Commit 59b86d85 authored Apr 28, 2017 by Hou Tao Committed by Trond Myklebust May 05, 2017

NFS: always treat the invocation of nfs_getattr as cache hit when noac is on

When using 'ls -l' to display a large directory, if noac option is used,
in function nfs_getattr() nfs_need_revalidate_inode() will always be true
for NFSv3 and the nfs_entry cache of the directory will be flushed. The
flush will lead to a fully reread of the directory entries from server.

To prevent the unnecessary RPCs, we need to check whether or not the
noac option is used, and always report the invocation of nfs_getattr()
as cache hit instead cache miss when it's on.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

parent 5c737cb2

fs/nfs/inode.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -734,7 +734,10 @@ int nfs_getattr(const struct path path, struct kstat stat,
	if (need_atime \|\| nfs_need_revalidate_inode(inode)) {		if (need_atime \|\| nfs_need_revalidate_inode(inode)) {
	struct nfs_server *server = NFS_SERVER(inode);		struct nfs_server *server = NFS_SERVER(inode);

			if (!(server->flags & NFS_MOUNT_NOAC))
	nfs_readdirplus_parent_cache_miss(path->dentry);		nfs_readdirplus_parent_cache_miss(path->dentry);
			else
			nfs_readdirplus_parent_cache_hit(path->dentry);
	err = __nfs_revalidate_inode(server, inode);		err = __nfs_revalidate_inode(server, inode);
	} else		} else
	nfs_readdirplus_parent_cache_hit(path->dentry);		nfs_readdirplus_parent_cache_hit(path->dentry);