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) <[email protected]> --- fs/iomap/buffered-io.c | 29 ++++++++++------------------- 1 file changed, 10 insertions(+), 19 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 844e95cacea8..c9b44f86d166 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -161,13 +161,6 @@ 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) { @@ -181,7 +174,8 @@ 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_count)) + unlock_page(page); } static void @@ -269,20 +263,17 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, if (ctx->bio && bio_end_sector(ctx->bio) == sector) 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. + * We need to increase the read count before submitting any + * previous bio to make sure that we don't prematurely unlock + * the page. */ if (iop) - atomic_inc(&iop->read_count); + atomic_add(plen, &iop->read_count); + + if (is_contig && + __bio_try_merge_page(ctx->bio, page, plen, poff, &same_page)) + goto done; if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) { gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL); -- 2.28.0
