[PATCH 5.4 22/60] nfsd: Dont keep looking up unhashed files in the nfsd file cache

Greg Kroah-Hartman
2021-03-22T12:56:53Z

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

commit d30881f573e565ebb5dbb50b31ed6106b5c81328 upstream.

If a file is unhashed, then we're going to reject it anyway and retry,
so make sure we skip it when we're doing the RCU lockless lookup.
This avoids a number of unnecessary nfserr_jukebox returns from
nfsd_file_acquire()

Fixes: 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/nfsd/filecache.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -751,6 +751,8 @@ nfsd_file_find_locked(struct inode *inod
continue;
if (!nfsd_match_cred(nf->nf_cred, current_cred()))
continue;
+ if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags))
+ continue;
if (nfsd_file_get(nf) != NULL)
return nf;
}