From patchwork Thu Nov 9 15:01:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paulo Alcantara X-Patchwork-Id: 13451194 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A2B1D2EE for ; Thu, 9 Nov 2023 15:02:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manguebit.com header.i=@manguebit.com header.b="WWfZdwzg" Received: from mx.manguebit.com (mx.manguebit.com [167.235.159.17]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93DE7358C for ; Thu, 9 Nov 2023 07:02:07 -0800 (PST) From: Paulo Alcantara DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manguebit.com; s=dkim; t=1699542124; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0s6fEJTJqnP1fAl1i4bwbAYuzeWkgLclqXUSSly8n98=; b=WWfZdwzgXhDA43ocqFVEi2S4kuKNFo+VWK9JKk50LDcdTk0wemK7o7s9EGTjEbH3cV21HD fvqaxMtQX04I78S0zC0tP3v8AHHbcClvDYml0SgMpkt28v1TUweu5TjFj5oSPSDiy7DJRK zH1YQ7Hqk/yBn3XLxWeEGU14Vopnf3E2NRYfP19DdyLlU0rs2PoebD6SaX+XsZoy7/mgK5 sLF+lufC8/Ay/R+TUSRhCnMcq616KmKc1iovp0XSeNpQgDaNo0gcjefSVqcq64h6Wlc8mM tog03PTYjzwCVDYiErjCSImOeayFVJlitdFnFJQaDLQsgjxdy7+FWZ6aA7G3hg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=manguebit.com; s=dkim; t=1699542124; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0s6fEJTJqnP1fAl1i4bwbAYuzeWkgLclqXUSSly8n98=; b=EqCI7/7XfLGP3MaH7wDBuCybidAraWZ6j87CfdlWSTEj5bTPZO0hkUJQuilOffWosDCUxY o4gPvpOEnXLJQUQwityXSW2XMewYDPeX4+d5oWtkkCyemEoRXLgvNclyx3BUeLH6A30NID aQTIiAUV9I6Y/fsyEOi8fg2HzZGtH0sqB2XYbRdX3Z+t51zP5NKrVQjTi5/68NfZhvJvY7 GEdEh6G6uV2gC45w2lPS18m9ZvKuUlFLLhx5r+fcI3IGNQSKkjm90FIjpDt/IZBavtP+40 rn/9RGVFp1otAkLqsC0zS886eYy+KEQe+GPMGqi30HkTy2D1VgauR0L16LfotQ== ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pc@manguebit.com smtp.mailfrom=pc@manguebit.com ARC-Seal: i=1; s=dkim; d=manguebit.com; t=1699542124; a=rsa-sha256; cv=none; b=eYoNeKv3t5jYnmSQ7pie2SAlbVRt+GYfTmIKQlcJG9SqEqBhIClLfiTz/d8+Ab4eYPOaPJ keH+dJbgdvNG+frtQy+6ztwq6SguwGTEsa72Gg1gYh9NyGg7I6kwi4iBVM4lHx/ILp2UT4 8aXhYHbPRtFe0IkHGjjm+Yu+4EaxNe/NhC1aE33nepa3Nn45pu0mNqKPZ2eVgO8/BotJSE NKS/7Ec8H6ew3elvb8bYizoYoNw+kq1IOIXSKPvBNjPxsxJfnOjPwNYi6Pkeu1PMyC44R0 H/weYetFxzmvVjDUHXgtlov+aa/zmr8D7a6jgdQUKNGe1uAx03qzP4lPBlYXWw== To: smfrench@gmail.com Cc: linux-cifs@vger.kernel.org, Paulo Alcantara , Eduard Bachmakov Subject: [PATCH] smb: client: fix mount when dns_resolver key is not available Date: Thu, 9 Nov 2023 12:01:48 -0300 Message-ID: <20231109150148.6273-1-pc@manguebit.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 There was a wrong assumption that with CONFIG_CIFS_DFS_UPCALL=y there would always be a dns_resolver key set up so we could unconditionally upcall to resolve UNC hostname rather than using the value provided by mount(2). Only require it when performing automount of junctions within a DFS share so users that don't have dns_resolver key still can mount their regular shares with server hostname resolved by mount.cifs(8). Fixes: 348a04a8d113 ("smb: client: get rid of dfs code dep in namespace.c") Tested-by: Eduard Bachmakov Reported-by: Eduard Bachmakov Closes: https://lore.kernel.org/all/CADCRUiNvZuiUZ0VGZZO9HRyPyw6x92kiA7o7Q4tsX5FkZqUkKg@mail.gmail.com/ Signed-off-by: Paulo Alcantara (SUSE) --- fs/smb/client/dfs.c | 18 +++++++++++++----- fs/smb/client/fs_context.h | 1 + fs/smb/client/namespace.c | 17 +++++++++++++++-- 3 files changed, 29 insertions(+), 7 deletions(-) diff --git a/fs/smb/client/dfs.c b/fs/smb/client/dfs.c index 81b84151450d..a8a1d386da65 100644 --- a/fs/smb/client/dfs.c +++ b/fs/smb/client/dfs.c @@ -263,15 +263,23 @@ static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx) return rc; } -/* Resolve UNC hostname in @ctx->source and set ip addr in @ctx->dstaddr */ +/* + * If @ctx->dfs_automount, then update @ctx->dstaddr earlier with the DFS root + * server from where we'll start following any referrals. Otherwise rely on the + * value provided by mount(2) as the user might not have dns_resolver key set up + * and therefore failing to upcall to resolve UNC hostname under @ctx->source. + */ static int update_fs_context_dstaddr(struct smb3_fs_context *ctx) { struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr; - int rc; + int rc = 0; - rc = dns_resolve_server_name_to_ip(ctx->source, addr, NULL); - if (!rc) - cifs_set_port(addr, ctx->port); + if (!ctx->nodfs && ctx->dfs_automount) { + rc = dns_resolve_server_name_to_ip(ctx->source, addr, NULL); + if (!rc) + cifs_set_port(addr, ctx->port); + ctx->dfs_automount = false; + } return rc; } diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h index 9d8d34af0211..cf46916286d0 100644 --- a/fs/smb/client/fs_context.h +++ b/fs/smb/client/fs_context.h @@ -268,6 +268,7 @@ struct smb3_fs_context { bool witness:1; /* use witness protocol */ char *leaf_fullpath; struct cifs_ses *dfs_root_ses; + bool dfs_automount:1; /* set for dfs automount only */ }; extern const struct fs_parameter_spec smb3_fs_parameters[]; diff --git a/fs/smb/client/namespace.c b/fs/smb/client/namespace.c index c8f5ed8a69f1..a6968573b775 100644 --- a/fs/smb/client/namespace.c +++ b/fs/smb/client/namespace.c @@ -117,6 +117,18 @@ cifs_build_devname(char *nodename, const char *prepath) return dev; } +static bool is_dfs_mount(struct dentry *dentry) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb); + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); + bool ret; + + spin_lock(&tcon->tc_lock); + ret = !!tcon->origin_fullpath; + spin_unlock(&tcon->tc_lock); + return ret; +} + /* Return full path out of a dentry set for automount */ static char *automount_fullpath(struct dentry *dentry, void *page) { @@ -212,8 +224,9 @@ static struct vfsmount *cifs_do_automount(struct path *path) ctx->source = NULL; goto out; } - cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s\n", - __func__, ctx->source, ctx->UNC, ctx->prepath); + ctx->dfs_automount = is_dfs_mount(mntpt); + cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s dfs_automount=%d\n", + __func__, ctx->source, ctx->UNC, ctx->prepath, ctx->dfs_automount); mnt = fc_mount(fc); out: