From dda0c3b738a8e4f1883e279636b5772fed21904c Mon Sep 17 00:00:00 2001 From: Kanonenvogel Date: Thu, 16 Apr 2015 04:41:28 +0400 Subject: [PATCH 2/2] Pipe locks Unnecessary KERNEL_LOCK()'s removed. Missing KERNEL_LOCKS() added. --- kern/sys_pipe.c | 67 +++++++++------------------------------------------------ 1 file changed, 10 insertions(+), 57 deletions(-) diff --git a/kern/sys_pipe.c b/kern/sys_pipe.c index 096663d..5259829 100644 --- a/kern/sys_pipe.c +++ b/kern/sys_pipe.c @@ -174,14 +174,10 @@ dopipe(struct proc *p, int *ufds, int flags) struct pipe *rpipe, *wpipe = NULL; int fds[2], error; - KERNEL_LOCK(); - lock = pool_get(&pipe_lock_pool, PR_WAITOK); rpipe = pool_get(&pipe_pool, PR_WAITOK); wpipe = pool_get(&pipe_pool, PR_WAITOK); - KERNEL_UNLOCK(); - rw_init(lock, "pipe_lock"); error = pipe_create(rpipe, wpipe, lock); @@ -304,9 +300,7 @@ pipe_create(struct pipe *cpipe, struct pipe *ppipe, struct rwlock *lock) if (error != 0) return (error); - KERNEL_LOCK(); getnanotime(&cpipe->pipe_ctime); - KERNEL_UNLOCK(); cpipe->pipe_atime = cpipe->pipe_ctime; cpipe->pipe_mtime = cpipe->pipe_ctime; @@ -333,13 +327,9 @@ pipelock(struct pipe *cpipe) while (cpipe->pipe_state & PIPE_LOCK) { cpipe->pipe_state |= PIPE_LWANT; - pipe_pair_unlock(cpipe); - KERNEL_LOCK(); error = tsleep(cpipe, PRIBIO|PCATCH, "pipelk", 0); - KERNEL_UNLOCK(); - pipe_pair_lock(cpipe); if (error) @@ -360,9 +350,7 @@ pipeunlock(struct pipe *cpipe) cpipe->pipe_state &= ~PIPE_LOCK; if (cpipe->pipe_state & PIPE_LWANT) { cpipe->pipe_state &= ~PIPE_LWANT; - KERNEL_LOCK(); wakeup(cpipe); - KERNEL_UNLOCK(); } } @@ -455,9 +443,7 @@ pipe_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) */ if (rpipe->pipe_state & PIPE_WANTW) { rpipe->pipe_state &= ~PIPE_WANTW; - KERNEL_LOCK(); wakeup(rpipe); - KERNEL_UNLOCK(); } /* @@ -481,16 +467,10 @@ pipe_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) error = EAGAIN; } else { rpipe->pipe_state |= PIPE_WANTR; - pipe_pair_unlock(rpipe); - - KERNEL_LOCK(); error = tsleep(rpipe, PRIBIO|PCATCH, "piperd", 0); - KERNEL_UNLOCK(); - pipe_pair_lock(rpipe); - if (error == 0) { error = pipelock(rpipe); } @@ -501,11 +481,8 @@ pipe_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) } pipeunlock(rpipe); - if (error == 0) { - KERNEL_LOCK(); + if (error == 0) getnanotime(&rpipe->pipe_atime); - KERNEL_UNLOCK(); - } unlocked_error: --rpipe->pipe_busy; @@ -514,18 +491,14 @@ unlocked_error: */ if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) { rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW); - KERNEL_LOCK(); wakeup(rpipe); - KERNEL_UNLOCK(); } else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) { /* * Handle write blocking hysteresis. */ if (rpipe->pipe_state & PIPE_WANTW) { rpipe->pipe_state &= ~PIPE_WANTW; - KERNEL_LOCK(); wakeup(rpipe); - KERNEL_UNLOCK(); } } @@ -591,9 +564,7 @@ pipe_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) { wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR); - KERNEL_LOCK(); wakeup(wpipe); - KERNEL_UNLOCK(); } goto out_unlock; @@ -707,9 +678,7 @@ retrywrite: */ if (wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; - KERNEL_LOCK(); wakeup(wpipe); - KERNEL_UNLOCK(); } /* @@ -727,16 +696,10 @@ retrywrite: pipeselwakeup(wpipe); wpipe->pipe_state |= PIPE_WANTW; - pipe_pair_unlock(rpipe); - - KERNEL_LOCK(); error = tsleep(wpipe, (PRIBIO + 1)|PCATCH, "pipewr", 0); - KERNEL_UNLOCK(); - pipe_pair_lock(rpipe); - if (error) break; /* @@ -754,9 +717,7 @@ retrywrite: if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) { wpipe->pipe_state &= ~(PIPE_WANT | PIPE_WANTR); - KERNEL_LOCK(); wakeup(wpipe); - KERNEL_UNLOCK(); } else if (wpipe->pipe_buffer.cnt > 0) { /* * If we have put any characters in the buffer, we wake up @@ -764,9 +725,7 @@ retrywrite: */ if (wpipe->pipe_state & PIPE_WANTR) { wpipe->pipe_state &= ~PIPE_WANTR; - KERNEL_LOCK(); wakeup(wpipe); - KERNEL_UNLOCK(); } } @@ -779,11 +738,8 @@ retrywrite: error = 0; } - if (error == 0) { - KERNEL_LOCK(); + if (error == 0) getnanotime(&wpipe->pipe_mtime); - KERNEL_UNLOCK(); - } /* * We have something to offer, wake up select/poll. */ @@ -965,12 +921,10 @@ pipeclose(struct pipe *cpipe) */ cpipe->pipe_state |= PIPE_EOF; while (cpipe->pipe_busy) { - KERNEL_LOCK(); wakeup(cpipe); cpipe->pipe_state |= PIPE_WANT; pipe_pair_unlock(cpipe); tsleep(cpipe, PRIBIO, "pipecl", 0); - KERNEL_UNLOCK(); pipe_pair_lock(cpipe); } @@ -980,13 +934,8 @@ pipeclose(struct pipe *cpipe) if ((ppipe = cpipe->pipe_peer) != NULL) { pipeselwakeup(ppipe); ppipe->pipe_state |= PIPE_EOF; - - KERNEL_LOCK(); wakeup(ppipe); - KERNEL_UNLOCK(); - ppipe->pipe_peer = NULL; - free_lock = 0; } else { free_lock = 1; @@ -998,14 +947,11 @@ pipeclose(struct pipe *cpipe) * free resources */ pipe_free_kmem(cpipe); - KERNEL_LOCK(); if (free_lock) { pool_put(&pipe_lock_pool, cpipe->pipe_lock); } pool_put(&pipe_pool, cpipe); - - KERNEL_UNLOCK(); } int @@ -1021,7 +967,9 @@ pipe_kqfilter(struct file *fp, struct knote *kn) switch (kn->kn_filter) { case EVFILT_READ: kn->kn_fop = &pipe_rfiltops; + KERNEL_LOCK(); SLIST_INSERT_HEAD(&rpipe->pipe_sel.si_note, kn, kn_selnext); + KERNEL_UNLOCK(); break; case EVFILT_WRITE: if (wpipe == NULL) { @@ -1030,7 +978,9 @@ pipe_kqfilter(struct file *fp, struct knote *kn) return (EPIPE); } kn->kn_fop = &pipe_wfiltops; + KERNEL_LOCK(); SLIST_INSERT_HEAD(&wpipe->pipe_sel.si_note, kn, kn_selnext); + KERNEL_UNLOCK(); break; default: pipe_pair_unlock(rpipe); @@ -1054,15 +1004,18 @@ filt_pipedetach(struct knote *kn) switch (kn->kn_filter) { case EVFILT_READ: + KERNEL_LOCK(); SLIST_REMOVE(&rpipe->pipe_sel.si_note, kn, knote, kn_selnext); + KERNEL_UNLOCK(); break; case EVFILT_WRITE: if (wpipe == NULL) { pipe_pair_unlock(rpipe); return; } - + KERNEL_LOCK(); SLIST_REMOVE(&wpipe->pipe_sel.si_note, kn, knote, kn_selnext); + KERNEL_UNLOCK(); break; } -- 1.9.3