[Cluster-devel] [PATCH v3 1/3] iomap: Permit pages without an iop to enter writeback

[Andreas Gruenbacher]

Create an iop in the writeback path if one doesn't exist.  This allows us
to avoid creating the iop in some cases.  We'll initially do that for pages
with inline data, but it can be extended to pages which are entirely within
an extent.  It also allows for an iop to be removed from pages in the
future (eg page split).

Co-developed-by: Matthew Wilcox (Oracle) <willy at infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org>
Signed-off-by: Andreas Gruenbacher <agruenba at redhat.com>
Reviewed-by: Christoph Hellwig <hch at lst.de>
---
 fs/iomap/buffered-io.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 9023717c5188..598fcfabc337 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1334,14 +1334,13 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 		struct writeback_control *wbc, struct inode *inode,
 		struct page *page, u64 end_offset)
 {
-	struct iomap_page *iop = to_iomap_page(page);
+	struct iomap_page *iop = iomap_page_create(inode, page);
 	struct iomap_ioend *ioend, *next;
 	unsigned len = i_blocksize(inode);
 	u64 file_offset; /* file offset of page */
 	int error = 0, count = 0, i;
 	LIST_HEAD(submit_list);
 
-	WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop);
 	WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) != 0);
 
 	/*
-- 
2.26.3