From 487c607df790d366e67a7d6a30adf785cdd98e55 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Aug 2023 19:22:00 +0200 Subject: [PATCH] block: use iomap for writes to block devices Use iomap in buffer_head compat mode to write to block devices. Signed-off-by: Christoph Hellwig Reviewed-by: Luis Chamberlain Reviewed-by: Pankaj Raghav Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230801172201.1923299-6-hch@lst.de Signed-off-by: Jens Axboe --- block/Kconfig | 1 + block/fops.c | 31 +++++++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/block/Kconfig b/block/Kconfig index 86122e459fe0..1a13ef0b1ca1 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -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. diff --git a/block/fops.c b/block/fops.c index f0b822c28ddf..063ece37d44e 100644 --- a/block/fops.c +++ b/block/fops.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #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)