From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx141.netapp.com ([216.240.21.12]:6038 "EHLO mx141.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242AbdBWVzy (ORCPT ); Thu, 23 Feb 2017 16:55:54 -0500 Subject: Re: [PATCH 2/2] NFSv4: fix getacl ERANGE for some ACL buffer sizes To: "J. Bruce Fields" References: <1487470070-32358-1-git-send-email-bfields@redhat.com> <1487470070-32358-3-git-send-email-bfields@redhat.com> <261D4020-D9E4-4F1E-81CF-11EAAEABA684@primarydata.com> <20170222223656.GG24122@parsley.fieldses.org> <6606b2d5-719f-9e27-6f95-eec8cebfb1a8@gmail.com> <20170223194321.GF9417@parsley.fieldses.org> <20170223195338.GG9417@parsley.fieldses.org> <20170223195420.GH9417@parsley.fieldses.org> CC: Weston Andros Adamson , Trond Myklebust , Anna Schumaker , linux-nfs list , Andreas Gruenbacher , Weston Andros Adamson From: Anna Schumaker Message-ID: Date: Thu, 23 Feb 2017 16:54:43 -0500 MIME-Version: 1.0 In-Reply-To: <20170223195420.GH9417@parsley.fieldses.org> Content-Type: text/plain; charset="windows-1252" Sender: linux-nfs-owner@vger.kernel.org List-ID: Thanks, Bruce and Dros! Anna On 02/23/2017 02:54 PM, J. Bruce Fields wrote: > From: Weston Andros Adamson > > We're not taking into account that the space needed for the (variable > length) attr bitmap, with the result that we'd sometimes get a spurious > ERANGE when the ACL data got close to the end of a page. > > Just add in an extra page to make sure. > > Signed-off-by: Weston Andros Adamson > Cc: stable@vger.kernel.org > Signed-off-by: J. Bruce Fields > --- > fs/nfs/nfs4proc.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index 0a0eaecf9676..60501e10625d 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -5069,7 +5069,7 @@ static void nfs4_write_cached_acl(struct inode *inode, struct page **pages, size > */ > static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen) > { > - struct page *pages[NFS4ACL_MAXPAGES] = {NULL, }; > + struct page *pages[NFS4ACL_MAXPAGES + 1] = {NULL, }; > struct nfs_getaclargs args = { > .fh = NFS_FH(inode), > .acl_pages = pages, > @@ -5083,13 +5083,9 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu > .rpc_argp = &args, > .rpc_resp = &res, > }; > - unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE); > + unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE) + 1; > int ret = -ENOMEM, i; > > - /* As long as we're doing a round trip to the server anyway, > - * let's be prepared for a page of acl data. */ > - if (npages == 0) > - npages = 1; > if (npages > ARRAY_SIZE(pages)) > return -ERANGE; > >