// 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 bio_max_segs(howmany(count, PAGE_SIZE)); } int xfs_rw_bdev( struct block_device *bdev, sector_t sector, unsigned int count, char *data, enum req_op 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(bdev, bio_max_vecs(left), op | REQ_META | REQ_SYNC, GFP_KERNEL); bio->bi_iter.bi_sector = sector; 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(prev->bi_bdev, bio_max_vecs(left), prev->bi_opf, GFP_KERNEL); bio->bi_iter.bi_sector = bio_end_sector(prev); bio_chain(prev, bio); 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; }