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1104 lines
26 KiB
C
1104 lines
26 KiB
C
/*
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* Copyright (c) 1996 John S. Dyson
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice immediately at the beginning of the file, without modification,
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* this list of conditions, and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Absolutely no warranty of function or purpose is made by the author
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* John S. Dyson.
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* 4. Modifications may be freely made to this file if the above conditions
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* are met.
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*
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* $FreeBSD$
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*/
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/*
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* This file contains a high-performance replacement for the socket-based
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* pipes scheme originally used in FreeBSD/4.4Lite. It does not support
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* all features of sockets, but does do everything that pipes normally
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* do.
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*/
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/*
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* This code has two modes of operation, a small write mode and a large
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* write mode. The small write mode acts like conventional pipes with
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* a kernel buffer. If the buffer is less than PIPE_MINDIRECT, then the
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* "normal" pipe buffering is done. If the buffer is between PIPE_MINDIRECT
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* and PIPE_SIZE in size, it is fully mapped and wired into the kernel, and
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* the receiving process can copy it directly from the pages in the sending
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* process.
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*
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* If the sending process receives a signal, it is possible that it will
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* go away, and certainly its address space can change, because control
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* is returned back to the user-mode side. In that case, the pipe code
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* arranges to copy the buffer supplied by the user process, to a pageable
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* kernel buffer, and the receiving process will grab the data from the
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* pageable kernel buffer. Since signals don't happen all that often,
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* the copy operation is normally eliminated.
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*
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* The constant PIPE_MINDIRECT is chosen to make sure that buffering will
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* happen for small transfers so that the system will not spend all of
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* its time context switching. PIPE_SIZE is constrained by the
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* amount of kernel virtual memory.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/fcntl.h>
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#include <sys/file.h>
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#include <sys/filedesc.h>
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#include <sys/filio.h>
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#include <sys/ttycom.h>
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#include <sys/stat.h>
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#include <sys/poll.h>
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#include <sys/select.h>
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#include <sys/signalvar.h>
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#include <sys/sysproto.h>
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#include <sys/pipe.h>
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#include <sys/uio.h>
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#include <vm/vm.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_param.h>
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#include <sys/lock.h>
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#include <vm/vm_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_page.h>
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#include <vm/vm_zone.h>
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/*
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* Use this define if you want to disable *fancy* VM things. Expect an
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* approx 30% decrease in transfer rate. This could be useful for
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* NetBSD or OpenBSD.
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*/
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/* #define PIPE_NODIRECT */
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/*
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* interfaces to the outside world
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*/
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static int pipe_read __P((struct file *fp, struct uio *uio,
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struct ucred *cred, int flags));
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static int pipe_write __P((struct file *fp, struct uio *uio,
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struct ucred *cred, int flags));
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static int pipe_close __P((struct file *fp, struct proc *p));
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static int pipe_poll __P((struct file *fp, int events, struct ucred *cred,
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struct proc *p));
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static int pipe_ioctl __P((struct file *fp, u_long cmd, caddr_t data, struct proc *p));
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static struct fileops pipeops =
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{ pipe_read, pipe_write, pipe_ioctl, pipe_poll, pipe_close };
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/*
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* Default pipe buffer size(s), this can be kind-of large now because pipe
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* space is pageable. The pipe code will try to maintain locality of
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* reference for performance reasons, so small amounts of outstanding I/O
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* will not wipe the cache.
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*/
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#define MINPIPESIZE (PIPE_SIZE/3)
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#define MAXPIPESIZE (2*PIPE_SIZE/3)
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/*
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* Maximum amount of kva for pipes -- this is kind-of a soft limit, but
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* is there so that on large systems, we don't exhaust it.
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*/
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#define MAXPIPEKVA (8*1024*1024)
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/*
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* Limit for direct transfers, we cannot, of course limit
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* the amount of kva for pipes in general though.
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*/
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#define LIMITPIPEKVA (16*1024*1024)
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/*
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* Limit the number of "big" pipes
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*/
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#define LIMITBIGPIPES 32
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static int nbigpipe;
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static int amountpipekva;
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static void pipeclose __P((struct pipe *cpipe));
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static void pipeinit __P((struct pipe *cpipe));
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static __inline int pipelock __P((struct pipe *cpipe, int catch));
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static __inline void pipeunlock __P((struct pipe *cpipe));
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static __inline void pipeselwakeup __P((struct pipe *cpipe));
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#ifndef PIPE_NODIRECT
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static int pipe_build_write_buffer __P((struct pipe *wpipe, struct uio *uio));
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static void pipe_destroy_write_buffer __P((struct pipe *wpipe));
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static int pipe_direct_write __P((struct pipe *wpipe, struct uio *uio));
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static void pipe_clone_write_buffer __P((struct pipe *wpipe));
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#endif
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static void pipespace __P((struct pipe *cpipe));
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static vm_zone_t pipe_zone;
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/*
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* The pipe system call for the DTYPE_PIPE type of pipes
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*/
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/* ARGSUSED */
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int
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pipe(p, uap)
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struct proc *p;
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struct pipe_args /* {
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int dummy;
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} */ *uap;
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{
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register struct filedesc *fdp = p->p_fd;
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struct file *rf, *wf;
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struct pipe *rpipe, *wpipe;
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int fd, error;
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if (pipe_zone == NULL)
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pipe_zone = zinit("PIPE", sizeof (struct pipe), 0, 0, 4);
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rpipe = zalloc( pipe_zone);
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pipeinit(rpipe);
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rpipe->pipe_state |= PIPE_DIRECTOK;
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wpipe = zalloc( pipe_zone);
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pipeinit(wpipe);
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wpipe->pipe_state |= PIPE_DIRECTOK;
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error = falloc(p, &rf, &fd);
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if (error)
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goto free2;
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p->p_retval[0] = fd;
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rf->f_flag = FREAD | FWRITE;
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rf->f_type = DTYPE_PIPE;
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rf->f_data = (caddr_t)rpipe;
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rf->f_ops = &pipeops;
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error = falloc(p, &wf, &fd);
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if (error)
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goto free3;
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wf->f_flag = FREAD | FWRITE;
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wf->f_type = DTYPE_PIPE;
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wf->f_data = (caddr_t)wpipe;
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wf->f_ops = &pipeops;
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p->p_retval[1] = fd;
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rpipe->pipe_peer = wpipe;
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wpipe->pipe_peer = rpipe;
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return (0);
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free3:
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fdp->fd_ofiles[p->p_retval[0]] = 0;
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ffree(rf);
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free2:
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(void)pipeclose(wpipe);
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(void)pipeclose(rpipe);
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return (error);
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}
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/*
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* Allocate kva for pipe circular buffer, the space is pageable
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*/
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static void
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pipespace(cpipe)
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struct pipe *cpipe;
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{
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int npages, error;
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npages = round_page(cpipe->pipe_buffer.size)/PAGE_SIZE;
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/*
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* Create an object, I don't like the idea of paging to/from
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* kernel_object.
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* XXX -- minor change needed here for NetBSD/OpenBSD VM systems.
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*/
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cpipe->pipe_buffer.object = vm_object_allocate(OBJT_DEFAULT, npages);
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cpipe->pipe_buffer.buffer = (caddr_t) vm_map_min(kernel_map);
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/*
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* Insert the object into the kernel map, and allocate kva for it.
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* The map entry is, by default, pageable.
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* XXX -- minor change needed here for NetBSD/OpenBSD VM systems.
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*/
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error = vm_map_find(kernel_map, cpipe->pipe_buffer.object, 0,
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(vm_offset_t *) &cpipe->pipe_buffer.buffer,
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cpipe->pipe_buffer.size, 1,
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VM_PROT_ALL, VM_PROT_ALL, 0);
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if (error != KERN_SUCCESS)
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panic("pipeinit: cannot allocate pipe -- out of kvm -- code = %d", error);
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amountpipekva += cpipe->pipe_buffer.size;
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}
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/*
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* initialize and allocate VM and memory for pipe
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*/
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static void
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pipeinit(cpipe)
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struct pipe *cpipe;
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{
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cpipe->pipe_buffer.in = 0;
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cpipe->pipe_buffer.out = 0;
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cpipe->pipe_buffer.cnt = 0;
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cpipe->pipe_buffer.size = PIPE_SIZE;
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/* Buffer kva gets dynamically allocated */
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cpipe->pipe_buffer.buffer = NULL;
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/* cpipe->pipe_buffer.object = invalid */
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cpipe->pipe_state = 0;
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cpipe->pipe_peer = NULL;
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cpipe->pipe_busy = 0;
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getnanotime(&cpipe->pipe_ctime);
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cpipe->pipe_atime = cpipe->pipe_ctime;
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cpipe->pipe_mtime = cpipe->pipe_ctime;
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bzero(&cpipe->pipe_sel, sizeof cpipe->pipe_sel);
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#ifndef PIPE_NODIRECT
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/*
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* pipe data structure initializations to support direct pipe I/O
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*/
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cpipe->pipe_map.cnt = 0;
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cpipe->pipe_map.kva = 0;
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cpipe->pipe_map.pos = 0;
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cpipe->pipe_map.npages = 0;
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/* cpipe->pipe_map.ms[] = invalid */
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#endif
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}
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/*
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* lock a pipe for I/O, blocking other access
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*/
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static __inline int
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pipelock(cpipe, catch)
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struct pipe *cpipe;
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int catch;
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{
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int error;
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while (cpipe->pipe_state & PIPE_LOCK) {
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cpipe->pipe_state |= PIPE_LWANT;
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if ((error = tsleep( cpipe,
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catch?(PRIBIO|PCATCH):PRIBIO, "pipelk", 0)) != 0) {
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return error;
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}
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}
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cpipe->pipe_state |= PIPE_LOCK;
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return 0;
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}
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/*
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* unlock a pipe I/O lock
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*/
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static __inline void
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pipeunlock(cpipe)
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struct pipe *cpipe;
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{
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cpipe->pipe_state &= ~PIPE_LOCK;
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if (cpipe->pipe_state & PIPE_LWANT) {
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cpipe->pipe_state &= ~PIPE_LWANT;
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wakeup(cpipe);
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}
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}
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static __inline void
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pipeselwakeup(cpipe)
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struct pipe *cpipe;
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{
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if (cpipe->pipe_state & PIPE_SEL) {
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cpipe->pipe_state &= ~PIPE_SEL;
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selwakeup(&cpipe->pipe_sel);
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}
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if ((cpipe->pipe_state & PIPE_ASYNC) && cpipe->pipe_sigio)
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pgsigio(cpipe->pipe_sigio, SIGIO, 0);
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}
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/* ARGSUSED */
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static int
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pipe_read(fp, uio, cred, flags)
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struct file *fp;
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struct uio *uio;
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struct ucred *cred;
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int flags;
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{
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struct pipe *rpipe = (struct pipe *) fp->f_data;
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int error;
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int nread = 0;
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u_int size;
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++rpipe->pipe_busy;
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error = pipelock(rpipe, 1);
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if (error)
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goto unlocked_error;
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while (uio->uio_resid) {
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/*
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* normal pipe buffer receive
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*/
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if (rpipe->pipe_buffer.cnt > 0) {
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size = rpipe->pipe_buffer.size - rpipe->pipe_buffer.out;
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if (size > rpipe->pipe_buffer.cnt)
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size = rpipe->pipe_buffer.cnt;
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if (size > (u_int) uio->uio_resid)
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size = (u_int) uio->uio_resid;
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error = uiomove(&rpipe->pipe_buffer.buffer[rpipe->pipe_buffer.out],
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size, uio);
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if (error) {
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break;
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}
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rpipe->pipe_buffer.out += size;
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if (rpipe->pipe_buffer.out >= rpipe->pipe_buffer.size)
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rpipe->pipe_buffer.out = 0;
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rpipe->pipe_buffer.cnt -= size;
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|
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/*
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* If there is no more to read in the pipe, reset
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* its pointers to the beginning. This improves
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* cache hit stats.
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*/
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if (rpipe->pipe_buffer.cnt == 0) {
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rpipe->pipe_buffer.in = 0;
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rpipe->pipe_buffer.out = 0;
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}
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nread += size;
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#ifndef PIPE_NODIRECT
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/*
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* Direct copy, bypassing a kernel buffer.
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*/
|
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} else if ((size = rpipe->pipe_map.cnt) &&
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(rpipe->pipe_state & PIPE_DIRECTW)) {
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caddr_t va;
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if (size > (u_int) uio->uio_resid)
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size = (u_int) uio->uio_resid;
|
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va = (caddr_t) rpipe->pipe_map.kva + rpipe->pipe_map.pos;
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error = uiomove(va, size, uio);
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if (error)
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break;
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nread += size;
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rpipe->pipe_map.pos += size;
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rpipe->pipe_map.cnt -= size;
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if (rpipe->pipe_map.cnt == 0) {
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rpipe->pipe_state &= ~PIPE_DIRECTW;
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wakeup(rpipe);
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}
|
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#endif
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} else {
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/*
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* detect EOF condition
|
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*/
|
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if (rpipe->pipe_state & PIPE_EOF) {
|
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/* XXX error = ? */
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break;
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}
|
|
|
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/*
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* If the "write-side" has been blocked, wake it up now.
|
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*/
|
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if (rpipe->pipe_state & PIPE_WANTW) {
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rpipe->pipe_state &= ~PIPE_WANTW;
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wakeup(rpipe);
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}
|
|
|
|
/*
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* Break if some data was read.
|
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*/
|
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if (nread > 0)
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break;
|
|
|
|
/*
|
|
* Unlock the pipe buffer for our remaining processing. We
|
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* will either break out with an error or we will sleep and
|
|
* relock to loop.
|
|
*/
|
|
pipeunlock(rpipe);
|
|
|
|
/*
|
|
* Handle non-blocking mode operation or
|
|
* wait for more data.
|
|
*/
|
|
if (fp->f_flag & FNONBLOCK)
|
|
error = EAGAIN;
|
|
else {
|
|
rpipe->pipe_state |= PIPE_WANTR;
|
|
if ((error = tsleep(rpipe, PRIBIO|PCATCH, "piperd", 0)) == 0)
|
|
error = pipelock(rpipe, 1);
|
|
}
|
|
if (error)
|
|
goto unlocked_error;
|
|
}
|
|
}
|
|
pipeunlock(rpipe);
|
|
|
|
if (error == 0)
|
|
getnanotime(&rpipe->pipe_atime);
|
|
unlocked_error:
|
|
--rpipe->pipe_busy;
|
|
|
|
/*
|
|
* PIPE_WANT processing only makes sense if pipe_busy is 0.
|
|
*/
|
|
if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) {
|
|
rpipe->pipe_state &= ~(PIPE_WANT|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 ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF)
|
|
pipeselwakeup(rpipe);
|
|
|
|
return error;
|
|
}
|
|
|
|
#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;
|
|
{
|
|
u_int size;
|
|
int i;
|
|
vm_offset_t addr, endaddr, paddr;
|
|
|
|
size = (u_int) 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);
|
|
for(i = 0, addr = trunc_page((vm_offset_t)uio->uio_iov->iov_base);
|
|
addr < endaddr;
|
|
addr += PAGE_SIZE, i+=1) {
|
|
|
|
vm_page_t m;
|
|
|
|
vm_fault_quick( (caddr_t) addr, VM_PROT_READ);
|
|
paddr = pmap_kextract(addr);
|
|
if (!paddr) {
|
|
int j;
|
|
for(j=0;j<i;j++)
|
|
vm_page_unwire(wpipe->pipe_map.ms[j], 1);
|
|
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);
|
|
|
|
/*
|
|
* 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;
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
bcopy((caddr_t) wpipe->pipe_map.kva+pos,
|
|
(caddr_t) wpipe->pipe_buffer.buffer,
|
|
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);
|
|
error = EPIPE;
|
|
goto error1;
|
|
}
|
|
if (wpipe->pipe_state & PIPE_WANTR) {
|
|
wpipe->pipe_state &= ~PIPE_WANTR;
|
|
wakeup(wpipe);
|
|
}
|
|
pipeselwakeup(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
|
|
|
|
static int
|
|
pipe_write(fp, uio, cred, flags)
|
|
struct file *fp;
|
|
struct uio *uio;
|
|
struct ucred *cred;
|
|
int flags;
|
|
{
|
|
int error = 0;
|
|
int orig_resid;
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* If it is advantageous to resize the pipe buffer, do
|
|
* so.
|
|
*/
|
|
if ((uio->uio_resid > PIPE_SIZE) &&
|
|
(nbigpipe < LIMITBIGPIPES) &&
|
|
(wpipe->pipe_state & PIPE_DIRECTW) == 0 &&
|
|
(wpipe->pipe_buffer.size <= PIPE_SIZE) &&
|
|
(wpipe->pipe_buffer.cnt == 0)) {
|
|
|
|
if (wpipe->pipe_buffer.buffer) {
|
|
amountpipekva -= wpipe->pipe_buffer.size;
|
|
kmem_free(kernel_map,
|
|
(vm_offset_t)wpipe->pipe_buffer.buffer,
|
|
wpipe->pipe_buffer.size);
|
|
}
|
|
|
|
#ifndef PIPE_NODIRECT
|
|
if (wpipe->pipe_map.kva) {
|
|
amountpipekva -= wpipe->pipe_buffer.size + PAGE_SIZE;
|
|
kmem_free(kernel_map,
|
|
wpipe->pipe_map.kva,
|
|
wpipe->pipe_buffer.size + PAGE_SIZE);
|
|
}
|
|
#endif
|
|
|
|
wpipe->pipe_buffer.in = 0;
|
|
wpipe->pipe_buffer.out = 0;
|
|
wpipe->pipe_buffer.cnt = 0;
|
|
wpipe->pipe_buffer.size = BIG_PIPE_SIZE;
|
|
wpipe->pipe_buffer.buffer = NULL;
|
|
++nbigpipe;
|
|
|
|
#ifndef PIPE_NODIRECT
|
|
wpipe->pipe_map.cnt = 0;
|
|
wpipe->pipe_map.kva = 0;
|
|
wpipe->pipe_map.pos = 0;
|
|
wpipe->pipe_map.npages = 0;
|
|
#endif
|
|
|
|
}
|
|
|
|
|
|
if( wpipe->pipe_buffer.buffer == NULL) {
|
|
if ((error = pipelock(wpipe,1)) == 0) {
|
|
pipespace(wpipe);
|
|
pipeunlock(wpipe);
|
|
} else {
|
|
return error;
|
|
}
|
|
}
|
|
|
|
++wpipe->pipe_busy;
|
|
orig_resid = uio->uio_resid;
|
|
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.
|
|
*/
|
|
if ((uio->uio_iov->iov_len >= PIPE_MINDIRECT) &&
|
|
(fp->f_flag & FNONBLOCK) == 0 &&
|
|
(wpipe->pipe_map.kva || (amountpipekva < LIMITPIPEKVA)) &&
|
|
(uio->uio_iov->iov_len >= PIPE_MINDIRECT)) {
|
|
error = pipe_direct_write( wpipe, uio);
|
|
if (error) {
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
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 (error)
|
|
break;
|
|
}
|
|
|
|
space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
|
|
|
|
/* Writes of size <= PIPE_BUF must be atomic. */
|
|
/* XXX perhaps they need to be contiguous to be atomic? */
|
|
if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF))
|
|
space = 0;
|
|
|
|
if (space > 0 && (wpipe->pipe_buffer.cnt < PIPE_SIZE)) {
|
|
/*
|
|
* This set the maximum transfer as a segment of
|
|
* the buffer.
|
|
*/
|
|
int size = wpipe->pipe_buffer.size - wpipe->pipe_buffer.in;
|
|
/*
|
|
* space is the size left in the buffer
|
|
*/
|
|
if (size > space)
|
|
size = space;
|
|
/*
|
|
* now limit it to the size of the uio transfer
|
|
*/
|
|
if (size > uio->uio_resid)
|
|
size = uio->uio_resid;
|
|
if ((error = pipelock(wpipe,1)) == 0) {
|
|
/*
|
|
* 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;
|
|
}
|
|
error = uiomove( &wpipe->pipe_buffer.buffer[wpipe->pipe_buffer.in],
|
|
size, uio);
|
|
pipeunlock(wpipe);
|
|
}
|
|
if (error)
|
|
break;
|
|
|
|
wpipe->pipe_buffer.in += size;
|
|
if (wpipe->pipe_buffer.in >= wpipe->pipe_buffer.size)
|
|
wpipe->pipe_buffer.in = 0;
|
|
|
|
wpipe->pipe_buffer.cnt += size;
|
|
} 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->pipe_state |= PIPE_WANTW;
|
|
if ((error = tsleep(wpipe, (PRIBIO+1)|PCATCH, "pipewr", 0)) != 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_WANT)) {
|
|
wpipe->pipe_state &= ~(PIPE_WANT|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 ((wpipe->pipe_buffer.cnt == 0) &&
|
|
(uio->uio_resid == 0) &&
|
|
(error == EPIPE))
|
|
error = 0;
|
|
|
|
if (error == 0)
|
|
getnanotime(&wpipe->pipe_mtime);
|
|
|
|
/*
|
|
* We have something to offer,
|
|
* wake up select/poll.
|
|
*/
|
|
if (wpipe->pipe_buffer.cnt)
|
|
pipeselwakeup(wpipe);
|
|
|
|
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;
|
|
register caddr_t data;
|
|
struct proc *p;
|
|
{
|
|
register 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:
|
|
if (mpipe->pipe_state & PIPE_DIRECTW)
|
|
*(int *)data = mpipe->pipe_map.cnt;
|
|
else
|
|
*(int *)data = mpipe->pipe_buffer.cnt;
|
|
return (0);
|
|
|
|
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);
|
|
|
|
}
|
|
return (ENOTTY);
|
|
}
|
|
|
|
int
|
|
pipe_poll(fp, events, cred, p)
|
|
struct file *fp;
|
|
int events;
|
|
struct ucred *cred;
|
|
struct proc *p;
|
|
{
|
|
register 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_state & PIPE_DIRECTW) ||
|
|
(rpipe->pipe_buffer.cnt > 0) ||
|
|
(rpipe->pipe_state & PIPE_EOF))
|
|
revents |= events & (POLLIN | POLLRDNORM);
|
|
|
|
if (events & (POLLOUT | POLLWRNORM))
|
|
if (wpipe == NULL || (wpipe->pipe_state & PIPE_EOF) ||
|
|
(((wpipe->pipe_state & PIPE_DIRECTW) == 0) &&
|
|
(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);
|
|
}
|
|
|
|
int
|
|
pipe_stat(pipe, ub)
|
|
register struct pipe *pipe;
|
|
register struct stat *ub;
|
|
{
|
|
bzero((caddr_t)ub, 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 + ub->st_blksize - 1) / ub->st_blksize;
|
|
ub->st_atimespec = pipe->pipe_atime;
|
|
ub->st_mtimespec = pipe->pipe_mtime;
|
|
ub->st_ctimespec = pipe->pipe_ctime;
|
|
/*
|
|
* Left as 0: st_dev, st_ino, st_nlink, st_uid, st_gid, 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;
|
|
|
|
fp->f_ops = &badfileops;
|
|
fp->f_data = NULL;
|
|
funsetown(cpipe->pipe_sigio);
|
|
pipeclose(cpipe);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* shutdown the pipe
|
|
*/
|
|
static void
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pipeclose(cpipe)
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struct pipe *cpipe;
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{
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struct pipe *ppipe;
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if (cpipe) {
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pipeselwakeup(cpipe);
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/*
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* If the other side is blocked, wake it up saying that
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* we want to close it down.
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*/
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while (cpipe->pipe_busy) {
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wakeup(cpipe);
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cpipe->pipe_state |= PIPE_WANT|PIPE_EOF;
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tsleep(cpipe, PRIBIO, "pipecl", 0);
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}
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/*
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* Disconnect from peer
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*/
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if ((ppipe = cpipe->pipe_peer) != NULL) {
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pipeselwakeup(ppipe);
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ppipe->pipe_state |= PIPE_EOF;
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wakeup(ppipe);
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ppipe->pipe_peer = NULL;
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}
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/*
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* free resources
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*/
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if (cpipe->pipe_buffer.buffer) {
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if (cpipe->pipe_buffer.size > PIPE_SIZE)
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--nbigpipe;
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amountpipekva -= cpipe->pipe_buffer.size;
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kmem_free(kernel_map,
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(vm_offset_t)cpipe->pipe_buffer.buffer,
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cpipe->pipe_buffer.size);
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}
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#ifndef PIPE_NODIRECT
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if (cpipe->pipe_map.kva) {
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amountpipekva -= cpipe->pipe_buffer.size + PAGE_SIZE;
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kmem_free(kernel_map,
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cpipe->pipe_map.kva,
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cpipe->pipe_buffer.size + PAGE_SIZE);
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}
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#endif
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zfree(pipe_zone, cpipe);
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}
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}
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