android/android_kernel_xiaomi_sm8450
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iomap: Convert read_count to read_bytes_pending

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Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-09-21 08:58:40 -07:00 committed by Darrick J. Wong
parent 0a195b91e8
commit 7d636676d2
1 changed files with 12 additions and 29 deletions
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41
fs/iomap/buffered-io.c
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@ -26,7 +26,7 @@
* to track sub-page uptodate status and I/O completions.
*/
struct iomap_page {
atomic_t read_count;
atomic_t read_bytes_pending;
atomic_t write_count;
spinlock_t uptodate_lock;
unsigned long uptodate[];
@ -72,7 +72,7 @@ iomap_page_release(struct page *page)
if (!iop)
return;
WARN_ON_ONCE(atomic_read(&iop->read_count));
WARN_ON_ONCE(atomic_read(&iop->read_bytes_pending));
WARN_ON_ONCE(atomic_read(&iop->write_count));
WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
PageUptodate(page));
@ -167,13 +167,6 @@ iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
SetPageUptodate(page);
}
static void
iomap_read_finish(struct iomap_page *iop, struct page *page)
{
if (!iop || atomic_dec_and_test(&iop->read_count))
unlock_page(page);
}
static void
iomap_read_page_end_io(struct bio_vec *bvec, int error)
{
@ -187,7 +180,8 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error)
iomap_set_range_uptodate(page, bvec->bv_offset, bvec->bv_len);
}
iomap_read_finish(iop, page);
if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending))
unlock_page(page);
}
static void
@ -267,30 +261,19 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
}
ctx->cur_page_in_bio = true;
if (iop)
atomic_add(plen, &iop->read_bytes_pending);
/*
* Try to merge into a previous segment if we can.
*/
/* Try to merge into a previous segment if we can */
sector = iomap_sector(iomap, pos);
if (ctx->bio && bio_end_sector(ctx->bio) == sector)
if (ctx->bio && bio_end_sector(ctx->bio) == sector) {
if (__bio_try_merge_page(ctx->bio, page, plen, poff,
&same_page))
goto done;
is_contig = true;
if (is_contig &&
__bio_try_merge_page(ctx->bio, page, plen, poff, &same_page)) {
if (!same_page && iop)
atomic_inc(&iop->read_count);
goto done;
}
/*
* If we start a new segment we need to increase the read count, and we
* need to do so before submitting any previous full bio to make sure
* that we don't prematurely unlock the page.
*/
if (iop)
atomic_inc(&iop->read_count);
if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) {
if (!is_contig || bio_full(ctx->bio, plen)) {
gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
gfp_t orig_gfp = gfp;
int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;