Author: glebius
Date: Tue May 17 23:15:16 2016
New Revision: 300097
URL: https://svnweb.freebsd.org/changeset/base/300097
Log:
Add a comment and KASSERT that a M_NOFREE mbuf has always EXT_EXTREF ext.
Submitted by: kmacy
Modified:
head/sys/kern/kern_mbuf.c
Modified: head/sys/kern/kern_mbuf.c
==============================================================================
--- head/sys/kern/kern_mbuf.c Tue May 17 23:14:17 2016 (r300096)
+++ head/sys/kern/kern_mbuf.c Tue May 17 23:15:16 2016 (r300097)
@@ -638,9 +638,16 @@ mb_free_ext(struct mbuf *m)
* Check if the header is embedded in the cluster. It is
* important that we can't touch any of the mbuf fields
* after we have freed the external storage, since mbuf
- * could have been embedded in it.
+ * could have been embedded in it. For now, the mbufs
+ * embedded into the cluster are always of type EXT_EXTREF,
+ * and for this type we won't free the mref.
*/
- freembuf = (m->m_flags & M_NOFREE) ? 0 : 1;
+ if (m->m_flags & M_NOFREE) {
+ freembuf = 0;
+ KASSERT(m->m_ext.ext_type == EXT_EXTREF,
+ ("%s: no-free mbuf %p has wrong type", __func__, m));
+ } else
+ freembuf = 1;
/* Free attached storage if this mbuf is the only reference to it. */
if (*refcnt == 1 || atomic_fetchadd_int(refcnt, -1) == 1) {
_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "[email protected]"
