Package: linux-2.6 Version: 2.6.32-15 Severity: important
This bug in present in all 2.6.32.x, 33.x and 34.x kernels. It is a regression in NFS code. When copying a large file (larger than the amount of available physical memory) to an NFS-mounted filesystem, swapper and rpciod on the client complain about page allocation failures and then kswapd goes into a deadlock, resulting in a system-wide crash. https://bugzilla.kernel.org/show_bug.cgi?id=16056 The following patch fixes it: dcafd9eb464f5a87512f28c133386773a596261 Author: Trond Myklebust <trond.mykleb...@netapp.com> Date: Wed Jul 14 16:51:48 2010 -0400 NFS: Don't let kswapd call nfs_wb_page() kswapd sets the GFP_KERNEL allocation flags, but is still liable to cause the system to lock up if it has to wait too long for an RPC call etc to succeed. Signed-off-by: Trond Myklebust <trond.mykleb...@netapp.com> diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 8d965bd..9af489f 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -491,8 +491,11 @@ static int nfs_release_page(struct page *page, gfp_t gfp) { 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) + /* Only do I/O if gfp is a superset of GFP_KERNEL and if + * we're not kswapd or some other memory allocator. + */ + if ((gfp & GFP_KERNEL) == GFP_KERNEL + && !(current->flags & PF_MEMALLOC)) nfs_wb_page(page->mapping->host, page); /* If PagePrivate() is set, then the page is not freeable */ if (PagePrivate(page)) -- Leszek "Tygrys" Urbanski, SCSA, SCNA "Unix-to-Unix Copy Program;" said PDP-1. "You will never find a more wretched hive of bugs and flamers. We must be cautious." -- DECWARS http://cygnus.moo.pl/ -- Cygnus High Altitude Balloon -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100716134322.ga27...@moo.pl
