Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f169.google.com ([209.85.223.169]:48922 "EHLO mail-ie0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932084AbaDXSPt (ORCPT ); Thu, 24 Apr 2014 14:15:49 -0400 Received: by mail-ie0-f169.google.com with SMTP id to1so2774738ieb.14 for ; Thu, 24 Apr 2014 11:15:48 -0700 (PDT) From: Weston Andros Adamson To: trond.myklebust@primarydata.com Cc: linux-nfs@vger.kernel.org, Weston Andros Adamson Subject: [PATCH 08/18 v2] nfs: page group syncing in write path Date: Thu, 24 Apr 2014 14:15:18 -0400 Message-Id: <1398363328-7100-9-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 write path, this is calling end_page_writeback and removing the head request from an inode. Both of these operations 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/write.c | 32 ++++++++++++++++++++------------ include/linux/nfs_page.h | 2 ++ 2 files changed, 22 insertions(+), 12 deletions(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index a65755a..a3e3065 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -201,12 +201,15 @@ static void nfs_set_page_writeback(struct page *page) } } -static void nfs_end_page_writeback(struct page *page) +static void nfs_end_page_writeback(struct nfs_page *req) { - struct inode *inode = page_file_mapping(page)->host; + struct inode *inode = page_file_mapping(req->wb_page)->host; struct nfs_server *nfss = NFS_SERVER(inode); - end_page_writeback(page); + if (!nfs_page_group_sync_on_bit(req, PG_WB_END)) + return; + + end_page_writeback(req->wb_page); if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); } @@ -397,15 +400,20 @@ static void nfs_inode_remove_request(struct nfs_page *req) { struct inode *inode = req->wb_context->dentry->d_inode; struct nfs_inode *nfsi = NFS_I(inode); + struct nfs_page *head; - spin_lock(&inode->i_lock); - if (likely(!PageSwapCache(req->wb_page))) { - set_page_private(req->wb_page, 0); - ClearPagePrivate(req->wb_page); - clear_bit(PG_MAPPED, &req->wb_flags); + if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { + head = req->wb_head; + + spin_lock(&inode->i_lock); + if (likely(!PageSwapCache(head->wb_page))) { + set_page_private(head->wb_page, 0); + ClearPagePrivate(head->wb_page); + clear_bit(PG_MAPPED, &head->wb_flags); + } + nfsi->npages--; + spin_unlock(&inode->i_lock); } - nfsi->npages--; - spin_unlock(&inode->i_lock); nfs_release_request(req); } @@ -599,7 +607,7 @@ remove_req: nfs_inode_remove_request(req); next: nfs_unlock_request(req); - nfs_end_page_writeback(req->wb_page); + nfs_end_page_writeback(req); do_destroy = !test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags); nfs_release_request(req); } @@ -964,7 +972,7 @@ static void nfs_redirty_request(struct nfs_page *req) { nfs_mark_request_dirty(req); nfs_unlock_request(req); - nfs_end_page_writeback(req->wb_page); + nfs_end_page_writeback(req); nfs_release_request(req); } diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 002f999..6500b85 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -31,6 +31,8 @@ enum { 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 */ + PG_WB_END, /* page group sync bit in write path */ + PG_REMOVE, /* page group sync bit in write path */ }; struct nfs_inode; -- 1.8.5.2 (Apple Git-48)