NFS: Add mount options for controlling the lookup cache
Add the following NFS-specific mount options to the parser.
-o lookupcache=all /* Default: cache positive & negative
dentries */
-o lookupcache=pos[itive] /* Don't cache negative dentries */
-o lookupcache=none /* Strict revalidation of all dentries */
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 81686ae..1e35586 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -91,6 +91,7 @@
/* Mount options that take string arguments */
Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
Opt_addr, Opt_mountaddr, Opt_clientaddr,
+ Opt_lookupcache,
/* Special mount options */
Opt_userspace, Opt_deprecated, Opt_sloppy,
@@ -154,6 +155,8 @@
{ Opt_mounthost, "mounthost=%s" },
{ Opt_mountaddr, "mountaddr=%s" },
+ { Opt_lookupcache, "lookupcache=%s" },
+
{ Opt_err, NULL }
};
@@ -200,6 +203,22 @@
{ Opt_sec_err, NULL }
};
+enum {
+ Opt_lookupcache_all, Opt_lookupcache_positive,
+ Opt_lookupcache_none,
+
+ Opt_lookupcache_err
+};
+
+static match_table_t nfs_lookupcache_tokens = {
+ { Opt_lookupcache_all, "all" },
+ { Opt_lookupcache_positive, "pos" },
+ { Opt_lookupcache_positive, "positive" },
+ { Opt_lookupcache_none, "none" },
+
+ { Opt_lookupcache_err, NULL }
+};
+
static void nfs_umount_begin(struct super_block *);
static int nfs_statfs(struct dentry *, struct kstatfs *);
@@ -1250,6 +1269,30 @@
&mnt->mount_server.addrlen);
kfree(string);
break;
+ case Opt_lookupcache:
+ string = match_strdup(args);
+ if (string == NULL)
+ goto out_nomem;
+ token = match_token(string,
+ nfs_lookupcache_tokens, args);
+ kfree(string);
+ switch (token) {
+ case Opt_lookupcache_all:
+ mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
+ break;
+ case Opt_lookupcache_positive:
+ mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
+ mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
+ break;
+ case Opt_lookupcache_none:
+ mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
+ break;
+ default:
+ errors++;
+ dfprintk(MOUNT, "NFS: invalid "
+ "lookupcache argument\n");
+ };
+ break;
/*
* Special options