From 420e3646bb7d93a571734034249fbb1ae1a7a5c7 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 19 Feb 2010 17:00:02 -0800 Subject: [PATCH] NFS: Reduce the number of unnecessary COMMIT calls If the caller is doing a non-blocking flush, and there are still writebacks pending on the wire, we can usually defer the COMMIT call until those writes are done. Also ensure that we honour the wbc->nonblocking flag. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index dc08a6fbde67..fc05e35da6a9 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1415,12 +1415,30 @@ static int nfs_commit_inode(struct inode *inode, int how) static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) { - int ret; + struct nfs_inode *nfsi = NFS_I(inode); + int flags = FLUSH_SYNC; + int ret = 0; - ret = nfs_commit_inode(inode, - wbc->sync_mode == WB_SYNC_ALL ? FLUSH_SYNC : 0); - if (ret >= 0) + /* Don't commit yet if this is a non-blocking flush and there are + * lots of outstanding writes for this mapping. + */ + if (wbc->sync_mode == WB_SYNC_NONE && + nfsi->ncommit <= (nfsi->npages >> 1)) + goto out_mark_dirty; + + if (wbc->nonblocking) + flags = 0; + ret = nfs_commit_inode(inode, flags); + if (ret >= 0) { + if (wbc->sync_mode == WB_SYNC_NONE) { + if (ret < wbc->nr_to_write) + wbc->nr_to_write -= ret; + else + wbc->nr_to_write = 0; + } return 0; + } +out_mark_dirty: __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return ret; } -- 2.39.2