From 7e381172cf6e0282a56374e50667515aed55166a Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 1 Feb 2010 14:17:41 -0500 Subject: [PATCH] NFS: Improve NFS iostat byte count accuracy for writes The bytes counted by the performance counters for NFS writes should reflect write and sync errors. If the write(2) system call reports an error, the bytes should not be counted. And, if the write is short, the actual number of bytes that was written should be counted, not the number of bytes that was requested. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/file.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index abbc20281ea4..ae8d02294e46 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -601,6 +601,7 @@ static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, { struct dentry * dentry = iocb->ki_filp->f_path.dentry; struct inode * inode = dentry->d_inode; + unsigned long written = 0; ssize_t result; size_t count = iov_length(iov, nr_segs); @@ -627,14 +628,18 @@ static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, if (!count) goto out; - nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count); result = generic_file_aio_write(iocb, iov, nr_segs, pos); + if (result > 0) + written = result; + /* Return error values for O_DSYNC and IS_SYNC() */ if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) { int err = nfs_do_fsync(nfs_file_open_context(iocb->ki_filp), inode); if (err < 0) result = err; } + if (result > 0) + nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written); out: return result; @@ -649,6 +654,7 @@ static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe, { struct dentry *dentry = filp->f_path.dentry; struct inode *inode = dentry->d_inode; + unsigned long written = 0; ssize_t ret; dprintk("NFS splice_write(%s/%s, %lu@%llu)\n", @@ -659,14 +665,17 @@ static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe, * The combination of splice and an O_APPEND destination is disallowed. */ - nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count); - ret = generic_file_splice_write(pipe, filp, ppos, count, flags); + if (ret > 0) + written = ret; + if (ret >= 0 && nfs_need_sync_write(filp, inode)) { int err = nfs_do_fsync(nfs_file_open_context(filp), inode); if (err < 0) ret = err; } + if (ret > 0) + nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written); return ret; } -- 2.20.1