NFS: add I/O performance counters

Invoke the byte and event counter macros where we want to count bytes and
events.

Clean-up: fix a possible NULL dereference in nfs_lock, and simplify
nfs_file_open.

Test-plan:
fsx and iozone on UP and SMP systems, with and without pre-emption.  Watch
for memory overwrite bugs, and performance loss (significantly more CPU
required per op).

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index a1554bead692..151b8dd0ac3b 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -34,6 +34,7 @@
 
 #include "nfs4_fs.h"
 #include "delegation.h"
+#include "iostat.h"
 
 #define NFS_PARANOIA 1
 /* #define NFS_DEBUG_VERBOSE 1 */
@@ -507,6 +508,8 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         struct nfs_fattr fattr;
         long            res;
 
+        nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
+
         lock_kernel();
 
         res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
@@ -713,6 +716,7 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
         parent = dget_parent(dentry);
         lock_kernel();
         dir = parent->d_inode;
+        nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
         inode = dentry->d_inode;
 
         if (!inode) {
@@ -844,6 +848,7 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
 
         dfprintk(VFS, "NFS: lookup(%s/%s)\n",
                 dentry->d_parent->d_name.name, dentry->d_name.name);
+        nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
 
         res = ERR_PTR(-ENAMETOOLONG);
         if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
@@ -1241,6 +1246,7 @@ static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
         dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
                 dentry->d_parent->d_name.name, dentry->d_name.name, 
                 atomic_read(&dentry->d_count));
+        nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
 
 #ifdef NFS_PARANOIA
 if (!dentry->d_inode)
@@ -1640,6 +1646,8 @@ int nfs_permission(struct inode *inode, int mask, struct nameidata *nd)
         struct rpc_cred *cred;
         int res = 0;
 
+        nfs_inc_stats(inode, NFSIOS_VFSACCESS);
+
         if (mask == 0)
                 goto out;
         /* Is this sys_access() ? */