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, 9 insertions, 11 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 387809f2d188..1cf07e4ad136 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -32,6 +32,7 @@
 #include <asm/system.h>
 
 #include "delegation.h"
+#include "iostat.h"
 
 #define NFSDBG_FACILITY         NFSDBG_FILE
 
@@ -102,18 +103,15 @@ static int nfs_check_flags(int flags)
 static int
 nfs_file_open(struct inode *inode, struct file *filp)
 {
-        struct nfs_server *server = NFS_SERVER(inode);
-        int (*open)(struct inode *, struct file *);
         int res;
 
         res = nfs_check_flags(filp->f_flags);
         if (res)
                 return res;
 
+        nfs_inc_stats(inode, NFSIOS_VFSOPEN);
         lock_kernel();
-        /* Do NFSv4 open() call */
-        if ((open = server->rpc_ops->file_open) != NULL)
-                res = open(inode, filp);
+        res = NFS_SERVER(inode)->rpc_ops->file_open(inode, filp);
         unlock_kernel();
         return res;
 }
@@ -124,6 +122,7 @@ nfs_file_release(struct inode *inode, struct file *filp)
         /* Ensure that dirty pages are flushed out with the right creds */
         if (filp->f_mode & FMODE_WRITE)
                 filemap_fdatawrite(filp->f_mapping);
+        nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
         return NFS_PROTO(inode)->file_release(inode, filp);
 }
 
@@ -199,6 +198,7 @@ nfs_file_flush(struct file *file)
 
         if ((file->f_mode & FMODE_WRITE) == 0)
                 return 0;
+        nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
         lock_kernel();
         /* Ensure that data+attribute caches are up to date after close() */
         status = nfs_wb_all(inode);
@@ -229,6 +229,7 @@ nfs_file_read(struct kiocb *iocb, char __user * buf, size_t count, loff_t pos)
                 (unsigned long) count, (unsigned long) pos);
 
         result = nfs_revalidate_file(inode, iocb->ki_filp);
+        nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count);
         if (!result)
                 result = generic_file_aio_read(iocb, buf, count, pos);
         return result;
@@ -282,6 +283,7 @@ nfs_fsync(struct file *file, struct dentry *dentry, int datasync)
 
         dfprintk(VFS, "nfs: fsync(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino);
 
+        nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
         lock_kernel();
         status = nfs_wb_all(inode);
         if (!status) {
@@ -378,6 +380,7 @@ nfs_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t
         if (!count)
                 goto out;
 
+        nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count);
         result = generic_file_aio_write(iocb, buf, count, pos);
 out:
         return result;
@@ -517,9 +520,7 @@ static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
                         inode->i_sb->s_id, inode->i_ino,
                         fl->fl_type, fl->fl_flags,
                         (long long)fl->fl_start, (long long)fl->fl_end);
-
-        if (!inode)
-                return -EINVAL;
+        nfs_inc_stats(inode, NFSIOS_VFSLOCK);
 
         /* No mandatory locks over NFS */
         if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
@@ -544,9 +545,6 @@ static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
                         inode->i_sb->s_id, inode->i_ino,
                         fl->fl_type, fl->fl_flags);
 
-        if (!inode)
-                return -EINVAL;
-
         /*
          * No BSD flocks over NFS allowed.
          * Note: we could try to fake a POSIX lock request here by