Now that each NFS mount point caches its own nlm_host structure, it can be
passed to nlmclnt_proc() for each lock request. By pinning an nlm_host for
each mount point, we trade the overhead of looking up or creating a fresh
nlm_host struct during every NLM procedure call for a little extra memory.
We also restrict the nlmclnt_proc symbol to limit the use of this call to
in-tree modules.
Note that nlm_lookup_host() (just removed from the client's per-request
NLM processing) could also trigger an nlm_host garbage collection. Now
client-side nlm_host garbage collection occurs only during NFS mount
processing. Since the NFS client now holds a reference on these nlm_host
structures, they wouldn't have been affected by garbage collection
anyway.
Given that nlm_lookup_host() reorders the global nlm_host chain after
every successful lookup, and that a garbage collection could be triggered
during the call, we've removed a significant amount of per-NLM-request
CPU processing overhead.
Sidebar: there are only a few remaining references to the internals of
NFS inodes in the client-side NLM code. The only references I found are
related to extracting or comparing the inode's file handle via NFS_FH().
One is in nlmclnt_grant(); the other is in nlmclnt_setlockargs().
Signed-off-by: Chuck Lever <[email protected]>
---
fs/lockd/clntproc.c | 33 ++++++++++-----------------------
fs/nfs/nfs3proc.c | 4 +++-
fs/nfs/proc.c | 4 +++-
include/linux/lockd/bind.h | 3 ++-
4 files changed, 18 insertions(+), 26 deletions(-)
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index a10343b..b1a4dba 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -145,34 +145,21 @@ static void nlmclnt_release_lockargs(struct nlm_rqst *req)
BUG_ON(req->a_args.lock.fl.fl_ops != NULL);
}
-/*
- * This is the main entry point for the NLM client.
+/**
+ * nlmclnt_proc - Perform a single client-side lock request
+ * @host: address of a valid nlm_host context representing the NLM server
+ * @cmd: fcntl-style file lock operation to perform
+ * @fl: address of arguments for the lock operation
+ *
*/
-int
-nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
+int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl)
{
- struct rpc_clnt *client = NFS_CLIENT(inode);
- struct sockaddr_in addr;
- struct nfs_server *nfssrv = NFS_SERVER(inode);
- struct nlm_host *host;
struct nlm_rqst *call;
sigset_t oldset;
unsigned long flags;
- int status, vers;
-
- vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
- if (NFS_PROTO(inode)->version > 3) {
- printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
- return -ENOLCK;
- }
-
- rpc_peeraddr(client, (struct sockaddr *) &addr, sizeof(addr));
- host = nlmclnt_lookup_host(&addr, client->cl_xprt->prot, vers,
- nfssrv->nfs_client->cl_hostname,
- strlen(nfssrv->nfs_client->cl_hostname));
- if (host == NULL)
- return -ENOLCK;
+ int status;
+ nlm_get_host(host);
call = nlm_alloc_call(host);
if (call == NULL)
return -ENOMEM;
@@ -219,7 +206,7 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
dprintk("lockd: clnt proc returns %d\n", status);
return status;
}
-EXPORT_SYMBOL(nlmclnt_proc);
+EXPORT_SYMBOL_GPL(nlmclnt_proc);
/*
* Allocate an NLM RPC call struct
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index 4cdc236..c11bb6a 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -796,7 +796,9 @@ static void nfs3_proc_commit_setup(struct nfs_write_data *data, int how)
static int
nfs3_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
{
- return nlmclnt_proc(filp->f_path.dentry->d_inode, cmd, fl);
+ struct inode *inode = filp->f_path.dentry->d_inode;
+
+ return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
}
const struct nfs_rpc_ops nfs_v3_clientops = {
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 4f80d88..c3fe1bc 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -609,7 +609,9 @@ nfs_proc_commit_setup(struct nfs_write_data *data, int how)
static int
nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
{
- return nlmclnt_proc(filp->f_path.dentry->d_inode, cmd, fl);
+ struct inode *inode = filp->f_path.dentry->d_inode;
+
+ return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
}
diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h
index 372c8df..59d51f1 100644
--- a/include/linux/lockd/bind.h
+++ b/include/linux/lockd/bind.h
@@ -42,7 +42,8 @@ extern struct nlm_host *nlmclnt_init(struct sockaddr *server_address,
unsigned short protocol);
extern void nlmclnt_done(struct nlm_host *host);
-extern int nlmclnt_proc(struct inode *, int, struct file_lock *);
+extern int nlmclnt_proc(struct nlm_host *host, int cmd,
+ struct file_lock *fl);
extern int lockd_up(int proto);
extern void lockd_down(void);