On Fri, Sep 11, 2020 at 12:47:05AM +0100, Matthew Wilcox (Oracle) wrote: > 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]> > Reviewed-by: Christoph Hellwig <[email protected]>
Looks ok, Reviewed-by: Darrick J. Wong <[email protected]> --D > --- > fs/iomap/buffered-io.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 1cf976a8e55c..64a5cb383f30 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -27,7 +27,7 @@ > */ > struct iomap_page { > atomic_t read_bytes_pending; > - atomic_t write_count; > + atomic_t write_bytes_pending; > spinlock_t uptodate_lock; > unsigned long uptodate[]; > }; > @@ -73,7 +73,7 @@ iomap_page_release(struct page *page) > if (!iop) > return; > WARN_ON_ONCE(atomic_read(&iop->read_bytes_pending)); > - WARN_ON_ONCE(atomic_read(&iop->write_count)); > + WARN_ON_ONCE(atomic_read(&iop->write_bytes_pending)); > WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) != > PageUptodate(page)); > kfree(iop); > @@ -1047,7 +1047,7 @@ EXPORT_SYMBOL_GPL(iomap_page_mkwrite); > > static void > iomap_finish_page_writeback(struct inode *inode, struct page *page, > - int error) > + int error, unsigned int len) > { > struct iomap_page *iop = to_iomap_page(page); > > @@ -1057,9 +1057,9 @@ iomap_finish_page_writeback(struct inode *inode, struct > page *page, > } > > WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop); > - WARN_ON_ONCE(iop && atomic_read(&iop->write_count) <= 0); > + WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) <= 0); > > - if (!iop || atomic_dec_and_test(&iop->write_count)) > + if (!iop || atomic_sub_and_test(len, &iop->write_bytes_pending)) > end_page_writeback(page); > } > > @@ -1093,7 +1093,8 @@ iomap_finish_ioend(struct iomap_ioend *ioend, int error) > > /* walk each page on bio, ending page IO on them */ > bio_for_each_segment_all(bv, bio, iter_all) > - iomap_finish_page_writeback(inode, bv->bv_page, error); > + iomap_finish_page_writeback(inode, bv->bv_page, error, > + bv->bv_len); > bio_put(bio); > } > /* The ioend has been freed by bio_put() */ > @@ -1309,8 +1310,8 @@ iomap_add_to_ioend(struct inode *inode, loff_t offset, > struct page *page, > > merged = __bio_try_merge_page(wpc->ioend->io_bio, page, len, poff, > &same_page); > - if (iop && !same_page) > - atomic_inc(&iop->write_count); > + if (iop) > + atomic_add(len, &iop->write_bytes_pending); > > if (!merged) { > if (bio_full(wpc->ioend->io_bio, len)) { > @@ -1353,7 +1354,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > LIST_HEAD(submit_list); > > WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop); > - WARN_ON_ONCE(iop && atomic_read(&iop->write_count) != 0); > + WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) != 0); > > /* > * Walk through the page to find areas to write back. If we run off the > -- > 2.28.0 >
