Both of these functions atomically unwire a page, optionally attempt to free the page, and enqueue or requeue the page. Add functions vm_page_release() and vm_page_release_locked() to perform the same task. The latter must be called with the page's object lock held. As a side effect of this refactoring, the buffer cache will no longer attempt to free mapped pages when completing direct I/O. This is consistent with the handling of pages by sendfile(SF_NOCACHE). Reviewed by: alc, kib MFC after: 2 weeks Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20986
1138 lines
28 KiB
C
1138 lines
28 KiB
C
/*-
|
|
* Copyright (c) 2013-2015 Gleb Smirnoff <glebius@FreeBSD.org>
|
|
* Copyright (c) 1998, David Greenman. 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.
|
|
* 3. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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
|
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
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*/
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|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/capsicum.h>
|
|
#include <sys/kernel.h>
|
|
#include <netinet/in.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/rwlock.h>
|
|
#include <sys/sf_buf.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/syscallsubr.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/vnode.h>
|
|
|
|
#include <net/vnet.h>
|
|
|
|
#include <security/audit/audit.h>
|
|
#include <security/mac/mac_framework.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_object.h>
|
|
#include <vm/vm_pager.h>
|
|
|
|
#define EXT_FLAG_SYNC EXT_FLAG_VENDOR1
|
|
#define EXT_FLAG_NOCACHE EXT_FLAG_VENDOR2
|
|
#define EXT_FLAG_CACHE_LAST EXT_FLAG_VENDOR3
|
|
|
|
/*
|
|
* Structure describing a single sendfile(2) I/O, which may consist of
|
|
* several underlying pager I/Os.
|
|
*
|
|
* The syscall context allocates the structure and initializes 'nios'
|
|
* to 1. As sendfile_swapin() runs through pages and starts asynchronous
|
|
* paging operations, it increments 'nios'.
|
|
*
|
|
* Every I/O completion calls sendfile_iodone(), which decrements the 'nios',
|
|
* and the syscall also calls sendfile_iodone() after allocating all mbufs,
|
|
* linking them and sending to socket. Whoever reaches zero 'nios' is
|
|
* responsible to * call pru_ready on the socket, to notify it of readyness
|
|
* of the data.
|
|
*/
|
|
struct sf_io {
|
|
volatile u_int nios;
|
|
u_int error;
|
|
int npages;
|
|
struct socket *so;
|
|
struct mbuf *m;
|
|
vm_page_t pa[];
|
|
};
|
|
|
|
/*
|
|
* Structure used to track requests with SF_SYNC flag.
|
|
*/
|
|
struct sendfile_sync {
|
|
struct mtx mtx;
|
|
struct cv cv;
|
|
unsigned count;
|
|
};
|
|
|
|
counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)];
|
|
|
|
static void
|
|
sfstat_init(const void *unused)
|
|
{
|
|
|
|
COUNTER_ARRAY_ALLOC(sfstat, sizeof(struct sfstat) / sizeof(uint64_t),
|
|
M_WAITOK);
|
|
}
|
|
SYSINIT(sfstat, SI_SUB_MBUF, SI_ORDER_FIRST, sfstat_init, NULL);
|
|
|
|
static int
|
|
sfstat_sysctl(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct sfstat s;
|
|
|
|
COUNTER_ARRAY_COPY(sfstat, &s, sizeof(s) / sizeof(uint64_t));
|
|
if (req->newptr)
|
|
COUNTER_ARRAY_ZERO(sfstat, sizeof(s) / sizeof(uint64_t));
|
|
return (SYSCTL_OUT(req, &s, sizeof(s)));
|
|
}
|
|
SYSCTL_PROC(_kern_ipc, OID_AUTO, sfstat, CTLTYPE_OPAQUE | CTLFLAG_RW,
|
|
NULL, 0, sfstat_sysctl, "I", "sendfile statistics");
|
|
|
|
static void
|
|
sendfile_free_mext(struct mbuf *m)
|
|
{
|
|
struct sf_buf *sf;
|
|
vm_page_t pg;
|
|
int flags;
|
|
|
|
KASSERT(m->m_flags & M_EXT && m->m_ext.ext_type == EXT_SFBUF,
|
|
("%s: m %p !M_EXT or !EXT_SFBUF", __func__, m));
|
|
|
|
sf = m->m_ext.ext_arg1;
|
|
pg = sf_buf_page(sf);
|
|
flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0;
|
|
|
|
sf_buf_free(sf);
|
|
vm_page_release(pg, flags);
|
|
|
|
if (m->m_ext.ext_flags & EXT_FLAG_SYNC) {
|
|
struct sendfile_sync *sfs = m->m_ext.ext_arg2;
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
static void
|
|
sendfile_free_mext_pg(struct mbuf *m)
|
|
{
|
|
struct mbuf_ext_pgs *ext_pgs;
|
|
vm_page_t pg;
|
|
int flags, i;
|
|
bool cache_last;
|
|
|
|
KASSERT(m->m_flags & M_EXT && m->m_ext.ext_type == EXT_PGS,
|
|
("%s: m %p !M_EXT or !EXT_PGS", __func__, m));
|
|
|
|
cache_last = m->m_ext.ext_flags & EXT_FLAG_CACHE_LAST;
|
|
ext_pgs = m->m_ext.ext_pgs;
|
|
flags = (m->m_ext.ext_flags & EXT_FLAG_NOCACHE) != 0 ? VPR_TRYFREE : 0;
|
|
|
|
for (i = 0; i < ext_pgs->npgs; i++) {
|
|
if (cache_last && i == ext_pgs->npgs - 1)
|
|
flags = 0;
|
|
pg = PHYS_TO_VM_PAGE(ext_pgs->pa[i]);
|
|
vm_page_release(pg, flags);
|
|
}
|
|
|
|
if (m->m_ext.ext_flags & EXT_FLAG_SYNC) {
|
|
struct sendfile_sync *sfs = m->m_ext.ext_arg2;
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Helper function to calculate how much data to put into page i of n.
|
|
* Only first and last pages are special.
|
|
*/
|
|
static inline off_t
|
|
xfsize(int i, int n, off_t off, off_t len)
|
|
{
|
|
|
|
if (i == 0)
|
|
return (omin(PAGE_SIZE - (off & PAGE_MASK), len));
|
|
|
|
if (i == n - 1 && ((off + len) & PAGE_MASK) > 0)
|
|
return ((off + len) & PAGE_MASK);
|
|
|
|
return (PAGE_SIZE);
|
|
}
|
|
|
|
/*
|
|
* Helper function to get offset within object for i page.
|
|
*/
|
|
static inline vm_ooffset_t
|
|
vmoff(int i, off_t off)
|
|
{
|
|
|
|
if (i == 0)
|
|
return ((vm_ooffset_t)off);
|
|
|
|
return (trunc_page(off + i * PAGE_SIZE));
|
|
}
|
|
|
|
/*
|
|
* Helper function used when allocation of a page or sf_buf failed.
|
|
* Pretend as if we don't have enough space, subtract xfsize() of
|
|
* all pages that failed.
|
|
*/
|
|
static inline void
|
|
fixspace(int old, int new, off_t off, int *space)
|
|
{
|
|
|
|
KASSERT(old > new, ("%s: old %d new %d", __func__, old, new));
|
|
|
|
/* Subtract last one. */
|
|
*space -= xfsize(old - 1, old, off, *space);
|
|
old--;
|
|
|
|
if (new == old)
|
|
/* There was only one page. */
|
|
return;
|
|
|
|
/* Subtract first one. */
|
|
if (new == 0) {
|
|
*space -= xfsize(0, old, off, *space);
|
|
new++;
|
|
}
|
|
|
|
/* Rest of pages are full sized. */
|
|
*space -= (old - new) * PAGE_SIZE;
|
|
|
|
KASSERT(*space >= 0, ("%s: space went backwards", __func__));
|
|
}
|
|
|
|
/*
|
|
* I/O completion callback.
|
|
*/
|
|
static void
|
|
sendfile_iodone(void *arg, vm_page_t *pg, int count, int error)
|
|
{
|
|
struct sf_io *sfio = arg;
|
|
struct socket *so = sfio->so;
|
|
|
|
for (int i = 0; i < count; i++)
|
|
if (pg[i] != bogus_page)
|
|
vm_page_xunbusy(pg[i]);
|
|
|
|
if (error)
|
|
sfio->error = error;
|
|
|
|
if (!refcount_release(&sfio->nios))
|
|
return;
|
|
|
|
CURVNET_SET(so->so_vnet);
|
|
if (sfio->error) {
|
|
/*
|
|
* I/O operation failed. The state of data in the socket
|
|
* is now inconsistent, and all what we can do is to tear
|
|
* it down. Protocol abort method would tear down protocol
|
|
* state, free all ready mbufs and detach not ready ones.
|
|
* We will free the mbufs corresponding to this I/O manually.
|
|
*
|
|
* The socket would be marked with EIO and made available
|
|
* for read, so that application receives EIO on next
|
|
* syscall and eventually closes the socket.
|
|
*/
|
|
so->so_proto->pr_usrreqs->pru_abort(so);
|
|
so->so_error = EIO;
|
|
|
|
mb_free_notready(sfio->m, sfio->npages);
|
|
} else
|
|
(void)(so->so_proto->pr_usrreqs->pru_ready)(so, sfio->m,
|
|
sfio->npages);
|
|
|
|
SOCK_LOCK(so);
|
|
sorele(so);
|
|
CURVNET_RESTORE();
|
|
free(sfio, M_TEMP);
|
|
}
|
|
|
|
/*
|
|
* Iterate through pages vector and request paging for non-valid pages.
|
|
*/
|
|
static int
|
|
sendfile_swapin(vm_object_t obj, struct sf_io *sfio, int *nios, off_t off,
|
|
off_t len, int npages, int rhpages, int flags)
|
|
{
|
|
vm_page_t *pa = sfio->pa;
|
|
int grabbed;
|
|
|
|
*nios = 0;
|
|
flags = (flags & SF_NODISKIO) ? VM_ALLOC_NOWAIT : 0;
|
|
|
|
/*
|
|
* First grab all the pages and wire them. Note that we grab
|
|
* only required pages. Readahead pages are dealt with later.
|
|
*/
|
|
VM_OBJECT_WLOCK(obj);
|
|
|
|
grabbed = vm_page_grab_pages(obj, OFF_TO_IDX(off),
|
|
VM_ALLOC_NORMAL | VM_ALLOC_WIRED | flags, pa, npages);
|
|
if (grabbed < npages) {
|
|
for (int i = grabbed; i < npages; i++)
|
|
pa[i] = NULL;
|
|
npages = grabbed;
|
|
rhpages = 0;
|
|
}
|
|
|
|
for (int i = 0; i < npages;) {
|
|
int j, a, count, rv;
|
|
|
|
/* Skip valid pages. */
|
|
if (vm_page_is_valid(pa[i], vmoff(i, off) & PAGE_MASK,
|
|
xfsize(i, npages, off, len))) {
|
|
vm_page_xunbusy(pa[i]);
|
|
SFSTAT_INC(sf_pages_valid);
|
|
i++;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Next page is invalid. Check if it belongs to pager. It
|
|
* may not be there, which is a regular situation for shmem
|
|
* pager. For vnode pager this happens only in case of
|
|
* a sparse file.
|
|
*
|
|
* Important feature of vm_pager_has_page() is the hint
|
|
* stored in 'a', about how many pages we can pagein after
|
|
* this page in a single I/O.
|
|
*/
|
|
if (!vm_pager_has_page(obj, OFF_TO_IDX(vmoff(i, off)), NULL,
|
|
&a)) {
|
|
pmap_zero_page(pa[i]);
|
|
pa[i]->valid = VM_PAGE_BITS_ALL;
|
|
MPASS(pa[i]->dirty == 0);
|
|
vm_page_xunbusy(pa[i]);
|
|
i++;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* We want to pagein as many pages as possible, limited only
|
|
* by the 'a' hint and actual request.
|
|
*/
|
|
count = min(a + 1, npages - i);
|
|
|
|
/*
|
|
* We should not pagein into a valid page, thus we first trim
|
|
* any valid pages off the end of request, and substitute
|
|
* to bogus_page those, that are in the middle.
|
|
*/
|
|
for (j = i + count - 1; j > i; j--) {
|
|
if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK,
|
|
xfsize(j, npages, off, len))) {
|
|
count--;
|
|
rhpages = 0;
|
|
} else
|
|
break;
|
|
}
|
|
for (j = i + 1; j < i + count - 1; j++)
|
|
if (vm_page_is_valid(pa[j], vmoff(j, off) & PAGE_MASK,
|
|
xfsize(j, npages, off, len))) {
|
|
vm_page_xunbusy(pa[j]);
|
|
SFSTAT_INC(sf_pages_valid);
|
|
SFSTAT_INC(sf_pages_bogus);
|
|
pa[j] = bogus_page;
|
|
}
|
|
|
|
refcount_acquire(&sfio->nios);
|
|
rv = vm_pager_get_pages_async(obj, pa + i, count, NULL,
|
|
i + count == npages ? &rhpages : NULL,
|
|
&sendfile_iodone, sfio);
|
|
if (rv != VM_PAGER_OK) {
|
|
for (j = i; j < i + count; j++) {
|
|
if (pa[j] != bogus_page) {
|
|
vm_page_lock(pa[j]);
|
|
vm_page_unwire(pa[j], PQ_INACTIVE);
|
|
vm_page_unlock(pa[j]);
|
|
}
|
|
}
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
return (EIO);
|
|
}
|
|
KASSERT(rv == VM_PAGER_OK, ("%s: pager fail obj %p page %p",
|
|
__func__, obj, pa[i]));
|
|
|
|
SFSTAT_INC(sf_iocnt);
|
|
SFSTAT_ADD(sf_pages_read, count);
|
|
if (i + count == npages)
|
|
SFSTAT_ADD(sf_rhpages_read, rhpages);
|
|
|
|
/*
|
|
* Restore the valid page pointers. They are already
|
|
* unbusied, but still wired.
|
|
*/
|
|
for (j = i; j < i + count; j++)
|
|
if (pa[j] == bogus_page) {
|
|
pa[j] = vm_page_lookup(obj,
|
|
OFF_TO_IDX(vmoff(j, off)));
|
|
KASSERT(pa[j], ("%s: page %p[%d] disappeared",
|
|
__func__, pa, j));
|
|
|
|
}
|
|
i += count;
|
|
(*nios)++;
|
|
}
|
|
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
|
|
if (*nios == 0 && npages != 0)
|
|
SFSTAT_INC(sf_noiocnt);
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
sendfile_getobj(struct thread *td, struct file *fp, vm_object_t *obj_res,
|
|
struct vnode **vp_res, struct shmfd **shmfd_res, off_t *obj_size,
|
|
int *bsize)
|
|
{
|
|
struct vattr va;
|
|
vm_object_t obj;
|
|
struct vnode *vp;
|
|
struct shmfd *shmfd;
|
|
int error;
|
|
|
|
vp = *vp_res = NULL;
|
|
obj = NULL;
|
|
shmfd = *shmfd_res = NULL;
|
|
*bsize = 0;
|
|
|
|
/*
|
|
* The file descriptor must be a regular file and have a
|
|
* backing VM object.
|
|
*/
|
|
if (fp->f_type == DTYPE_VNODE) {
|
|
vp = fp->f_vnode;
|
|
vn_lock(vp, LK_SHARED | LK_RETRY);
|
|
if (vp->v_type != VREG) {
|
|
error = EINVAL;
|
|
goto out;
|
|
}
|
|
*bsize = vp->v_mount->mnt_stat.f_iosize;
|
|
error = VOP_GETATTR(vp, &va, td->td_ucred);
|
|
if (error != 0)
|
|
goto out;
|
|
*obj_size = va.va_size;
|
|
obj = vp->v_object;
|
|
if (obj == NULL) {
|
|
error = EINVAL;
|
|
goto out;
|
|
}
|
|
} else if (fp->f_type == DTYPE_SHM) {
|
|
error = 0;
|
|
shmfd = fp->f_data;
|
|
obj = shmfd->shm_object;
|
|
*obj_size = shmfd->shm_size;
|
|
} else {
|
|
error = EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
VM_OBJECT_WLOCK(obj);
|
|
if ((obj->flags & OBJ_DEAD) != 0) {
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
error = EBADF;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Temporarily increase the backing VM object's reference
|
|
* count so that a forced reclamation of its vnode does not
|
|
* immediately destroy it.
|
|
*/
|
|
vm_object_reference_locked(obj);
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
*obj_res = obj;
|
|
*vp_res = vp;
|
|
*shmfd_res = shmfd;
|
|
|
|
out:
|
|
if (vp != NULL)
|
|
VOP_UNLOCK(vp, 0);
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
sendfile_getsock(struct thread *td, int s, struct file **sock_fp,
|
|
struct socket **so)
|
|
{
|
|
int error;
|
|
|
|
*sock_fp = NULL;
|
|
*so = NULL;
|
|
|
|
/*
|
|
* The socket must be a stream socket and connected.
|
|
*/
|
|
error = getsock_cap(td, s, &cap_send_rights,
|
|
sock_fp, NULL, NULL);
|
|
if (error != 0)
|
|
return (error);
|
|
*so = (*sock_fp)->f_data;
|
|
if ((*so)->so_type != SOCK_STREAM)
|
|
return (EINVAL);
|
|
if (SOLISTENING(*so))
|
|
return (ENOTCONN);
|
|
return (0);
|
|
}
|
|
|
|
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,
|
|
struct thread *td)
|
|
{
|
|
struct file *sock_fp;
|
|
struct vnode *vp;
|
|
struct vm_object *obj;
|
|
struct socket *so;
|
|
struct mbuf_ext_pgs *ext_pgs;
|
|
struct mbuf *m, *mh, *mhtail;
|
|
struct sf_buf *sf;
|
|
struct shmfd *shmfd;
|
|
struct sendfile_sync *sfs;
|
|
struct vattr va;
|
|
off_t off, sbytes, rem, obj_size;
|
|
int bsize, error, ext_pgs_idx, hdrlen, max_pgs, softerr;
|
|
bool use_ext_pgs;
|
|
|
|
obj = NULL;
|
|
so = NULL;
|
|
m = mh = NULL;
|
|
sfs = NULL;
|
|
hdrlen = sbytes = 0;
|
|
softerr = 0;
|
|
use_ext_pgs = false;
|
|
|
|
error = sendfile_getobj(td, fp, &obj, &vp, &shmfd, &obj_size, &bsize);
|
|
if (error != 0)
|
|
return (error);
|
|
|
|
error = sendfile_getsock(td, sockfd, &sock_fp, &so);
|
|
if (error != 0)
|
|
goto out;
|
|
|
|
#ifdef MAC
|
|
error = mac_socket_check_send(td->td_ucred, so);
|
|
if (error != 0)
|
|
goto out;
|
|
#endif
|
|
|
|
SFSTAT_INC(sf_syscalls);
|
|
SFSTAT_ADD(sf_rhpages_requested, SF_READAHEAD(flags));
|
|
|
|
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");
|
|
}
|
|
|
|
rem = nbytes ? omin(nbytes, obj_size - offset) : obj_size - offset;
|
|
|
|
/*
|
|
* Protect against multiple writers to the socket.
|
|
*
|
|
* XXXRW: Historically this has assumed non-interruptibility, so now
|
|
* we implement that, but possibly shouldn't.
|
|
*/
|
|
(void)sblock(&so->so_snd, SBL_WAIT | SBL_NOINTR);
|
|
|
|
/*
|
|
* Loop through the pages of the file, starting with the requested
|
|
* offset. Get a file page (do I/O if necessary), map the file page
|
|
* into an sf_buf, attach an mbuf header to the sf_buf, and queue
|
|
* it on the socket.
|
|
* This is done in two loops. The inner loop turns as many pages
|
|
* as it can, up to available socket buffer space, without blocking
|
|
* into mbufs to have it bulk delivered into the socket send buffer.
|
|
* The outer loop checks the state and available space of the socket
|
|
* and takes care of the overall progress.
|
|
*/
|
|
for (off = offset; rem > 0; ) {
|
|
struct sf_io *sfio;
|
|
vm_page_t *pa;
|
|
struct mbuf *mtail;
|
|
int nios, space, npages, rhpages;
|
|
|
|
mtail = NULL;
|
|
/*
|
|
* Check the socket state for ongoing connection,
|
|
* no errors and space in socket buffer.
|
|
* If space is low allow for the remainder of the
|
|
* file to be processed if it fits the socket buffer.
|
|
* Otherwise block in waiting for sufficient space
|
|
* to proceed, or if the socket is nonblocking, return
|
|
* to userland with EAGAIN while reporting how far
|
|
* we've come.
|
|
* We wait until the socket buffer has significant free
|
|
* space to do bulk sends. This makes good use of file
|
|
* system read ahead and allows packet segmentation
|
|
* offloading hardware to take over lots of work. If
|
|
* we were not careful here we would send off only one
|
|
* sfbuf at a time.
|
|
*/
|
|
SOCKBUF_LOCK(&so->so_snd);
|
|
if (so->so_snd.sb_lowat < so->so_snd.sb_hiwat / 2)
|
|
so->so_snd.sb_lowat = so->so_snd.sb_hiwat / 2;
|
|
retry_space:
|
|
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
|
|
error = EPIPE;
|
|
SOCKBUF_UNLOCK(&so->so_snd);
|
|
goto done;
|
|
} else if (so->so_error) {
|
|
error = so->so_error;
|
|
so->so_error = 0;
|
|
SOCKBUF_UNLOCK(&so->so_snd);
|
|
goto done;
|
|
}
|
|
if ((so->so_state & SS_ISCONNECTED) == 0) {
|
|
SOCKBUF_UNLOCK(&so->so_snd);
|
|
error = ENOTCONN;
|
|
goto done;
|
|
}
|
|
|
|
space = sbspace(&so->so_snd);
|
|
if (space < rem &&
|
|
(space <= 0 ||
|
|
space < so->so_snd.sb_lowat)) {
|
|
if (so->so_state & SS_NBIO) {
|
|
SOCKBUF_UNLOCK(&so->so_snd);
|
|
error = EAGAIN;
|
|
goto done;
|
|
}
|
|
/*
|
|
* sbwait drops the lock while sleeping.
|
|
* When we loop back to retry_space the
|
|
* state may have changed and we retest
|
|
* for it.
|
|
*/
|
|
error = sbwait(&so->so_snd);
|
|
/*
|
|
* An error from sbwait usually indicates that we've
|
|
* been interrupted by a signal. If we've sent anything
|
|
* then return bytes sent, otherwise return the error.
|
|
*/
|
|
if (error != 0) {
|
|
SOCKBUF_UNLOCK(&so->so_snd);
|
|
goto done;
|
|
}
|
|
goto retry_space;
|
|
}
|
|
SOCKBUF_UNLOCK(&so->so_snd);
|
|
|
|
/*
|
|
* At the beginning of the first loop check if any headers
|
|
* are specified and copy them into mbufs. Reduce space in
|
|
* the socket buffer by the size of the header mbuf chain.
|
|
* Clear hdr_uio here and hdrlen at the end of the first loop.
|
|
*/
|
|
if (hdr_uio != NULL && hdr_uio->uio_resid > 0) {
|
|
hdr_uio->uio_td = td;
|
|
hdr_uio->uio_rw = UIO_WRITE;
|
|
mh = m_uiotombuf(hdr_uio, M_WAITOK, space, 0, 0);
|
|
hdrlen = m_length(mh, &mhtail);
|
|
space -= hdrlen;
|
|
/*
|
|
* If header consumed all the socket buffer space,
|
|
* don't waste CPU cycles and jump to the end.
|
|
*/
|
|
if (space == 0) {
|
|
sfio = NULL;
|
|
nios = 0;
|
|
goto prepend_header;
|
|
}
|
|
hdr_uio = NULL;
|
|
}
|
|
|
|
if (vp != NULL) {
|
|
error = vn_lock(vp, LK_SHARED);
|
|
if (error != 0)
|
|
goto done;
|
|
error = VOP_GETATTR(vp, &va, td->td_ucred);
|
|
if (error != 0 || off >= va.va_size) {
|
|
VOP_UNLOCK(vp, 0);
|
|
goto done;
|
|
}
|
|
if (va.va_size != obj_size) {
|
|
obj_size = va.va_size;
|
|
rem = nbytes ?
|
|
omin(nbytes + offset, obj_size) : obj_size;
|
|
rem -= off;
|
|
}
|
|
}
|
|
|
|
if (space > rem)
|
|
space = rem;
|
|
else if (space > PAGE_SIZE) {
|
|
/*
|
|
* Use page boundaries when possible for large
|
|
* requests.
|
|
*/
|
|
if (off & PAGE_MASK)
|
|
space -= (PAGE_SIZE - (off & PAGE_MASK));
|
|
space = trunc_page(space);
|
|
if (off & PAGE_MASK)
|
|
space += (PAGE_SIZE - (off & PAGE_MASK));
|
|
}
|
|
|
|
npages = howmany(space + (off & PAGE_MASK), PAGE_SIZE);
|
|
|
|
/*
|
|
* Calculate maximum allowed number of pages for readahead
|
|
* at this iteration. If SF_USER_READAHEAD was set, we don't
|
|
* do any heuristics and use exactly the value supplied by
|
|
* application. Otherwise, we allow readahead up to "rem".
|
|
* If application wants more, let it be, but there is no
|
|
* reason to go above MAXPHYS. Also check against "obj_size",
|
|
* since vm_pager_has_page() can hint beyond EOF.
|
|
*/
|
|
if (flags & SF_USER_READAHEAD) {
|
|
rhpages = SF_READAHEAD(flags);
|
|
} else {
|
|
rhpages = howmany(rem + (off & PAGE_MASK), PAGE_SIZE) -
|
|
npages;
|
|
rhpages += SF_READAHEAD(flags);
|
|
}
|
|
rhpages = min(howmany(MAXPHYS, PAGE_SIZE), rhpages);
|
|
rhpages = min(howmany(obj_size - trunc_page(off), PAGE_SIZE) -
|
|
npages, rhpages);
|
|
|
|
sfio = malloc(sizeof(struct sf_io) +
|
|
npages * sizeof(vm_page_t), M_TEMP, M_WAITOK);
|
|
refcount_init(&sfio->nios, 1);
|
|
sfio->so = so;
|
|
sfio->error = 0;
|
|
|
|
error = sendfile_swapin(obj, sfio, &nios, off, space, npages,
|
|
rhpages, flags);
|
|
if (error != 0) {
|
|
if (vp != NULL)
|
|
VOP_UNLOCK(vp, 0);
|
|
free(sfio, M_TEMP);
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* Loop and construct maximum sized mbuf chain to be bulk
|
|
* dumped into socket buffer.
|
|
*/
|
|
pa = sfio->pa;
|
|
|
|
/*
|
|
* Use unmapped mbufs if enabled for TCP. Unmapped
|
|
* bufs are restricted to TCP as that is what has been
|
|
* tested. In particular, unmapped mbufs have not
|
|
* been tested with UNIX-domain sockets.
|
|
*/
|
|
if (mb_use_ext_pgs &&
|
|
so->so_proto->pr_protocol == IPPROTO_TCP) {
|
|
use_ext_pgs = true;
|
|
max_pgs = MBUF_PEXT_MAX_PGS;
|
|
|
|
/* Start at last index, to wrap on first use. */
|
|
ext_pgs_idx = max_pgs - 1;
|
|
}
|
|
|
|
for (int i = 0; i < npages; i++) {
|
|
struct mbuf *m0;
|
|
|
|
/*
|
|
* If a page wasn't grabbed successfully, then
|
|
* trim the array. Can happen only with SF_NODISKIO.
|
|
*/
|
|
if (pa[i] == NULL) {
|
|
SFSTAT_INC(sf_busy);
|
|
fixspace(npages, i, off, &space);
|
|
npages = i;
|
|
softerr = EBUSY;
|
|
break;
|
|
}
|
|
|
|
if (use_ext_pgs) {
|
|
off_t xfs;
|
|
|
|
ext_pgs_idx++;
|
|
if (ext_pgs_idx == max_pgs) {
|
|
m0 = mb_alloc_ext_pgs(M_WAITOK, false,
|
|
sendfile_free_mext_pg);
|
|
|
|
if (flags & SF_NOCACHE) {
|
|
m0->m_ext.ext_flags |=
|
|
EXT_FLAG_NOCACHE;
|
|
|
|
/*
|
|
* See comment below regarding
|
|
* ignoring SF_NOCACHE for the
|
|
* last page.
|
|
*/
|
|
if ((npages - i <= max_pgs) &&
|
|
((off + space) & PAGE_MASK) &&
|
|
(rem > space || rhpages > 0))
|
|
m0->m_ext.ext_flags |=
|
|
EXT_FLAG_CACHE_LAST;
|
|
}
|
|
if (sfs != NULL) {
|
|
m0->m_ext.ext_flags |=
|
|
EXT_FLAG_SYNC;
|
|
m0->m_ext.ext_arg2 = sfs;
|
|
mtx_lock(&sfs->mtx);
|
|
sfs->count++;
|
|
mtx_unlock(&sfs->mtx);
|
|
}
|
|
ext_pgs = m0->m_ext.ext_pgs;
|
|
if (i == 0)
|
|
sfio->m = m0;
|
|
ext_pgs_idx = 0;
|
|
|
|
/* Append to mbuf chain. */
|
|
if (mtail != NULL)
|
|
mtail->m_next = m0;
|
|
else
|
|
m = m0;
|
|
mtail = m0;
|
|
ext_pgs->first_pg_off =
|
|
vmoff(i, off) & PAGE_MASK;
|
|
}
|
|
if (nios) {
|
|
mtail->m_flags |= M_NOTREADY;
|
|
ext_pgs->nrdy++;
|
|
}
|
|
|
|
ext_pgs->pa[ext_pgs_idx] = VM_PAGE_TO_PHYS(pa[i]);
|
|
ext_pgs->npgs++;
|
|
xfs = xfsize(i, npages, off, space);
|
|
ext_pgs->last_pg_len = xfs;
|
|
MBUF_EXT_PGS_ASSERT_SANITY(ext_pgs);
|
|
mtail->m_len += xfs;
|
|
mtail->m_ext.ext_size += PAGE_SIZE;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Get a sendfile buf. When allocating the
|
|
* first buffer for mbuf chain, we usually
|
|
* wait as long as necessary, but this wait
|
|
* can be interrupted. For consequent
|
|
* buffers, do not sleep, since several
|
|
* threads might exhaust the buffers and then
|
|
* deadlock.
|
|
*/
|
|
sf = sf_buf_alloc(pa[i],
|
|
m != NULL ? SFB_NOWAIT : SFB_CATCH);
|
|
if (sf == NULL) {
|
|
SFSTAT_INC(sf_allocfail);
|
|
for (int j = i; j < npages; j++) {
|
|
vm_page_lock(pa[j]);
|
|
vm_page_unwire(pa[j], PQ_INACTIVE);
|
|
vm_page_unlock(pa[j]);
|
|
}
|
|
if (m == NULL)
|
|
softerr = ENOBUFS;
|
|
fixspace(npages, i, off, &space);
|
|
npages = i;
|
|
break;
|
|
}
|
|
|
|
m0 = m_get(M_WAITOK, MT_DATA);
|
|
m0->m_ext.ext_buf = (char *)sf_buf_kva(sf);
|
|
m0->m_ext.ext_size = PAGE_SIZE;
|
|
m0->m_ext.ext_arg1 = sf;
|
|
m0->m_ext.ext_type = EXT_SFBUF;
|
|
m0->m_ext.ext_flags = EXT_FLAG_EMBREF;
|
|
m0->m_ext.ext_free = sendfile_free_mext;
|
|
/*
|
|
* SF_NOCACHE sets the page as being freed upon send.
|
|
* However, we ignore it for the last page in 'space',
|
|
* if the page is truncated, and we got more data to
|
|
* send (rem > space), or if we have readahead
|
|
* configured (rhpages > 0).
|
|
*/
|
|
if ((flags & SF_NOCACHE) &&
|
|
(i != npages - 1 ||
|
|
!((off + space) & PAGE_MASK) ||
|
|
!(rem > space || rhpages > 0)))
|
|
m0->m_ext.ext_flags |= EXT_FLAG_NOCACHE;
|
|
if (sfs != NULL) {
|
|
m0->m_ext.ext_flags |= EXT_FLAG_SYNC;
|
|
m0->m_ext.ext_arg2 = sfs;
|
|
mtx_lock(&sfs->mtx);
|
|
sfs->count++;
|
|
mtx_unlock(&sfs->mtx);
|
|
}
|
|
m0->m_ext.ext_count = 1;
|
|
m0->m_flags |= (M_EXT | M_RDONLY);
|
|
if (nios)
|
|
m0->m_flags |= M_NOTREADY;
|
|
m0->m_data = (char *)sf_buf_kva(sf) +
|
|
(vmoff(i, off) & PAGE_MASK);
|
|
m0->m_len = xfsize(i, npages, off, space);
|
|
|
|
if (i == 0)
|
|
sfio->m = m0;
|
|
|
|
/* Append to mbuf chain. */
|
|
if (mtail != NULL)
|
|
mtail->m_next = m0;
|
|
else
|
|
m = m0;
|
|
mtail = m0;
|
|
}
|
|
|
|
if (vp != NULL)
|
|
VOP_UNLOCK(vp, 0);
|
|
|
|
/* Keep track of bytes processed. */
|
|
off += space;
|
|
rem -= space;
|
|
|
|
/* Prepend header, if any. */
|
|
if (hdrlen) {
|
|
prepend_header:
|
|
mhtail->m_next = m;
|
|
m = mh;
|
|
mh = NULL;
|
|
}
|
|
|
|
if (m == NULL) {
|
|
KASSERT(softerr, ("%s: m NULL, no error", __func__));
|
|
error = softerr;
|
|
free(sfio, M_TEMP);
|
|
goto done;
|
|
}
|
|
|
|
/* Add the buffer chain to the socket buffer. */
|
|
KASSERT(m_length(m, NULL) == space + hdrlen,
|
|
("%s: mlen %u space %d hdrlen %d",
|
|
__func__, m_length(m, NULL), space, hdrlen));
|
|
|
|
CURVNET_SET(so->so_vnet);
|
|
if (nios == 0) {
|
|
/*
|
|
* If sendfile_swapin() didn't initiate any I/Os,
|
|
* which happens if all data is cached in VM, then
|
|
* we can send data right now without the
|
|
* PRUS_NOTREADY flag.
|
|
*/
|
|
free(sfio, M_TEMP);
|
|
error = (*so->so_proto->pr_usrreqs->pru_send)
|
|
(so, 0, m, NULL, NULL, td);
|
|
} else {
|
|
sfio->npages = npages;
|
|
soref(so);
|
|
error = (*so->so_proto->pr_usrreqs->pru_send)
|
|
(so, PRUS_NOTREADY, m, NULL, NULL, td);
|
|
sendfile_iodone(sfio, NULL, 0, 0);
|
|
}
|
|
CURVNET_RESTORE();
|
|
|
|
m = NULL; /* pru_send always consumes */
|
|
if (error)
|
|
goto done;
|
|
sbytes += space + hdrlen;
|
|
if (hdrlen)
|
|
hdrlen = 0;
|
|
if (softerr) {
|
|
error = softerr;
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Send trailers. Wimp out and use writev(2).
|
|
*/
|
|
if (trl_uio != NULL) {
|
|
sbunlock(&so->so_snd);
|
|
error = kern_writev(td, sockfd, trl_uio);
|
|
if (error == 0)
|
|
sbytes += td->td_retval[0];
|
|
goto out;
|
|
}
|
|
|
|
done:
|
|
sbunlock(&so->so_snd);
|
|
out:
|
|
/*
|
|
* If there was no error we have to clear td->td_retval[0]
|
|
* because it may have been set by writev.
|
|
*/
|
|
if (error == 0) {
|
|
td->td_retval[0] = 0;
|
|
}
|
|
if (sent != NULL) {
|
|
(*sent) = sbytes;
|
|
}
|
|
if (obj != NULL)
|
|
vm_object_deallocate(obj);
|
|
if (so)
|
|
fdrop(sock_fp, td);
|
|
if (m)
|
|
m_freem(m);
|
|
if (mh)
|
|
m_freem(mh);
|
|
|
|
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;
|
|
|
|
return (error);
|
|
}
|
|
|
|
static int
|
|
sendfile(struct thread *td, struct sendfile_args *uap, int compat)
|
|
{
|
|
struct sf_hdtr hdtr;
|
|
struct uio *hdr_uio, *trl_uio;
|
|
struct file *fp;
|
|
off_t sbytes;
|
|
int error;
|
|
|
|
/*
|
|
* File offset must be positive. If it goes beyond EOF
|
|
* we send only the header/trailer and no payload data.
|
|
*/
|
|
if (uap->offset < 0)
|
|
return (EINVAL);
|
|
|
|
sbytes = 0;
|
|
hdr_uio = trl_uio = NULL;
|
|
|
|
if (uap->hdtr != NULL) {
|
|
error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
|
|
if (error != 0)
|
|
goto out;
|
|
if (hdtr.headers != NULL) {
|
|
error = copyinuio(hdtr.headers, hdtr.hdr_cnt,
|
|
&hdr_uio);
|
|
if (error != 0)
|
|
goto out;
|
|
#ifdef COMPAT_FREEBSD4
|
|
/*
|
|
* In FreeBSD < 5.0 the nbytes to send also included
|
|
* the header. If compat is specified subtract the
|
|
* header size from nbytes.
|
|
*/
|
|
if (compat) {
|
|
if (uap->nbytes > hdr_uio->uio_resid)
|
|
uap->nbytes -= hdr_uio->uio_resid;
|
|
else
|
|
uap->nbytes = 0;
|
|
}
|
|
#endif
|
|
}
|
|
if (hdtr.trailers != NULL) {
|
|
error = copyinuio(hdtr.trailers, hdtr.trl_cnt,
|
|
&trl_uio);
|
|
if (error != 0)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
AUDIT_ARG_FD(uap->fd);
|
|
|
|
/*
|
|
* sendfile(2) can start at any offset within a file so we require
|
|
* CAP_READ+CAP_SEEK = CAP_PREAD.
|
|
*/
|
|
if ((error = fget_read(td, uap->fd, &cap_pread_rights, &fp)) != 0)
|
|
goto out;
|
|
|
|
error = fo_sendfile(fp, uap->s, hdr_uio, trl_uio, uap->offset,
|
|
uap->nbytes, &sbytes, uap->flags, td);
|
|
fdrop(fp, td);
|
|
|
|
if (uap->sbytes != NULL)
|
|
copyout(&sbytes, uap->sbytes, sizeof(off_t));
|
|
|
|
out:
|
|
free(hdr_uio, M_IOV);
|
|
free(trl_uio, M_IOV);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* sendfile(2)
|
|
*
|
|
* int sendfile(int fd, int s, off_t offset, size_t nbytes,
|
|
* struct sf_hdtr *hdtr, off_t *sbytes, int flags)
|
|
*
|
|
* Send a file specified by 'fd' and starting at 'offset' to a socket
|
|
* specified by 's'. Send only 'nbytes' of the file or until EOF if nbytes ==
|
|
* 0. Optionally add a header and/or trailer to the socket output. If
|
|
* specified, write the total number of bytes sent into *sbytes.
|
|
*/
|
|
int
|
|
sys_sendfile(struct thread *td, struct sendfile_args *uap)
|
|
{
|
|
|
|
return (sendfile(td, uap, 0));
|
|
}
|
|
|
|
#ifdef COMPAT_FREEBSD4
|
|
int
|
|
freebsd4_sendfile(struct thread *td, struct freebsd4_sendfile_args *uap)
|
|
{
|
|
struct sendfile_args args;
|
|
|
|
args.fd = uap->fd;
|
|
args.s = uap->s;
|
|
args.offset = uap->offset;
|
|
args.nbytes = uap->nbytes;
|
|
args.hdtr = uap->hdtr;
|
|
args.sbytes = uap->sbytes;
|
|
args.flags = uap->flags;
|
|
|
|
return (sendfile(td, &args, 1));
|
|
}
|
|
#endif /* COMPAT_FREEBSD4 */
|