I recently observed a significant slowdown in a long-running
test on NFSv4.0 mounts.
An OPEN for write seems to block the NFS server from offering
delegations on that file for a few seconds. The problem is that
when that file is closed, the filecache retains an open-for-write
file descriptor until the laundrette runs. That keeps the inode's
i_writecount positive until the cached file is finally unhashed
and closed.
Force the NFSv4 CLOSE logic to call filp_close() to eliminate
the underlying cached open-for-write file as soon as the client
closes the file.
This minor change claws back about 80% of the performance
regression.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3ac40ba7efe1..0b3059b8b36c 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -613,10 +613,14 @@ static void __nfs4_file_put_access(struct nfs4_file *fp, int oflag)
if (atomic_read(&fp->fi_access[1 - oflag]) == 0)
swap(f2, fp->fi_fds[O_RDWR]);
spin_unlock(&fp->fi_lock);
- if (f1)
+ if (f1) {
+ nfsd_file_close_inode_sync(locks_inode(f1->nf_file));
nfsd_file_put(f1);
- if (f2)
+ }
+ if (f2) {
+ nfsd_file_close_inode_sync(locks_inode(f2->nf_file));
nfsd_file_put(f2);
+ }
}
}
