_head compat mode to write to block devices.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: default avatarPankaj Raghav <p.raghav@samsung.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChristian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230801172201.1923299-6-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a05f7bd9

block/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
menuconfig BLOCK

       bool "Enable the block layer" if EXPERT

       default y

       select FS_IOMAP

       select SBITMAP

       help

	 Provide block layer support for the kernel.

block/fops.c

+29 −2
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/falloc.h>

#include <linux/suspend.h>

#include <linux/fs.h>

#include <linux/iomap.h>

#include <linux/module.h>

#include "blk.h"
@@ -386,6 +387,27 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 
	return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));

}



static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length,

		unsigned int flags, struct iomap *iomap, struct iomap *srcmap)

{

	struct block_device *bdev = I_BDEV(inode);

	loff_t isize = i_size_read(inode);



	iomap->bdev = bdev;

	iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev));

	if (iomap->offset >= isize)

		return -EIO;

	iomap->type = IOMAP_MAPPED;

	iomap->addr = iomap->offset;

	iomap->length = isize - iomap->offset;

	iomap->flags |= IOMAP_F_BUFFER_HEAD;

	return 0;

}



static const struct iomap_ops blkdev_iomap_ops = {

	.iomap_begin		= blkdev_iomap_begin,

};



static int blkdev_writepage(struct page *page, struct writeback_control *wbc)

{

	return block_write_full_page(page, blkdev_get_block, wbc);
@@ -556,6 +578,11 @@ blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) 
	return written;

}



static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from)

{

	return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops);

}



/*

 * Write data to the block device.  Only intended for the block device itself

 * and the raw driver which basically is a fake block device.
@@ -605,9 +632,9 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) 
		ret = blkdev_direct_write(iocb, from);

		if (ret >= 0 && iov_iter_count(from))

			ret = direct_write_fallback(iocb, from, ret,

					generic_perform_write(iocb, from));

					blkdev_buffered_write(iocb, from));

	} else {

		ret = generic_perform_write(iocb, from);

		ret = blkdev_buffered_write(iocb, from);

	}



	if (ret > 0)