cifs: reinstate sharing of tree connections

Use a similar approach to the SMB session sharing. Add a list of tcons
attached to each SMB session. Move the refcount to non-atomic. Protect
all of the above with the cifs_tcp_ses_lock. Add functions to
properly find and put references to the tcons.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 128 insertions, 108 deletions

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 59841a68b0b6..1d6dfa8923ca 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -107,12 +107,13 @@ void cifs_dump_mids(struct TCP_Server_Info *server)
 #ifdef CONFIG_PROC_FS
 static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
 {
-        struct list_head *tmp, *tmp2, *tmp3;
+        struct list_head *tmp1, *tmp2, *tmp3;
         struct mid_q_entry *mid_entry;
         struct TCP_Server_Info *server;
         struct cifsSesInfo *ses;
         struct cifsTconInfo *tcon;
-        int i;
+        int i, j;
+        __u32 dev_type;
 
         seq_puts(m,
                     "Display Internal CIFS Data Structures for Debugging\n"
@@ -123,8 +124,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
 
         i = 0;
         read_lock(&cifs_tcp_ses_lock);
-        list_for_each(tmp, &cifs_tcp_ses_list) {
-                server = list_entry(tmp, struct TCP_Server_Info,
+        list_for_each(tmp1, &cifs_tcp_ses_list) {
+                server = list_entry(tmp1, struct TCP_Server_Info,
                                     tcp_ses_list);
                 i++;
                 list_for_each(tmp2, &server->smb_ses_list) {
@@ -133,12 +134,12 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
                         if ((ses->serverDomain == NULL) ||
                                 (ses->serverOS == NULL) ||
                                 (ses->serverNOS == NULL)) {
-                                seq_printf(m, "\nentry for %s not fully "
-                                           "displayed\n\t", ses->serverName);
+                                seq_printf(m, "\n%d) entry for %s not fully "
+                                           "displayed\n\t", i, ses->serverName);
                         } else {
                                 seq_printf(m,
-                                    "\n%d) Name: %s  Domain: %s Mounts: %d OS:"
-                                    " %s  \n\tNOS: %s\tCapability: 0x%x\n\tSMB"
+                                    "\n%d) Name: %s  Domain: %s Uses: %d OS:"
+                                    " %s\n\tNOS: %s\tCapability: 0x%x\n\tSMB"
                                     " session status: %d\t",
                                 i, ses->serverName, ses->serverDomain,
                                 ses->ses_count, ses->serverOS, ses->serverNOS,
@@ -156,14 +157,44 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
                                 atomic_read(&server->num_waiters));
 #endif
 
-                        seq_puts(m, "\nMIDs:\n");
+                        seq_puts(m, "\n\tShares:");
+                        j = 0;
+                        list_for_each(tmp3, &ses->tcon_list) {
+                                tcon = list_entry(tmp3, struct cifsTconInfo,
+                                                  tcon_list);
+                                ++j;
+                                dev_type = le32_to_cpu(tcon->fsDevInfo.DeviceType);
+                                seq_printf(m, "\n\t%d) %s Mounts: %d ", j,
+                                           tcon->treeName, tcon->tc_count);
+                                if (tcon->nativeFileSystem) {
+                                        seq_printf(m, "Type: %s ",
+                                                   tcon->nativeFileSystem);
+                                }
+                                seq_printf(m, "DevInfo: 0x%x Attributes: 0x%x"
+                                        "\nPathComponentMax: %d Status: 0x%d",
+                                        le32_to_cpu(tcon->fsDevInfo.DeviceCharacteristics),
+                                        le32_to_cpu(tcon->fsAttrInfo.Attributes),
+                                        le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength),
+                                        tcon->tidStatus);
+                                if (dev_type == FILE_DEVICE_DISK)
+                                        seq_puts(m, " type: DISK ");
+                                else if (dev_type == FILE_DEVICE_CD_ROM)
+                                        seq_puts(m, " type: CDROM ");
+                                else
+                                        seq_printf(m, " type: %d ", dev_type);
+
+                                if (tcon->need_reconnect)
+                                        seq_puts(m, "\tDISCONNECTED ");
+                                seq_putc(m, '\n');
+                        }
+
+                        seq_puts(m, "\n\tMIDs:\n");
 
                         spin_lock(&GlobalMid_Lock);
                         list_for_each(tmp3, &server->pending_mid_q) {
-                                mid_entry = list_entry(tmp3, struct
-                                        mid_q_entry,
+                                mid_entry = list_entry(tmp3, struct mid_q_entry,
                                         qhead);
-                                seq_printf(m, "State: %d com: %d pid:"
+                                seq_printf(m, "\tState: %d com: %d pid:"
                                                 " %d tsk: %p mid %d\n",
                                                 mid_entry->midState,
                                                 (int)mid_entry->command,
@@ -177,41 +208,6 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
         read_unlock(&cifs_tcp_ses_lock);
         seq_putc(m, '\n');
 
-        seq_puts(m, "Shares:");
-
-        i = 0;
-        read_lock(&GlobalSMBSeslock);
-        list_for_each(tmp, &GlobalTreeConnectionList) {
-                __u32 dev_type;
-                i++;
-                tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
-                dev_type = le32_to_cpu(tcon->fsDevInfo.DeviceType);
-                seq_printf(m, "\n%d) %s Uses: %d ", i,
-                                 tcon->treeName, atomic_read(&tcon->useCount));
-                if (tcon->nativeFileSystem) {
-                        seq_printf(m, "Type: %s ",
-                                         tcon->nativeFileSystem);
-                }
-                seq_printf(m, "DevInfo: 0x%x Attributes: 0x%x"
-                                 "\nPathComponentMax: %d Status: %d",
-                            le32_to_cpu(tcon->fsDevInfo.DeviceCharacteristics),
-                            le32_to_cpu(tcon->fsAttrInfo.Attributes),
-                            le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength),
-                            tcon->tidStatus);
-                if (dev_type == FILE_DEVICE_DISK)
-                        seq_puts(m, " type: DISK ");
-                else if (dev_type == FILE_DEVICE_CD_ROM)
-                        seq_puts(m, " type: CDROM ");
-                else
-                        seq_printf(m, " type: %d ", dev_type);
-
-                if (tcon->need_reconnect)
-                        seq_puts(m, "\tDISCONNECTED ");
-        }
-        read_unlock(&GlobalSMBSeslock);
-
-        seq_putc(m, '\n');
-
         /* BB add code to dump additional info such as TCP session info now */
         return 0;
 }
@@ -235,7 +231,9 @@ static ssize_t cifs_stats_proc_write(struct file *file,
 {
         char c;
         int rc;
-        struct list_head *tmp;
+        struct list_head *tmp1, *tmp2, *tmp3;
+        struct TCP_Server_Info *server;
+        struct cifsSesInfo *ses;
         struct cifsTconInfo *tcon;
 
         rc = get_user(c, buffer);
@@ -243,33 +241,42 @@ static ssize_t cifs_stats_proc_write(struct file *file,
                 return rc;
 
         if (c == '1' || c == 'y' || c == 'Y' || c == '0') {
-                read_lock(&GlobalSMBSeslock);
 #ifdef CONFIG_CIFS_STATS2
                 atomic_set(&totBufAllocCount, 0);
                 atomic_set(&totSmBufAllocCount, 0);
 #endif /* CONFIG_CIFS_STATS2 */
-                list_for_each(tmp, &GlobalTreeConnectionList) {
-                        tcon = list_entry(tmp, struct cifsTconInfo,
-                                        cifsConnectionList);
-                        atomic_set(&tcon->num_smbs_sent, 0);
-                        atomic_set(&tcon->num_writes, 0);
-                        atomic_set(&tcon->num_reads, 0);
-                        atomic_set(&tcon->num_oplock_brks, 0);
-                        atomic_set(&tcon->num_opens, 0);
-                        atomic_set(&tcon->num_closes, 0);
-                        atomic_set(&tcon->num_deletes, 0);
-                        atomic_set(&tcon->num_mkdirs, 0);
-                        atomic_set(&tcon->num_rmdirs, 0);
-                        atomic_set(&tcon->num_renames, 0);
-                        atomic_set(&tcon->num_t2renames, 0);
-                        atomic_set(&tcon->num_ffirst, 0);
-                        atomic_set(&tcon->num_fnext, 0);
-                        atomic_set(&tcon->num_fclose, 0);
-                        atomic_set(&tcon->num_hardlinks, 0);
-                        atomic_set(&tcon->num_symlinks, 0);
-                        atomic_set(&tcon->num_locks, 0);
+                read_lock(&cifs_tcp_ses_lock);
+                list_for_each(tmp1, &cifs_tcp_ses_list) {
+                        server = list_entry(tmp1, struct TCP_Server_Info,
+                                            tcp_ses_list);
+                        list_for_each(tmp2, &server->smb_session_list) {
+                                ses = list_entry(tmp2, struct cifsSesInfo,
+                                                 smb_session_list);
+                                list_for_each(tmp3, &ses->tcon_list) {
+                                        tcon = list_entry(tmp3,
+                                                          struct cifsTconInfo,
+                                                          tcon_list);
+                                        atomic_set(&tcon->num_smbs_sent, 0);
+                                        atomic_set(&tcon->num_writes, 0);
+                                        atomic_set(&tcon->num_reads, 0);
+                                        atomic_set(&tcon->num_oplock_brks, 0);
+                                        atomic_set(&tcon->num_opens, 0);
+                                        atomic_set(&tcon->num_closes, 0);
+                                        atomic_set(&tcon->num_deletes, 0);
+                                        atomic_set(&tcon->num_mkdirs, 0);
+                                        atomic_set(&tcon->num_rmdirs, 0);
+                                        atomic_set(&tcon->num_renames, 0);
+                                        atomic_set(&tcon->num_t2renames, 0);
+                                        atomic_set(&tcon->num_ffirst, 0);
+                                        atomic_set(&tcon->num_fnext, 0);
+                                        atomic_set(&tcon->num_fclose, 0);
+                                        atomic_set(&tcon->num_hardlinks, 0);
+                                        atomic_set(&tcon->num_symlinks, 0);
+                                        atomic_set(&tcon->num_locks, 0);
+                                }
+                        }
                 }
-                read_unlock(&GlobalSMBSeslock);
+                read_unlock(&cifs_tcp_ses_lock);
         }
 
         return count;
@@ -278,7 +285,9 @@ static ssize_t cifs_stats_proc_write(struct file *file,
 static int cifs_stats_proc_show(struct seq_file *m, void *v)
 {
         int i;
-        struct list_head *tmp;
+        struct list_head *tmp1, *tmp2, *tmp3;
+        struct TCP_Server_Info *server;
+        struct cifsSesInfo *ses;
         struct cifsTconInfo *tcon;
 
         seq_printf(m,
@@ -307,44 +316,55 @@ static int cifs_stats_proc_show(struct seq_file *m, void *v)
                 GlobalCurrentXid, GlobalMaxActiveXid);
 
         i = 0;
-        read_lock(&GlobalSMBSeslock);
-        list_for_each(tmp, &GlobalTreeConnectionList) {
-                i++;
-                tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
-                seq_printf(m, "\n%d) %s", i, tcon->treeName);
-                if (tcon->need_reconnect)
-                        seq_puts(m, "\tDISCONNECTED ");
-                seq_printf(m, "\nSMBs: %d Oplock Breaks: %d",
-                        atomic_read(&tcon->num_smbs_sent),
-                        atomic_read(&tcon->num_oplock_brks));
-                seq_printf(m, "\nReads:  %d Bytes: %lld",
-                        atomic_read(&tcon->num_reads),
-                        (long long)(tcon->bytes_read));
-                seq_printf(m, "\nWrites: %d Bytes: %lld",
-                        atomic_read(&tcon->num_writes),
-                        (long long)(tcon->bytes_written));
-                seq_printf(m,
-                        "\nLocks: %d HardLinks: %d Symlinks: %d",
-                        atomic_read(&tcon->num_locks),
-                        atomic_read(&tcon->num_hardlinks),
-                        atomic_read(&tcon->num_symlinks));
-
-                seq_printf(m, "\nOpens: %d Closes: %d Deletes: %d",
-                        atomic_read(&tcon->num_opens),
-                        atomic_read(&tcon->num_closes),
-                        atomic_read(&tcon->num_deletes));
-                seq_printf(m, "\nMkdirs: %d Rmdirs: %d",
-                        atomic_read(&tcon->num_mkdirs),
-                        atomic_read(&tcon->num_rmdirs));
-                seq_printf(m, "\nRenames: %d T2 Renames %d",
-                        atomic_read(&tcon->num_renames),
-                        atomic_read(&tcon->num_t2renames));
-                seq_printf(m, "\nFindFirst: %d FNext %d FClose %d",
-                        atomic_read(&tcon->num_ffirst),
-                        atomic_read(&tcon->num_fnext),
-                        atomic_read(&tcon->num_fclose));
+        read_lock(&cifs_tcp_ses_lock);
+        list_for_each(tmp1, &cifs_tcp_ses_list) {
+                server = list_entry(tmp1, struct TCP_Server_Info,
+                                    tcp_ses_list);
+                list_for_each(tmp2, &server->smb_ses_list) {
+                        ses = list_entry(tmp2, struct cifsSesInfo,
+                                         smb_ses_list);
+                        list_for_each(tmp3, &ses->tcon_list) {
+                                tcon = list_entry(tmp3,
+                                                  struct cifsTconInfo,
+                                                  tcon_list);
+                                i++;
+                                seq_printf(m, "\n%d) %s", i, tcon->treeName);
+                                if (tcon->need_reconnect)
+                                        seq_puts(m, "\tDISCONNECTED ");
+                                seq_printf(m, "\nSMBs: %d Oplock Breaks: %d",
+                                        atomic_read(&tcon->num_smbs_sent),
+                                        atomic_read(&tcon->num_oplock_brks));
+                                seq_printf(m, "\nReads:  %d Bytes: %lld",
+                                        atomic_read(&tcon->num_reads),
+                                        (long long)(tcon->bytes_read));
+                                seq_printf(m, "\nWrites: %d Bytes: %lld",
+                                        atomic_read(&tcon->num_writes),
+                                        (long long)(tcon->bytes_written));
+                                seq_printf(m, "\nLocks: %d HardLinks: %d "
+                                              "Symlinks: %d",
+                                        atomic_read(&tcon->num_locks),
+                                        atomic_read(&tcon->num_hardlinks),
+                                        atomic_read(&tcon->num_symlinks));
+                                seq_printf(m, "\nOpens: %d Closes: %d"
+                                              "Deletes: %d",
+                                        atomic_read(&tcon->num_opens),
+                                        atomic_read(&tcon->num_closes),
+                                        atomic_read(&tcon->num_deletes));
+                                seq_printf(m, "\nMkdirs: %d Rmdirs: %d",
+                                        atomic_read(&tcon->num_mkdirs),
+                                        atomic_read(&tcon->num_rmdirs));
+                                seq_printf(m, "\nRenames: %d T2 Renames %d",
+                                        atomic_read(&tcon->num_renames),
+                                        atomic_read(&tcon->num_t2renames));
+                                seq_printf(m, "\nFindFirst: %d FNext %d "
+                                              "FClose %d",
+                                        atomic_read(&tcon->num_ffirst),
+                                        atomic_read(&tcon->num_fnext),
+                                        atomic_read(&tcon->num_fclose));
+                        }
+                }
         }
-        read_unlock(&GlobalSMBSeslock);
+        read_unlock(&cifs_tcp_ses_lock);
 
         seq_putc(m, '\n');
         return 0;