Author: adrian
Date: Sun Dec 1 03:53:21 2013
New Revision: 258788
URL: http://svnweb.freebsd.org/changeset/base/258788
Log:
Migrate the sendfile_sync structure into a public(ish) API in preparation
for extending and reusing it.
The sendfile_sync wrapper is mostly just a "mbuf transaction" wrapper,
used to indicate that the backing store for a group of mbufs has completed.
It's only being used by sendfile for now and it's only implementing a
sleep/wakeup rendezvous. However, there are other potential signaling
paths (kqueue) and other potential uses (socket zero-copy write) where the
same mechanism would also be useful.
So, with that in mind:
* extract the sendfile_sync code out into sf_sync_*() methods
* teach the sf_sync_alloc method about the current config flag -
it will eventually know about kqueue.
* move the sendfile_sync code out of do_sendfile() - the only thing
it now knows about is the sfs pointer. The guts of the sync
rendezvous (setup, rendezvous/wait, free) is now done in the
syscall wrapper.
* .. and teach the 32-bit compat sendfile call the same.
This should be a no-op. It's primarily preparation work for teaching
the sendfile_sync about kqueue notification.
Tested:
* Peter Holm's sendfile stress / regression scripts
Sponsored by: Netflix, Inc.
Added:
head/sys/sys/sf_sync.h (contents, props changed)
Modified:
head/sys/compat/freebsd32/freebsd32_misc.c
head/sys/kern/kern_descrip.c
head/sys/kern/uipc_syscalls.c
head/sys/sys/file.h
Modified: head/sys/compat/freebsd32/freebsd32_misc.c
==============================================================================
--- head/sys/compat/freebsd32/freebsd32_misc.c Sun Dec 1 02:58:48 2013
(r258787)
+++ head/sys/compat/freebsd32/freebsd32_misc.c Sun Dec 1 03:53:21 2013
(r258788)
@@ -83,6 +83,9 @@ __FBSDID("$FreeBSD$");
#include <sys/msg.h>
#include <sys/sem.h>
#include <sys/shm.h>
+#include <sys/condvar.h>
+#include <sys/sf_buf.h>
+#include <sys/sf_sync.h>
#ifdef INET
#include <netinet/in.h>
@@ -1653,12 +1656,14 @@ freebsd32_do_sendfile(struct thread *td,
off_t offset;
int error;
off_t sbytes;
+ struct sendfile_sync *sfs;
offset = PAIR32TO64(off_t, uap->offset);
if (offset < 0)
return (EINVAL);
hdr_uio = trl_uio = NULL;
+ sfs = NULL;
if (uap->hdtr != NULL) {
error = copyin(uap->hdtr, &hdtr32, sizeof(hdtr32));
@@ -1692,8 +1697,21 @@ freebsd32_do_sendfile(struct thread *td,
goto out;
}
+ /*
+ * If we need to wait for completion, initialise the sfsync
+ * state here.
+ */
+ if (uap->flags & SF_SYNC)
+ sfs = sf_sync_alloc(uap->flags & SF_SYNC);
+
error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, offset,
- uap->nbytes, &sbytes, uap->flags, compat ? SFK_COMPAT : 0, td);
+ uap->nbytes, &sbytes, uap->flags, compat ? SFK_COMPAT : 0,
+ sfs, td);
+ if (sfs != NULL) {
+ sf_sync_syscall_wait(sfs);
+ sf_sync_free(sfs);
+ }
+
fdrop(fp, td);
if (uap->sbytes != NULL)
copyout(&sbytes, uap->sbytes, sizeof(off_t));
Modified: head/sys/kern/kern_descrip.c
==============================================================================
--- head/sys/kern/kern_descrip.c Sun Dec 1 02:58:48 2013
(r258787)
+++ head/sys/kern/kern_descrip.c Sun Dec 1 03:53:21 2013
(r258788)
@@ -3949,7 +3949,7 @@ badfo_chown(struct file *fp, uid_t uid,
static int
badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
- int kflags, struct thread *td)
+ int kflags, struct sendfile_sync *sfs, struct thread *td)
{
return (EBADF);
@@ -3988,7 +3988,7 @@ invfo_chown(struct file *fp, uid_t uid,
int
invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
- int kflags, struct thread *td)
+ int kflags, struct sendfile_sync *sfs, struct thread *td)
{
return (EINVAL);
Modified: head/sys/kern/uipc_syscalls.c
==============================================================================
--- head/sys/kern/uipc_syscalls.c Sun Dec 1 02:58:48 2013
(r258787)
+++ head/sys/kern/uipc_syscalls.c Sun Dec 1 03:53:21 2013
(r258788)
@@ -64,6 +64,7 @@ __FBSDID("$FreeBSD$");
#include <sys/protosw.h>
#include <sys/rwlock.h>
#include <sys/sf_buf.h>
+#include <sys/sf_sync.h>
#include <sys/sysent.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
@@ -1844,12 +1845,6 @@ getsockaddr(namp, uaddr, len)
return (error);
}
-struct sendfile_sync {
- struct mtx mtx;
- struct cv cv;
- unsigned count;
-};
-
/*
* Detach mapped page and release resources back to the system.
*/
@@ -1871,15 +1866,94 @@ sf_buf_mext(struct mbuf *mb, void *addr,
if (m->wire_count == 0 && m->object == NULL)
vm_page_free(m);
vm_page_unlock(m);
- if (addr == NULL)
- return (EXT_FREE_OK);
- sfs = addr;
+ if (addr != NULL) {
+ sfs = addr;
+ sf_sync_deref(sfs);
+ }
+ return (EXT_FREE_OK);
+}
+
+void
+sf_sync_deref(struct sendfile_sync *sfs)
+{
+
+ if (sfs == NULL)
+ return;
+
mtx_lock(&sfs->mtx);
KASSERT(sfs->count> 0, ("Sendfile sync botchup count == 0"));
if (--sfs->count == 0)
cv_signal(&sfs->cv);
mtx_unlock(&sfs->mtx);
- return (EXT_FREE_OK);
+}
+
+/*
+ * Allocate a sendfile_sync state structure.
+ *
+ * For now this only knows about the "sleep" sync, but later it will
+ * grow various other personalities.
+ */
+struct sendfile_sync *
+sf_sync_alloc(uint32_t flags)
+{
+ struct sendfile_sync *sfs;
+
+ sfs = malloc(sizeof *sfs, M_TEMP, M_WAITOK | M_ZERO);
+ mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF);
+ cv_init(&sfs->cv, "sendfile");
+ sfs->flags = flags;
+
+ return (sfs);
+}
+
+/*
+ * Take a reference to a sfsync instance.
+ *
+ * This has to map 1:1 to free calls coming in via sf_buf_mext(),
+ * so typically this will be referenced once for each mbuf allocated.
+ */
+void
+sf_sync_ref(struct sendfile_sync *sfs)
+{
+
+ if (sfs == NULL)
+ return;
+
+ mtx_lock(&sfs->mtx);
+ sfs->count++;
+ mtx_unlock(&sfs->mtx);
+}
+
+void
+sf_sync_syscall_wait(struct sendfile_sync *sfs)
+{
+
+ if (sfs == NULL)
+ return;
+
+ mtx_lock(&sfs->mtx);
+ if (sfs->count != 0)
+ cv_wait(&sfs->cv, &sfs->mtx);
+ KASSERT(sfs->count == 0, ("sendfile sync still busy"));
+ mtx_unlock(&sfs->mtx);
+}
+
+void
+sf_sync_free(struct sendfile_sync *sfs)
+{
+
+ if (sfs == NULL)
+ return;
+
+ /*
+ * XXX we should ensure that nothing else has this
+ * locked before freeing.
+ */
+ mtx_lock(&sfs->mtx);
+ KASSERT(sfs->count == 0, ("sendfile sync still busy"));
+ cv_destroy(&sfs->cv);
+ mtx_destroy(&sfs->mtx);
+ free(sfs, M_TEMP);
}
/*
@@ -1909,6 +1983,7 @@ do_sendfile(struct thread *td, struct se
cap_rights_t rights;
int error;
off_t sbytes;
+ struct sendfile_sync *sfs;
/*
* File offset must be positive. If it goes beyond EOF
@@ -1918,6 +1993,7 @@ do_sendfile(struct thread *td, struct se
return (EINVAL);
hdr_uio = trl_uio = NULL;
+ sfs = NULL;
if (uap->hdtr != NULL) {
error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
@@ -1947,9 +2023,31 @@ do_sendfile(struct thread *td, struct se
goto out;
}
+ /*
+ * If we need to wait for completion, initialise the sfsync
+ * state here.
+ */
+ if (uap->flags & SF_SYNC)
+ sfs = sf_sync_alloc(uap->flags & SF_SYNC);
+
error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset,
- uap->nbytes, &sbytes, uap->flags, compat ? SFK_COMPAT : 0, td);
+ uap->nbytes, &sbytes, uap->flags, compat ? SFK_COMPAT : 0, sfs, td);
+
+ /*
+ * If appropriate, do the wait and free here.
+ */
+ if (sfs != NULL) {
+ sf_sync_syscall_wait(sfs);
+ sf_sync_free(sfs);
+ }
+
+ /*
+ * XXX Should we wait until the send has completed before freeing the
source
+ * file handle? It's the previous behaviour, sure, but is it required?
+ * We've wired down the page references after all.
+ */
fdrop(fp, td);
+
if (uap->sbytes != NULL) {
copyout(&sbytes, uap->sbytes, sizeof(off_t));
}
@@ -2177,7 +2275,7 @@ kern_sendfile_getsock(struct thread *td,
int
vn_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
- int kflags, struct thread *td)
+ int kflags, struct sendfile_sync *sfs, struct thread *td)
{
struct file *sock_fp;
struct vnode *vp;
@@ -2187,7 +2285,6 @@ vn_sendfile(struct file *fp, int sockfd,
struct sf_buf *sf;
struct vm_page *pg;
struct shmfd *shmfd;
- struct sendfile_sync *sfs;
struct vattr va;
off_t off, xfsize, fsbytes, sbytes, rem, obj_size;
int error, bsize, nd, hdrlen, mnw;
@@ -2197,7 +2294,6 @@ vn_sendfile(struct file *fp, int sockfd,
obj = NULL;
so = NULL;
m = NULL;
- sfs = NULL;
fsbytes = sbytes = 0;
hdrlen = mnw = 0;
rem = nbytes;
@@ -2222,12 +2318,6 @@ vn_sendfile(struct file *fp, int sockfd,
if (flags & SF_MNOWAIT)
mnw = 1;
- if (flags & SF_SYNC) {
- sfs = malloc(sizeof *sfs, M_TEMP, M_WAITOK | M_ZERO);
- mtx_init(&sfs->mtx, "sendfile", NULL, MTX_DEF);
- cv_init(&sfs->cv, "sendfile");
- }
-
#ifdef MAC
error = mac_socket_check_send(td->td_ucred, so);
if (error != 0)
@@ -2472,11 +2562,12 @@ retry_space:
loopbytes += xfsize;
off += xfsize;
- if (sfs != NULL) {
- mtx_lock(&sfs->mtx);
- sfs->count++;
- mtx_unlock(&sfs->mtx);
- }
+ /*
+ * XXX eventually this should be a sfsync
+ * method call!
+ */
+ if (sfs != NULL)
+ sf_sync_ref(sfs);
}
if (vp != NULL)
@@ -2558,16 +2649,6 @@ out:
if (m)
m_freem(m);
- if (sfs != NULL) {
- mtx_lock(&sfs->mtx);
- if (sfs->count != 0)
- cv_wait(&sfs->cv, &sfs->mtx);
- KASSERT(sfs->count == 0, ("sendfile sync still busy"));
- cv_destroy(&sfs->cv);
- mtx_destroy(&sfs->mtx);
- free(sfs, M_TEMP);
- }
-
if (error == ERESTART)
error = EINTR;
Modified: head/sys/sys/file.h
==============================================================================
--- head/sys/sys/file.h Sun Dec 1 02:58:48 2013 (r258787)
+++ head/sys/sys/file.h Sun Dec 1 03:53:21 2013 (r258788)
@@ -88,6 +88,9 @@ foffset_get(struct file *fp)
return (foffset_lock(fp, FOF_NOLOCK));
}
+/* XXX pollution? */
+struct sendfile_sync;
+
typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
struct ucred *active_cred, int flags,
struct thread *td);
@@ -107,7 +110,8 @@ typedef int fo_chown_t(struct file *fp,
struct ucred *active_cred, struct thread *td);
typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes,
- off_t *sent, int flags, int kflags, struct thread *td);
+ off_t *sent, int flags, int kflags,
+ struct sendfile_sync *sfs, struct thread *td);
typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
struct thread *td);
typedef int fo_flags_t;
@@ -368,11 +372,11 @@ fo_chown(struct file *fp, uid_t uid, gid
static __inline int
fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
- int kflags, struct thread *td)
+ int kflags, struct sendfile_sync *sfs, struct thread *td)
{
return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
- nbytes, sent, flags, kflags, td));
+ nbytes, sent, flags, kflags, sfs, td));
}
static __inline int
Added: head/sys/sys/sf_sync.h
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/sys/sf_sync.h Sun Dec 1 03:53:21 2013 (r258788)
@@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 2013 Adrian Chadd <[email protected]>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_SF_SYNC_H_
+#define _SYS_SF_SYNC_H_
+
+struct sendfile_sync {
+ uint32_t flags;
+ struct mtx mtx;
+ struct cv cv;
+ unsigned count;
+};
+
+extern struct sendfile_sync * sf_sync_alloc(uint32_t flags);
+extern void sf_sync_syscall_wait(struct sendfile_sync *);
+extern void sf_sync_free(struct sendfile_sync *);
+extern void sf_sync_ref(struct sendfile_sync *);
+extern void sf_sync_deref(struct sendfile_sync *);
+
+#endif /* !_SYS_SF_BUF_H_ */
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