+++ /dev/null
-From: Peter Zijlstra <a.p.zijlstra@chello.nl>
-Subject: nfs: disable data cache revalidation for swapfiles
-Patch-mainline: No
-References: FATE#303834
-
-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 <a.p.zijlstra@chello.nl>
-Acked-by: Neil Brown <neilb@suse.de>
-Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
-
----
- fs/nfs/inode.c | 6 ++++
- fs/nfs/write.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++-----------
- 2 files changed, 64 insertions(+), 13 deletions(-)
-
-Index: linux-2.6.26/fs/nfs/inode.c
-===================================================================
---- linux-2.6.26.orig/fs/nfs/inode.c
-+++ linux-2.6.26/fs/nfs/inode.c
-@@ -824,6 +824,12 @@ int nfs_revalidate_mapping_nolock(struct
- 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_timeout(inode) || NFS_STALE(inode)) {
- ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
-Index: linux-2.6.26/fs/nfs/write.c
-===================================================================
---- linux-2.6.26.orig/fs/nfs/write.c
-+++ linux-2.6.26/fs/nfs/write.c
-@@ -106,25 +106,62 @@ static void nfs_context_set_write_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;
- }
-@@ -228,7 +265,7 @@ static int nfs_page_async_flush(struct n
-
- 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) {
- spin_unlock(&inode->i_lock);
- return 0;
-@@ -351,8 +388,14 @@ static int nfs_inode_add_request(struct
- 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,
-@@ -374,8 +417,10 @@ static void nfs_inode_remove_request(str
- 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) {
-@@ -579,7 +624,7 @@ static struct nfs_page *nfs_try_to_updat
- 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;
-
-@@ -1490,7 +1535,7 @@ int nfs_wb_page_cancel(struct inode *ino
- if (ret < 0)
- goto out;
- }
-- if (!PagePrivate(page))
-+ if (!nfs_page_has_request(page))
- return 0;
- ret = nfs_sync_mapping_wait(page_file_mapping(page), &wbc, FLUSH_INVALIDATE);
- out:
projects / people / pmueller / ipfire-2.x.git / blobdiff