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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2010 Red Hat, Inc.
* Copyright (C) 2016-2023 Christoph Hellwig.
*/
#include <linux/iomap.h>
#include <linux/pagemap.h>
#include "internal.h"
#include "trace.h"
static void iomap_read_end_io(struct bio *bio)
{
int error = blk_status_to_errno(bio->bi_status);
struct folio_iter fi;
bio_for_each_folio_all(fi, bio)
iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error);
bio_put(bio);
}
static void iomap_bio_submit_read(struct iomap_read_folio_ctx *ctx)
{
struct bio *bio = ctx->read_ctx;
if (bio)
submit_bio(bio);
}
static int iomap_bio_read_folio_range(const struct iomap_iter *iter,
struct iomap_read_folio_ctx *ctx, size_t plen)
{
struct folio *folio = ctx->cur_folio;
const struct iomap *iomap = &iter->iomap;
loff_t pos = iter->pos;
size_t poff = offset_in_folio(folio, pos);
loff_t length = iomap_length(iter);
sector_t sector;
struct bio *bio = ctx->read_ctx;
sector = iomap_sector(iomap, pos);
if (!bio || bio_end_sector(bio) != sector ||
!bio_add_folio(bio, folio, plen, poff)) {
gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
gfp_t orig_gfp = gfp;
unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
if (bio)
submit_bio(bio);
if (ctx->rac) /* same as readahead_gfp_mask */
gfp |= __GFP_NORETRY | __GFP_NOWARN;
bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
gfp);
/*
* If the bio_alloc fails, try it again for a single page to
* avoid having to deal with partial page reads. This emulates
* what do_mpage_read_folio does.
*/
if (!bio)
bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
if (ctx->rac)
bio->bi_opf |= REQ_RAHEAD;
bio->bi_iter.bi_sector = sector;
bio->bi_end_io = iomap_read_end_io;
bio_add_folio_nofail(bio, folio, plen, poff);
ctx->read_ctx = bio;
}
return 0;
}
const struct iomap_read_ops iomap_bio_read_ops = {
.read_folio_range = iomap_bio_read_folio_range,
.submit_read = iomap_bio_submit_read,
};
EXPORT_SYMBOL_GPL(iomap_bio_read_ops);
int iomap_bio_read_folio_range_sync(const struct iomap_iter *iter,
struct folio *folio, loff_t pos, size_t len)
{
const struct iomap *srcmap = iomap_iter_srcmap(iter);
struct bio_vec bvec;
struct bio bio;
bio_init(&bio, srcmap->bdev, &bvec, 1, REQ_OP_READ);
bio.bi_iter.bi_sector = iomap_sector(srcmap, pos);
bio_add_folio_nofail(&bio, folio, len, offset_in_folio(folio, pos));
return submit_bio_wait(&bio);
}
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