svn commit: r289154 - head/sys/dev/ntb/if_ntb

[Conrad E. Meyer]

Author: cem
Date: Sun Oct 11 20:59:02 2015
New Revision: 289154
URL: https://svnweb.freebsd.org/changeset/base/289154

Log:
  NTB: MFV b77b2637: Link toggle memory leak
  
  Each link-up will allocate a new NTB receive buffer when the NTB
  properties are negotiated with the remote system.  These allocations did
  not check for existing buffers and thus did not free them.  Now, the
  driver will check for an existing buffer and free it if not of the
  correct size, before trying to alloc a new one.
  
  Authored by:	Jon Mason
  Obtained from:	Linux
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/sys/dev/ntb/if_ntb/if_ntb.c

Modified: head/sys/dev/ntb/if_ntb/if_ntb.c
==============================================================================
--- head/sys/dev/ntb/if_ntb/if_ntb.c	Sun Oct 11 20:58:00 2015	(r289153)
+++ head/sys/dev/ntb/if_ntb/if_ntb.c	Sun Oct 11 20:59:02 2015	(r289154)
@@ -1129,12 +1129,20 @@ ntb_set_mw(struct ntb_netdev *nt, int nu
 {
 	struct ntb_transport_mw *mw = &nt->mw[num_mw];
 
+	/* No need to re-setup */
+	if (mw->size == size)
+		return (0);
+
+	if (mw->size != 0)
+		ntb_free_mw(nt, num_mw);
+
 	/* Alloc memory for receiving data.  Must be 4k aligned */
 	mw->size = size;
 
 	mw->virt_addr = contigmalloc(mw->size, M_NTB_IF, M_ZERO, 0,
 	    BUS_SPACE_MAXADDR, mw->size, 0);
 	if (mw->virt_addr == NULL) {
+		mw->size = 0;
 		printf("ntb: Unable to allocate MW buffer of size %d\n",
 		    (int)mw->size);
 		return (ENOMEM);