Add support for ext_pgs mbufs to nfsm_strtom().

Also, add a new function nfsm_add_ext_pgs() which will either add a page
or add a new ext_pgs mbuf with a page to the mbuf list. Used by nfsm_strtom().
This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Since ND_EXTPG is never set yet, there is no semantic change at this time.
This commit is contained in:
Rick Macklem 2020-07-05 21:55:16 +00:00
parent 4543c1c329
commit 34fc29e0c9
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=362949
2 changed files with 73 additions and 12 deletions

View File

@ -832,22 +832,38 @@ nfsm_strtom(struct nfsrv_descript *nd, const char *cp, int siz)
bytesize = NFSX_UNSIGNED + siz + rem;
m2 = nd->nd_mb;
cp2 = nd->nd_bpos;
left = M_TRAILINGSPACE(m2);
if ((nd->nd_flag & ND_EXTPG) != 0)
left = nd->nd_bextpgsiz;
else
left = M_TRAILINGSPACE(m2);
KASSERT(((m2->m_flags & (M_EXT | M_EXTPG)) ==
(M_EXT | M_EXTPG) && (nd->nd_flag & ND_EXTPG) != 0) ||
((m2->m_flags & (M_EXT | M_EXTPG)) !=
(M_EXT | M_EXTPG) && (nd->nd_flag & ND_EXTPG) == 0),
("nfsm_strtom: ext_pgs and non-ext_pgs mbufs mixed"));
/*
* Loop around copying the string to mbuf(s).
*/
while (siz > 0) {
if (left == 0) {
if (siz > ncl_mbuf_mlen)
NFSMCLGET(m1, M_WAITOK);
else
NFSMGET(m1);
m1->m_len = 0;
m2->m_next = m1;
m2 = m1;
cp2 = mtod(m2, caddr_t);
left = M_TRAILINGSPACE(m2);
if ((nd->nd_flag & ND_EXTPG) != 0) {
m2 = nfsm_add_ext_pgs(m2,
nd->nd_maxextsiz, &nd->nd_bextpg);
cp2 = (char *)(void *)PHYS_TO_DMAP(
m2->m_epg_pa[nd->nd_bextpg]);
nd->nd_bextpgsiz = left = PAGE_SIZE;
} else {
if (siz > ncl_mbuf_mlen)
NFSMCLGET(m1, M_WAITOK);
else
NFSMGET(m1);
m1->m_len = 0;
cp2 = mtod(m1, char *);
left = M_TRAILINGSPACE(m1);
m2->m_next = m1;
m2 = m1;
}
}
if (left >= siz)
xfer = siz;
@ -855,18 +871,31 @@ nfsm_strtom(struct nfsrv_descript *nd, const char *cp, int siz)
xfer = left;
NFSBCOPY(cp, cp2, xfer);
cp += xfer;
cp2 += xfer;
m2->m_len += xfer;
siz -= xfer;
left -= xfer;
if ((nd->nd_flag & ND_EXTPG) != 0) {
nd->nd_bextpgsiz -= xfer;
m2->m_epg_last_len += xfer;
}
if (siz == 0 && rem) {
if (left < rem)
panic("nfsm_strtom");
NFSBZERO(cp2 + xfer, rem);
NFSBZERO(cp2, rem);
m2->m_len += rem;
cp2 += rem;
if ((nd->nd_flag & ND_EXTPG) != 0) {
nd->nd_bextpgsiz -= rem;
m2->m_epg_last_len += rem;
}
}
}
nd->nd_mb = m2;
nd->nd_bpos = mtod(m2, caddr_t) + m2->m_len;
if ((nd->nd_flag & ND_EXTPG) != 0)
nd->nd_bpos = cp2;
else
nd->nd_bpos = mtod(m2, char *) + m2->m_len;
return (bytesize);
}
@ -4845,3 +4874,34 @@ nfsm_set(struct nfsrv_descript *nd, u_int offs)
} else
nd->nd_bpos = mtod(m, char *) + offs;
}
/*
* Grow a ext_pgs mbuf list. Either allocate another page or add
* an mbuf to the list.
*/
struct mbuf *
nfsm_add_ext_pgs(struct mbuf *m, int maxextsiz, int *bextpg)
{
struct mbuf *mp;
vm_page_t pg;
if ((m->m_epg_npgs + 1) * PAGE_SIZE > maxextsiz) {
mp = mb_alloc_ext_plus_pages(PAGE_SIZE, M_WAITOK);
*bextpg = 0;
m->m_next = mp;
} else {
do {
pg = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
VM_ALLOC_NOOBJ | VM_ALLOC_NODUMP |
VM_ALLOC_WIRED);
if (pg == NULL)
vm_wait(NULL);
} while (pg == NULL);
m->m_epg_pa[m->m_epg_npgs] = VM_PAGE_TO_PHYS(pg);
*bextpg = m->m_epg_npgs;
m->m_epg_npgs++;
m->m_epg_last_len = 0;
mp = m;
}
return (mp);
}

View File

@ -361,6 +361,7 @@ void nfsv4_freeslot(struct nfsclsession *, int);
struct ucred *nfsrv_getgrpscred(struct ucred *);
struct nfsdevice *nfsv4_findmirror(struct nfsmount *);
void nfsm_set(struct nfsrv_descript *, u_int);
struct mbuf *nfsm_add_ext_pgs(struct mbuf *, int, int *);
/* nfs_clcomsubs.c */
void nfsm_uiombuf(struct nfsrv_descript *, struct uio *, int);