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/pagelist.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index ed0db61f8543..2b5e769beb16 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -258,6 +258,7 @@ bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) static inline void nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) { + struct inode *inode; WARN_ON_ONCE(prev == req); if (!prev) { @@ -276,12 +277,16 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev) * nfs_page_group_destroy is called */ kref_get(&req->wb_head->wb_kref); - /* grab extra ref if head request has extra ref from - * the write/commit path to handle handoff between write - * and commit lists */ + /* grab extra ref and bump the request count if head request + * has extra ref from the write/commit path to handle handoff + * between write and commit lists. */ if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) { + inode = page_file_mapping(req->wb_page)->host; set_bit(PG_INODE_REF, &req->wb_flags); kref_get(&req->wb_kref); + spin_lock(&inode->i_lock); + NFS_I(inode)->nrequests++; + spin_unlock(&inode->i_lock); } } } -- cgit v1.2.3