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NetBSD/sys/kern/sys_pipe.c
thorpej a180cee23b Pool deals fairly well with physical memory shortage, but it doesn't 
deal with shortages of the VM maps where the backing pages are mapped
(usually kmem_map).  Try to deal with this:

* Group all information about the backend allocator for a pool in a
  separate structure.  The pool references this structure, rather than
  the individual fields.
* Change the pool_init() API accordingly, and adjust all callers.
* Link all pools using the same backend allocator on a list.
* The backend allocator is responsible for waiting for physical memory
  to become available, but will still fail if it cannot callocate KVA
  space for the pages.  If this happens, carefully drain all pools using
  the same backend allocator, so that some KVA space can be freed.
* Change pool_reclaim() to indicate if it actually succeeded in freeing
  some pages, and use that information to make draining easier and more
  efficient.
* Get rid of PR_URGENT.  There was only one use of it, and it could be
  dealt with by the caller.

From art@openbsd.org.
2002-03-08 20:48:27 +00:00

1822 lines
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/* $NetBSD: sys_pipe.c,v 1.23 2002/03/08 20:48:41 thorpej Exp $ */
/*
* Copyright (c) 1996 John S. Dyson
* 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 immediately at the beginning of the file, without modification,
* 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. Absolutely no warranty of function or purpose is made by the author
* John S. Dyson.
* 4. Modifications may be freely made to this file if the above conditions
* are met.
*
* $FreeBSD: src/sys/kern/sys_pipe.c,v 1.82 2001/06/15 20:45:01 jlemon Exp $
*/
/*
* This file contains a high-performance replacement for the socket-based
* pipes scheme originally used in FreeBSD/4.4Lite. It does not support
* all features of sockets, but does do everything that pipes normally
* do.
*
* Adaption for NetBSD UVM, including uvm_loan() based direct write, was
* written by Jaromir Dolecek.
*/
/*
* This code has two modes of operation, a small write mode and a large
* write mode. The small write mode acts like conventional pipes with
* a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the
* "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT
* and PIPE_SIZE in size, it is fully mapped into the kernel (on FreeBSD,
* those pages are also wired), and the receiving process can copy it directly
* from the pages in the sending process.
*
* If the sending process receives a signal, it is possible that it will
* go away, and certainly its address space can change, because control
* is returned back to the user-mode side. In that case, the pipe code
* arranges to copy the buffer supplied by the user process on FreeBSD, to
* a pageable kernel buffer, and the receiving process will grab the data
* from the pageable kernel buffer. Since signals don't happen all that often,
* the copy operation is normally eliminated.
* For NetBSD, the pages are mapped read-only, COW for kernel by uvm_loan(),
* so no explicit handling need to be done, all is handled by standard VM
* facilities.
*
* The constant PIPE_MINDIRECT is chosen to make sure that buffering will
* happen for small transfers so that the system will not spend all of
* its time context switching. PIPE_SIZE is constrained by the
* amount of kernel virtual memory.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_pipe.c,v 1.23 2002/03/08 20:48:41 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#include <sys/ttycom.h>
#include <sys/stat.h>
#include <sys/poll.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <sys/uio.h>
#include <sys/lock.h>
#ifdef __FreeBSD__
#include <sys/mutex.h>
#include <sys/selinfo.h>
#include <sys/sysproto.h>
#elif defined(__NetBSD__)
#include <sys/select.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <uvm/uvm.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#endif /* NetBSD, FreeBSD */
#include <sys/pipe.h>
#ifdef __NetBSD__
/*
* Avoid microtime(9), it's slow. We don't guard the read from time(9)
* with splclock(9) since we don't actually need to be THAT sure the access
* is atomic.
*/
#define vfs_timestamp(tv) (*(tv) = time)
#endif
/*
* Use this define if you want to disable *fancy* VM things. Expect an
* approx 30% decrease in transfer rate. This could be useful for
* OpenBSD.
*/
/* #define PIPE_NODIRECT */
/*
* interfaces to the outside world
*/
#ifdef __FreeBSD__
static int pipe_read __P((struct file *fp, struct uio *uio,
struct ucred *cred, int flags, struct proc *p));
static int pipe_write __P((struct file *fp, struct uio *uio,
struct ucred *cred, int flags, struct proc *p));
static int pipe_close __P((struct file *fp, struct proc *p));
static int pipe_poll __P((struct file *fp, int events, struct ucred *cred,
struct proc *p));
static int pipe_kqfilter __P((struct file *fp, struct knote *kn));
static int pipe_stat __P((struct file *fp, struct stat *sb, struct proc *p));
static int pipe_ioctl __P((struct file *fp, u_long cmd, caddr_t data, struct proc *p));
static struct fileops pipeops = {
pipe_read, pipe_write, pipe_ioctl, pipe_poll, pipe_kqfilter,
pipe_stat, pipe_close
};
static void filt_pipedetach(struct knote *kn);
static int filt_piperead(struct knote *kn, long hint);
static int filt_pipewrite(struct knote *kn, long hint);
static struct filterops pipe_rfiltops =
{ 1, NULL, filt_pipedetach, filt_piperead };
static struct filterops pipe_wfiltops =
{ 1, NULL, filt_pipedetach, filt_pipewrite };
#endif /* FreeBSD */
#ifdef __NetBSD__
static int pipe_read __P((struct file *fp, off_t *offset, struct uio *uio,
struct ucred *cred, int flags));
static int pipe_write __P((struct file *fp, off_t *offset, struct uio *uio,
struct ucred *cred, int flags));
static int pipe_close __P((struct file *fp, struct proc *p));
static int pipe_poll __P((struct file *fp, int events, struct proc *p));
static int pipe_fcntl __P((struct file *fp, u_int com, caddr_t data,
struct proc *p));
static int pipe_stat __P((struct file *fp, struct stat *sb, struct proc *p));
static int pipe_ioctl __P((struct file *fp, u_long cmd, caddr_t data, struct proc *p));
static struct fileops pipeops =
{ pipe_read, pipe_write, pipe_ioctl, pipe_fcntl, pipe_poll,
pipe_stat, pipe_close };
#endif /* NetBSD */
/*
* Default pipe buffer size(s), this can be kind-of large now because pipe
* space is pageable. The pipe code will try to maintain locality of
* reference for performance reasons, so small amounts of outstanding I/O
* will not wipe the cache.
*/
#define MINPIPESIZE (PIPE_SIZE/3)
#define MAXPIPESIZE (2*PIPE_SIZE/3)
/*
* Maximum amount of kva for pipes -- this is kind-of a soft limit, but
* is there so that on large systems, we don't exhaust it.
*/
#define MAXPIPEKVA (8*1024*1024)
static int maxpipekva = MAXPIPEKVA;
/*
* Limit for direct transfers, we cannot, of course limit
* the amount of kva for pipes in general though.
*/
#define LIMITPIPEKVA (16*1024*1024)
static int limitpipekva = LIMITPIPEKVA;
/*
* Limit the number of "big" pipes
*/
#define LIMITBIGPIPES 32
static int maxbigpipes = LIMITBIGPIPES;
static int nbigpipe = 0;
/*
* Amount of KVA consumed by pipe buffers.
*/
static int amountpipekva = 0;
static void pipeclose __P((struct pipe *));
static void pipe_free_kmem __P((struct pipe *));
static int pipe_create __P((struct pipe **, int));
static __inline int pipelock __P((struct pipe *, int));
static __inline void pipeunlock __P((struct pipe *));
static __inline void pipeselwakeup __P((struct pipe *, struct pipe *));
static int pipespace __P((struct pipe *, int));
#ifdef __FreeBSD__
#ifndef PIPE_NODIRECT
static int pipe_build_write_buffer __P((struct pipe *wpipe, struct uio *uio));
static void pipe_destroy_write_buffer __P((struct pipe *wpipe));
static int pipe_direct_write __P((struct pipe *wpipe, struct uio *uio));
static void pipe_clone_write_buffer __P((struct pipe *wpipe));
#endif
static vm_zone_t pipe_zone;
#endif /* FreeBSD */
#ifdef __NetBSD__
#ifndef PIPE_NODIRECT
static int pipe_direct_write __P((struct pipe *, struct uio *));
static int pipe_loan_alloc __P((struct pipe *, int));
static void pipe_loan_free __P((struct pipe *));
#endif /* PIPE_NODIRECT */
static struct pool pipe_pool;
#endif /* NetBSD */
/*
* The pipe system call for the DTYPE_PIPE type of pipes
*/
/* ARGSUSED */
#ifdef __FreeBSD__
int
pipe(p, uap)
struct proc *p;
struct pipe_args /* {
int dummy;
} */ *uap;
#elif defined(__NetBSD__)
int
sys_pipe(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
#endif
{
struct file *rf, *wf;
struct pipe *rpipe, *wpipe;
int fd, error;
#ifdef __FreeBSD__
if (pipe_zone == NULL)
pipe_zone = zinit("PIPE", sizeof(struct pipe), 0, 0, 4);
rpipe = wpipe = NULL;
if (pipe_create(&rpipe, 1) || pipe_create(&wpipe, 1)) {
pipeclose(rpipe);
pipeclose(wpipe);
return (ENFILE);
}
error = falloc(p, &rf, &fd);
if (error) {
pipeclose(rpipe);
pipeclose(wpipe);
return (error);
}
fhold(rf);
p->p_retval[0] = fd;
/*
* Warning: once we've gotten past allocation of the fd for the
* read-side, we can only drop the read side via fdrop() in order
* to avoid races against processes which manage to dup() the read
* side while we are blocked trying to allocate the write side.
*/
rf->f_flag = FREAD | FWRITE;
rf->f_type = DTYPE_PIPE;
rf->f_data = (caddr_t)rpipe;
rf->f_ops = &pipeops;
error = falloc(p, &wf, &fd);
if (error) {
struct filedesc *fdp = p->p_fd;
if (fdp->fd_ofiles[p->p_retval[0]] == rf) {
fdp->fd_ofiles[p->p_retval[0]] = NULL;
fdrop(rf, p);
}
fdrop(rf, p);
/* rpipe has been closed by fdrop(). */
pipeclose(wpipe);
return (error);
}
wf->f_flag = FREAD | FWRITE;
wf->f_type = DTYPE_PIPE;
wf->f_data = (caddr_t)wpipe;
wf->f_ops = &pipeops;
p->p_retval[1] = fd;
rpipe->pipe_peer = wpipe;
wpipe->pipe_peer = rpipe;
fdrop(rf, p);
#endif /* FreeBSD */
#ifdef __NetBSD__
rpipe = wpipe = NULL;
if (pipe_create(&rpipe, 1) || pipe_create(&wpipe, 0)) {
pipeclose(rpipe);
pipeclose(wpipe);
return (ENFILE);
}
/*
* Note: the file structure returned from falloc() is marked
* as 'larval' initially. Unless we mark it as 'mature' by
* FILE_SET_MATURE(), any attempt to do anything with it would
* return EBADF, including e.g. dup(2) or close(2). This avoids
* file descriptor races if we block in the second falloc().
*/
error = falloc(p, &rf, &fd);
if (error)
goto free2;
retval[0] = fd;
rf->f_flag = FREAD;
rf->f_type = DTYPE_PIPE;
rf->f_data = (caddr_t)rpipe;
rf->f_ops = &pipeops;
error = falloc(p, &wf, &fd);
if (error)
goto free3;
retval[1] = fd;
wf->f_flag = FWRITE;
wf->f_type = DTYPE_PIPE;
wf->f_data = (caddr_t)wpipe;
wf->f_ops = &pipeops;
rpipe->pipe_peer = wpipe;
wpipe->pipe_peer = rpipe;
FILE_SET_MATURE(rf);
FILE_SET_MATURE(wf);
FILE_UNUSE(rf, p);
FILE_UNUSE(wf, p);
return (0);
free3:
FILE_UNUSE(rf, p);
ffree(rf);
fdremove(p->p_fd, retval[0]);
free2:
pipeclose(wpipe);
pipeclose(rpipe);
#endif /* NetBSD */
return (error);
}
/*
* Allocate kva for pipe circular buffer, the space is pageable
* This routine will 'realloc' the size of a pipe safely, if it fails
* it will retain the old buffer.
* If it fails it will return ENOMEM.
*/
static int
pipespace(cpipe, size)
struct pipe *cpipe;
int size;
{
caddr_t buffer;
#ifdef __FreeBSD__
struct vm_object *object;
int npages, error;
npages = round_page(size)/PAGE_SIZE;
/*
* Create an object, I don't like the idea of paging to/from
* kernel_object.
*/
mtx_lock(&vm_mtx);
object = vm_object_allocate(OBJT_DEFAULT, npages);
buffer = (caddr_t) vm_map_min(kernel_map);
/*
* Insert the object into the kernel map, and allocate kva for it.
* The map entry is, by default, pageable.
*/
error = vm_map_find(kernel_map, object, 0,
(vm_offset_t *) &buffer, size, 1,
VM_PROT_ALL, VM_PROT_ALL, 0);
if (error != KERN_SUCCESS) {
vm_object_deallocate(object);
mtx_unlock(&vm_mtx);
return (ENOMEM);
}
#endif /* FreeBSD */
#ifdef __NetBSD__
/*
* Allocate pageable virtual address space. Physical memory is allocated
* on demand.
*/
buffer = (caddr_t) uvm_km_valloc(kernel_map, round_page(size));
if (buffer == NULL)
return (ENOMEM);
#endif /* NetBSD */
/* free old resources if we're resizing */
pipe_free_kmem(cpipe);
#ifdef __FreeBSD__
mtx_unlock(&vm_mtx);
cpipe->pipe_buffer.object = object;
#endif
cpipe->pipe_buffer.buffer = buffer;
cpipe->pipe_buffer.size = size;
cpipe->pipe_buffer.in = 0;
cpipe->pipe_buffer.out = 0;
cpipe->pipe_buffer.cnt = 0;
amountpipekva += cpipe->pipe_buffer.size;
return (0);
}
/*
* initialize and allocate VM and memory for pipe
*/
static int
pipe_create(cpipep, allockva)
struct pipe **cpipep;
int allockva;
{
struct pipe *cpipe;
int error;
#ifdef __FreeBSD__
*cpipep = zalloc(pipe_zone);
#endif
#ifdef __NetBSD__
*cpipep = pool_get(&pipe_pool, M_WAITOK);
#endif
if (*cpipep == NULL)
return (ENOMEM);
cpipe = *cpipep;
/* Initialize */
memset(cpipe, 0, sizeof(*cpipe));
cpipe->pipe_state = PIPE_SIGNALR;
if (allockva && (error = pipespace(cpipe, PIPE_SIZE)))
return (error);
vfs_timestamp(&cpipe->pipe_ctime);
cpipe->pipe_atime = cpipe->pipe_ctime;
cpipe->pipe_mtime = cpipe->pipe_ctime;
#ifdef __NetBSD__
cpipe->pipe_pgid = NO_PID;
lockinit(&cpipe->pipe_lock, PRIBIO | PCATCH, "pipelk", 0, 0);
#endif
return (0);
}
/*
* lock a pipe for I/O, blocking other access
*/
static __inline int
pipelock(cpipe, catch)
struct pipe *cpipe;
int catch;
{
int error;
#ifdef __FreeBSD__
while (cpipe->pipe_state & PIPE_LOCK) {
cpipe->pipe_state |= PIPE_LWANT;
error = tsleep(cpipe, catch ? (PRIBIO | PCATCH) : PRIBIO,
"pipelk", 0);
if (error != 0)
return (error);
}
cpipe->pipe_state |= PIPE_LOCK;
return (0);
#endif
#ifdef __NetBSD__
do {
error = lockmgr(&cpipe->pipe_lock, LK_EXCLUSIVE, NULL);
} while (!catch && (error == EINTR || error == ERESTART));
return (error);
#endif
}
/*
* unlock a pipe I/O lock
*/
static __inline void
pipeunlock(cpipe)
struct pipe *cpipe;
{
#ifdef __FreeBSD__
cpipe->pipe_state &= ~PIPE_LOCK;
if (cpipe->pipe_state & PIPE_LWANT) {
cpipe->pipe_state &= ~PIPE_LWANT;
wakeup(cpipe);
}
#endif
#ifdef __NetBSD__
lockmgr(&cpipe->pipe_lock, LK_RELEASE, NULL);
#endif
}
/*
* Select/poll wakup. This also sends SIGIO to peer connected to
* 'sigpipe' side of pipe.
*/
static __inline void
pipeselwakeup(selp, sigp)
struct pipe *selp, *sigp;
{
if (selp->pipe_state & PIPE_SEL) {
selp->pipe_state &= ~PIPE_SEL;
selwakeup(&selp->pipe_sel);
}
#ifdef __FreeBSD__
if (sigp && (sigp->pipe_state & PIPE_ASYNC) && sigp->pipe_sigio)
pgsigio(sigp->pipe_sigio, SIGIO, 0);
KNOTE(&selp->pipe_sel.si_note, 0);
#endif
#ifdef __NetBSD__
if (sigp && (sigp->pipe_state & PIPE_ASYNC)
&& sigp->pipe_pgid != NO_PID){
struct proc *p;
if (sigp->pipe_pgid < 0)
gsignal(-sigp->pipe_pgid, SIGIO);
else if (sigp->pipe_pgid > 0 && (p = pfind(sigp->pipe_pgid)) != 0)
psignal(p, SIGIO);
}
#endif /* NetBSD */
}
/* ARGSUSED */
#ifdef __FreeBSD__
static int
pipe_read(fp, uio, cred, flags, p)
struct file *fp;
struct uio *uio;
struct ucred *cred;
int flags;
struct proc *p;
#elif defined(__NetBSD__)
static int
pipe_read(fp, offset, uio, cred, flags)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
#endif
{
struct pipe *rpipe = (struct pipe *) fp->f_data;
int error;
size_t nread = 0;
size_t size;
size_t ocnt;
++rpipe->pipe_busy;
error = pipelock(rpipe, 1);
if (error)
goto unlocked_error;
ocnt = rpipe->pipe_buffer.cnt;
while (uio->uio_resid) {
/*
* normal pipe buffer receive
*/
if (rpipe->pipe_buffer.cnt > 0) {
size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out;
if (size > rpipe->pipe_buffer.cnt)
size = rpipe->pipe_buffer.cnt;
if (size > uio->uio_resid)
size = uio->uio_resid;
error = uiomove(&rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out],
size, uio);
if (error)
break;
rpipe->pipe_buffer.out += size;
if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size)
rpipe->pipe_buffer.out = 0;
rpipe->pipe_buffer.cnt -= size;
/*
* If there is no more to read in the pipe, reset
* its pointers to the beginning. This improves
* cache hit stats.
*/
if (rpipe->pipe_buffer.cnt == 0) {
rpipe->pipe_buffer.in = 0;
rpipe->pipe_buffer.out = 0;
}
nread += size;
#ifndef PIPE_NODIRECT
/*
* Direct copy, bypassing a kernel buffer.
*/
} else if ((size = rpipe->pipe_map.cnt) &&
(rpipe->pipe_state & PIPE_DIRECTW)) {
caddr_t va;
if (size > uio->uio_resid)
size = uio->uio_resid;
va = (caddr_t) rpipe->pipe_map.kva +
rpipe->pipe_map.pos;
error = uiomove(va, size, uio);
if (error)
break;
nread += size;
rpipe->pipe_map.pos += size;
rpipe->pipe_map.cnt -= size;
if (rpipe->pipe_map.cnt == 0) {
rpipe->pipe_state &= ~PIPE_DIRECTW;
wakeup(rpipe);
}
#endif
} else {
/*
* detect EOF condition
* read returns 0 on EOF, no need to set error
*/
if (rpipe->pipe_state & PIPE_EOF)
break;
/*
* If the "write-side" has been blocked, wake it up now.
*/
if (rpipe->pipe_state & PIPE_WANTW) {
rpipe->pipe_state &= ~PIPE_WANTW;
wakeup(rpipe);
}
/*
* Break if some data was read.
*/
if (nread > 0)
break;
/*
* don't block on non-blocking I/O
*/
if (fp->f_flag & FNONBLOCK) {
error = EAGAIN;
break;
}
/*
* Unlock the pipe buffer for our remaining processing.
* We will either break out with an error or we will
* sleep and relock to loop.
*/
pipeunlock(rpipe);
/*
* We want to read more, wake up select/poll.
*/
pipeselwakeup(rpipe, rpipe->pipe_peer);
rpipe->pipe_state |= PIPE_WANTR;
error = tsleep(rpipe, PRIBIO | PCATCH, "piperd", 0);
if (error != 0 || (error = pipelock(rpipe, 1)))
goto unlocked_error;
}
}
pipeunlock(rpipe);
if (error == 0)
vfs_timestamp(&rpipe->pipe_atime);
unlocked_error:
--rpipe->pipe_busy;
/*
* PIPE_WANTCLOSE processing only makes sense if pipe_busy is 0.
*/
if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANTCLOSE)) {
rpipe->pipe_state &= ~(PIPE_WANTCLOSE|PIPE_WANTW);
wakeup(rpipe);
} else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) {
/*
* Handle write blocking hysteresis.
*/
if (rpipe->pipe_state & PIPE_WANTW) {
rpipe->pipe_state &= ~PIPE_WANTW;
wakeup(rpipe);
}
}
/*
* If anything was read off the buffer, signal to the writer it's
* possible to write more data. Also send signal if we are here for the
* first time after last write.
*/
if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF
&& (ocnt != rpipe->pipe_buffer.cnt || (rpipe->pipe_state & PIPE_SIGNALR))) {
pipeselwakeup(rpipe, rpipe->pipe_peer);
rpipe->pipe_state &= ~PIPE_SIGNALR;
}
return (error);
}
#ifdef __FreeBSD__
#ifndef PIPE_NODIRECT
/*
* Map the sending processes' buffer into kernel space and wire it.
* This is similar to a physical write operation.
*/
static int
pipe_build_write_buffer(wpipe, uio)
struct pipe *wpipe;
struct uio *uio;
{
size_t size;
int i;
vm_offset_t addr, endaddr, paddr;
size = uio->uio_iov->iov_len;
if (size > wpipe->pipe_buffer.size)
size = wpipe->pipe_buffer.size;
endaddr = round_page((vm_offset_t)uio->uio_iov->iov_base + size);
mtx_lock(&vm_mtx);
addr = trunc_page((vm_offset_t)uio->uio_iov->iov_base);
for (i = 0; addr < endaddr; addr += PAGE_SIZE, i++) {
vm_page_t m;
if (vm_fault_quick((caddr_t)addr, VM_PROT_READ) < 0 ||
(paddr = pmap_kextract(addr)) == 0) {
int j;
for (j = 0; j < i; j++)
vm_page_unwire(wpipe->pipe_map.ms[j], 1);
mtx_unlock(&vm_mtx);
return (EFAULT);
}
m = PHYS_TO_VM_PAGE(paddr);
vm_page_wire(m);
wpipe->pipe_map.ms[i] = m;
}
/*
* set up the control block
*/
wpipe->pipe_map.npages = i;
wpipe->pipe_map.pos =
((vm_offset_t) uio->uio_iov->iov_base) & PAGE_MASK;
wpipe->pipe_map.cnt = size;
/*
* and map the buffer
*/
if (wpipe->pipe_map.kva == 0) {
/*
* We need to allocate space for an extra page because the
* address range might (will) span pages at times.
*/
wpipe->pipe_map.kva = kmem_alloc_pageable(kernel_map,
wpipe->pipe_buffer.size + PAGE_SIZE);
amountpipekva += wpipe->pipe_buffer.size + PAGE_SIZE;
}
pmap_qenter(wpipe->pipe_map.kva, wpipe->pipe_map.ms,
wpipe->pipe_map.npages);
mtx_unlock(&vm_mtx);
/*
* and update the uio data
*/
uio->uio_iov->iov_len -= size;
uio->uio_iov->iov_base += size;
if (uio->uio_iov->iov_len == 0)
uio->uio_iov++;
uio->uio_resid -= size;
uio->uio_offset += size;
return (0);
}
/*
* unmap and unwire the process buffer
*/
static void
pipe_destroy_write_buffer(wpipe)
struct pipe *wpipe;
{
int i;
mtx_lock(&vm_mtx);
if (wpipe->pipe_map.kva) {
pmap_qremove(wpipe->pipe_map.kva, wpipe->pipe_map.npages);
if (amountpipekva > maxpipekva) {
vm_offset_t kva = wpipe->pipe_map.kva;
wpipe->pipe_map.kva = 0;
kmem_free(kernel_map, kva,
wpipe->pipe_buffer.size + PAGE_SIZE);
amountpipekva -= wpipe->pipe_buffer.size + PAGE_SIZE;
}
}
for (i = 0; i < wpipe->pipe_map.npages; i++)
vm_page_unwire(wpipe->pipe_map.ms[i], 1);
mtx_unlock(&vm_mtx);
}
/*
* In the case of a signal, the writing process might go away. This
* code copies the data into the circular buffer so that the source
* pages can be freed without loss of data.
*/
static void
pipe_clone_write_buffer(wpipe)
struct pipe *wpipe;
{
int size;
int pos;
size = wpipe->pipe_map.cnt;
pos = wpipe->pipe_map.pos;
memcpy((caddr_t) wpipe->pipe_buffer.buffer,
(caddr_t) wpipe->pipe_map.kva + pos, size);
wpipe->pipe_buffer.in = size;
wpipe->pipe_buffer.out = 0;
wpipe->pipe_buffer.cnt = size;
wpipe->pipe_state &= ~PIPE_DIRECTW;
pipe_destroy_write_buffer(wpipe);
}
/*
* This implements the pipe buffer write mechanism. Note that only
* a direct write OR a normal pipe write can be pending at any given time.
* If there are any characters in the pipe buffer, the direct write will
* be deferred until the receiving process grabs all of the bytes from
* the pipe buffer. Then the direct mapping write is set-up.
*/
static int
pipe_direct_write(wpipe, uio)
struct pipe *wpipe;
struct uio *uio;
{
int error;
retry:
while (wpipe->pipe_state & PIPE_DIRECTW) {
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
wpipe->pipe_state |= PIPE_WANTW;
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdww", 0);
if (error)
goto error1;
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
goto error1;
}
}
wpipe->pipe_map.cnt = 0; /* transfer not ready yet */
if (wpipe->pipe_buffer.cnt > 0) {
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
wpipe->pipe_state |= PIPE_WANTW;
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdwc", 0);
if (error)
goto error1;
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
goto error1;
}
goto retry;
}
wpipe->pipe_state |= PIPE_DIRECTW;
error = pipe_build_write_buffer(wpipe, uio);
if (error) {
wpipe->pipe_state &= ~PIPE_DIRECTW;
goto error1;
}
error = 0;
while (!error && (wpipe->pipe_state & PIPE_DIRECTW)) {
if (wpipe->pipe_state & PIPE_EOF) {
pipelock(wpipe, 0);
pipe_destroy_write_buffer(wpipe);
pipeunlock(wpipe);
pipeselwakeup(wpipe, wpipe);
error = EPIPE;
goto error1;
}
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
pipeselwakeup(wpipe, wpipe);
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdwt", 0);
}
pipelock(wpipe,0);
if (wpipe->pipe_state & PIPE_DIRECTW) {
/*
* this bit of trickery substitutes a kernel buffer for
* the process that might be going away.
*/
pipe_clone_write_buffer(wpipe);
} else {
pipe_destroy_write_buffer(wpipe);
}
pipeunlock(wpipe);
return (error);
error1:
wakeup(wpipe);
return (error);
}
#endif /* !PIPE_NODIRECT */
#endif /* FreeBSD */
#ifdef __NetBSD__
#ifndef PIPE_NODIRECT
/*
* Allocate structure for loan transfer.
*/
static int
pipe_loan_alloc(wpipe, npages)
struct pipe *wpipe;
int npages;
{
vsize_t len;
len = (vsize_t)npages << PAGE_SHIFT;
wpipe->pipe_map.kva = uvm_km_valloc_wait(kernel_map, len);
if (wpipe->pipe_map.kva == 0)
return (ENOMEM);
amountpipekva += len;
wpipe->pipe_map.npages = npages;
wpipe->pipe_map.pgs = malloc(npages * sizeof(struct vm_page *), M_PIPE,
M_WAITOK);
return (0);
}
/*
* Free resources allocated for loan transfer.
*/
static void
pipe_loan_free(wpipe)
struct pipe *wpipe;
{
vsize_t len;
len = (vsize_t)wpipe->pipe_map.npages << PAGE_SHIFT;
uvm_km_free(kernel_map, wpipe->pipe_map.kva, len);
wpipe->pipe_map.kva = 0;
amountpipekva -= len;
free(wpipe->pipe_map.pgs, M_PIPE);
wpipe->pipe_map.pgs = NULL;
}
/*
* NetBSD direct write, using uvm_loan() mechanism.
* This implements the pipe buffer write mechanism. Note that only
* a direct write OR a normal pipe write can be pending at any given time.
* If there are any characters in the pipe buffer, the direct write will
* be deferred until the receiving process grabs all of the bytes from
* the pipe buffer. Then the direct mapping write is set-up.
*/
static int
pipe_direct_write(wpipe, uio)
struct pipe *wpipe;
struct uio *uio;
{
int error, npages, j;
struct vm_page **pgs;
vaddr_t bbase, kva, base, bend;
vsize_t blen, bcnt;
voff_t bpos;
retry:
while (wpipe->pipe_state & PIPE_DIRECTW) {
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
wpipe->pipe_state |= PIPE_WANTW;
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdww", 0);
if (error)
goto error;
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
goto error;
}
}
wpipe->pipe_map.cnt = 0; /* transfer not ready yet */
if (wpipe->pipe_buffer.cnt > 0) {
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
wpipe->pipe_state |= PIPE_WANTW;
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdwc", 0);
if (error)
goto error;
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
goto error;
}
goto retry;
}
/*
* Handle first PIPE_CHUNK_SIZE bytes of buffer. Deal with buffers
* not aligned to PAGE_SIZE.
*/
bbase = (vaddr_t)uio->uio_iov->iov_base;
base = trunc_page(bbase);
bend = round_page(bbase + uio->uio_iov->iov_len);
blen = bend - base;
bpos = bbase - base;
if (blen > PIPE_DIRECT_CHUNK) {
blen = PIPE_DIRECT_CHUNK;
bend = base + blen;
bcnt = PIPE_DIRECT_CHUNK - bpos;
} else {
bcnt = uio->uio_iov->iov_len;
}
npages = blen >> PAGE_SHIFT;
wpipe->pipe_map.pos = bpos;
wpipe->pipe_map.cnt = bcnt;
/*
* Free the old kva if we need more pages than we have
* allocated.
*/
if (wpipe->pipe_map.kva && npages > wpipe->pipe_map.npages)
pipe_loan_free(wpipe);
/* Allocate new kva. */
if (wpipe->pipe_map.kva == 0) {
error = pipe_loan_alloc(wpipe, npages);
if (error) {
goto error;
}
}
/* Loan the write buffer memory from writer process */
pgs = wpipe->pipe_map.pgs;
error = uvm_loan(&uio->uio_procp->p_vmspace->vm_map, base, blen,
pgs, UVM_LOAN_TOPAGE);
if (error) {
pgs = NULL;
goto cleanup;
}
/* Enter the loaned pages to kva */
kva = wpipe->pipe_map.kva;
for (j = 0; j < npages; j++, kva += PAGE_SIZE) {
pmap_kenter_pa(kva, VM_PAGE_TO_PHYS(pgs[j]), VM_PROT_READ);
}
pmap_update(pmap_kernel());
wpipe->pipe_state |= PIPE_DIRECTW;
while (!error && (wpipe->pipe_state & PIPE_DIRECTW)) {
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
break;
}
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
pipeselwakeup(wpipe, wpipe);
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdwt", 0);
}
if (error)
wpipe->pipe_state &= ~PIPE_DIRECTW;
cleanup:
pipelock(wpipe, 0);
if (pgs != NULL) {
pmap_kremove(wpipe->pipe_map.kva, blen);
uvm_unloan(pgs, npages, UVM_LOAN_TOPAGE);
}
if (error || amountpipekva > maxpipekva)
pipe_loan_free(wpipe);
pipeunlock(wpipe);
if (error) {
pipeselwakeup(wpipe, wpipe);
/*
* If nothing was read from what we offered, return error
* straight on. Otherwise update uio resid first. Caller
* will deal with the error condition, returning short
* write, error, or restarting the write(2) as appropriate.
*/
if (wpipe->pipe_map.cnt == bcnt) {
error:
wakeup(wpipe);
return (error);
}
bcnt -= wpipe->pipe_map.cnt;
}
uio->uio_resid -= bcnt;
/* uio_offset not updated, not set/used for write(2) */
uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + bcnt;
uio->uio_iov->iov_len -= bcnt;
if (uio->uio_iov->iov_len == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
}
return (error);
}
#endif /* !PIPE_NODIRECT */
#endif /* NetBSD */
#ifdef __FreeBSD__
static int
pipe_write(fp, uio, cred, flags, p)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
struct proc *p;
#elif defined(__NetBSD__)
static int
pipe_write(fp, offset, uio, cred, flags)
struct file *fp;
off_t *offset;
struct uio *uio;
struct ucred *cred;
int flags;
#endif
{
int error = 0;
struct pipe *wpipe, *rpipe;
rpipe = (struct pipe *) fp->f_data;
wpipe = rpipe->pipe_peer;
/*
* detect loss of pipe read side, issue SIGPIPE if lost.
*/
if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF))
return (EPIPE);
++wpipe->pipe_busy;
/*
* If it is advantageous to resize the pipe buffer, do
* so.
*/
if ((uio->uio_resid > PIPE_SIZE) &&
(nbigpipe < maxbigpipes) &&
#ifndef PIPE_NODIRECT
(wpipe->pipe_state & PIPE_DIRECTW) == 0 &&
#endif
(wpipe->pipe_buffer.size <= PIPE_SIZE) &&
(wpipe->pipe_buffer.cnt == 0)) {
if ((error = pipelock(wpipe,1)) == 0) {
if (pipespace(wpipe, BIG_PIPE_SIZE) == 0)
nbigpipe++;
pipeunlock(wpipe);
} else {
/*
* If an error occurred, unbusy and return, waking up
* any waiting readers.
*/
--wpipe->pipe_busy;
if (wpipe->pipe_busy == 0
&& (wpipe->pipe_state & PIPE_WANTCLOSE)) {
wpipe->pipe_state &=
~(PIPE_WANTCLOSE | PIPE_WANTR);
wakeup(wpipe);
}
return (error);
}
}
#ifdef __FreeBSD__
KASSERT(wpipe->pipe_buffer.buffer != NULL, ("pipe buffer gone"));
#endif
while (uio->uio_resid) {
int space;
#ifndef PIPE_NODIRECT
/*
* If the transfer is large, we can gain performance if
* we do process-to-process copies directly.
* If the write is non-blocking, we don't use the
* direct write mechanism.
*
* The direct write mechanism will detect the reader going
* away on us.
*/
if ((uio->uio_iov->iov_len >= PIPE_MINDIRECT) &&
(fp->f_flag & FNONBLOCK) == 0 &&
(wpipe->pipe_map.kva || (amountpipekva < limitpipekva))) {
error = pipe_direct_write(wpipe, uio);
/*
* Break out if error occured, unless it's ENOMEM.
* ENOMEM means we failed to allocate some resources
* for direct write, so we just fallback to ordinary
* write. If the direct write was successful,
* process rest of data via ordinary write.
*/
if (!error)
continue;
if (error != ENOMEM)
break;
}
#endif /* PIPE_NODIRECT */
/*
* Pipe buffered writes cannot be coincidental with
* direct writes. We wait until the currently executing
* direct write is completed before we start filling the
* pipe buffer. We break out if a signal occurs or the
* reader goes away.
*/
retrywrite:
while (wpipe->pipe_state & PIPE_DIRECTW) {
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
error = tsleep(wpipe, PRIBIO | PCATCH, "pipbww", 0);
if (wpipe->pipe_state & PIPE_EOF)
break;
if (error)
break;
}
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
break;
}
space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
/* Writes of size <= PIPE_BUF must be atomic. */
if ((space < uio->uio_resid) && (uio->uio_resid <= PIPE_BUF))
space = 0;
if (space > 0) {
int size; /* Transfer size */
int segsize; /* first segment to transfer */
if ((error = pipelock(wpipe,1)) != 0)
break;
/*
* It is possible for a direct write to
* slip in on us... handle it here...
*/
if (wpipe->pipe_state & PIPE_DIRECTW) {
pipeunlock(wpipe);
goto retrywrite;
}
/*
* If a process blocked in uiomove, our
* value for space might be bad.
*
* XXX will we be ok if the reader has gone
* away here?
*/
if (space > wpipe->pipe_buffer.size -
wpipe->pipe_buffer.cnt) {
pipeunlock(wpipe);
goto retrywrite;
}
/*
* Transfer size is minimum of uio transfer
* and free space in pipe buffer.
*/
if (space > uio->uio_resid)
size = uio->uio_resid;
else
size = space;
/*
* First segment to transfer is minimum of
* transfer size and contiguous space in
* pipe buffer. If first segment to transfer
* is less than the transfer size, we've got
* a wraparound in the buffer.
*/
segsize = wpipe->pipe_buffer.size -
wpipe->pipe_buffer.in;
if (segsize > size)
segsize = size;
/* Transfer first segment */
error = uiomove(&wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in],
segsize, uio);
if (error == 0 && segsize < size) {
/*
* Transfer remaining part now, to
* support atomic writes. Wraparound
* happened.
*/
#ifdef DEBUG
if (wpipe->pipe_buffer.in + segsize !=
wpipe->pipe_buffer.size)
panic("Expected pipe buffer wraparound disappeared");
#endif
error = uiomove(&wpipe->pipe_buffer.buffer[0],
size - segsize, uio);
}
if (error == 0) {
wpipe->pipe_buffer.in += size;
if (wpipe->pipe_buffer.in >=
wpipe->pipe_buffer.size) {
#ifdef DEBUG
if (wpipe->pipe_buffer.in != size - segsize + wpipe->pipe_buffer.size)
panic("Expected wraparound bad");
#endif
wpipe->pipe_buffer.in = size - segsize;
}
wpipe->pipe_buffer.cnt += size;
#ifdef DEBUG
if (wpipe->pipe_buffer.cnt > wpipe->pipe_buffer.size)
panic("Pipe buffer overflow");
#endif
}
pipeunlock(wpipe);
if (error)
break;
} else {
/*
* If the "read-side" has been blocked, wake it up now.
*/
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
/*
* don't block on non-blocking I/O
*/
if (fp->f_flag & FNONBLOCK) {
error = EAGAIN;
break;
}
/*
* We have no more space and have something to offer,
* wake up select/poll.
*/
pipeselwakeup(wpipe, wpipe);
wpipe->pipe_state |= PIPE_WANTW;
error = tsleep(wpipe, PRIBIO | PCATCH, "pipewr", 0);
if (error != 0)
break;
/*
* If read side wants to go away, we just issue a signal
* to ourselves.
*/
if (wpipe->pipe_state & PIPE_EOF) {
error = EPIPE;
break;
}
}
}
--wpipe->pipe_busy;
if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANTCLOSE)) {
wpipe->pipe_state &= ~(PIPE_WANTCLOSE | PIPE_WANTR);
wakeup(wpipe);
} else if (wpipe->pipe_buffer.cnt > 0) {
/*
* If we have put any characters in the buffer, we wake up
* the reader.
*/
if (wpipe->pipe_state & PIPE_WANTR) {
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
}
/*
* Don't return EPIPE if I/O was successful
*/
if ((error == EPIPE) && (wpipe->pipe_buffer.cnt == 0)
&& (uio->uio_resid == 0))
error = 0;
if (error == 0)
vfs_timestamp(&wpipe->pipe_mtime);
/*
* We have something to offer, wake up select/poll.
* wpipe->pipe_map.cnt is always 0 in this point (direct write
* is only done synchronously), so check only wpipe->pipe_buffer.cnt
*/
if (wpipe->pipe_buffer.cnt)
pipeselwakeup(wpipe, wpipe);
/*
* Arrange for next read(2) to do a signal.
*/
wpipe->pipe_state |= PIPE_SIGNALR;
return (error);
}
/*
* we implement a very minimal set of ioctls for compatibility with sockets.
*/
int
pipe_ioctl(fp, cmd, data, p)
struct file *fp;
u_long cmd;
caddr_t data;
struct proc *p;
{
struct pipe *mpipe = (struct pipe *)fp->f_data;
switch (cmd) {
case FIONBIO:
return (0);
case FIOASYNC:
if (*(int *)data) {
mpipe->pipe_state |= PIPE_ASYNC;
} else {
mpipe->pipe_state &= ~PIPE_ASYNC;
}
return (0);
case FIONREAD:
#ifndef PIPE_NODIRECT
if (mpipe->pipe_state & PIPE_DIRECTW)
*(int *)data = mpipe->pipe_map.cnt;
else
#endif
*(int *)data = mpipe->pipe_buffer.cnt;
return (0);
#ifdef __FreeBSD__
case FIOSETOWN:
return (fsetown(*(int *)data, &mpipe->pipe_sigio));
case FIOGETOWN:
*(int *)data = fgetown(mpipe->pipe_sigio);
return (0);
/* This is deprecated, FIOSETOWN should be used instead. */
case TIOCSPGRP:
return (fsetown(-(*(int *)data), &mpipe->pipe_sigio));
/* This is deprecated, FIOGETOWN should be used instead. */
case TIOCGPGRP:
*(int *)data = -fgetown(mpipe->pipe_sigio);
return (0);
#endif /* FreeBSD */
#ifdef __NetBSD__
case TIOCSPGRP:
mpipe->pipe_pgid = *(int *)data;
return (0);
case TIOCGPGRP:
*(int *)data = mpipe->pipe_pgid;
return (0);
#endif /* NetBSD */
}
return (ENOTTY);
}
int
pipe_poll(fp, events, p)
struct file *fp;
int events;
struct proc *p;
{
struct pipe *rpipe = (struct pipe *)fp->f_data;
struct pipe *wpipe;
int revents = 0;
wpipe = rpipe->pipe_peer;
if (events & (POLLIN | POLLRDNORM))
if ((rpipe->pipe_buffer.cnt > 0) ||
#ifndef PIPE_NODIRECT
(rpipe->pipe_state & PIPE_DIRECTW) ||
#endif
(rpipe->pipe_state & PIPE_EOF))
revents |= events & (POLLIN | POLLRDNORM);
if (events & (POLLOUT | POLLWRNORM))
if (wpipe == NULL || (wpipe->pipe_state & PIPE_EOF)
|| (
#ifndef PIPE_NODIRECT
((wpipe->pipe_state & PIPE_DIRECTW) == 0) &&
#endif
(wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF))
revents |= events & (POLLOUT | POLLWRNORM);
if ((rpipe->pipe_state & PIPE_EOF) ||
(wpipe == NULL) ||
(wpipe->pipe_state & PIPE_EOF))
revents |= POLLHUP;
if (revents == 0) {
if (events & (POLLIN | POLLRDNORM)) {
selrecord(p, &rpipe->pipe_sel);
rpipe->pipe_state |= PIPE_SEL;
}
if (events & (POLLOUT | POLLWRNORM)) {
selrecord(p, &wpipe->pipe_sel);
wpipe->pipe_state |= PIPE_SEL;
}
}
return (revents);
}
static int
pipe_stat(fp, ub, p)
struct file *fp;
struct stat *ub;
struct proc *p;
{
struct pipe *pipe = (struct pipe *)fp->f_data;
memset((caddr_t)ub, 0, sizeof(*ub));
ub->st_mode = S_IFIFO;
ub->st_blksize = pipe->pipe_buffer.size;
ub->st_size = pipe->pipe_buffer.cnt;
ub->st_blocks = (ub->st_size) ? 1 : 0;
#ifdef __FreeBSD__
ub->st_atimespec = pipe->pipe_atime;
ub->st_mtimespec = pipe->pipe_mtime;
ub->st_ctimespec = pipe->pipe_ctime;
#endif /* FreeBSD */
#ifdef __NetBSD__
TIMEVAL_TO_TIMESPEC(&pipe->pipe_atime, &ub->st_atimespec)
TIMEVAL_TO_TIMESPEC(&pipe->pipe_mtime, &ub->st_mtimespec);
TIMEVAL_TO_TIMESPEC(&pipe->pipe_ctime, &ub->st_ctimespec);
#endif /* NetBSD */
ub->st_uid = fp->f_cred->cr_uid;
ub->st_gid = fp->f_cred->cr_gid;
/*
* Left as 0: st_dev, st_ino, st_nlink, st_rdev, st_flags, st_gen.
* XXX (st_dev, st_ino) should be unique.
*/
return (0);
}
/* ARGSUSED */
static int
pipe_close(fp, p)
struct file *fp;
struct proc *p;
{
struct pipe *cpipe = (struct pipe *)fp->f_data;
#ifdef __FreeBSD__
fp->f_ops = &badfileops;
funsetown(cpipe->pipe_sigio);
#endif
fp->f_data = NULL;
pipeclose(cpipe);
return (0);
}
static void
pipe_free_kmem(cpipe)
struct pipe *cpipe;
{
#ifdef __FreeBSD__
mtx_assert(&vm_mtx, MA_OWNED);
#endif
if (cpipe->pipe_buffer.buffer != NULL) {
if (cpipe->pipe_buffer.size > PIPE_SIZE)
--nbigpipe;
amountpipekva -= cpipe->pipe_buffer.size;
#ifdef __FreeBSD__
kmem_free(kernel_map,
(vm_offset_t)cpipe->pipe_buffer.buffer,
cpipe->pipe_buffer.size);
#elif defined(__NetBSD__)
uvm_km_free(kernel_map,
(vaddr_t)cpipe->pipe_buffer.buffer,
cpipe->pipe_buffer.size);
#endif /* NetBSD */
cpipe->pipe_buffer.buffer = NULL;
}
#ifndef PIPE_NODIRECT
if (cpipe->pipe_map.kva != 0) {
#ifdef __FreeBSD__
amountpipekva -= cpipe->pipe_buffer.size + PAGE_SIZE;
kmem_free(kernel_map,
cpipe->pipe_map.kva,
cpipe->pipe_buffer.size + PAGE_SIZE);
#elif defined(__NetBSD__)
pipe_loan_free(cpipe);
#endif /* NetBSD */
cpipe->pipe_map.cnt = 0;
cpipe->pipe_map.kva = 0;
cpipe->pipe_map.pos = 0;
cpipe->pipe_map.npages = 0;
}
#endif /* !PIPE_NODIRECT */
}
/*
* shutdown the pipe
*/
static void
pipeclose(cpipe)
struct pipe *cpipe;
{
struct pipe *ppipe;
if (!cpipe)
return;
pipeselwakeup(cpipe, cpipe);
/*
* If the other side is blocked, wake it up saying that
* we want to close it down.
*/
while (cpipe->pipe_busy) {
wakeup(cpipe);
cpipe->pipe_state |= PIPE_WANTCLOSE | PIPE_EOF;
tsleep(cpipe, PRIBIO, "pipecl", 0);
}
/*
* Disconnect from peer
*/
if ((ppipe = cpipe->pipe_peer) != NULL) {
pipeselwakeup(ppipe, ppipe);
ppipe->pipe_state |= PIPE_EOF;
wakeup(ppipe);
ppipe->pipe_peer = NULL;
}
/*
* free resources
*/
#ifdef __FreeBSD__
mtx_lock(&vm_mtx);
pipe_free_kmem(cpipe);
/* XXX: erm, doesn't zalloc already have its own locks and
* not need the giant vm lock?
*/
zfree(pipe_zone, cpipe);
mtx_unlock(&vm_mtx);
#endif /* FreeBSD */
#ifdef __NetBSD__
pipe_free_kmem(cpipe);
(void) lockmgr(&cpipe->pipe_lock, LK_DRAIN, NULL);
pool_put(&pipe_pool, cpipe);
#endif
}
#ifdef __FreeBSD__
/*ARGSUSED*/
static int
pipe_kqfilter(struct file *fp, struct knote *kn)
{
struct pipe *cpipe = (struct pipe *)kn->kn_fp->f_data;
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_fop = &pipe_rfiltops;
break;
case EVFILT_WRITE:
kn->kn_fop = &pipe_wfiltops;
cpipe = cpipe->pipe_peer;
break;
default:
return (1);
}
kn->kn_hook = (caddr_t)cpipe;
SLIST_INSERT_HEAD(&cpipe->pipe_sel.si_note, kn, kn_selnext);
return (0);
}
static void
filt_pipedetach(struct knote *kn)
{
struct pipe *cpipe = (struct pipe *)kn->kn_fp->f_data;
SLIST_REMOVE(&cpipe->pipe_sel.si_note, kn, knote, kn_selnext);
}
/*ARGSUSED*/
static int
filt_piperead(struct knote *kn, long hint)
{
struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
struct pipe *wpipe = rpipe->pipe_peer;
kn->kn_data = rpipe->pipe_buffer.cnt;
if ((kn->kn_data == 0) && (rpipe->pipe_state & PIPE_DIRECTW))
kn->kn_data = rpipe->pipe_map.cnt;
if ((rpipe->pipe_state & PIPE_EOF) ||
(wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) {
kn->kn_flags |= EV_EOF;
return (1);
}
return (kn->kn_data > 0);
}
/*ARGSUSED*/
static int
filt_pipewrite(struct knote *kn, long hint)
{
struct pipe *rpipe = (struct pipe *)kn->kn_fp->f_data;
struct pipe *wpipe = rpipe->pipe_peer;
if ((wpipe == NULL) || (wpipe->pipe_state & PIPE_EOF)) {
kn->kn_data = 0;
kn->kn_flags |= EV_EOF;
return (1);
}
kn->kn_data = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
if (wpipe->pipe_state & PIPE_DIRECTW)
kn->kn_data = 0;
return (kn->kn_data >= PIPE_BUF);
}
#endif /* FreeBSD */
#ifdef __NetBSD__
static int
pipe_fcntl(fp, cmd, data, p)
struct file *fp;
u_int cmd;
caddr_t data;
struct proc *p;
{
if (cmd == F_SETFL)
return (0);
else
return (EOPNOTSUPP);
}
/*
* Handle pipe sysctls.
*/
int
sysctl_dopipe(name, namelen, oldp, oldlenp, newp, newlen)
int *name;
u_int namelen;
void *oldp;
size_t *oldlenp;
void *newp;
size_t newlen;
{
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR); /* overloaded */
switch (name[0]) {
case KERN_PIPE_MAXKVASZ:
return (sysctl_int(oldp, oldlenp, newp, newlen, &maxpipekva));
case KERN_PIPE_LIMITKVA:
return (sysctl_int(oldp, oldlenp, newp, newlen, &limitpipekva));
case KERN_PIPE_MAXBIGPIPES:
return (sysctl_int(oldp, oldlenp, newp, newlen, &maxbigpipes));
case KERN_PIPE_NBIGPIPES:
return (sysctl_rdint(oldp, oldlenp, newp, nbigpipe));
case KERN_PIPE_KVASIZE:
return (sysctl_rdint(oldp, oldlenp, newp, amountpipekva));
default:
return (EOPNOTSUPP);
}
/* NOTREACHED */
}
/*
* Initialize pipe structs.
*/
void
pipe_init(void)
{
pool_init(&pipe_pool, sizeof(struct pipe), 0, 0, 0, "pipepl", NULL);
}
#endif /* __NetBSD __ */
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