60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2019 Christoph Hellwig.
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*/
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#include "xfs.h"
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static inline unsigned int bio_max_vecs(unsigned int count)
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{
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return bio_max_segs(howmany(count, PAGE_SIZE));
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}
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int
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xfs_rw_bdev(
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struct block_device *bdev,
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sector_t sector,
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unsigned int count,
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char *data,
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enum req_op op)
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{
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unsigned int is_vmalloc = is_vmalloc_addr(data);
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unsigned int left = count;
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int error;
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struct bio *bio;
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if (is_vmalloc && op == REQ_OP_WRITE)
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flush_kernel_vmap_range(data, count);
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bio = bio_alloc(bdev, bio_max_vecs(left), op | REQ_META | REQ_SYNC,
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GFP_KERNEL);
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bio->bi_iter.bi_sector = sector;
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do {
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struct page *page = kmem_to_page(data);
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unsigned int off = offset_in_page(data);
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unsigned int len = min_t(unsigned, left, PAGE_SIZE - off);
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while (bio_add_page(bio, page, len, off) != len) {
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struct bio *prev = bio;
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bio = bio_alloc(prev->bi_bdev, bio_max_vecs(left),
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prev->bi_opf, GFP_KERNEL);
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bio->bi_iter.bi_sector = bio_end_sector(prev);
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bio_chain(prev, bio);
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submit_bio(prev);
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}
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data += len;
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left -= len;
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} while (left > 0);
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error = submit_bio_wait(bio);
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bio_put(bio);
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if (is_vmalloc && op == REQ_OP_READ)
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invalidate_kernel_vmap_range(data, count);
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return error;
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}
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