[PATCH v4 5/5] NFS: Don't ask for readdirplus if files are being written to

[trondmy@kernel.org]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

If a file is being written to, then readdirplus isn't going to help with
retrieving attributes, since we will have to flush out writes anyway in
order to sync the mtime/ctime.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/inode.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 1bef81f5373a..00500c369c5f 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -837,6 +837,7 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	int err = 0;
 	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
 	bool do_update = false;
+	bool record_cache = !nfs_have_writebacks(inode);
 
 	trace_nfs_getattr_enter(inode);
 
@@ -845,7 +846,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 			STATX_INO | STATX_SIZE | STATX_BLOCKS;
 
 	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
-		nfs_readdirplus_parent_cache_hit(path->dentry);
+		if (record_cache)
+			nfs_readdirplus_parent_cache_hit(path->dentry);
 		goto out_no_revalidate;
 	}
 
@@ -894,17 +896,18 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	if (request_mask & STATX_BLOCKS)
 		do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
 
-	if (do_update) {
+	if (record_cache) {
 		/* Update the attribute cache */
-		if (!(server->flags & NFS_MOUNT_NOAC))
+		if (do_update && !(server->flags & NFS_MOUNT_NOAC))
 			nfs_readdirplus_parent_cache_miss(path->dentry);
 		else
 			nfs_readdirplus_parent_cache_hit(path->dentry);
+	}
+	if (do_update) {
 		err = __nfs_revalidate_inode(server, inode);
 		if (err)
 			goto out;
-	} else
-		nfs_readdirplus_parent_cache_hit(path->dentry);
+	}
 out_no_revalidate:
 	/* Only return attributes that were revalidated. */
 	stat->result_mask = nfs_get_valid_attrmask(inode) | request_mask;
-- 
2.35.1