diff options
| -rw-r--r-- | sys/kern/sys_pipe.c | 107 |
1 files changed, 66 insertions, 41 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index 3170847..79a9804 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -436,29 +436,6 @@ pipespace(cpipe, size) } /* - * Initialize and allocate VM and memory for pipe. The structure - * will start out zero'd from the ctor, so we just manage the kmem. - */ -static int -pipe_create(pipe) - struct pipe *pipe; -{ - int error; - - /* - * Reduce to 1/4th pipe size if we're over our global max. - */ - if (amountpipekva > maxpipekva / 2) - error = pipespace(pipe, SMALL_PIPE_SIZE); - else - error = pipespace(pipe, PIPE_SIZE); - if (error) - return (error); - - return (0); -} - -/* * lock a pipe for I/O, blocking other access */ static __inline int @@ -511,6 +488,35 @@ pipeselwakeup(cpipe) KNOTE(&cpipe->pipe_sel.si_note, 0); } +/* + * Initialize and allocate VM and memory for pipe. The structure + * will start out zero'd from the ctor, so we just manage the kmem. + */ +static int +pipe_create(pipe) + struct pipe *pipe; +{ + int error; + + PIPE_LOCK(pipe); + pipelock(pipe, 0); + PIPE_UNLOCK(pipe); + /* + * Reduce to 1/4th pipe size if we're over our global max. + */ + if (amountpipekva > maxpipekva / 2) + error = pipespace(pipe, SMALL_PIPE_SIZE); + else + error = pipespace(pipe, PIPE_SIZE); + PIPE_LOCK(pipe); + pipeunlock(pipe); + PIPE_UNLOCK(pipe); + if (error) + return (error); + + return (0); +} + /* ARGSUSED */ static int pipe_read(fp, uio, active_cred, flags, td) @@ -870,6 +876,10 @@ retry: wpipe->pipe_state |= PIPE_DIRECTW; pipelock(wpipe, 0); + if (wpipe->pipe_state & PIPE_EOF) { + error = EPIPE; + goto error2; + } PIPE_UNLOCK(wpipe); error = pipe_build_write_buffer(wpipe, uio); PIPE_LOCK(wpipe); @@ -901,6 +911,8 @@ retry: } pipelock(wpipe,0); + if (wpipe->pipe_state & PIPE_EOF) + error = EPIPE; if (wpipe->pipe_state & PIPE_DIRECTW) { /* * this bit of trickery substitutes a kernel buffer for @@ -912,6 +924,7 @@ retry: pipe_destroy_write_buffer(wpipe); PIPE_LOCK(wpipe); } +error2: pipeunlock(wpipe); return (error); @@ -965,10 +978,14 @@ pipe_write(fp, uio, active_cred, flags, td) (wpipe->pipe_buffer.cnt == 0)) { if ((error = pipelock(wpipe, 1)) == 0) { - PIPE_UNLOCK(wpipe); - if (pipespace(wpipe, BIG_PIPE_SIZE) == 0) - atomic_add_int(&nbigpipe, 1); - PIPE_LOCK(wpipe); + if (wpipe->pipe_state & PIPE_EOF) + error = EPIPE; + else { + PIPE_UNLOCK(wpipe); + if (pipespace(wpipe, BIG_PIPE_SIZE) == 0) + atomic_add_int(&nbigpipe, 1); + PIPE_LOCK(wpipe); + } pipeunlock(wpipe); } } @@ -1028,15 +1045,13 @@ pipe_write(fp, uio, active_cred, flags, td) } error = msleep(wpipe, PIPE_MTX(rpipe), PRIBIO | PCATCH, "pipbww", 0); - if (wpipe->pipe_state & PIPE_EOF) + if (wpipe->pipe_state & PIPE_EOF) { + error = EPIPE; break; + } if (error) break; } - if (wpipe->pipe_state & PIPE_EOF) { - error = EPIPE; - break; - } space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; @@ -1050,9 +1065,11 @@ pipe_write(fp, uio, active_cred, flags, td) int segsize; /* first segment to transfer */ /* - * It is possible for a direct write to - * slip in on us... handle it here... + * It is possible for a direct write/EOF to + * slip in on us... handle them here... */ + if (wpipe->pipe_state & PIPE_EOF) + goto lost_wpipe; if (wpipe->pipe_state & PIPE_DIRECTW) { pipeunlock(wpipe); goto retrywrite; @@ -1133,6 +1150,7 @@ pipe_write(fp, uio, active_cred, flags, td) panic("Pipe buffer overflow"); } +lost_wpipe: pipeunlock(wpipe); } if (error) @@ -1455,9 +1473,10 @@ pipeclose(cpipe) * If the other side is blocked, wake it up saying that * we want to close it down. */ + cpipe->pipe_state |= PIPE_EOF; while (cpipe->pipe_busy) { wakeup(cpipe); - cpipe->pipe_state |= PIPE_WANT | PIPE_EOF; + cpipe->pipe_state |= PIPE_WANT; msleep(cpipe, PIPE_MTX(cpipe), PRIBIO, "pipecl", 0); } @@ -1481,10 +1500,12 @@ pipeclose(cpipe) * doing that, or the pipe might disappear out from under * us. */ + pipelock(cpipe, 0); PIPE_UNLOCK(cpipe); pipe_free_kmem(cpipe); PIPE_LOCK(cpipe); cpipe->pipe_present = 0; + pipeunlock(cpipe); /* * If both endpoints are now closed, release the memory for the @@ -1507,22 +1528,25 @@ pipe_kqfilter(struct file *fp, struct knote *kn) struct pipe *cpipe; cpipe = kn->kn_fp->f_data; + PIPE_LOCK(cpipe); 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; - if (!cpipe->pipe_present) + if (!cpipe->pipe_peer->pipe_present) { /* other end of pipe has been closed */ + PIPE_UNLOCK(cpipe); return (EPIPE); + } + cpipe = cpipe->pipe_peer; break; default: + PIPE_UNLOCK(cpipe); return (1); } - PIPE_LOCK(cpipe); SLIST_INSERT_HEAD(&cpipe->pipe_sel.si_note, kn, kn_selnext); PIPE_UNLOCK(cpipe); return (0); @@ -1533,13 +1557,14 @@ filt_pipedetach(struct knote *kn) { struct pipe *cpipe = (struct pipe *)kn->kn_fp->f_data; + PIPE_LOCK(cpipe); if (kn->kn_filter == EVFILT_WRITE) { - if (cpipe->pipe_peer == NULL) + if (!cpipe->pipe_peer->pipe_present) { + PIPE_UNLOCK(cpipe); return; + } cpipe = cpipe->pipe_peer; } - - PIPE_LOCK(cpipe); SLIST_REMOVE(&cpipe->pipe_sel.si_note, kn, knote, kn_selnext); PIPE_UNLOCK(cpipe); } |
