* Re: [PATCH 2/2] cifs: Fix locking usage for tcon fields
2026-01-31 8:02 ` [PATCH 2/2] cifs: Fix locking usage for tcon fields nspmangalore
@ 2026-01-31 10:07 ` Shyam Prasad N
2026-01-31 14:58 ` kernel test robot
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Shyam Prasad N @ 2026-01-31 10:07 UTC (permalink / raw)
To: linux-cifs, smfrench, pc, bharathsm; +Cc: Shyam Prasad N, stable
On Sat, Jan 31, 2026 at 1:33 PM <nspmangalore@gmail.com> wrote:
>
> From: Shyam Prasad N <sprasad@microsoft.com>
>
> 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 <sprasad@microsoft.com>
> ---
> 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 ++
> 4 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
> index 1db7ab6c2529c..84c3aea18a1a7 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(&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(&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 c1aaf77e187b6..6f930d6c78adb 100644
> --- a/fs/smb/client/smb2ops.c
> +++ b/fs/smb/client/smb2ops.c
> @@ -3091,7 +3091,9 @@ 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);
> }
> @@ -3160,13 +3162,9 @@ 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);
> 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);
> --
> 2.43.0
>
Please ignore this. I'll send a v2 soon.
--
Regards,
Shyam
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 2/2] cifs: Fix locking usage for tcon fields
2026-01-31 8:02 ` [PATCH 2/2] cifs: Fix locking usage for tcon fields nspmangalore
2026-01-31 10:07 ` Shyam Prasad N
@ 2026-01-31 14:58 ` kernel test robot
2026-01-31 15:50 ` kernel test robot
2026-01-31 15:54 ` kernel test robot
3 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2026-01-31 14:58 UTC (permalink / raw)
To: nspmangalore, linux-cifs, smfrench, pc, bharathsm
Cc: oe-kbuild-all, Shyam Prasad N, stable
Hi,
kernel test robot noticed the following build errors:
[auto build test ERROR on cifs/for-next]
[also build test ERROR on linus/master v6.19-rc7 next-20260130]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/nspmangalore-gmail-com/cifs-Fix-locking-usage-for-tcon-fields/20260131-160419
base: git://git.samba.org/sfrench/cifs-2.6.git for-next
patch link: https://lore.kernel.org/r/20260131080239.943483-2-sprasad%40microsoft.com
patch subject: [PATCH 2/2] cifs: Fix locking usage for tcon fields
config: x86_64-randconfig-004-20260131 (https://download.01.org/0day-ci/archive/20260131/202601312208.PzE9vcRG-lkp@intel.com/config)
compiler: gcc-13 (Debian 13.3.0-16) 13.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260131/202601312208.PzE9vcRG-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601312208.PzE9vcRG-lkp@intel.com/
All errors (new ones prefixed by >>):
fs/smb/client/smb2ops.c: In function 'smb2_get_dfs_refer':
>> fs/smb/client/smb2ops.c:3178:17: error: too few arguments to function 'cifs_put_tcon'
3178 | cifs_put_tcon(tcon);
| ^~~~~~~~~~~~~
In file included from fs/smb/client/smb2ops.c:20:
fs/smb/client/cifsproto.h:273:6: note: declared here
273 | void cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace);
| ^~~~~~~~~~~~~
--
fs/smb/client/cached_dir.c: In function 'cfids_laundromat_worker':
>> fs/smb/client/cached_dir.c:795:36: error: 'tcon' undeclared (first use in this function)
795 | spin_lock(&tcon->tc_lock);
| ^~~~
fs/smb/client/cached_dir.c:795:36: note: each undeclared identifier is reported only once for each function it appears in
vim +/cifs_put_tcon +3178 fs/smb/client/smb2ops.c
3078
3079 static int
3080 smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
3081 const char *search_name,
3082 struct dfs_info3_param **target_nodes,
3083 unsigned int *num_of_nodes,
3084 const struct nls_table *nls_codepage, int remap)
3085 {
3086 int rc;
3087 __le16 *utf16_path = NULL;
3088 int utf16_path_len = 0;
3089 struct cifs_tcon *tcon;
3090 struct fsctl_get_dfs_referral_req *dfs_req = NULL;
3091 struct get_dfs_referral_rsp *dfs_rsp = NULL;
3092 u32 dfs_req_size = 0, dfs_rsp_size = 0;
3093 int retry_once = 0;
3094
3095 cifs_dbg(FYI, "%s: path: %s\n", __func__, search_name);
3096
3097 /*
3098 * Try to use the IPC tcon, otherwise just use any
3099 */
3100 tcon = ses->tcon_ipc;
3101 if (tcon == NULL) {
3102 spin_lock(&cifs_tcp_ses_lock);
3103 tcon = list_first_entry_or_null(&ses->tcon_list,
3104 struct cifs_tcon,
3105 tcon_list);
3106 if (tcon) {
3107 spin_lock(&tcon->tc_lock);
3108 tcon->tc_count++;
3109 spin_unlock(&tcon->tc_lock);
3110 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
3111 netfs_trace_tcon_ref_get_dfs_refer);
3112 }
3113 spin_unlock(&cifs_tcp_ses_lock);
3114 }
3115
3116 if (tcon == NULL) {
3117 cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n",
3118 ses);
3119 rc = -ENOTCONN;
3120 goto out;
3121 }
3122
3123 utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX,
3124 &utf16_path_len,
3125 nls_codepage, remap);
3126 if (!utf16_path) {
3127 rc = -ENOMEM;
3128 goto out;
3129 }
3130
3131 dfs_req_size = sizeof(*dfs_req) + utf16_path_len;
3132 dfs_req = kzalloc(dfs_req_size, GFP_KERNEL);
3133 if (!dfs_req) {
3134 rc = -ENOMEM;
3135 goto out;
3136 }
3137
3138 /* Highest DFS referral version understood */
3139 dfs_req->MaxReferralLevel = DFS_VERSION;
3140
3141 /* Path to resolve in an UTF-16 null-terminated string */
3142 memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);
3143
3144 for (;;) {
3145 rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
3146 FSCTL_DFS_GET_REFERRALS,
3147 (char *)dfs_req, dfs_req_size, CIFSMaxBufSize,
3148 (char **)&dfs_rsp, &dfs_rsp_size);
3149 if (fatal_signal_pending(current)) {
3150 rc = -EINTR;
3151 break;
3152 }
3153 if (!is_retryable_error(rc) || retry_once++)
3154 break;
3155 usleep_range(512, 2048);
3156 }
3157
3158 if (!rc && !dfs_rsp)
3159 rc = smb_EIO(smb_eio_trace_dfsref_no_rsp);
3160 if (rc) {
3161 if (!is_retryable_error(rc) && rc != -ENOENT && rc != -EOPNOTSUPP)
3162 cifs_tcon_dbg(FYI, "%s: ioctl error: rc=%d\n", __func__, rc);
3163 goto out;
3164 }
3165
3166 rc = parse_dfs_referrals(dfs_rsp, dfs_rsp_size,
3167 num_of_nodes, target_nodes,
3168 nls_codepage, remap, search_name,
3169 true /* is_unicode */);
3170 if (rc && rc != -ENOENT) {
3171 cifs_tcon_dbg(VFS, "%s: failed to parse DFS referral %s: %d\n",
3172 __func__, search_name, rc);
3173 }
3174
3175 out:
3176 if (tcon && !tcon->ipc) {
3177 /* ipc tcons are not refcounted */
> 3178 cifs_put_tcon(tcon);
3179 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
3180 netfs_trace_tcon_ref_dec_dfs_refer);
3181 }
3182 kfree(utf16_path);
3183 kfree(dfs_req);
3184 kfree(dfs_rsp);
3185 return rc;
3186 }
3187
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 2/2] cifs: Fix locking usage for tcon fields
2026-01-31 8:02 ` [PATCH 2/2] cifs: Fix locking usage for tcon fields nspmangalore
2026-01-31 10:07 ` Shyam Prasad N
2026-01-31 14:58 ` kernel test robot
@ 2026-01-31 15:50 ` kernel test robot
2026-01-31 15:54 ` kernel test robot
3 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2026-01-31 15:50 UTC (permalink / raw)
To: nspmangalore, linux-cifs, smfrench, pc, bharathsm
Cc: oe-kbuild-all, Shyam Prasad N, stable
Hi,
kernel test robot noticed the following build errors:
[auto build test ERROR on cifs/for-next]
[also build test ERROR on linus/master v6.19-rc7 next-20260130]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/nspmangalore-gmail-com/cifs-Fix-locking-usage-for-tcon-fields/20260131-160419
base: git://git.samba.org/sfrench/cifs-2.6.git for-next
patch link: https://lore.kernel.org/r/20260131080239.943483-2-sprasad%40microsoft.com
patch subject: [PATCH 2/2] cifs: Fix locking usage for tcon fields
config: microblaze-defconfig (https://download.01.org/0day-ci/archive/20260131/202601312343.JPu2GSIi-lkp@intel.com/config)
compiler: microblaze-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260131/202601312343.JPu2GSIi-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601312343.JPu2GSIi-lkp@intel.com/
All errors (new ones prefixed by >>):
fs/smb/client/smb2ops.c: In function 'smb2_get_dfs_refer':
>> fs/smb/client/smb2ops.c:3178:17: error: too few arguments to function 'cifs_put_tcon'; expected 2, have 1
3178 | cifs_put_tcon(tcon);
| ^~~~~~~~~~~~~
In file included from fs/smb/client/smb2ops.c:20:
fs/smb/client/cifsproto.h:273:6: note: declared here
273 | void cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace);
| ^~~~~~~~~~~~~
vim +/cifs_put_tcon +3178 fs/smb/client/smb2ops.c
3078
3079 static int
3080 smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
3081 const char *search_name,
3082 struct dfs_info3_param **target_nodes,
3083 unsigned int *num_of_nodes,
3084 const struct nls_table *nls_codepage, int remap)
3085 {
3086 int rc;
3087 __le16 *utf16_path = NULL;
3088 int utf16_path_len = 0;
3089 struct cifs_tcon *tcon;
3090 struct fsctl_get_dfs_referral_req *dfs_req = NULL;
3091 struct get_dfs_referral_rsp *dfs_rsp = NULL;
3092 u32 dfs_req_size = 0, dfs_rsp_size = 0;
3093 int retry_once = 0;
3094
3095 cifs_dbg(FYI, "%s: path: %s\n", __func__, search_name);
3096
3097 /*
3098 * Try to use the IPC tcon, otherwise just use any
3099 */
3100 tcon = ses->tcon_ipc;
3101 if (tcon == NULL) {
3102 spin_lock(&cifs_tcp_ses_lock);
3103 tcon = list_first_entry_or_null(&ses->tcon_list,
3104 struct cifs_tcon,
3105 tcon_list);
3106 if (tcon) {
3107 spin_lock(&tcon->tc_lock);
3108 tcon->tc_count++;
3109 spin_unlock(&tcon->tc_lock);
3110 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
3111 netfs_trace_tcon_ref_get_dfs_refer);
3112 }
3113 spin_unlock(&cifs_tcp_ses_lock);
3114 }
3115
3116 if (tcon == NULL) {
3117 cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n",
3118 ses);
3119 rc = -ENOTCONN;
3120 goto out;
3121 }
3122
3123 utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX,
3124 &utf16_path_len,
3125 nls_codepage, remap);
3126 if (!utf16_path) {
3127 rc = -ENOMEM;
3128 goto out;
3129 }
3130
3131 dfs_req_size = sizeof(*dfs_req) + utf16_path_len;
3132 dfs_req = kzalloc(dfs_req_size, GFP_KERNEL);
3133 if (!dfs_req) {
3134 rc = -ENOMEM;
3135 goto out;
3136 }
3137
3138 /* Highest DFS referral version understood */
3139 dfs_req->MaxReferralLevel = DFS_VERSION;
3140
3141 /* Path to resolve in an UTF-16 null-terminated string */
3142 memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);
3143
3144 for (;;) {
3145 rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
3146 FSCTL_DFS_GET_REFERRALS,
3147 (char *)dfs_req, dfs_req_size, CIFSMaxBufSize,
3148 (char **)&dfs_rsp, &dfs_rsp_size);
3149 if (fatal_signal_pending(current)) {
3150 rc = -EINTR;
3151 break;
3152 }
3153 if (!is_retryable_error(rc) || retry_once++)
3154 break;
3155 usleep_range(512, 2048);
3156 }
3157
3158 if (!rc && !dfs_rsp)
3159 rc = smb_EIO(smb_eio_trace_dfsref_no_rsp);
3160 if (rc) {
3161 if (!is_retryable_error(rc) && rc != -ENOENT && rc != -EOPNOTSUPP)
3162 cifs_tcon_dbg(FYI, "%s: ioctl error: rc=%d\n", __func__, rc);
3163 goto out;
3164 }
3165
3166 rc = parse_dfs_referrals(dfs_rsp, dfs_rsp_size,
3167 num_of_nodes, target_nodes,
3168 nls_codepage, remap, search_name,
3169 true /* is_unicode */);
3170 if (rc && rc != -ENOENT) {
3171 cifs_tcon_dbg(VFS, "%s: failed to parse DFS referral %s: %d\n",
3172 __func__, search_name, rc);
3173 }
3174
3175 out:
3176 if (tcon && !tcon->ipc) {
3177 /* ipc tcons are not refcounted */
> 3178 cifs_put_tcon(tcon);
3179 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
3180 netfs_trace_tcon_ref_dec_dfs_refer);
3181 }
3182 kfree(utf16_path);
3183 kfree(dfs_req);
3184 kfree(dfs_rsp);
3185 return rc;
3186 }
3187
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 2/2] cifs: Fix locking usage for tcon fields
2026-01-31 8:02 ` [PATCH 2/2] cifs: Fix locking usage for tcon fields nspmangalore
` (2 preceding siblings ...)
2026-01-31 15:50 ` kernel test robot
@ 2026-01-31 15:54 ` kernel test robot
3 siblings, 0 replies; 5+ messages in thread
From: kernel test robot @ 2026-01-31 15:54 UTC (permalink / raw)
To: nspmangalore, linux-cifs, smfrench, pc, bharathsm
Cc: oe-kbuild-all, Shyam Prasad N, stable
Hi,
kernel test robot noticed the following build errors:
[auto build test ERROR on cifs/for-next]
[also build test ERROR on linus/master v6.19-rc7 next-20260130]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/nspmangalore-gmail-com/cifs-Fix-locking-usage-for-tcon-fields/20260131-160419
base: git://git.samba.org/sfrench/cifs-2.6.git for-next
patch link: https://lore.kernel.org/r/20260131080239.943483-2-sprasad%40microsoft.com
patch subject: [PATCH 2/2] cifs: Fix locking usage for tcon fields
config: s390-allnoconfig-bpf (https://download.01.org/0day-ci/archive/20260131/202601311634.9WVpg186-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 15.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260131/202601311634.9WVpg186-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601311634.9WVpg186-lkp@intel.com/
All errors (new ones prefixed by >>):
fs/smb/client/smb2ops.c: In function 'smb2_get_dfs_refer':
>> fs/smb/client/smb2ops.c:3178:17: error: too few arguments to function 'cifs_put_tcon'; expected 2, have 1
3178 | cifs_put_tcon(tcon);
| ^~~~~~~~~~~~~
In file included from fs/smb/client/smb2ops.c:20:
fs/smb/client/cifsproto.h:273:6: note: declared here
273 | void cifs_put_tcon(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace);
| ^~~~~~~~~~~~~
vim +/cifs_put_tcon +3178 fs/smb/client/smb2ops.c
3078
3079 static int
3080 smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
3081 const char *search_name,
3082 struct dfs_info3_param **target_nodes,
3083 unsigned int *num_of_nodes,
3084 const struct nls_table *nls_codepage, int remap)
3085 {
3086 int rc;
3087 __le16 *utf16_path = NULL;
3088 int utf16_path_len = 0;
3089 struct cifs_tcon *tcon;
3090 struct fsctl_get_dfs_referral_req *dfs_req = NULL;
3091 struct get_dfs_referral_rsp *dfs_rsp = NULL;
3092 u32 dfs_req_size = 0, dfs_rsp_size = 0;
3093 int retry_once = 0;
3094
3095 cifs_dbg(FYI, "%s: path: %s\n", __func__, search_name);
3096
3097 /*
3098 * Try to use the IPC tcon, otherwise just use any
3099 */
3100 tcon = ses->tcon_ipc;
3101 if (tcon == NULL) {
3102 spin_lock(&cifs_tcp_ses_lock);
3103 tcon = list_first_entry_or_null(&ses->tcon_list,
3104 struct cifs_tcon,
3105 tcon_list);
3106 if (tcon) {
3107 spin_lock(&tcon->tc_lock);
3108 tcon->tc_count++;
3109 spin_unlock(&tcon->tc_lock);
3110 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
3111 netfs_trace_tcon_ref_get_dfs_refer);
3112 }
3113 spin_unlock(&cifs_tcp_ses_lock);
3114 }
3115
3116 if (tcon == NULL) {
3117 cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n",
3118 ses);
3119 rc = -ENOTCONN;
3120 goto out;
3121 }
3122
3123 utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX,
3124 &utf16_path_len,
3125 nls_codepage, remap);
3126 if (!utf16_path) {
3127 rc = -ENOMEM;
3128 goto out;
3129 }
3130
3131 dfs_req_size = sizeof(*dfs_req) + utf16_path_len;
3132 dfs_req = kzalloc(dfs_req_size, GFP_KERNEL);
3133 if (!dfs_req) {
3134 rc = -ENOMEM;
3135 goto out;
3136 }
3137
3138 /* Highest DFS referral version understood */
3139 dfs_req->MaxReferralLevel = DFS_VERSION;
3140
3141 /* Path to resolve in an UTF-16 null-terminated string */
3142 memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);
3143
3144 for (;;) {
3145 rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
3146 FSCTL_DFS_GET_REFERRALS,
3147 (char *)dfs_req, dfs_req_size, CIFSMaxBufSize,
3148 (char **)&dfs_rsp, &dfs_rsp_size);
3149 if (fatal_signal_pending(current)) {
3150 rc = -EINTR;
3151 break;
3152 }
3153 if (!is_retryable_error(rc) || retry_once++)
3154 break;
3155 usleep_range(512, 2048);
3156 }
3157
3158 if (!rc && !dfs_rsp)
3159 rc = smb_EIO(smb_eio_trace_dfsref_no_rsp);
3160 if (rc) {
3161 if (!is_retryable_error(rc) && rc != -ENOENT && rc != -EOPNOTSUPP)
3162 cifs_tcon_dbg(FYI, "%s: ioctl error: rc=%d\n", __func__, rc);
3163 goto out;
3164 }
3165
3166 rc = parse_dfs_referrals(dfs_rsp, dfs_rsp_size,
3167 num_of_nodes, target_nodes,
3168 nls_codepage, remap, search_name,
3169 true /* is_unicode */);
3170 if (rc && rc != -ENOENT) {
3171 cifs_tcon_dbg(VFS, "%s: failed to parse DFS referral %s: %d\n",
3172 __func__, search_name, rc);
3173 }
3174
3175 out:
3176 if (tcon && !tcon->ipc) {
3177 /* ipc tcons are not refcounted */
> 3178 cifs_put_tcon(tcon);
3179 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
3180 netfs_trace_tcon_ref_dec_dfs_refer);
3181 }
3182 kfree(utf16_path);
3183 kfree(dfs_req);
3184 kfree(dfs_rsp);
3185 return rc;
3186 }
3187
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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