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c2b1adc462
Move bio logic in the buffered io code into its own file and remove CONFIG_BLOCK gating for iomap read/readahead. [1] https://lore.kernel.org/linux-fsdevel/aMK2GuumUf93ep99@infradead.org/ Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
89 lines
2.4 KiB
C
89 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2010 Red Hat, Inc.
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* Copyright (C) 2016-2023 Christoph Hellwig.
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*/
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#include <linux/iomap.h>
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#include <linux/pagemap.h>
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#include "internal.h"
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#include "trace.h"
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static void iomap_read_end_io(struct bio *bio)
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{
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int error = blk_status_to_errno(bio->bi_status);
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struct folio_iter fi;
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bio_for_each_folio_all(fi, bio)
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iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error);
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bio_put(bio);
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}
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static void iomap_bio_submit_read(struct iomap_read_folio_ctx *ctx)
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{
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struct bio *bio = ctx->read_ctx;
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if (bio)
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submit_bio(bio);
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}
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static int iomap_bio_read_folio_range(const struct iomap_iter *iter,
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struct iomap_read_folio_ctx *ctx, size_t plen)
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{
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struct folio *folio = ctx->cur_folio;
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const struct iomap *iomap = &iter->iomap;
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loff_t pos = iter->pos;
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size_t poff = offset_in_folio(folio, pos);
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loff_t length = iomap_length(iter);
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sector_t sector;
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struct bio *bio = ctx->read_ctx;
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sector = iomap_sector(iomap, pos);
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if (!bio || bio_end_sector(bio) != sector ||
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!bio_add_folio(bio, folio, plen, poff)) {
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gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
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gfp_t orig_gfp = gfp;
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unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
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if (bio)
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submit_bio(bio);
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if (ctx->rac) /* same as readahead_gfp_mask */
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gfp |= __GFP_NORETRY | __GFP_NOWARN;
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bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
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gfp);
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/*
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* If the bio_alloc fails, try it again for a single page to
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* avoid having to deal with partial page reads. This emulates
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* what do_mpage_read_folio does.
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*/
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if (!bio)
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bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
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if (ctx->rac)
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bio->bi_opf |= REQ_RAHEAD;
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bio->bi_iter.bi_sector = sector;
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bio->bi_end_io = iomap_read_end_io;
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bio_add_folio_nofail(bio, folio, plen, poff);
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ctx->read_ctx = bio;
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}
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return 0;
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}
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const struct iomap_read_ops iomap_bio_read_ops = {
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.read_folio_range = iomap_bio_read_folio_range,
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.submit_read = iomap_bio_submit_read,
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};
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EXPORT_SYMBOL_GPL(iomap_bio_read_ops);
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int iomap_bio_read_folio_range_sync(const struct iomap_iter *iter,
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struct folio *folio, loff_t pos, size_t len)
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{
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const struct iomap *srcmap = iomap_iter_srcmap(iter);
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struct bio_vec bvec;
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struct bio bio;
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bio_init(&bio, srcmap->bdev, &bvec, 1, REQ_OP_READ);
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bio.bi_iter.bi_sector = iomap_sector(srcmap, pos);
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bio_add_folio_nofail(&bio, folio, len, offset_in_folio(folio, pos));
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return submit_bio_wait(&bio);
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}
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