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// 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));
}
static void
xfs_flush_bdev_async_endio(
struct bio *bio)
{
complete(bio->bi_private);
}
/*
* Submit a request for an async cache flush to run. If the request queue does
* not require flush operations, just skip it altogether. If the caller needs
* to wait for the flush completion at a later point in time, they must supply a
* valid completion. This will be signalled when the flush completes. The
* caller never sees the bio that is issued here.
*/
void
xfs_flush_bdev_async(
struct bio *bio,
struct block_device *bdev,
struct completion *done)
{
struct request_queue *q = bdev->bd_disk->queue;
if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) {
complete(done);
return;
}
bio_init(bio, NULL, 0);
bio_set_dev(bio, bdev);
bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC;
bio->bi_private = done;
bio->bi_end_io = xfs_flush_bdev_async_endio;
submit_bio(bio);
}
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(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;
}
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