From fac56c4651ae95f3f2b468c2cf1884cf0e6d18c1 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Thu, 23 Oct 2025 18:59:47 -0300 Subject: smb: client: handle lack of IPC in dfs_cache_refresh() In very rare cases, DFS mounts could end up with SMB sessions without any IPC connections. These mounts are only possible when having unexpired cached DFS referrals, hence not requiring any IPC connections during the mount process. Try to establish those missing IPC connections when refreshing DFS referrals. If the server is still rejecting it, then simply ignore and leave expired cached DFS referral for any potential DFS failovers. Reported-by: Jay Shin Signed-off-by: Paulo Alcantara (Red Hat) Cc: David Howells Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French --- fs/smb/client/connect.c | 38 +++++++++++++++++--------------------- 1 file changed, 17 insertions(+), 21 deletions(-) (limited to 'fs/smb/client/connect.c') diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index dd12f3eb61dc..d65ab7e4b1c2 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -2015,39 +2015,31 @@ static int match_session(struct cifs_ses *ses, /** * cifs_setup_ipc - helper to setup the IPC tcon for the session * @ses: smb session to issue the request on - * @ctx: the superblock configuration context to use for building the - * new tree connection for the IPC (interprocess communication RPC) + * @seal: if encryption is requested * * A new IPC connection is made and stored in the session * tcon_ipc. The IPC tcon has the same lifetime as the session. */ -static int -cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) +struct cifs_tcon *cifs_setup_ipc(struct cifs_ses *ses, bool seal) { int rc = 0, xid; struct cifs_tcon *tcon; char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0}; - bool seal = false; struct TCP_Server_Info *server = ses->server; /* * If the mount request that resulted in the creation of the * session requires encryption, force IPC to be encrypted too. */ - if (ctx->seal) { - if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) - seal = true; - else { - cifs_server_dbg(VFS, - "IPC: server doesn't support encryption\n"); - return -EOPNOTSUPP; - } + if (seal && !(server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)) { + cifs_server_dbg(VFS, "IPC: server doesn't support encryption\n"); + return ERR_PTR(-EOPNOTSUPP); } /* no need to setup directory caching on IPC share, so pass in false */ tcon = tcon_info_alloc(false, netfs_trace_tcon_ref_new_ipc); if (tcon == NULL) - return -ENOMEM; + return ERR_PTR(-ENOMEM); spin_lock(&server->srv_lock); scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname); @@ -2057,13 +2049,13 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) tcon->ses = ses; tcon->ipc = true; tcon->seal = seal; - rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls); + rc = server->ops->tree_connect(xid, ses, unc, tcon, ses->local_nls); free_xid(xid); if (rc) { - cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc); + cifs_server_dbg(VFS | ONCE, "failed to connect to IPC (rc=%d)\n", rc); tconInfoFree(tcon, netfs_trace_tcon_ref_free_ipc_fail); - goto out; + return ERR_PTR(rc); } cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid); @@ -2071,9 +2063,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) spin_lock(&tcon->tc_lock); tcon->status = TID_GOOD; spin_unlock(&tcon->tc_lock); - ses->tcon_ipc = tcon; -out: - return rc; + return tcon; } static struct cifs_ses * @@ -2347,6 +2337,7 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr; struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr; + struct cifs_tcon *ipc; struct cifs_ses *ses; unsigned int xid; int retries = 0; @@ -2525,7 +2516,12 @@ retry_new_session: list_add(&ses->smb_ses_list, &server->smb_ses_list); spin_unlock(&cifs_tcp_ses_lock); - cifs_setup_ipc(ses, ctx); + ipc = cifs_setup_ipc(ses, ctx->seal); + spin_lock(&cifs_tcp_ses_lock); + spin_lock(&ses->ses_lock); + ses->tcon_ipc = !IS_ERR(ipc) ? ipc : NULL; + spin_unlock(&ses->ses_lock); + spin_unlock(&cifs_tcp_ses_lock); free_xid(xid); -- cgit From 895ad6f7083b0c9f1902b23b84136298a492cbeb Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Tue, 28 Oct 2025 18:43:46 +0100 Subject: smb: client: call smbd_destroy() in the same splace as kernel_sock_shutdown()/sock_release() With commit b0432201a11b ("smb: client: let destroy_mr_list() keep smbdirect_mr_io memory if registered") the changes from commit 214bab448476 ("cifs: Call MID callback before destroying transport") and commit 1d2a4f57cebd ("cifs:smbd When reconnecting to server, call smbd_destroy() after all MIDs have been called") are no longer needed. And it's better to use the same logic flow, so that the chance of smbdirect related problems is smaller. Fixes: 214bab448476 ("cifs: Call MID callback before destroying transport") Fixes: 1d2a4f57cebd ("cifs:smbd When reconnecting to server, call smbd_destroy() after all MIDs have been called") Cc: Steve French Cc: Tom Talpey Cc: Long Li Cc: Namjae Jeon Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Stefan Metzmacher Signed-off-by: Steve French --- fs/smb/client/connect.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'fs/smb/client/connect.c') diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index d65ab7e4b1c2..55cb4b0cbd48 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -310,6 +310,8 @@ cifs_abort_connection(struct TCP_Server_Info *server) server->ssocket->flags); sock_release(server->ssocket); server->ssocket = NULL; + } else if (cifs_rdma_enabled(server)) { + smbd_destroy(server); } server->sequence_number = 0; server->session_estab = false; @@ -338,12 +340,6 @@ cifs_abort_connection(struct TCP_Server_Info *server) mid_execute_callback(mid); release_mid(mid); } - - if (cifs_rdma_enabled(server)) { - cifs_server_lock(server); - smbd_destroy(server); - cifs_server_unlock(server); - } } static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets) -- cgit