From cb1410c71e0b6b2eba8c1890645a76ff86169d24 Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson Date: Wed, 12 Nov 2014 12:08:00 -0500 Subject: NFS: fix subtle change in COMMIT behavior Recent work in the pgio layer made it possible for there to be more than one request per page. This caused a subtle change in commit behavior, because write.c:nfs_commit_unstable_pages compares the number of *pages* waiting for writeback against the number of requests on a commit list to choose when to send a COMMIT in a non-blocking flush. This is probably hard to hit in normal operation - you have to be using rsize/wsize < PAGE_SIZE, or pnfs with lots of boundaries that are not page aligned to have a noticeable change in behavior. Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index f83b02dc916..d489ff3f438 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -670,7 +670,8 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) nfs_lock_request(req); spin_lock(&inode->i_lock); - if (!nfsi->npages && NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) + if (!nfsi->nrequests && + NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) inode->i_version++; /* * Swap-space should not get truncated. Hence no need to plug the race @@ -681,9 +682,11 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) SetPagePrivate(req->wb_page); set_page_private(req->wb_page, (unsigned long)req); } - nfsi->npages++; + nfsi->nrequests++; /* this a head request for a page group - mark it as having an - * extra reference so sub groups can follow suit */ + * extra reference so sub groups can follow suit. + * This flag also informs pgio layer when to bump nrequests when + * adding subrequests. */ WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags)); kref_get(&req->wb_kref); spin_unlock(&inode->i_lock); @@ -709,7 +712,11 @@ static void nfs_inode_remove_request(struct nfs_page *req) wake_up_page(head->wb_page, PG_private); clear_bit(PG_MAPPED, &head->wb_flags); } - nfsi->npages--; + nfsi->nrequests--; + spin_unlock(&inode->i_lock); + } else { + spin_lock(&inode->i_lock); + nfsi->nrequests--; spin_unlock(&inode->i_lock); } @@ -1735,7 +1742,7 @@ static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_contr /* Don't commit yet if this is a non-blocking flush and there * are a lot of outstanding writes for this mapping. */ - if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1)) + if (nfsi->commit_info.ncommit <= (nfsi->nrequests >> 1)) goto out_mark_dirty; /* don't wait for the COMMIT response */ -- cgit v1.2.3-70-g09d2 From 5a254d08b086d80cbead2ebcee6d2a4b3a15587a Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Sun, 23 Nov 2014 12:47:17 +0800 Subject: nfs: replace nfs_add_stats with nfs_inc_stats when add one Signed-off-by: Li RongQing Signed-off-by: Trond Myklebust --- fs/nfs/read.c | 2 +- fs/nfs/write.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/nfs/write.c') diff --git a/fs/nfs/read.c b/fs/nfs/read.c index beff2769c5c..c91a4799c56 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -269,7 +269,7 @@ int nfs_readpage(struct file *file, struct page *page) dprintk("NFS: nfs_readpage (%p %ld@%lu)\n", page, PAGE_CACHE_SIZE, page_file_index(page)); nfs_inc_stats(inode, NFSIOS_VFSREADPAGE); - nfs_add_stats(inode, NFSIOS_READPAGES, 1); + nfs_inc_stats(inode, NFSIOS_READPAGES); /* * Try to flush any pending writes to the file.. diff --git a/fs/nfs/write.c b/fs/nfs/write.c index d489ff3f438..af3af685a9e 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -575,7 +575,7 @@ static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, st int ret; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); - nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); + nfs_inc_stats(inode, NFSIOS_WRITEPAGES); nfs_pageio_cond_complete(pgio, page_file_index(page)); ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE); -- cgit v1.2.3-70-g09d2