Return-Path: Received: from mail-io0-f195.google.com ([209.85.223.195]:38798 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751804AbdHCNpr (ORCPT ); Thu, 3 Aug 2017 09:45:47 -0400 Received: by mail-io0-f195.google.com with SMTP id o9so1296583iod.5 for ; Thu, 03 Aug 2017 06:45:47 -0700 (PDT) From: Trond Myklebust To: Chuck Lever , linux-nfs@vger.kernel.org Subject: [PATCH v2 10/28] NFS: Teach nfs_try_to_update_request() to deal with request page_groups Date: Thu, 3 Aug 2017 09:45:05 -0400 Message-Id: <20170803134523.4922-11-trond.myklebust@primarydata.com> In-Reply-To: <20170803134523.4922-10-trond.myklebust@primarydata.com> References: <20170803134523.4922-1-trond.myklebust@primarydata.com> <20170803134523.4922-2-trond.myklebust@primarydata.com> <20170803134523.4922-3-trond.myklebust@primarydata.com> <20170803134523.4922-4-trond.myklebust@primarydata.com> <20170803134523.4922-5-trond.myklebust@primarydata.com> <20170803134523.4922-6-trond.myklebust@primarydata.com> <20170803134523.4922-7-trond.myklebust@primarydata.com> <20170803134523.4922-8-trond.myklebust@primarydata.com> <20170803134523.4922-9-trond.myklebust@primarydata.com> <20170803134523.4922-10-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Simplify the code, and avoid some flushes to disk. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 60 ++++++++++++++++++++-------------------------------------- 1 file changed, 20 insertions(+), 40 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index ee981353d4aa..0b4d1ef168e0 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1107,39 +1107,19 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, end = offset + bytes; - for (;;) { - if (!(PagePrivate(page) || PageSwapCache(page))) - return NULL; - spin_lock(&inode->i_lock); - req = nfs_page_find_head_request_locked(NFS_I(inode), page); - if (req == NULL) - goto out_unlock; - - /* should be handled by nfs_flush_incompatible */ - WARN_ON_ONCE(req->wb_head != req); - WARN_ON_ONCE(req->wb_this_page != req); - - rqend = req->wb_offset + req->wb_bytes; - /* - * Tell the caller to flush out the request if - * the offsets are non-contiguous. - * Note: nfs_flush_incompatible() will already - * have flushed out requests having wrong owners. - */ - if (offset > rqend - || end < req->wb_offset) - goto out_flushme; - - if (nfs_lock_request(req)) - break; + req = nfs_lock_and_join_requests(page); + if (IS_ERR_OR_NULL(req)) + return req; - /* The request is locked, so wait and then retry */ - spin_unlock(&inode->i_lock); - error = nfs_wait_on_request(req); - nfs_release_request(req); - if (error != 0) - goto out_err; - } + rqend = req->wb_offset + req->wb_bytes; + /* + * Tell the caller to flush out the request if + * the offsets are non-contiguous. + * Note: nfs_flush_incompatible() will already + * have flushed out requests having wrong owners. + */ + if (offset > rqend || end < req->wb_offset) + goto out_flushme; /* Okay, the request matches. Update the region */ if (offset < req->wb_offset) { @@ -1150,17 +1130,17 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, req->wb_bytes = end - req->wb_offset; else req->wb_bytes = rqend - req->wb_offset; -out_unlock: - if (req) - nfs_clear_request_commit(req); - spin_unlock(&inode->i_lock); return req; out_flushme: - spin_unlock(&inode->i_lock); - nfs_release_request(req); + /* + * Note: we mark the request dirty here because + * nfs_lock_and_join_requests() cannot preserve + * commit flags, so we have to replay the write. + */ + nfs_mark_request_dirty(req); + nfs_unlock_and_release_request(req); error = nfs_wb_page(inode, page); -out_err: - return ERR_PTR(error); + return (error < 0) ? ERR_PTR(error) : NULL; } /* -- 2.13.3