From 6663f8a23e7cb60d798c5ffbd9c716b62b204f2a Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Tue, 25 May 2021 16:59:18 -0700 Subject: sglist: Add sglist_append_single_mbuf(). This function appends the contents of a single mbuf to an sglist rather than an entire mbuf chain. Reviewed by: gallatin, markj Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D30135 --- sys/kern/subr_sglist.c | 15 +++++++++++++++ sys/sys/sglist.h | 1 + 2 files changed, 16 insertions(+) (limited to 'sys') diff --git a/sys/kern/subr_sglist.c b/sys/kern/subr_sglist.c index 71be45b4231d..7c520fda00f5 100644 --- a/sys/kern/subr_sglist.c +++ b/sys/kern/subr_sglist.c @@ -466,6 +466,21 @@ sglist_append_mbuf(struct sglist *sg, struct mbuf *m0) return (0); } +/* + * Append the segments that describe a single mbuf to a scatter/gather + * list. If there are insufficient segments, then this fails with + * EFBIG. + */ +int +sglist_append_single_mbuf(struct sglist *sg, struct mbuf *m) +{ + if ((m->m_flags & M_EXTPG) != 0) + return (sglist_append_mbuf_epg(sg, m, + mtod(m, vm_offset_t), m->m_len)); + else + return (sglist_append(sg, m->m_data, m->m_len)); +} + /* * Append the segments that describe a buffer spanning an array of VM * pages. The buffer begins at an offset of 'pgoff' in the first diff --git a/sys/sys/sglist.h b/sys/sys/sglist.h index 82a3ac6ed6ac..bf8aa482e3ce 100644 --- a/sys/sys/sglist.h +++ b/sys/sys/sglist.h @@ -94,6 +94,7 @@ int sglist_append_phys(struct sglist *sg, vm_paddr_t paddr, size_t len); int sglist_append_sglist(struct sglist *sg, struct sglist *source, size_t offset, size_t length); +int sglist_append_single_mbuf(struct sglist *sg, struct mbuf *m); int sglist_append_uio(struct sglist *sg, struct uio *uio); int sglist_append_user(struct sglist *sg, void *buf, size_t len, struct thread *td); -- cgit v1.3