PERFORCE change 86068 for review
Robert Watson
rwatson at FreeBSD.org
Sun Oct 30 06:11:22 PST 2005
http://perforce.freebsd.org/chv.cgi?CH=86068
Change 86068 by rwatson at rwatson_zoo on 2005/10/30 14:10:56
First cut at breaking out mbuf copyin/etc code from sosend() into
sosend_copyin(). Compiles.
Affected files ...
.. //depot/projects/netsmp/src/sys/kern/uipc_socket.c#14 edit
Differences ...
==== //depot/projects/netsmp/src/sys/kern/uipc_socket.c#14 (text+ko) ====
@@ -569,6 +569,131 @@
return (error);
}
+/*
+ * sosend_copyin() accepts a uio and prepares an mbuf chain holding part or
+ * all of the data referenced by the uio. If desired, it uses zero-copy.
+ * *space will be updated to reflect data copied in.
+ *
+ * NB: If atomic I/O is requested, the caller must already have checked that
+ * space can hold resid bytes.
+ *
+ * NB: In the event of an error, the caller may need to free the partial
+ * chain pointed to by *mpp. The contents of both *uio and *space may be
+ * modified even in the case of an error.
+ */
+static int
+sosend_copyin(struct uio *uio, struct mbuf **retmp, int atomic, long *space,
+ int flags)
+{
+ struct mbuf *m, **mp, *top;
+ long len, resid;
+ int error;
+#ifdef ZERO_COPY_SOCKETS
+ int cow_send;
+#endif
+
+ *retmp = top = NULL;
+ mp = ⊤
+ len = 0;
+ resid = uio->uio_resid;
+ error = 0;
+ do {
+#ifdef ZERO_COPY_SOCKETS
+ cow_send = 0;
+#endif /* ZERO_COPY_SOCKETS */
+ if (resid >= MINCLSIZE) {
+#ifdef ZERO_COPY_SOCKETS
+ if (top == NULL) {
+ MGETHDR(m, M_TRYWAIT, MT_DATA);
+ if (m == NULL) {
+ error = ENOBUFS;
+ goto out;
+ }
+ m->m_pkthdr.len = 0;
+ m->m_pkthdr.rcvif = NULL;
+ } else {
+ MGET(m, M_TRYWAIT, MT_DATA);
+ if (m == NULL) {
+ error = ENOBUFS;
+ goto out;
+ }
+ }
+ if (so_zero_copy_send &&
+ resid>=PAGE_SIZE &&
+ *space>=PAGE_SIZE &&
+ uio->uio_iov->iov_len>=PAGE_SIZE) {
+ so_zerocp_stats.size_ok++;
+ so_zerocp_stats.align_ok++;
+ cow_send = socow_setup(m, uio);
+ len = cow_send;
+ }
+ if (!cow_send) {
+ MCLGET(m, M_TRYWAIT);
+ if ((m->m_flags & M_EXT) == 0) {
+ m_free(m);
+ m = NULL;
+ } else {
+ len = min(min(MCLBYTES, resid),
+ *space);
+ }
+ }
+#else /* ZERO_COPY_SOCKETS */
+ if (top == NULL) {
+ m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR);
+ m->m_pkthdr.len = 0;
+ m->m_pkthdr.rcvif = NULL;
+ } else
+ m = m_getcl(M_TRYWAIT, MT_DATA, 0);
+ len = min(min(MCLBYTES, resid), *space);
+#endif /* ZERO_COPY_SOCKETS */
+ } else {
+ if (top == NULL) {
+ m = m_gethdr(M_TRYWAIT, MT_DATA);
+ m->m_pkthdr.len = 0;
+ m->m_pkthdr.rcvif = NULL;
+
+ len = min(min(MHLEN, resid), *space);
+ /*
+ * For datagram protocols, leave room
+ * for protocol headers in first mbuf.
+ */
+ if (atomic && m && len < MHLEN)
+ MH_ALIGN(m, len);
+ } else {
+ m = m_get(M_TRYWAIT, MT_DATA);
+ len = min(min(MLEN, resid), *space);
+ }
+ }
+ if (m == NULL) {
+ error = ENOBUFS;
+ goto out;
+ }
+
+ *space -= len;
+#ifdef ZERO_COPY_SOCKETS
+ if (cow_send)
+ error = 0;
+ else
+#endif /* ZERO_COPY_SOCKETS */
+ error = uiomove(mtod(m, void *), (int)len, uio);
+ resid = uio->uio_resid;
+ m->m_len = len;
+ *mp = m;
+ top->m_pkthdr.len += len;
+ if (error)
+ goto out;
+ mp = &m->m_next;
+ if (resid <= 0) {
+ if (flags & MSG_EOR)
+ top->m_flags |= M_EOR;
+ break;
+ }
+ } while (*space > 0 && atomic);
+out:
+ *retmp = top;
+ return (error);
+}
+
#define SBLOCKWAIT(f) (((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
/*
* Send on a socket.
@@ -613,9 +738,7 @@
int flags;
struct thread *td;
{
- struct mbuf **mp;
- struct mbuf *m;
- long space, len = 0, resid;
+ long space, resid;
int clen = 0, error, dontroute;
int atomic = sosendallatonce(so) || top;
#ifdef ZERO_COPY_SOCKETS
@@ -682,6 +805,7 @@
snderr(so->so_proto->pr_flags & PR_CONNREQUIRED ?
ENOTCONN : EDESTADDRREQ);
}
+
space = sbspace(&so->so_snd);
if (flags & MSG_OOB)
space += 1024;
@@ -699,153 +823,61 @@
goto restart;
}
SOCKBUF_UNLOCK(&so->so_snd);
- mp = ⊤
space -= clen;
do {
- if (uio == NULL) {
- /*
- * Data is prepackaged in "top".
- */
- resid = 0;
- if (flags & MSG_EOR)
- top->m_flags |= M_EOR;
- } else do {
-#ifdef ZERO_COPY_SOCKETS
- cow_send = 0;
-#endif /* ZERO_COPY_SOCKETS */
- if (resid >= MINCLSIZE) {
-#ifdef ZERO_COPY_SOCKETS
- if (top == NULL) {
- MGETHDR(m, M_TRYWAIT, MT_DATA);
- if (m == NULL) {
- error = ENOBUFS;
- SOCKBUF_LOCK(&so->so_snd);
- goto release;
- }
- m->m_pkthdr.len = 0;
- m->m_pkthdr.rcvif = NULL;
- } else {
- MGET(m, M_TRYWAIT, MT_DATA);
- if (m == NULL) {
- error = ENOBUFS;
- SOCKBUF_LOCK(&so->so_snd);
- goto release;
- }
- }
- if (so_zero_copy_send &&
- resid>=PAGE_SIZE &&
- space>=PAGE_SIZE &&
- uio->uio_iov->iov_len>=PAGE_SIZE) {
- so_zerocp_stats.size_ok++;
- so_zerocp_stats.align_ok++;
- cow_send = socow_setup(m, uio);
- len = cow_send;
- }
- if (!cow_send) {
- MCLGET(m, M_TRYWAIT);
- if ((m->m_flags & M_EXT) == 0) {
- m_free(m);
- m = NULL;
- } else {
- len = min(min(MCLBYTES, resid), space);
- }
- }
-#else /* ZERO_COPY_SOCKETS */
- if (top == NULL) {
- m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR);
- m->m_pkthdr.len = 0;
- m->m_pkthdr.rcvif = NULL;
- } else
- m = m_getcl(M_TRYWAIT, MT_DATA, 0);
- len = min(min(MCLBYTES, resid), space);
-#endif /* ZERO_COPY_SOCKETS */
+ if (uio == NULL) {
+ resid = 0;
+ if (flags & MSG_EOR)
+ top->m_flags |= M_EOR;
} else {
- if (top == NULL) {
- m = m_gethdr(M_TRYWAIT, MT_DATA);
- m->m_pkthdr.len = 0;
- m->m_pkthdr.rcvif = NULL;
-
- len = min(min(MHLEN, resid), space);
- /*
- * For datagram protocols, leave room
- * for protocol headers in first mbuf.
- */
- if (atomic && m && len < MHLEN)
- MH_ALIGN(m, len);
- } else {
- m = m_get(M_TRYWAIT, MT_DATA);
- len = min(min(MLEN, resid), space);
+ error = sosend_copyin(uio, &top, atomic,
+ &space, flags);
+ if (error != 0) {
+ SOCKBUF_LOCK(&so->so_snd);
+ goto release;
}
+ resid = uio->uio_resid;
}
- if (m == NULL) {
- error = ENOBUFS;
- SOCKBUF_LOCK(&so->so_snd);
- goto release;
+ if (dontroute) {
+ SOCK_LOCK(so);
+ so->so_options |= SO_DONTROUTE;
+ SOCK_UNLOCK(so);
}
-
- space -= len;
-#ifdef ZERO_COPY_SOCKETS
- if (cow_send)
- error = 0;
- else
-#endif /* ZERO_COPY_SOCKETS */
- error = uiomove(mtod(m, void *), (int)len, uio);
- resid = uio->uio_resid;
- m->m_len = len;
- *mp = m;
- top->m_pkthdr.len += len;
- if (error) {
- SOCKBUF_LOCK(&so->so_snd);
- goto release;
- }
- mp = &m->m_next;
- if (resid <= 0) {
- if (flags & MSG_EOR)
- top->m_flags |= M_EOR;
- break;
- }
- } while (space > 0 && atomic);
- if (dontroute) {
- SOCK_LOCK(so);
- so->so_options |= SO_DONTROUTE;
- SOCK_UNLOCK(so);
- }
- /*
- * XXX all the SBS_CANTSENDMORE checks previously
- * done could be out of date. We could have recieved
- * a reset packet in an interrupt or maybe we slept
- * while doing page faults in uiomove() etc. We could
- * probably recheck again inside the locking protection
- * here, but there are probably other places that this
- * also happens. We must rethink this.
- */
- error = (*so->so_proto->pr_usrreqs->pru_send)(so,
- (flags & MSG_OOB) ? PRUS_OOB :
+ /*
+ * XXX all the SBS_CANTSENDMORE checks previously
+ * done could be out of date. We could have recieved
+ * a reset packet in an interrupt or maybe we slept
+ * while doing page faults in uiomove() etc. We could
+ * probably recheck again inside the locking protection
+ * here, but there are probably other places that this
+ * also happens. We must rethink this.
+ */
+ error = (*so->so_proto->pr_usrreqs->pru_send)(so,
+ (flags & MSG_OOB) ? PRUS_OOB :
/*
* If the user set MSG_EOF, the protocol
* understands this flag and nothing left to
* send then use PRU_SEND_EOF instead of PRU_SEND.
*/
- ((flags & MSG_EOF) &&
- (so->so_proto->pr_flags & PR_IMPLOPCL) &&
- (resid <= 0)) ?
+ ((flags & MSG_EOF) &&
+ (so->so_proto->pr_flags & PR_IMPLOPCL) &&
+ (resid <= 0)) ?
PRUS_EOF :
/* If there is more to send set PRUS_MORETOCOME */
- (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
- top, addr, control, td);
- if (dontroute) {
- SOCK_LOCK(so);
- so->so_options &= ~SO_DONTROUTE;
- SOCK_UNLOCK(so);
- }
- clen = 0;
- control = NULL;
- top = NULL;
- mp = ⊤
- if (error) {
- SOCKBUF_LOCK(&so->so_snd);
- goto release;
- }
+ (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
+ top, addr, control, td);
+ if (dontroute) {
+ SOCK_LOCK(so);
+ so->so_options &= ~SO_DONTROUTE;
+ SOCK_UNLOCK(so);
+ }
+ clen = 0;
+ control = NULL;
+ top = NULL;
+ if (error) {
+ SOCKBUF_LOCK(&so->so_snd);
+ goto release;
+ }
} while (resid && space > 0);
SOCKBUF_LOCK(&so->so_snd);
} while (resid);
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