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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-09-21 18:58:40 +0300 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2020-09-21 18:59:26 +0300 |
| commit | 7d636676d2841ba5d92462dfa99a89c2f2da8919 (patch) | |
| tree | 2576896da6201cf60b064b2c6f165c17093bc3a7 /fs/iomap | |
| parent | 0a195b91e8991367a94ee199f3af7faa7607e7db (diff) | |
| download | linux-7d636676d2841ba5d92462dfa99a89c2f2da8919.tar.xz | |
iomap: Convert read_count to read_bytes_pending
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>
Diffstat (limited to 'fs/iomap')
| -rw-r--r-- | fs/iomap/buffered-io.c | 41 |
1 files changed, 12 insertions, 29 deletions
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 9f0fa495ab69..46370cea30c8 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -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)); @@ -168,13 +168,6 @@ iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len) } 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) { struct page *page = bvec->bv_page; @@ -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; |