Commit 39c910a4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Anna Schumaker
Browse files

nfs: do not extend writes to the entire folio 



nfs_update_folio has code to extend a write to the entire page under
certain conditions.  With the support for large folios this now
suddenly extents to the variable sized and potentially much larger folio.
Add code to limit the extension to the page boundaries of the start and
end of the write, which matches the historic expecation and the code
comments.

Fixes: b73fe2dd6cd5 ("nfs: add support for large folios")
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 3921ae08

fs/nfs/write.c

+6 −2
Original line number Diff line number Diff line
@@ -1351,8 +1351,12 @@ int nfs_update_folio(struct file *file, struct folio *folio, 
		goto out;



	if (nfs_can_extend_write(file, folio, pagelen)) {

		count = max(count + offset, pagelen);

		offset = 0;

		unsigned int end = count + offset;



		offset = round_down(offset, PAGE_SIZE);

		if (end < pagelen)

			end = min(round_up(end, PAGE_SIZE), pagelen);

		count = end - offset;

	}



	status = nfs_writepage_setup(ctx, folio, offset, count);