linux-kernel - [PATCH 1/4] NFS: slight optimization for walking list for delegations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <152506269054.7246.3941740801391514623.stgit@noble>
Date:   Mon, 30 Apr 2018 14:31:30 +1000
From:   NeilBrown <neilb@...e.com>
To:     "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
        Trond Myklebust <trond.myklebust@...marydata.com>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Anna Schumaker <anna.schumaker@...app.com>
Cc:     linux-nfs@...r.kernel.org, Lai Jiangshan <jiangshanlai@...il.com>,
        Josh Triplett <josh@...htriplett.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/4] NFS: slight optimization for walking list for
 delegations

There are 3 places where we walk the list of delegations
for an nfs_client.
In each case there are two nested loops, one for nfs_servers
and one for nfs_delegations.

When we find an interesting delegation we try to get an active
reference to the server.  If that fails, it is pointless to
continue to look at the other delegation for the server as
we will never be able to get an active reference.
So instead of continuing in the inner loop, break out
and continue in the outer loop.
---
 fs/nfs/delegation.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 1819d0d0ba4b..af32365894c8 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -495,7 +495,7 @@ int nfs_client_return_marked_delegations(struct nfs_client *clp)
 			if (!nfs_delegation_need_return(delegation))
 				continue;
 			if (!nfs_sb_active(server->super))
-				continue;
+				break;
 			inode = nfs_delegation_grab_inode(delegation);
 			if (inode == NULL) {
 				rcu_read_unlock();
@@ -887,7 +887,7 @@ void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
 						&delegation->flags) == 0)
 				continue;
 			if (!nfs_sb_active(server->super))
-				continue;
+				break;
 			inode = nfs_delegation_grab_inode(delegation);
 			if (inode == NULL) {
 				rcu_read_unlock();
@@ -995,7 +995,7 @@ void nfs_reap_expired_delegations(struct nfs_client *clp)
 						&delegation->flags) == 0)
 				continue;
 			if (!nfs_sb_active(server->super))
-				continue;
+				break;
 			inode = nfs_delegation_grab_inode(delegation);
 			if (inode == NULL) {
 				rcu_read_unlock();