From 6ad5b3255b9e3d6d94154738aacd5119bf9c8f6e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 28 Jun 2019 19:27:26 -0700 Subject: xfs: use bios directly to read and write the log recovery buffers The xfs_buf structure is basically used as a glorified container for a memory allocation in the log recovery code. Replace it with a call to kmem_alloc_large and a simple abstraction to read into or write from it synchronously using chained bios. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_bio_io.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 fs/xfs/xfs_bio_io.c (limited to 'fs/xfs/xfs_bio_io.c') diff --git a/fs/xfs/xfs_bio_io.c b/fs/xfs/xfs_bio_io.c new file mode 100644 index 000000000000..757c1d9293eb --- /dev/null +++ b/fs/xfs/xfs_bio_io.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019 Christoph Hellwig. + */ +#include "xfs.h" + +static inline unsigned int bio_max_vecs(unsigned int count) +{ + return min_t(unsigned, howmany(count, PAGE_SIZE), BIO_MAX_PAGES); +} + +int +xfs_rw_bdev( + struct block_device *bdev, + sector_t sector, + unsigned int count, + char *data, + unsigned int op) + +{ + unsigned int is_vmalloc = is_vmalloc_addr(data); + unsigned int left = count; + int error; + struct bio *bio; + + if (is_vmalloc && op == REQ_OP_WRITE) + flush_kernel_vmap_range(data, count); + + bio = bio_alloc(GFP_KERNEL, bio_max_vecs(left)); + bio_set_dev(bio, bdev); + bio->bi_iter.bi_sector = sector; + bio->bi_opf = op | REQ_META | REQ_SYNC; + + do { + struct page *page = kmem_to_page(data); + unsigned int off = offset_in_page(data); + unsigned int len = min_t(unsigned, left, PAGE_SIZE - off); + + while (bio_add_page(bio, page, len, off) != len) { + struct bio *prev = bio; + + bio = bio_alloc(GFP_KERNEL, bio_max_vecs(left)); + bio_copy_dev(bio, prev); + bio->bi_iter.bi_sector = bio_end_sector(prev); + bio->bi_opf = prev->bi_opf; + bio_chain(bio, prev); + + submit_bio(prev); + } + + data += len; + left -= len; + } while (left > 0); + + error = submit_bio_wait(bio); + bio_put(bio); + + if (is_vmalloc && op == REQ_OP_READ) + invalidate_kernel_vmap_range(data, count); + return error; +} -- cgit v1.2.3