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

diff --git a/sys/dev/ntb/if_ntb/if_ntb.c b/sys/dev/ntb/if_ntb/if_ntb.c
index 101691d0bf0f8ad57aae3f0056be2366d429fd16..09c1736c3fc75aee5dfc2d978381c010ab100243 100644 (file)
--- a/sys/dev/ntb/if_ntb/if_ntb.c
+++ b/sys/dev/ntb/if_ntb/if_ntb.c
@@ -1129,12 +1129,20 @@ ntb_set_mw(struct ntb_netdev *nt, int num_mw, unsigned int size)
 {
        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);