From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiaotian Feng Subject: [PATCH -mmotm 25/30] nfs: disable data cache revalidation for swapfiles Date: Tue, 13 Jul 2010 06:21:33 -0400 Message-ID: <20100713102132.2835.45692.sendpatchset@danny.redhat> References: <20100713101650.2835.15245.sendpatchset@danny.redhat> Cc: riel@redhat.com, cl@linux-foundation.org, a.p.zijlstra@chello.nl, Xiaotian Feng , linux-kernel@vger.kernel.org, lwang@redhat.com, penberg@cs.helsinki.fi, akpm@linux-foundation.org, davem@davemloft.net To: linux-mm@kvack.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org Return-path: In-Reply-To: <20100713101650.2835.15245.sendpatchset@danny.redhat> Sender: owner-linux-mm@kvack.org List-ID: >>From ee72952409a0b811d61f435682e6d161e3b5189b Mon Sep 17 00:00:00 2001 From: Xiaotian Feng Date: Tue, 13 Jul 2010 13:10:49 +0800 Subject: [PATCH 25/30] nfs: disable data cache revalidation for swapfiles Do as Trond suggested: http://lkml.org/lkml/2006/8/25/348 Disable NFS data cache revalidation on swap files since it doesn't really make sense to have other clients change the file while you are using it. Thereby we can stop setting PG_private on swap pages, since there ought to be no further races with invalidate_inode_pages2() to deal with. And since we cannot set PG_private we cannot use page->private (which is already used by PG_swapcache pages anyway) to store the nfs_page. Thus augment the new nfs_page_find_request logic. Signed-off-by: Peter Zijlstra Signed-off-by: Suresh Jayaraman Signed-off-by: Xiaotian Feng --- fs/nfs/inode.c | 6 +++++ fs/nfs/write.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 63 insertions(+), 12 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 099b351..45293af 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -798,6 +798,12 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping) struct nfs_inode *nfsi = NFS_I(inode); int ret = 0; + /* + * swapfiles are not supposed to be shared. + */ + if (IS_SWAPFILE(inode)) + goto out; + if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) || nfs_attribute_cache_expired(inode) || NFS_STALE(inode)) { diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 109a970..0d7ea95 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -109,25 +109,62 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); } -static struct nfs_page *nfs_page_find_request_locked(struct page *page) +static struct nfs_page * +__nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page, int get) { struct nfs_page *req = NULL; - if (PagePrivate(page)) { + if (PagePrivate(page)) req = (struct nfs_page *)page_private(page); - if (req != NULL) - kref_get(&req->wb_kref); - } + else if (unlikely(PageSwapCache(page))) + req = radix_tree_lookup(&nfsi->nfs_page_tree, page_file_index(page)); + + if (get && req) + kref_get(&req->wb_kref); + return req; } +static inline struct nfs_page * +nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page) +{ + return __nfs_page_find_request_locked(nfsi, page, 1); +} + +static int __nfs_page_has_request(struct page *page) +{ + struct inode *inode = page_file_mapping(page)->host; + struct nfs_page *req = NULL; + + spin_lock(&inode->i_lock); + req = __nfs_page_find_request_locked(NFS_I(inode), page, 0); + spin_unlock(&inode->i_lock); + + /* + * hole here plugged by the caller holding onto PG_locked + */ + + return req != NULL; +} + +static inline int nfs_page_has_request(struct page *page) +{ + if (PagePrivate(page)) + return 1; + + if (unlikely(PageSwapCache(page))) + return __nfs_page_has_request(page); + + return 0; +} + static struct nfs_page *nfs_page_find_request(struct page *page) { struct inode *inode = page_file_mapping(page)->host; struct nfs_page *req = NULL; spin_lock(&inode->i_lock); - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); spin_unlock(&inode->i_lock); return req; } @@ -230,7 +267,7 @@ static struct nfs_page *nfs_find_and_lock_request(struct page *page) spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); if (req == NULL) break; if (nfs_set_page_tag_locked(req)) @@ -383,8 +420,14 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req) if (nfs_have_delegation(inode, FMODE_WRITE)) nfsi->change_attr++; } - SetPagePrivate(req->wb_page); - set_page_private(req->wb_page, (unsigned long)req); + /* + * Swap-space should not get truncated. Hence no need to plug the race + * with invalidate/truncate. + */ + if (likely(!PageSwapCache(req->wb_page))) { + SetPagePrivate(req->wb_page); + set_page_private(req->wb_page, (unsigned long)req); + } nfsi->npages++; kref_get(&req->wb_kref); radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, @@ -406,8 +449,10 @@ static void nfs_inode_remove_request(struct nfs_page *req) BUG_ON (!NFS_WBACK_BUSY(req)); spin_lock(&inode->i_lock); - set_page_private(req->wb_page, 0); - ClearPagePrivate(req->wb_page); + if (likely(!PageSwapCache(req->wb_page))) { + set_page_private(req->wb_page, 0); + ClearPagePrivate(req->wb_page); + } radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index); nfsi->npages--; if (!nfsi->npages) { @@ -575,7 +620,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); if (req == NULL) goto out_unlock; -- 1.7.1.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756706Ab0GMKWa (ORCPT ); Tue, 13 Jul 2010 06:22:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25743 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756521Ab0GMKW0 (ORCPT ); Tue, 13 Jul 2010 06:22:26 -0400 Date: Tue, 13 Jul 2010 06:21:33 -0400 From: Xiaotian Feng To: linux-mm@kvack.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org Cc: riel@redhat.com, cl@linux-foundation.org, a.p.zijlstra@chello.nl, Xiaotian Feng , linux-kernel@vger.kernel.org, lwang@redhat.com, penberg@cs.helsinki.fi, akpm@linux-foundation.org, davem@davemloft.net Message-Id: <20100713102132.2835.45692.sendpatchset@danny.redhat> In-Reply-To: <20100713101650.2835.15245.sendpatchset@danny.redhat> References: <20100713101650.2835.15245.sendpatchset@danny.redhat> Subject: [PATCH -mmotm 25/30] nfs: disable data cache revalidation for swapfiles Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>From ee72952409a0b811d61f435682e6d161e3b5189b Mon Sep 17 00:00:00 2001 From: Xiaotian Feng Date: Tue, 13 Jul 2010 13:10:49 +0800 Subject: [PATCH 25/30] nfs: disable data cache revalidation for swapfiles Do as Trond suggested: http://lkml.org/lkml/2006/8/25/348 Disable NFS data cache revalidation on swap files since it doesn't really make sense to have other clients change the file while you are using it. Thereby we can stop setting PG_private on swap pages, since there ought to be no further races with invalidate_inode_pages2() to deal with. And since we cannot set PG_private we cannot use page->private (which is already used by PG_swapcache pages anyway) to store the nfs_page. Thus augment the new nfs_page_find_request logic. Signed-off-by: Peter Zijlstra Signed-off-by: Suresh Jayaraman Signed-off-by: Xiaotian Feng --- fs/nfs/inode.c | 6 +++++ fs/nfs/write.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 63 insertions(+), 12 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 099b351..45293af 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -798,6 +798,12 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping) struct nfs_inode *nfsi = NFS_I(inode); int ret = 0; + /* + * swapfiles are not supposed to be shared. + */ + if (IS_SWAPFILE(inode)) + goto out; + if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) || nfs_attribute_cache_expired(inode) || NFS_STALE(inode)) { diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 109a970..0d7ea95 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -109,25 +109,62 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); } -static struct nfs_page *nfs_page_find_request_locked(struct page *page) +static struct nfs_page * +__nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page, int get) { struct nfs_page *req = NULL; - if (PagePrivate(page)) { + if (PagePrivate(page)) req = (struct nfs_page *)page_private(page); - if (req != NULL) - kref_get(&req->wb_kref); - } + else if (unlikely(PageSwapCache(page))) + req = radix_tree_lookup(&nfsi->nfs_page_tree, page_file_index(page)); + + if (get && req) + kref_get(&req->wb_kref); + return req; } +static inline struct nfs_page * +nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page) +{ + return __nfs_page_find_request_locked(nfsi, page, 1); +} + +static int __nfs_page_has_request(struct page *page) +{ + struct inode *inode = page_file_mapping(page)->host; + struct nfs_page *req = NULL; + + spin_lock(&inode->i_lock); + req = __nfs_page_find_request_locked(NFS_I(inode), page, 0); + spin_unlock(&inode->i_lock); + + /* + * hole here plugged by the caller holding onto PG_locked + */ + + return req != NULL; +} + +static inline int nfs_page_has_request(struct page *page) +{ + if (PagePrivate(page)) + return 1; + + if (unlikely(PageSwapCache(page))) + return __nfs_page_has_request(page); + + return 0; +} + static struct nfs_page *nfs_page_find_request(struct page *page) { struct inode *inode = page_file_mapping(page)->host; struct nfs_page *req = NULL; spin_lock(&inode->i_lock); - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); spin_unlock(&inode->i_lock); return req; } @@ -230,7 +267,7 @@ static struct nfs_page *nfs_find_and_lock_request(struct page *page) spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); if (req == NULL) break; if (nfs_set_page_tag_locked(req)) @@ -383,8 +420,14 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req) if (nfs_have_delegation(inode, FMODE_WRITE)) nfsi->change_attr++; } - SetPagePrivate(req->wb_page); - set_page_private(req->wb_page, (unsigned long)req); + /* + * Swap-space should not get truncated. Hence no need to plug the race + * with invalidate/truncate. + */ + if (likely(!PageSwapCache(req->wb_page))) { + SetPagePrivate(req->wb_page); + set_page_private(req->wb_page, (unsigned long)req); + } nfsi->npages++; kref_get(&req->wb_kref); radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, @@ -406,8 +449,10 @@ static void nfs_inode_remove_request(struct nfs_page *req) BUG_ON (!NFS_WBACK_BUSY(req)); spin_lock(&inode->i_lock); - set_page_private(req->wb_page, 0); - ClearPagePrivate(req->wb_page); + if (likely(!PageSwapCache(req->wb_page))) { + set_page_private(req->wb_page, 0); + ClearPagePrivate(req->wb_page); + } radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index); nfsi->npages--; if (!nfsi->npages) { @@ -575,7 +620,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode, spin_lock(&inode->i_lock); for (;;) { - req = nfs_page_find_request_locked(page); + req = nfs_page_find_request_locked(NFS_I(inode), page); if (req == NULL) goto out_unlock; -- 1.7.1.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 7CC816201FE for ; Tue, 13 Jul 2010 06:21:51 -0400 (EDT) Date: Tue, 13 Jul 2010 06:21:33 -0400 From: Xiaotian Feng Message-Id: <20100713102132.2835.45692.sendpatchset@danny.redhat> In-Reply-To: <20100713101650.2835.15245.sendpatchset@danny.redhat> References: <20100713101650.2835.15245.sendpatchset@danny.redhat> Subject: [PATCH -mmotm 25/30] nfs: disable data cache revalidation for swapfiles Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org Cc: riel@redhat.com, cl@linux-foundation.org, a.p.zijlstra@chello.nl, Xiaotian Feng , linux-kernel@vger.kernel.org, lwang@redhat.com, penberg@cs.helsinki.fi, akpm@linux-foundation.org, davem@davemloft.net List-ID: