[linux-cifs-client] [PATCH] cifs: consolidate reconnect logic in smb_init routines

Jeff Layton jlayton at redhat.com
Sat Aug 15 10:06:27 MDT 2009


There's a large cut and paste chunk of code in smb_init and
small_smb_init to handle reconnects. Break it out into a separate
function, clean it up and have both routines call it.

Signed-off-by: Jeff Layton <jlayton at redhat.com>
---
 fs/cifs/cifssmb.c |  314 +++++++++++++++++++++--------------------------------
 1 files changed, 124 insertions(+), 190 deletions(-)

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 1866bc2..4bdca05 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -100,110 +100,138 @@ static void mark_open_files_invalid(struct cifsTconInfo *pTcon)
 	   to this tcon */
 }
 
-/* Allocate and return pointer to an SMB request buffer, and set basic
-   SMB information in the SMB header.  If the return code is zero, this
-   function must have filled in request_buf pointer */
+/* reconnect the socket, tcon, and smb session if needed */
 static int
-small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
-		void **request_buf)
+cifs_reconnect_tcon(struct cifsTconInfo *tcon, int smb_command)
 {
 	int rc = 0;
+	struct cifsSesInfo *ses;
+	struct TCP_Server_Info *server;
+	struct nls_table *nls_codepage;
 
-	/* SMBs NegProt, SessSetup, uLogoff do not have tcon yet so
-	   check for tcp and smb session status done differently
-	   for those three - in the calling routine */
-	if (tcon) {
-		if (tcon->tidStatus == CifsExiting) {
-			/* only tree disconnect, open, and write,
-			(and ulogoff which does not have tcon)
-			are allowed as we start force umount */
-			if ((smb_command != SMB_COM_WRITE_ANDX) &&
-			   (smb_command != SMB_COM_OPEN_ANDX) &&
-			   (smb_command != SMB_COM_TREE_DISCONNECT)) {
-				cFYI(1, ("can not send cmd %d while umounting",
-					smb_command));
-				return -ENODEV;
-			}
+	/*
+	 * SMBs NegProt, SessSetup, uLogoff do not have tcon yet so check for
+	 * tcp and smb session status done differently for those three - in the
+	 * calling routine
+	 */
+	if (!tcon)
+		return 0;
+
+	ses = tcon->ses;
+	server = ses->server;
+
+	/*
+	 * only tree disconnect, open, and write, (and ulogoff which does not
+	 * have tcon) are allowed as we start force umount
+	 */
+	if (tcon->tidStatus == CifsExiting) {
+		if (smb_command != SMB_COM_WRITE_ANDX &&
+		    smb_command != SMB_COM_OPEN_ANDX &&
+		    smb_command != SMB_COM_TREE_DISCONNECT) {
+			cFYI(1, ("can not send cmd %d while umounting",
+				smb_command));
+			return -ENODEV;
 		}
-		if ((tcon->ses) && (tcon->ses->status != CifsExiting) &&
-				  (tcon->ses->server)) {
-			struct nls_table *nls_codepage;
-				/* Give Demultiplex thread up to 10 seconds to
-				   reconnect, should be greater than cifs socket
-				   timeout which is 7 seconds */
-			while (tcon->ses->server->tcpStatus ==
-							 CifsNeedReconnect) {
-				wait_event_interruptible_timeout(tcon->ses->server->response_q,
-					(tcon->ses->server->tcpStatus ==
-							CifsGood), 10 * HZ);
-				if (tcon->ses->server->tcpStatus ==
-							CifsNeedReconnect) {
-					/* on "soft" mounts we wait once */
-					if (!tcon->retry ||
-					   (tcon->ses->status == CifsExiting)) {
-						cFYI(1, ("gave up waiting on "
-						      "reconnect in smb_init"));
-						return -EHOSTDOWN;
-					} /* else "hard" mount - keep retrying
-					     until process is killed or server
-					     comes back on-line */
-				} else /* TCP session is reestablished now */
-					break;
-			}
+	}
 
-			nls_codepage = load_nls_default();
-		/* need to prevent multiple threads trying to
-		simultaneously reconnect the same SMB session */
-			down(&tcon->ses->sesSem);
-			if (tcon->ses->need_reconnect)
-				rc = cifs_setup_session(0, tcon->ses,
-							nls_codepage);
-			if (!rc && (tcon->need_reconnect)) {
-				mark_open_files_invalid(tcon);
-				rc = CIFSTCon(0, tcon->ses, tcon->treeName,
-					      tcon, nls_codepage);
-				up(&tcon->ses->sesSem);
-				/* BB FIXME add code to check if wsize needs
-				   update due to negotiated smb buffer size
-				   shrinking */
-				if (rc == 0) {
-					atomic_inc(&tconInfoReconnectCount);
-					/* tell server Unix caps we support */
-					if (tcon->ses->capabilities & CAP_UNIX)
-						reset_cifs_unix_caps(
-						0 /* no xid */,
-						tcon,
-						NULL /* we do not know sb */,
-						NULL /* no vol info */);
-				}
+	if (ses->status == CifsExiting)
+		return -EIO;
 
-				cFYI(1, ("reconnect tcon rc = %d", rc));
-				/* Removed call to reopen open files here.
-				   It is safer (and faster) to reopen files
-				   one at a time as needed in read and write */
-
-				/* Check if handle based operation so we
-				   know whether we can continue or not without
-				   returning to caller to reset file handle */
-				switch (smb_command) {
-					case SMB_COM_READ_ANDX:
-					case SMB_COM_WRITE_ANDX:
-					case SMB_COM_CLOSE:
-					case SMB_COM_FIND_CLOSE2:
-					case SMB_COM_LOCKING_ANDX: {
-						unload_nls(nls_codepage);
-						return -EAGAIN;
-					}
-				}
-			} else {
-				up(&tcon->ses->sesSem);
-			}
-			unload_nls(nls_codepage);
+	/*
+	 * Give demultiplex thread up to 10 seconds to reconnect, should be
+	 * greater than cifs socket timeout which is 7 seconds
+	 */
+	while (server->tcpStatus == CifsNeedReconnect) {
+		wait_event_interruptible_timeout(server->response_q,
+			(server->tcpStatus == CifsGood), 10 * HZ);
 
-		} else {
-			return -EIO;
+		/* is TCP session is reestablished now ?*/
+		if (server->tcpStatus != CifsNeedReconnect)
+			break;
+
+		/*
+		 * on "soft" mounts we wait once. Hard mounts keep
+		 * retrying until process is killed or server comes
+		 * back on-line
+		 */
+		if (!tcon->retry || ses->status == CifsExiting) {
+			cFYI(1, ("gave up waiting on reconnect in smb_init"));
+			return -EHOSTDOWN;
 		}
 	}
+
+	if (!ses->need_reconnect && !tcon->need_reconnect)
+		return 0;
+
+	nls_codepage = load_nls_default();
+
+	/*
+	 * need to prevent multiple threads trying to simultaneously
+	 * reconnect the same SMB session
+	 */
+	down(&ses->sesSem);
+	if (ses->need_reconnect)
+		rc = cifs_setup_session(0, ses, nls_codepage);
+
+	/* do we need to reconnect tcon? */
+	if (rc || !tcon->need_reconnect) {
+		up(&ses->sesSem);
+		goto out;
+	}
+
+	mark_open_files_invalid(tcon);
+	rc = CIFSTCon(0, ses, tcon->treeName, tcon, nls_codepage);
+	up(&ses->sesSem);
+	cFYI(1, ("reconnect tcon rc = %d", rc));
+
+	if (rc)
+		goto out;
+
+	/*
+	 * FIXME: check if wsize needs updated due to negotiated smb buffer
+	 * 	  size shrinking
+	 */
+	atomic_inc(&tconInfoReconnectCount);
+
+	/* tell server Unix caps we support */
+	if (ses->capabilities & CAP_UNIX)
+		reset_cifs_unix_caps(0, tcon, NULL, NULL);
+
+	/*
+	 * Removed call to reopen open files here. It is safer (and faster) to
+	 * reopen files one at a time as needed in read and write.
+	 *
+	 * FIXME: what about file locks? don't we need to reclaim them ASAP?
+	 */
+
+	/*
+	 * Check if handle based operation so we know whether we can continue
+	 * or not without returning to caller to reset file handle
+	 */
+	switch (smb_command) {
+		case SMB_COM_READ_ANDX:
+		case SMB_COM_WRITE_ANDX:
+		case SMB_COM_CLOSE:
+		case SMB_COM_FIND_CLOSE2:
+		case SMB_COM_LOCKING_ANDX:
+			rc = -EAGAIN;
+	}
+
+out:
+	unload_nls(nls_codepage);
+	return rc;
+}
+
+/* Allocate and return pointer to an SMB request buffer, and set basic
+   SMB information in the SMB header.  If the return code is zero, this
+   function must have filled in request_buf pointer */
+static int
+small_smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
+		void **request_buf)
+{
+	int rc = 0;
+
+	rc = cifs_reconnect_tcon(tcon, smb_command);
 	if (rc)
 		return rc;
 
@@ -256,101 +284,7 @@ smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
 {
 	int rc = 0;
 
-	/* SMBs NegProt, SessSetup, uLogoff do not have tcon yet so
-	   check for tcp and smb session status done differently
-	   for those three - in the calling routine */
-	if (tcon) {
-		if (tcon->tidStatus == CifsExiting) {
-			/* only tree disconnect, open, and write,
-			  (and ulogoff which does not have tcon)
-			  are allowed as we start force umount */
-			if ((smb_command != SMB_COM_WRITE_ANDX) &&
-			   (smb_command != SMB_COM_OPEN_ANDX) &&
-			   (smb_command != SMB_COM_TREE_DISCONNECT)) {
-				cFYI(1, ("can not send cmd %d while umounting",
-					smb_command));
-				return -ENODEV;
-			}
-		}
-
-		if ((tcon->ses) && (tcon->ses->status != CifsExiting) &&
-				  (tcon->ses->server)) {
-			struct nls_table *nls_codepage;
-				/* Give Demultiplex thread up to 10 seconds to
-				   reconnect, should be greater than cifs socket
-				   timeout which is 7 seconds */
-			while (tcon->ses->server->tcpStatus ==
-							CifsNeedReconnect) {
-				wait_event_interruptible_timeout(tcon->ses->server->response_q,
-					(tcon->ses->server->tcpStatus ==
-							CifsGood), 10 * HZ);
-				if (tcon->ses->server->tcpStatus ==
-						CifsNeedReconnect) {
-					/* on "soft" mounts we wait once */
-					if (!tcon->retry ||
-					   (tcon->ses->status == CifsExiting)) {
-						cFYI(1, ("gave up waiting on "
-						      "reconnect in smb_init"));
-						return -EHOSTDOWN;
-					} /* else "hard" mount - keep retrying
-					     until process is killed or server
-					     comes on-line */
-				} else /* TCP session is reestablished now */
-					break;
-			}
-			nls_codepage = load_nls_default();
-		/* need to prevent multiple threads trying to
-		simultaneously reconnect the same SMB session */
-			down(&tcon->ses->sesSem);
-			if (tcon->ses->need_reconnect)
-				rc = cifs_setup_session(0, tcon->ses,
-							nls_codepage);
-			if (!rc && (tcon->need_reconnect)) {
-				mark_open_files_invalid(tcon);
-				rc = CIFSTCon(0, tcon->ses, tcon->treeName,
-					      tcon, nls_codepage);
-				up(&tcon->ses->sesSem);
-				/* BB FIXME add code to check if wsize needs
-				update due to negotiated smb buffer size
-				shrinking */
-				if (rc == 0) {
-					atomic_inc(&tconInfoReconnectCount);
-					/* tell server Unix caps we support */
-					if (tcon->ses->capabilities & CAP_UNIX)
-						reset_cifs_unix_caps(
-						0 /* no xid */,
-						tcon,
-						NULL /* do not know sb */,
-						NULL /* no vol info */);
-				}
-
-				cFYI(1, ("reconnect tcon rc = %d", rc));
-				/* Removed call to reopen open files here.
-				   It is safer (and faster) to reopen files
-				   one at a time as needed in read and write */
-
-				/* Check if handle based operation so we
-				   know whether we can continue or not without
-				   returning to caller to reset file handle */
-				switch (smb_command) {
-					case SMB_COM_READ_ANDX:
-					case SMB_COM_WRITE_ANDX:
-					case SMB_COM_CLOSE:
-					case SMB_COM_FIND_CLOSE2:
-					case SMB_COM_LOCKING_ANDX: {
-						unload_nls(nls_codepage);
-						return -EAGAIN;
-					}
-				}
-			} else {
-				up(&tcon->ses->sesSem);
-			}
-			unload_nls(nls_codepage);
-
-		} else {
-			return -EIO;
-		}
-	}
+	rc = cifs_reconnect_tcon(tcon, smb_command);
 	if (rc)
 		return rc;
 
-- 
1.6.2.5



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