NFS: slight optimization for walking list for delegations
authorNeilBrown <neilb@suse.com>
Thu, 31 May 2018 05:23:22 +0000 (15:23 +1000)
committerTrond Myklebust <trond.myklebust@hammerspace.com>
Thu, 31 May 2018 18:59:19 +0000 (14:59 -0400)
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.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
fs/nfs/delegation.c

index 1819d0d0ba4b14b92ad311ae2cf588f7f1ecb6a2..b9cd3864335b299670896b5ff9a129184256476e 100644 (file)
@@ -495,7 +495,7 @@ restart:
                        if (!nfs_delegation_need_return(delegation))
                                continue;
                        if (!nfs_sb_active(server->super))
-                               continue;
+                               break; /* continue in outer loop */
                        inode = nfs_delegation_grab_inode(delegation);
                        if (inode == NULL) {
                                rcu_read_unlock();
@@ -887,7 +887,7 @@ restart:
                                                &delegation->flags) == 0)
                                continue;
                        if (!nfs_sb_active(server->super))
-                               continue;
+                               break; /* continue in outer loop */
                        inode = nfs_delegation_grab_inode(delegation);
                        if (inode == NULL) {
                                rcu_read_unlock();
@@ -995,7 +995,7 @@ restart:
                                                &delegation->flags) == 0)
                                continue;
                        if (!nfs_sb_active(server->super))
-                               continue;
+                               break; /* continue in outer loop */
                        inode = nfs_delegation_grab_inode(delegation);
                        if (inode == NULL) {
                                rcu_read_unlock();