From d812e575822a2b7ab1a7cadae2571505ec6ec2bd Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 19 Mar 2010 13:55:17 -0400 Subject: NFS: Prevent another deadlock in nfs_release_page() We should not attempt to free the page if __GFP_FS is not set. Otherwise we can deadlock as per http://bugzilla.kernel.org/show_bug.cgi?id=15578 Signed-off-by: Trond Myklebust Cc: stable@kernel.org --- fs/nfs/file.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nfs/file.c b/fs/nfs/file.c index ae8d02294e4..ae0d9273653 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -491,7 +491,8 @@ static int nfs_release_page(struct page *page, gfp_t gfp) { dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); - if (gfp & __GFP_WAIT) + /* 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 PagePrivate() is set, then the page is not freeable */ if (PagePrivate(page)) -- cgit v1.2.3 From 556ae3bb32cabe483375b857dda1322384c57b65 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Sun, 21 Mar 2010 12:10:36 -0400 Subject: NFS: don't try to decode GETATTR if DELEGRETURN returned error The reply parsing code attempts to decode the GETATTR response even if the DELEGRETURN portion of the compound returned an error. The GETATTR response won't actually exist if that's the case and we're asking the parser to read past the end of the response. This bug is fairly benign. The parser catches this without reading past the end of the response and decode_getfattr returns -EIO. Earlier kernels however had decode_op_hdr using the READ_BUF macro, and this bug would make this printk pop any time the client got an error from a delegreturn: kernel: decode_op_hdr: reply buffer overflowed in line XXXX More recent kernels seem to have replaced this printk with a dprintk. Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust --- fs/nfs/nfs4xdr.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 4d338be492c..dd17713413a 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -5552,6 +5552,8 @@ static int nfs4_xdr_dec_delegreturn(struct rpc_rqst *rqstp, __be32 *p, struct nf if (status != 0) goto out; status = decode_delegreturn(&xdr); + if (status != 0) + goto out; decode_getfattr(&xdr, res->fattr, res->server, !RPC_IS_ASYNC(rqstp->rq_task)); out: -- cgit v1.2.3