From 0c88c156dfb335e3ae4fc50a76b88082544d1d3c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 3 Aug 2010 17:22:16 -0400 Subject: [PATCH] NFS: kswapd must not block in nfs_release_page commit b608b283a962caaa280756bc8563016a71712acf upstream See https://bugzilla.kernel.org/show_bug.cgi?id=16056 If other processes are blocked waiting for kswapd to free up some memory so that they can make progress, then we cannot allow kswapd to block on those processes. Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/file.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 61b3bf503ee1..9f83d9fe9a61 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -27,6 +27,8 @@ #include #include #include +#include +#include #include #include @@ -484,11 +486,19 @@ static void nfs_invalidate_page(struct page *page, unsigned long offset) */ static int nfs_release_page(struct page *page, gfp_t gfp) { + struct address_space *mapping = page->mapping; + dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); /* Only do I/O if gfp is a superset of GFP_KERNEL */ - if ((gfp & GFP_KERNEL) == GFP_KERNEL) - nfs_wb_page(page->mapping->host, page); + if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL) { + int how = FLUSH_SYNC; + + /* Don't let kswapd deadlock waiting for OOM RPC calls */ + if (current_is_kswapd()) + how = 0; + nfs_commit_inode(mapping->host, how); + } /* If PagePrivate() is set, then the page is not freeable */ if (PagePrivate(page)) return 0; -- 2.34.1