* Rename M_WAIT mbuf subsystem flag to M_TRYWAIT.

  This is because calls with M_WAIT (now M_TRYWAIT) may not wait
  forever when nothing is available for allocation, and may end up
  returning NULL. Hopefully we now communicate more of the right thing
  to developers and make it very clear that it's necessary to check whether
  calls with M_(TRY)WAIT also resulted in a failed allocation.
  M_TRYWAIT basically means "try harder, block if necessary, but don't
  necessarily wait forever." The time spent blocking is tunable with
  the kern.ipc.mbuf_wait sysctl.
  M_WAIT is now deprecated but still defined for the next little while.

* Fix a typo in a comment in mbuf.h

* Fix some code that was actually passing the mbuf subsystem's M_WAIT to
  malloc(). Made it pass M_WAITOK instead. If we were ever to redefine the
  value of the M_WAIT flag, this could have became a big problem.

6 files changed, 33 insertions, 33 deletions

diff --git a/sys/nfsserver/nfs_serv.c b/sys/nfsserver/nfs_serv.c
index 0334f74..648384e 100644
--- a/sys/nfsserver/nfs_serv.c
+++ b/sys/nfsserver/nfs_serv.c
@@ -689,8 +689,8 @@ nfsrv_readlink(nfsd, slp, procp, mrq)
 	len = 0;
 	i = 0;
 	while (len < NFS_MAXPATHLEN) {
-		MGET(mp, M_WAIT, MT_DATA);
-		MCLGET(mp, M_WAIT);
+		MGET(mp, M_TRYWAIT, MT_DATA);
+		MCLGET(mp, M_TRYWAIT);
 		mp->m_len = NFSMSIZ(mp);
 		if (len == 0)
 			mp3 = mp2 = mp;
@@ -940,8 +940,8 @@ nfsrv_read(nfsd, slp, procp, mrq)
 				i++;
 			}
 			if (left > 0) {
-				MGET(m, M_WAIT, MT_DATA);
-				MCLGET(m, M_WAIT);
+				MGET(m, M_TRYWAIT, MT_DATA);
+				MCLGET(m, M_TRYWAIT);
 				m->m_len = 0;
 				m2->m_next = m;
 				m2 = m;
diff --git a/sys/nfsserver/nfs_srvcache.c b/sys/nfsserver/nfs_srvcache.c
index 99fae0e..e7b10dd 100644
--- a/sys/nfsserver/nfs_srvcache.c
+++ b/sys/nfsserver/nfs_srvcache.c
@@ -201,7 +201,7 @@ loop:
 			} else if (rp->rc_flag & RC_REPMBUF) {
 				nfsstats.srvcache_nonidemdonehits++;
 				*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
-						M_WAIT);
+						M_TRYWAIT);
 				ret = RC_REPLY;
 			} else {
 				nfsstats.srvcache_idemdonehits++;
@@ -313,7 +313,7 @@ loop:
 					rp->rc_flag |= RC_REPSTATUS;
 				} else {
 					rp->rc_reply = m_copym(repmbuf,
-						0, M_COPYALL, M_WAIT);
+						0, M_COPYALL, M_TRYWAIT);
 					rp->rc_flag |= RC_REPMBUF;
 				}
 			}
diff --git a/sys/nfsserver/nfs_srvsock.c b/sys/nfsserver/nfs_srvsock.c
index f1ace4e..fefeea8 100644
--- a/sys/nfsserver/nfs_srvsock.c
+++ b/sys/nfsserver/nfs_srvsock.c
@@ -590,7 +590,7 @@ tryagain:
 			goto tryagain;
 		}
 		while (rep->r_flags & R_MUSTRESEND) {
-			m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
+			m = m_copym(rep->r_mreq, 0, M_COPYALL, M_TRYWAIT);
 			nfsstats.rpcretries++;
 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
 			if (error) {
@@ -1014,7 +1014,7 @@ kerbauth:
 	 * For stream protocols, insert a Sun RPC Record Mark.
 	 */
 	if (nmp->nm_sotype == SOCK_STREAM) {
-		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
+		M_PREPEND(m, NFSX_UNSIGNED, M_TRYWAIT);
 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
 			 (m->m_pkthdr.len - NFSX_UNSIGNED));
 	}
@@ -1058,7 +1058,7 @@ tryagain:
 		if (nmp->nm_soflags & PR_CONNREQUIRED)
 			error = nfs_sndlock(rep);
 		if (!error) {
-			m2 = m_copym(m, 0, M_COPYALL, M_WAIT);
+			m2 = m_copym(m, 0, M_COPYALL, M_TRYWAIT);
 			error = nfs_send(nmp->nm_so, nmp->nm_nam, m2, rep);
 			if (nmp->nm_soflags & PR_CONNREQUIRED)
 				nfs_sndunlock(rep);
@@ -1237,7 +1237,7 @@ nfs_rephead(siz, nd, slp, err, cache, frev, mrq, mbp, bposp)
 	caddr_t bpos;
 	struct mbuf *mb, *mb2;
 
-	MGETHDR(mreq, M_WAIT, MT_DATA);
+	MGETHDR(mreq, M_TRYWAIT, MT_DATA);
 	mb = mreq;
 	/*
 	 * If this is a big reply, use a cluster else
@@ -1245,7 +1245,7 @@ nfs_rephead(siz, nd, slp, err, cache, frev, mrq, mbp, bposp)
 	 */
 	siz += RPC_REPLYSIZ;
 	if ((max_hdr + siz) >= MINCLSIZE) {
-		MCLGET(mreq, M_WAIT);
+		MCLGET(mreq, M_TRYWAIT);
 	} else
 		mreq->m_data += max_hdr;
 	tl = mtod(mreq, u_int32_t *);
@@ -1686,9 +1686,9 @@ nfs_realign(pm, hsiz)
 
 	while ((m = *pm) != NULL) {
 		if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
-			MGET(n, M_WAIT, MT_DATA);
+			MGET(n, M_TRYWAIT, MT_DATA);
 			if (m->m_len >= MINCLSIZE) {
-				MCLGET(n, M_WAIT);
+				MCLGET(n, M_TRYWAIT);
 			}
 			n->m_len = 0;
 			break;
@@ -1978,7 +1978,7 @@ nfs_msg(p, server, msg)
  * Socket upcall routine for the nfsd sockets.
  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
  * Essentially do as much as possible non-blocking, else punt and it will
- * be called with M_WAIT from an nfsd.
+ * be called with M_TRYWAIT from an nfsd.
  */
 void
 nfsrv_rcv(so, arg, waitflag)
diff --git a/sys/nfsserver/nfs_srvsubs.c b/sys/nfsserver/nfs_srvsubs.c
index 95138c3..c7e6917 100644
--- a/sys/nfsserver/nfs_srvsubs.c
+++ b/sys/nfsserver/nfs_srvsubs.c
@@ -588,9 +588,9 @@ nfsm_reqh(vp, procid, hsiz, bposp)
 	struct nfsmount *nmp;
 	int nqflag;
 
-	MGET(mb, M_WAIT, MT_DATA);
+	MGET(mb, M_TRYWAIT, MT_DATA);
 	if (hsiz >= MINCLSIZE)
-		MCLGET(mb, M_WAIT);
+		MCLGET(mb, M_TRYWAIT);
 	mb->m_len = 0;
 	bpos = mtod(mb, caddr_t);
 
@@ -646,9 +646,9 @@ nfsm_rpchead(cr, nmflag, procid, auth_type, auth_len, auth_str, verf_len,
 	int siz, grpsiz, authsiz;
 
 	authsiz = nfsm_rndup(auth_len);
-	MGETHDR(mb, M_WAIT, MT_DATA);
+	MGETHDR(mb, M_TRYWAIT, MT_DATA);
 	if ((authsiz + 10 * NFSX_UNSIGNED) >= MINCLSIZE) {
-		MCLGET(mb, M_WAIT);
+		MCLGET(mb, M_TRYWAIT);
 	} else if ((authsiz + 10 * NFSX_UNSIGNED) < MHLEN) {
 		MH_ALIGN(mb, authsiz + 10 * NFSX_UNSIGNED);
 	} else {
@@ -711,9 +711,9 @@ nfsm_rpchead(cr, nmflag, procid, auth_type, auth_len, auth_str, verf_len,
 		siz = auth_len;
 		while (siz > 0) {
 			if (M_TRAILINGSPACE(mb) == 0) {
-				MGET(mb2, M_WAIT, MT_DATA);
+				MGET(mb2, M_TRYWAIT, MT_DATA);
 				if (siz >= MINCLSIZE)
-					MCLGET(mb2, M_WAIT);
+					MCLGET(mb2, M_TRYWAIT);
 				mb->m_next = mb2;
 				mb = mb2;
 				mb->m_len = 0;
@@ -744,9 +744,9 @@ nfsm_rpchead(cr, nmflag, procid, auth_type, auth_len, auth_str, verf_len,
 		siz = verf_len;
 		while (siz > 0) {
 			if (M_TRAILINGSPACE(mb) == 0) {
-				MGET(mb2, M_WAIT, MT_DATA);
+				MGET(mb2, M_TRYWAIT, MT_DATA);
 				if (siz >= MINCLSIZE)
-					MCLGET(mb2, M_WAIT);
+					MCLGET(mb2, M_TRYWAIT);
 				mb->m_next = mb2;
 				mb = mb2;
 				mb->m_len = 0;
@@ -887,9 +887,9 @@ nfsm_uiotombuf(uiop, mq, siz, bpos)
 		while (left > 0) {
 			mlen = M_TRAILINGSPACE(mp);
 			if (mlen == 0) {
-				MGET(mp, M_WAIT, MT_DATA);
+				MGET(mp, M_TRYWAIT, MT_DATA);
 				if (clflg)
-					MCLGET(mp, M_WAIT);
+					MCLGET(mp, M_TRYWAIT);
 				mp->m_len = 0;
 				mp2->m_next = mp;
 				mp2 = mp;
@@ -919,7 +919,7 @@ nfsm_uiotombuf(uiop, mq, siz, bpos)
 	}
 	if (rem > 0) {
 		if (rem > M_TRAILINGSPACE(mp)) {
-			MGET(mp, M_WAIT, MT_DATA);
+			MGET(mp, M_TRYWAIT, MT_DATA);
 			mp->m_len = 0;
 			mp2->m_next = mp;
 		}
@@ -968,7 +968,7 @@ nfsm_disct(mdp, dposp, siz, left, cp2)
 	} else if (siz > MHLEN) {
 		panic("nfs S too big");
 	} else {
-		MGET(mp2, M_WAIT, MT_DATA);
+		MGET(mp2, M_TRYWAIT, MT_DATA);
 		mp2->m_next = mp->m_next;
 		mp->m_next = mp2;
 		mp->m_len -= left;
@@ -1061,9 +1061,9 @@ nfsm_strtmbuf(mb, bpos, cp, siz)
 	}
 	/* Loop around adding mbufs */
 	while (siz > 0) {
-		MGET(m1, M_WAIT, MT_DATA);
+		MGET(m1, M_TRYWAIT, MT_DATA);
 		if (siz > MLEN)
-			MCLGET(m1, M_WAIT);
+			MCLGET(m1, M_TRYWAIT);
 		m1->m_len = NFSMSIZ(m1);
 		m2->m_next = m1;
 		m2 = m1;
diff --git a/sys/nfsserver/nfs_syscalls.c b/sys/nfsserver/nfs_syscalls.c
index d1a8ead..4eb5c86 100644
--- a/sys/nfsserver/nfs_syscalls.c
+++ b/sys/nfsserver/nfs_syscalls.c
@@ -480,7 +480,7 @@ nfssvc_nfsd(nsd, argp, p)
 					slp->ns_flag &= ~SLP_NEEDQ;
 					(void) nfs_slplock(slp, 1);
 					nfsrv_rcv(slp->ns_so, (caddr_t)slp,
-						M_WAIT);
+						M_TRYWAIT);
 					nfs_slpunlock(slp);
 				}
 				error = nfsrv_dorec(slp, nfsd, &nd);
@@ -632,7 +632,7 @@ nfssvc_nfsd(nsd, argp, p)
 			 * Record Mark.
 			 */
 			if (sotype == SOCK_STREAM) {
-				M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
+				M_PREPEND(m, NFSX_UNSIGNED, M_TRYWAIT);
 				*mtod(m, u_int32_t *) = htonl(0x80000000 | siz);
 			}
 			if (slp->ns_so->so_proto->pr_flags & PR_CONNREQUIRED)
diff --git a/sys/nfsserver/nfsm_subs.h b/sys/nfsserver/nfsm_subs.h
index 0990fe4..d58ef15 100644
--- a/sys/nfsserver/nfsm_subs.h
+++ b/sys/nfsserver/nfsm_subs.h
@@ -94,7 +94,7 @@ struct mbuf *nfsm_rpchead __P((struct ucred *cr, int nmflag, int procid,
 #define	nfsm_build(a,c,s) \
 	do { \
 		if ((s) > M_TRAILINGSPACE(mb)) { \
-			MGET(mb2, M_WAIT, MT_DATA); \
+			MGET(mb2, M_TRYWAIT, MT_DATA); \
 			if ((s) > MLEN) \
 				panic("build > MLEN"); \
 			mb->m_next = mb2; \
@@ -491,8 +491,8 @@ struct mbuf *nfsm_rpchead __P((struct ucred *cr, int nmflag, int procid,
 		if (bp >= be) { \
 			if (mp == mb) \
 				mp->m_len += bp-bpos; \
-			MGET(mp, M_WAIT, MT_DATA); \
-			MCLGET(mp, M_WAIT); \
+			MGET(mp, M_TRYWAIT, MT_DATA); \
+			MCLGET(mp, M_TRYWAIT); \
 			mp->m_len = NFSMSIZ(mp); \
 			mp2->m_next = mp; \
 			mp2 = mp; \