From 7d28631786b2333c5d48ad25172eb159aaa2945f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 25 Jan 2023 14:34:30 +0100 Subject: mpage: stop using bdev_{read,write}_page Patch series "remove ->rw_page". This series removes the ->rw_page block_device_operation, which is an old and clumsy attempt at a simple read/write fast path for the block layer. It isn't actually used by the fastest block layer operations that we support (polled I/O through io_uring), but only used by the mpage buffered I/O helpers which are some of the slowest I/O we have and do not make any difference there at all, and zram which is a block device abused to duplicate the zram functionality. Given that zram is heavily used we need to make sure there is a good replacement for synchronous I/O, so this series adds a new flag for drivers that complete I/O synchronously and uses that flag to use on-stack bios and synchronous submission for them in the swap code. This patch (of 7): These are micro-optimizations for synchronous I/O, which do not matter compared to all the other inefficiencies in the legacy buffer_head based mpage code. Link: https://lkml.kernel.org/r/20230125133436.447864-1-hch@lst.de Link: https://lkml.kernel.org/r/20230125133436.447864-2-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Dan Williams Cc: Keith Busch Cc: Dave Jiang Cc: Ira Weiny Cc: Jens Axboe Cc: Minchan Kim Cc: Sergey Senozhatsky Cc: Vishal Verma Signed-off-by: Andrew Morton --- fs/mpage.c | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'fs/mpage.c') diff --git a/fs/mpage.c b/fs/mpage.c index b8e7975159bc..55988ea994ee 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -269,11 +269,6 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) alloc_new: if (args->bio == NULL) { - if (first_hole == blocks_per_page) { - if (!bdev_read_page(bdev, blocks[0] << (blkbits - 9), - &folio->page)) - goto out; - } args->bio = bio_alloc(bdev, bio_max_segs(args->nr_pages), opf, gfp); if (args->bio == NULL) @@ -585,11 +580,6 @@ page_is_mapped: alloc_new: if (bio == NULL) { - if (first_unmapped == blocks_per_page) { - if (!bdev_write_page(bdev, blocks[0] << (blkbits - 9), - page, wbc)) - goto out; - } bio = bio_alloc(bdev, BIO_MAX_VECS, REQ_OP_WRITE | wbc_to_write_flags(wbc), GFP_NOFS); -- cgit