Remove unused CIFSSMBNotify worker function

The CIFSSMBNotify worker is unused, pending changes to allow it to be called
via inotify, so move it into its own experimental config option so it does
not get built in, until the necessary VFS support is fixed.  It used to
be used in dnotify, but according to Jeff, inotify needs minor changes
before we can reenable this.

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

fs/cifs/cifsfs.c

@@ -981,10 +981,10 @@ init_cifs(void)
 	int rc = 0;
 	cifs_proc_init();
 	INIT_LIST_HEAD(&cifs_tcp_ses_list);
-#ifdef CONFIG_CIFS_EXPERIMENTAL
+#ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* unused temporarily */
 	INIT_LIST_HEAD(&GlobalDnotifyReqList);
 	INIT_LIST_HEAD(&GlobalDnotifyRsp_Q);
-#endif
+#endif /* was needed for dnotify, and will be needed for inotify when VFS fix */
 /*
  *  Initialize Global counters
  */

fs/cifs/cifsglob.h

@@ -780,10 +780,12 @@ GLOBAL_EXTERN spinlock_t		cifs_tcp_ses_lock;
  */
 GLOBAL_EXTERN spinlock_t	cifs_file_list_lock;
 
+#ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* unused temporarily */
 /* Outstanding dir notify requests */
 GLOBAL_EXTERN struct list_head GlobalDnotifyReqList;
 /* DirNotify response queue */
 GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q;
+#endif /* was needed for dnotify, and will be needed for inotify when VFS fix */
 
 /*
  * Global transaction id (XID) information

fs/cifs/cifsproto.h

@@ -386,6 +386,12 @@ extern int calc_seckey(struct cifsSesInfo *);
 extern void calc_lanman_hash(const char *password, const char *cryptkey,
 				bool encrypt, char *lnm_session_key);
 #endif /* CIFS_WEAK_PW_HASH */
+#ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* unused temporarily */
+extern int CIFSSMBNotify(const int xid, struct cifsTconInfo *tcon,
+			const int notify_subdirs, const __u16 netfid,
+			__u32 filter, struct file *file, int multishot,
+			const struct nls_table *nls_codepage);
+#endif /* was needed for dnotify, and will be needed for inotify when VFS fix */
 extern int CIFSSMBCopy(int xid,
 			struct cifsTconInfo *source_tcon,
 			const char *fromName,
@@ -393,10 +399,6 @@ extern int CIFSSMBCopy(int xid,
 			const char *toName, const int flags,
 			const struct nls_table *nls_codepage,
 			int remap_special_chars);
-extern int CIFSSMBNotify(const int xid, struct cifsTconInfo *tcon,
-			const int notify_subdirs, const __u16 netfid,
-			__u32 filter, struct file *file, int multishot,
-			const struct nls_table *nls_codepage);
 extern ssize_t CIFSSMBQAllEAs(const int xid, struct cifsTconInfo *tcon,
 			const unsigned char *searchName,
 			const unsigned char *ea_name, char *EAData,

fs/cifs/cifssmb.c

@@ -5418,79 +5418,6 @@ setPermsRetry:
 	return rc;
 }
 
-int CIFSSMBNotify(const int xid, struct cifsTconInfo *tcon,
-		  const int notify_subdirs, const __u16 netfid,
-		  __u32 filter, struct file *pfile, int multishot,
-		  const struct nls_table *nls_codepage)
-{
-	int rc = 0;
-	struct smb_com_transaction_change_notify_req *pSMB = NULL;
-	struct smb_com_ntransaction_change_notify_rsp *pSMBr = NULL;
-	struct dir_notify_req *dnotify_req;
-	int bytes_returned;
-
-	cFYI(1, "In CIFSSMBNotify for file handle %d", (int)netfid);
-	rc = smb_init(SMB_COM_NT_TRANSACT, 23, tcon, (void **) &pSMB,
-		      (void **) &pSMBr);
-	if (rc)
-		return rc;
-
-	pSMB->TotalParameterCount = 0 ;
-	pSMB->TotalDataCount = 0;
-	pSMB->MaxParameterCount = cpu_to_le32(2);
-	/* BB find exact data count max from sess structure BB */
-	pSMB->MaxDataCount = 0; /* same in little endian or be */
-/* BB VERIFY verify which is correct for above BB */
-	pSMB->MaxDataCount = cpu_to_le32((tcon->ses->server->maxBuf -
-					     MAX_CIFS_HDR_SIZE) & 0xFFFFFF00);
-
-	pSMB->MaxSetupCount = 4;
-	pSMB->Reserved = 0;
-	pSMB->ParameterOffset = 0;
-	pSMB->DataCount = 0;
-	pSMB->DataOffset = 0;
-	pSMB->SetupCount = 4; /* single byte does not need le conversion */
-	pSMB->SubCommand = cpu_to_le16(NT_TRANSACT_NOTIFY_CHANGE);
-	pSMB->ParameterCount = pSMB->TotalParameterCount;
-	if (notify_subdirs)
-		pSMB->WatchTree = 1; /* one byte - no le conversion needed */
-	pSMB->Reserved2 = 0;
-	pSMB->CompletionFilter = cpu_to_le32(filter);
-	pSMB->Fid = netfid; /* file handle always le */
-	pSMB->ByteCount = 0;
-
-	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-			 (struct smb_hdr *)pSMBr, &bytes_returned,
-			 CIFS_ASYNC_OP);
-	if (rc) {
-		cFYI(1, "Error in Notify = %d", rc);
-	} else {
-		/* Add file to outstanding requests */
-		/* BB change to kmem cache alloc */
-		dnotify_req = kmalloc(
-						sizeof(struct dir_notify_req),
-						 GFP_KERNEL);
-		if (dnotify_req) {
-			dnotify_req->Pid = pSMB->hdr.Pid;
-			dnotify_req->PidHigh = pSMB->hdr.PidHigh;
-			dnotify_req->Mid = pSMB->hdr.Mid;
-			dnotify_req->Tid = pSMB->hdr.Tid;
-			dnotify_req->Uid = pSMB->hdr.Uid;
-			dnotify_req->netfid = netfid;
-			dnotify_req->pfile = pfile;
-			dnotify_req->filter = filter;
-			dnotify_req->multishot = multishot;
-			spin_lock(&GlobalMid_Lock);
-			list_add_tail(&dnotify_req->lhead,
-					&GlobalDnotifyReqList);
-			spin_unlock(&GlobalMid_Lock);
-		} else
-			rc = -ENOMEM;
-	}
-	cifs_buf_release(pSMB);
-	return rc;
-}
-
 #ifdef CONFIG_CIFS_XATTR
 /*
  * Do a path-based QUERY_ALL_EAS call and parse the result. This is a common
@@ -5787,5 +5714,99 @@ SetEARetry:
 
 	return rc;
 }
-
 #endif
+
+#ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* BB unused temporarily */
+/*
+ *	Years ago the kernel added a "dnotify" function for Samba server,
+ *	to allow network clients (such as Windows) to display updated
+ *	lists of files in directory listings automatically when
+ *	files are added by one user when another user has the
+ *	same directory open on their desktop.  The Linux cifs kernel
+ *	client hooked into the kernel side of this interface for
+ *	the same reason, but ironically when the VFS moved from
+ *	"dnotify" to "inotify" it became harder to plug in Linux
+ *	network file system clients (the most obvious use case
+ *	for notify interfaces is when multiple users can update
+ *	the contents of the same directory - exactly what network
+ *	file systems can do) although the server (Samba) could
+ *	still use it.  For the short term we leave the worker
+ *	function ifdeffed out (below) until inotify is fixed
+ *	in the VFS to make it easier to plug in network file
+ *	system clients.  If inotify turns out to be permanently
+ *	incompatible for network fs clients, we could instead simply
+ *	expose this config flag by adding a future cifs (and smb2) notify ioctl.
+ */
+int CIFSSMBNotify(const int xid, struct cifsTconInfo *tcon,
+		  const int notify_subdirs, const __u16 netfid,
+		  __u32 filter, struct file *pfile, int multishot,
+		  const struct nls_table *nls_codepage)
+{
+	int rc = 0;
+	struct smb_com_transaction_change_notify_req *pSMB = NULL;
+	struct smb_com_ntransaction_change_notify_rsp *pSMBr = NULL;
+	struct dir_notify_req *dnotify_req;
+	int bytes_returned;
+
+	cFYI(1, "In CIFSSMBNotify for file handle %d", (int)netfid);
+	rc = smb_init(SMB_COM_NT_TRANSACT, 23, tcon, (void **) &pSMB,
+		      (void **) &pSMBr);
+	if (rc)
+		return rc;
+
+	pSMB->TotalParameterCount = 0 ;
+	pSMB->TotalDataCount = 0;
+	pSMB->MaxParameterCount = cpu_to_le32(2);
+	/* BB find exact data count max from sess structure BB */
+	pSMB->MaxDataCount = 0; /* same in little endian or be */
+/* BB VERIFY verify which is correct for above BB */
+	pSMB->MaxDataCount = cpu_to_le32((tcon->ses->server->maxBuf -
+					     MAX_CIFS_HDR_SIZE) & 0xFFFFFF00);
+
+	pSMB->MaxSetupCount = 4;
+	pSMB->Reserved = 0;
+	pSMB->ParameterOffset = 0;
+	pSMB->DataCount = 0;
+	pSMB->DataOffset = 0;
+	pSMB->SetupCount = 4; /* single byte does not need le conversion */
+	pSMB->SubCommand = cpu_to_le16(NT_TRANSACT_NOTIFY_CHANGE);
+	pSMB->ParameterCount = pSMB->TotalParameterCount;
+	if (notify_subdirs)
+		pSMB->WatchTree = 1; /* one byte - no le conversion needed */
+	pSMB->Reserved2 = 0;
+	pSMB->CompletionFilter = cpu_to_le32(filter);
+	pSMB->Fid = netfid; /* file handle always le */
+	pSMB->ByteCount = 0;
+
+	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
+			 (struct smb_hdr *)pSMBr, &bytes_returned,
+			 CIFS_ASYNC_OP);
+	if (rc) {
+		cFYI(1, "Error in Notify = %d", rc);
+	} else {
+		/* Add file to outstanding requests */
+		/* BB change to kmem cache alloc */
+		dnotify_req = kmalloc(
+						sizeof(struct dir_notify_req),
+						 GFP_KERNEL);
+		if (dnotify_req) {
+			dnotify_req->Pid = pSMB->hdr.Pid;
+			dnotify_req->PidHigh = pSMB->hdr.PidHigh;
+			dnotify_req->Mid = pSMB->hdr.Mid;
+			dnotify_req->Tid = pSMB->hdr.Tid;
+			dnotify_req->Uid = pSMB->hdr.Uid;
+			dnotify_req->netfid = netfid;
+			dnotify_req->pfile = pfile;
+			dnotify_req->filter = filter;
+			dnotify_req->multishot = multishot;
+			spin_lock(&GlobalMid_Lock);
+			list_add_tail(&dnotify_req->lhead,
+					&GlobalDnotifyReqList);
+			spin_unlock(&GlobalMid_Lock);
+		} else
+			rc = -ENOMEM;
+	}
+	cifs_buf_release(pSMB);
+	return rc;
+}
+#endif /* was needed for dnotify, and will be needed for inotify when VFS fix */