Commit 8fa4592a authored Oct 01, 2015 by Trond Myklebust

NFS: Fix a write performance regression



If all other conditions in nfs_can_extend_write() are met, and there
are no locks, then we should be able to assume close-to-open semantics
and the ability to extend our write to cover the whole page.

With this patch, the xfstests generic/074 test completes in 242s instead
of >1400s on my test rig.

Fixes: bd61e0a9 ("locks: convert posix locks to file_lock_context")
Cc: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

parent 40f90271

fs/nfs/write.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1223,7 +1223,7 @@ static int nfs_can_extend_write(struct file file, struct page page, struct ino
		return 1;
		if (!flctx \|\| (list_empty_careful(&flctx->flc_flock) &&
		list_empty_careful(&flctx->flc_posix)))
		return 0;
		return 1;

		/* Check to see if there are whole file write locks */
		ret = 0;