Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:33135 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750927AbaAWSxG (ORCPT ); Thu, 23 Jan 2014 13:53:06 -0500 Date: Thu, 23 Jan 2014 13:53:05 -0500 From: "J. Bruce Fields" To: Jeff Layton Cc: linux-nfs@vger.kernel.org, sandeen@redhat.com Subject: [PATCH] nfsd4: decrease nfsd4_encode_fattr stack usage Message-ID: <20140123185304.GA28223@fieldses.org> References: <20140109213335.GA21559@fieldses.org> <20140109191934.5a66c3d8@tlielax.poochiereds.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20140109191934.5a66c3d8@tlielax.poochiereds.net> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" A struct svc_fh is 320 bytes on x86_64, it'd be better not to have these on the stack. kmalloc'ing them probably isn't ideal either, but this is the simplest thing to do. If it turns out to be a problem in the readdir case then we could add a svc_fh to nfsd4_readdir and pass that in. Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4xdr.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) On Thu, Jan 09, 2014 at 07:19:34PM -0500, Jeff Layton wrote: > On Thu, 9 Jan 2014 16:33:35 -0500 > > nfsd: fix encode_entryplus_baggage stack usage ... > I think this is probably the best solution... > > Acked-by: Jeff Layton Thanks. While we're at it, here's the v4 case. --b. diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 8198ecf..63f2395 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2058,7 +2058,7 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp, u32 bmval1 = bmval[1]; u32 bmval2 = bmval[2]; struct kstat stat; - struct svc_fh tempfh; + struct svc_fh *tempfh = NULL; struct kstatfs statfs; int buflen = count << 2; __be32 *attrlenp; @@ -2105,11 +2105,15 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp, goto out_nfserr; } if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) { - fh_init(&tempfh, NFS4_FHSIZE); - status = fh_compose(&tempfh, exp, dentry, NULL); + tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL); + status = nfserr_jukebox; + if (!tempfh) + goto out; + fh_init(tempfh, NFS4_FHSIZE); + status = fh_compose(tempfh, exp, dentry, NULL); if (status) goto out; - fhp = &tempfh; + fhp = tempfh; } if (bmval0 & (FATTR4_WORD0_ACL | FATTR4_WORD0_ACLSUPPORT | FATTR4_WORD0_SUPPORTED_ATTRS)) { @@ -2495,8 +2499,8 @@ out: security_release_secctx(context, contextlen); #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ kfree(acl); - if (fhp == &tempfh) - fh_put(&tempfh); + if (tempfh) + fh_put(tempfh); return status; out_nfserr: status = nfserrno(err); -- 1.7.9.5