Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f170.google.com ([209.85.223.170]:33738 "EHLO mail-ie0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932084AbaDXSPr (ORCPT ); Thu, 24 Apr 2014 14:15:47 -0400 Received: by mail-ie0-f170.google.com with SMTP id rd18so2778366iec.1 for ; Thu, 24 Apr 2014 11:15:47 -0700 (PDT) From: Weston Andros Adamson To: trond.myklebust@primarydata.com Cc: linux-nfs@vger.kernel.org, Weston Andros Adamson Subject: [PATCH 07/18 v2] nfs: page group syncing in read path Date: Thu, 24 Apr 2014 14:15:17 -0400 Message-Id: <1398363328-7100-8-git-send-email-dros@primarydata.com> In-Reply-To: <1398363328-7100-1-git-send-email-dros@primarydata.com> References: <1398363328-7100-1-git-send-email-dros@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Operations that modify state for a whole page must be syncronized across all requests within a page group. In the read path, this is calling unlock_page and SetPageUptodate. Both of these functions should not be called until all requests in a page group have reached the point where they would call them. This patch should have no effect yet since all page groups currently have one request, but will come into play when pg_test functions are modified to split pages into sub-page regions. Signed-off-by: Weston Andros Adamson --- fs/nfs/read.c | 22 +++++++++++++++++----- include/linux/nfs_page.h | 2 ++ 2 files changed, 19 insertions(+), 5 deletions(-) diff --git a/fs/nfs/read.c b/fs/nfs/read.c index f814e8a..a889319 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -105,10 +105,16 @@ static void nfs_readpage_release(struct nfs_page *req) { struct inode *d_inode = req->wb_context->dentry->d_inode; - if (PageUptodate(req->wb_page)) - nfs_readpage_to_fscache(d_inode, req->wb_page, 0); + dprintk("NFS: read done (%s/%llu %d@%lld)\n", d_inode->i_sb->s_id, + (unsigned long long)NFS_FILEID(d_inode), req->wb_bytes, + (long long)req_offset(req)); - unlock_page(req->wb_page); + if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) { + if (PageUptodate(req->wb_page)) + nfs_readpage_to_fscache(d_inode, req->wb_page, 0); + + unlock_page(req->wb_page); + } dprintk("NFS: read done (%s/%Lu %d@%Ld)\n", req->wb_context->dentry->d_inode->i_sb->s_id, @@ -118,6 +124,12 @@ static void nfs_readpage_release(struct nfs_page *req) nfs_release_request(req); } +static void nfs_page_group_set_uptodate(struct nfs_page *req) +{ + if (nfs_page_group_sync_on_bit(req, PG_UPTODATE)) + SetPageUptodate(req->wb_page); +} + /* Note io was page aligned */ static void nfs_read_completion(struct nfs_pgio_header *hdr) { @@ -140,9 +152,9 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr) bytes += req->wb_bytes; if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) { if (bytes <= hdr->good_bytes) - SetPageUptodate(page); + nfs_page_group_set_uptodate(req); } else - SetPageUptodate(page); + nfs_page_group_set_uptodate(req); nfs_list_remove_request(req); nfs_readpage_release(req); } diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index b99deb7..002f999 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -29,6 +29,8 @@ enum { PG_INODE_REF, /* extra ref held by inode (head req only) */ PG_HEADLOCK, /* page group lock of wb_head */ PG_TEARDOWN, /* page group sync for destroy */ + PG_UNLOCKPAGE, /* page group sync bit in read path */ + PG_UPTODATE, /* page group sync bit in read path */ }; struct nfs_inode; -- 1.8.5.2 (Apple Git-48)