From: Trond Myklebust Subject: [PATCH 2/2] NFS: Error when mounting the same filesystem with different options Date: Wed, 16 May 2007 22:13:23 -0400 Message-ID: <20070517021323.32447.13696.stgit@heimdal.trondhjem.org> References: <17994.32412.173039.15055@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Neil Brown , Paul Krizak , Trond Myklebust , Ian Kent To: nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1HoVUd-00053A-3e for nfs@lists.sourceforge.net; Wed, 16 May 2007 19:13:30 -0700 Received: from c-69-242-210-120.hsd1.mi.comcast.net ([69.242.210.120] helo=heimdal.trondhjem.org) by mail.sourceforge.net with esmtp (Exim 4.44) id 1HoVUf-00075q-IE for nfs@lists.sourceforge.net; Wed, 16 May 2007 19:13:30 -0700 In-Reply-To: <17994.32412.173039.15055@notabene.brown> List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net From: Trond Myklebust Unless the user sets the NFS_MOUNT_NOSHAREDCACHE mount flag, we should return EBUSY if the filesystem is already mounted on a superblock that has set conflicting mount options. Signed-off-by: Trond Myklebust --- fs/nfs/super.c | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 42 insertions(+), 1 deletions(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index c03120a..f7f8844 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -601,7 +601,9 @@ static int nfs_compare_super(struct super_block *sb, void *data) { struct nfs_server *server = data, *old = NFS_SB(sb); - if (old->nfs_client != server->nfs_client) + if (memcmp(&old->nfs_client->cl_addr, + &server->nfs_client->cl_addr, + sizeof(old->nfs_client->cl_addr)) != 0) return 0; /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */ if (old->flags & NFS_MOUNT_UNSHARED) @@ -611,6 +613,39 @@ static int nfs_compare_super(struct super_block *sb, void *data) return 1; } +#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS) + +static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags) +{ + const struct nfs_server *a = s->s_fs_info; + const struct rpc_clnt *clnt_a = a->client; + const struct rpc_clnt *clnt_b = b->client; + + if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK)) + goto Ebusy; + if (a->nfs_client != b->nfs_client) + goto Ebusy; + if (a->flags != b->flags) + goto Ebusy; + if (a->wsize != b->wsize) + goto Ebusy; + if (a->rsize != b->rsize) + goto Ebusy; + if (a->acregmin != b->acregmin) + goto Ebusy; + if (a->acregmax != b->acregmax) + goto Ebusy; + if (a->acdirmin != b->acdirmin) + goto Ebusy; + if (a->acdirmax != b->acdirmax) + goto Ebusy; + if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor) + goto Ebusy; + return 0; +Ebusy: + return -EBUSY; +} + static int nfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt) { @@ -645,8 +680,11 @@ static int nfs_get_sb(struct file_system_type *fs_type, } if (s->s_fs_info != server) { + error = nfs_compare_mount_options(s, server, flags); nfs_free_server(server); server = NULL; + if (error < 0) + goto error_splat_super; } if (!s->s_root) { @@ -903,8 +941,11 @@ static int nfs4_get_sb(struct file_system_type *fs_type, } if (s->s_fs_info != server) { + error = nfs_compare_mount_options(s, server, flags); nfs_free_server(server); server = NULL; + if (error < 0) + goto error_splat_super; } if (!s->s_root) { ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs