Commit 0fb2d720 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Darrick J. Wong
Browse files

iomap: Convert write_count to write_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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 7d636676

fs/iomap/buffered-io.c

+10 −9
Original line number Diff line number Diff line
@@ -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