[PATCH] cifs: handle termination of cifs oplockd kernel thread

Signed-off-by: Steve French (sfrench@us.ibm.com)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 23 insertions, 15 deletions

diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 21a246473a91..bd3b55e1be17 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -1,6 +1,7 @@
 Version 1.34
 ------------
 Fix error mapping of the TOO_MANY_LINKS (hardlinks) case.
+Do not oops if user kills cifs oplock kernel thread.
 
 Version 1.33
 ------------
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 6322aada491f..8cc23e7d0d5d 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -835,6 +835,7 @@ static int cifs_oplock_thread(void * dummyarg)
                 }
         } while(!signal_pending(current));
         complete_and_exit (&cifs_oplock_exited, 0);
+        oplockThread = NULL;
 }
 
 static int __init
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e3b177a90b37..437be1efe99e 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -384,7 +384,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                 if(server->tcpStatus == CifsExiting) {
                         break;
                 } else if (server->tcpStatus == CifsNeedReconnect) {
-                        cFYI(1,("Reconnecting after server stopped responding"));
+                        cFYI(1,("Reconnect after server stopped responding"));
                         cifs_reconnect(server);
                         cFYI(1,("call to reconnect done"));
                         csocket = server->ssocket;
@@ -396,7 +396,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                         continue;
                 } else if (length <= 0) {
                         if(server->tcpStatus == CifsNew) {
-                                cFYI(1,("tcp session abended prematurely (after SMBnegprot)"));
+                                cFYI(1,("tcp session abend after SMBnegprot"));
                                 /* some servers kill the TCP session rather than
                                    returning an SMB negprot error, in which
                                    case reconnecting here is not going to help,
@@ -407,14 +407,15 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
                                 cFYI(1,("cifsd thread killed"));
                                 break;
                         }
-                        cFYI(1,("Reconnecting after unexpected peek error %d",length));
+                        cFYI(1,("Reconnect after unexpected peek error %d",
+                                length));
                         cifs_reconnect(server);
                         csocket = server->ssocket;
                         wake_up(&server->response_q);
                         continue;
                 } else if (length < 4) {
                         cFYI(1,
-                            ("Frame less than four bytes received  %d bytes long.",
+                            ("Frame under four bytes received (%d bytes long)",
                               length));
                         cifs_reconnect(server);
                         csocket = server->ssocket;
@@ -593,7 +594,7 @@ multi_t2_fnd:
                                         smallbuf = NULL;
                         }
                         wake_up_process(task_to_wake);
-                } else if ((is_valid_oplock_break(smb_buffer) == FALSE) 
+                } else if ((is_valid_oplock_break(smb_buffer) == FALSE)
                     && (isMultiRsp == FALSE)) {                          
                         cERROR(1, ("No task to wake, unknown frame rcvd!"));
                         cifs_dump_mem("Received Data is: ",temp,sizeof(struct smb_hdr));
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 75fd3bd6e233..db14b503d89e 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -452,25 +452,30 @@ is_valid_oplock_break(struct smb_hdr *buf)
                         atomic_inc(&tcon->num_oplock_brks);
 #endif
                         list_for_each(tmp1,&tcon->openFileList){
-                                netfile = list_entry(tmp1,struct cifsFileInfo,tlist);
+                                netfile = list_entry(tmp1,struct cifsFileInfo,
+                                                     tlist);
                                 if(pSMB->Fid == netfile->netfid) {
                                         struct cifsInodeInfo *pCifsInode;
                                         read_unlock(&GlobalSMBSeslock);
-                                        cFYI(1,("Matching file id, processing oplock break"));
+                                        cFYI(1,("file id match, oplock break"));
                                         pCifsInode = 
                                                 CIFS_I(netfile->pInode);
                                         pCifsInode->clientCanCacheAll = FALSE;
                                         if(pSMB->OplockLevel == 0)
-                                                pCifsInode->clientCanCacheRead = FALSE;
+                                                pCifsInode->clientCanCacheRead
+                                                        = FALSE;
                                         pCifsInode->oplockPending = TRUE;
-                                        AllocOplockQEntry(netfile->pInode, netfile->netfid, tcon);
+                                        AllocOplockQEntry(netfile->pInode,
+                                                          netfile->netfid,
+                                                          tcon);
                                         cFYI(1,("about to wake up oplock thd"));
-                                        wake_up_process(oplockThread);               
+                                        if(oplockThread)
+                                            wake_up_process(oplockThread);
                                         return TRUE;
                                 }
                         }
                         read_unlock(&GlobalSMBSeslock);
-                        cFYI(1,("No matching file for oplock break on connection"));
+                        cFYI(1,("No matching file for oplock break"));
                         return TRUE;
                 }
         }
@@ -491,7 +496,7 @@ dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
 
         buffer = (unsigned char *) smb_buf;
         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
-                if (i % 8 == 0) {       /* we have reached the beginning of line  */
+                if (i % 8 == 0) {       /* have reached the beginning of line */
                         printk(KERN_DEBUG "| ");
                         j = 0;
                 }
@@ -502,7 +507,7 @@ dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
                 else
                         debug_line[1 + (2 * j)] = '_';
 
-                if (i % 8 == 7) {       /* we have reached end of line, time to print ascii */
+                if (i % 8 == 7) { /* reached end of line, time to print ascii */
                         debug_line[16] = 0;
                         printk(" | %s\n", debug_line);
                 }
@@ -577,7 +582,7 @@ cifs_convertUCSpath(char *target, const __le16 * source, int maxlen,
                                 }
                 }
                 j++;
-                /* check to make sure we do not overrun callers allocated temp buffer */
+                /* make sure we do not overrun callers allocated temp buffer */
                 if(j >= (2 * NAME_MAX))
                         break;
         }
@@ -599,7 +604,7 @@ cifsConvertToUCS(__le16 * target, const char *source, int maxlen,
         char src_char;
 
         if(!mapChars) 
-                return cifs_strtoUCS((wchar_t *) target, source, PATH_MAX, cp); 
+                return cifs_strtoUCS((wchar_t *) target, source, PATH_MAX, cp);
 
         for(i = 0, j = 0; i < maxlen; j++) {
                 src_char = source[i];