Date: Thu, 29 Aug 2013 23:46:39 +0000 (UTC) From: Navdeep Parhar <np@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r255047 - head/sys/sys Message-ID: <201308292346.r7TNkde1085558@svn.freebsd.org>
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Author: np Date: Thu Aug 29 23:46:38 2013 New Revision: 255047 URL: http://svnweb.freebsd.org/changeset/base/255047 Log: Add a routine for attaching an mbuf to a buffer with an external refcount. This one is willing to work with buffers that may already be referenced. MEXTADD/m_extadd are suitable only for the first attachment to a cluster -- they initialize the refcount to 1. Modified: head/sys/sys/mbuf.h Modified: head/sys/sys/mbuf.h ============================================================================== --- head/sys/sys/mbuf.h Thu Aug 29 23:11:58 2013 (r255046) +++ head/sys/sys/mbuf.h Thu Aug 29 23:46:38 2013 (r255047) @@ -545,6 +545,28 @@ m_gettype(int size) return (type); } +/* + * Associated an external reference counted buffer with an mbuf. + */ +static __inline void +m_extaddref(struct mbuf *m, caddr_t buf, u_int size, u_int *ref_cnt, + int (*freef)(struct mbuf *, void *, void *), void *arg1, void *arg2) +{ + + KASSERT(ref_cnt != NULL, ("%s: ref_cnt not provided", __func__)); + + atomic_add_int(ref_cnt, 1); + m->m_flags |= M_EXT; + m->m_ext.ext_buf = buf; + m->m_ext.ref_cnt = ref_cnt; + m->m_data = m->m_ext.ext_buf; + m->m_ext.ext_size = size; + m->m_ext.ext_free = freef; + m->m_ext.ext_arg1 = arg1; + m->m_ext.ext_arg2 = arg2; + m->m_ext.ext_type = EXT_EXTREF; +} + static __inline uma_zone_t m_getzone(int size) {
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