From: "trondmy@kernel.org" <trondmy@kernel.org>
Date: Tue, 18 Jan 2022 19:25:42 -0500
Subject: [PATCH] NFS: Don't overfill uncached readdir pages
Git-commit: d9c4e39c1f8f8a8ebaccf00b8f22c14364b2d27e
Patch-mainline: v5.17
References: git-fixes
If we're doing an uncached read of the directory, then we ideally want
to read only the exact set of entries that will fit in the buffer
supplied by the getdents() system call. So unlike the case where we're
reading into the page cache, let's send only one READDIR call, before
trying to fill up the buffer.
Fixes: 35df59d3ef69 ("NFS: Reduce number of RPC calls when doing uncached readdir")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>
---
fs/nfs/dir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -870,7 +870,8 @@ static int nfs_readdir_xdr_to_array(stru
status = nfs_readdir_page_filler(desc, entry, pages, pglen,
arrays, narrays);
- } while (!status && nfs_readdir_page_needs_filling(page));
+ } while (!status && nfs_readdir_page_needs_filling(page) &&
+ page_mapping(page));
nfs_readdir_free_pages(pages, array_size);
out_release_label: