From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6A7FB418E0F; Sat, 28 Feb 2026 17:45:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772300730; cv=none; b=cxaSv6AaUYgjZRy2vBwkwhC8w3c0ODu3feXUDRiy8ZabZul6Jsw37Dm4EqDJiy9zVl66HR/bFI5YBaq0U9PZsCliD1VOq1nR7KYVXDEddCvPlmUkWoyuMA7wv76ewYmjSHPghWWbZDGaYFXYMpF+Aqp45AbvlkMwPv2MIePbZtw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772300730; c=relaxed/simple; bh=s86EvEk4BoaoT1WuJ9i9KlB0ECiih2ij5rPXYWYCir8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=vGtaJRhwzPRJ/k81SkBAcRX8rrfs7hN+MMPPYp3qAMdx1WPgUQf5vlPUtejyjLgF0uLxgWDk7/v64Sw+2Hnsw7QIP/YQKrdv/Nc94Cp/Qw8JlCVI/AFc0dQN7mX4HydPKePXlZckgcDZ8pREpBc6KnRthXjbxs7YVU5tkCDqnv4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tToEiY8w; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tToEiY8w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFAE5C19425; Sat, 28 Feb 2026 17:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772300730; bh=s86EvEk4BoaoT1WuJ9i9KlB0ECiih2ij5rPXYWYCir8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tToEiY8wbNxuBsceL3CAoNYaHUN1dAPB1wyC0l2l1qrMReB+JhNLxBMvL+T/BqVH9 kGPmGRb/ROZPf6tVnoOmwZ09hQlT0Q2YdV5MkJoRC4EnzK2ZyuUWBYC+NsbnHhJP7S OLx0QQvN3JdCK22VI6v/U6ONBNUgdA/GvJzwCiLVs5BckylLU+33Vbyvst3ZBnPWcX jLsgPubbTmoAWiZJETPScVr7hSYRNWhvj7/aYhizEF6zhSUhC5ZJBcOpUHqvH/Hppe n3Dbulu/zp0P4ioRZhvZiSQfza86um+TFWFi/VtuVFck0yvrgYVVaqIFSmISkuKQpm Ldrgjw3xTBpmA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Shyam Prasad N , Steve French , Sasha Levin Subject: [PATCH 6.19 764/844] cifs: Fix locking usage for tcon fields Date: Sat, 28 Feb 2026 12:31:17 -0500 Message-ID: <20260228173244.1509663-765-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228173244.1509663-1-sashal@kernel.org> References: <20260228173244.1509663-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Shyam Prasad N [ Upstream commit 96c4af418586ee9a6aab61738644366426e05316 ] We used to use the cifs_tcp_ses_lock to protect a lot of objects that are not just the server, ses or tcon lists. We later introduced srv_lock, ses_lock and tc_lock to protect fields within the corresponding structs. This was done to provide a more granular protection and avoid unnecessary serialization. There were still a couple of uses of cifs_tcp_ses_lock to provide tcon fields. In this patch, I've replaced them with tc_lock. Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/smb/client/cached_dir.c | 4 ++-- fs/smb/client/smb2misc.c | 6 +++--- fs/smb/client/smb2ops.c | 8 +++----- fs/smb/client/smb2pdu.c | 2 ++ fs/smb/client/trace.h | 1 + 5 files changed, 11 insertions(+), 10 deletions(-) diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c index 1db7ab6c2529c..569030b3e68d4 100644 --- a/fs/smb/client/cached_dir.c +++ b/fs/smb/client/cached_dir.c @@ -788,11 +788,11 @@ static void cfids_laundromat_worker(struct work_struct *work) cfid->dentry = NULL; if (cfid->is_open) { - spin_lock(&cifs_tcp_ses_lock); + spin_lock(&cfid->tcon->tc_lock); ++cfid->tcon->tc_count; trace_smb3_tcon_ref(cfid->tcon->debug_id, cfid->tcon->tc_count, netfs_trace_tcon_ref_get_cached_laundromat); - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&cfid->tcon->tc_lock); queue_work(serverclose_wq, &cfid->close_work); } else /* diff --git a/fs/smb/client/smb2misc.c b/fs/smb/client/smb2misc.c index f3cb62d914502..0871b9f1f86a6 100644 --- a/fs/smb/client/smb2misc.c +++ b/fs/smb/client/smb2misc.c @@ -820,14 +820,14 @@ smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid, int rc; cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count); - spin_lock(&cifs_tcp_ses_lock); + spin_lock(&tcon->tc_lock); if (tcon->tc_count <= 0) { struct TCP_Server_Info *server = NULL; trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, netfs_trace_tcon_ref_see_cancelled_close); WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative"); - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&tcon->tc_lock); if (tcon->ses) { server = tcon->ses->server; @@ -841,7 +841,7 @@ smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid, tcon->tc_count++; trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, netfs_trace_tcon_ref_get_cancelled_close); - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&tcon->tc_lock); rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0, persistent_fid, volatile_fid); diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index edfd6a4e87e8b..d76d79e50e8e7 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -3088,7 +3088,9 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, struct cifs_tcon, tcon_list); if (tcon) { + spin_lock(&tcon->tc_lock); tcon->tc_count++; + spin_unlock(&tcon->tc_lock); trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, netfs_trace_tcon_ref_get_dfs_refer); } @@ -3157,13 +3159,9 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, out: if (tcon && !tcon->ipc) { /* ipc tcons are not refcounted */ - spin_lock(&cifs_tcp_ses_lock); - tcon->tc_count--; + cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_dfs_refer); trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, netfs_trace_tcon_ref_dec_dfs_refer); - /* tc_count can never go negative */ - WARN_ON(tcon->tc_count < 0); - spin_unlock(&cifs_tcp_ses_lock); } kfree(utf16_path); kfree(dfs_req); diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index 5d57c895ca37a..c7e086dfb1765 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -4239,7 +4239,9 @@ void smb2_reconnect_server(struct work_struct *work) list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { if (tcon->need_reconnect || tcon->need_reopen_files) { + spin_lock(&tcon->tc_lock); tcon->tc_count++; + spin_unlock(&tcon->tc_lock); trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, netfs_trace_tcon_ref_get_reconnect_server); list_add_tail(&tcon->rlist, &tmp_list); diff --git a/fs/smb/client/trace.h b/fs/smb/client/trace.h index a584a77431132..191f02344dcdd 100644 --- a/fs/smb/client/trace.h +++ b/fs/smb/client/trace.h @@ -189,6 +189,7 @@ EM(netfs_trace_tcon_ref_put_cancelled_close_fid, "PUT Cn-Fid") \ EM(netfs_trace_tcon_ref_put_cancelled_mid, "PUT Cn-Mid") \ EM(netfs_trace_tcon_ref_put_mnt_ctx, "PUT MntCtx") \ + EM(netfs_trace_tcon_ref_put_dfs_refer, "PUT DfsRfr") \ EM(netfs_trace_tcon_ref_put_reconnect_server, "PUT Reconn") \ EM(netfs_trace_tcon_ref_put_tlink, "PUT Tlink ") \ EM(netfs_trace_tcon_ref_see_cancelled_close, "SEE Cn-Cls") \ -- 2.51.0