Date: Wed, 2 May 2012 19:32:11 +0000 (UTC) From: Peter Holm <pho@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r234932 - head/sys/dev/sound/pcm Message-ID: <201205021932.q42JWBMs099729@svn.freebsd.org>
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Author: pho Date: Wed May 2 19:32:11 2012 New Revision: 234932 URL: http://svn.freebsd.org/changeset/base/234932 Log: Added D_TRACKCLOSE to sndstat_cdevsw to fix the situation when another process is in open() or stat() for the device node, then close() from the owning process does not result in cdevsw close method call. This fixes the pemanent "Device busy" seen. Changed the sndstat_lock from mutex to sx. This allows to extend the region covered by the lock, to include the uiomove() call in sndstat_read() and bufptr increment. This fixes the "panic: sbuf_put_byte called with finished or corrupt sbuf" seen. In collaboration with: kib MFC after: 1 week Modified: head/sys/dev/sound/pcm/sndstat.c Modified: head/sys/dev/sound/pcm/sndstat.c ============================================================================== --- head/sys/dev/sound/pcm/sndstat.c Wed May 2 18:41:58 2012 (r234931) +++ head/sys/dev/sound/pcm/sndstat.c Wed May 2 19:32:11 2012 (r234932) @@ -53,6 +53,7 @@ static struct cdevsw sndstat_cdevsw = { .d_close = sndstat_close, .d_read = sndstat_read, .d_name = "sndstat", + .d_flags = D_TRACKCLOSE, }; struct sndstat_entry { @@ -63,7 +64,7 @@ struct sndstat_entry { int type, unit; }; -static struct mtx sndstat_lock; +static struct sx sndstat_lock; static struct sbuf sndstat_sbuf; static struct cdev *sndstat_dev = NULL; static int sndstat_bufptr = -1; @@ -93,16 +94,14 @@ sysctl_hw_snd_sndstat_pid(SYSCTL_HANDLER if (sndstat_dev == NULL) return (EINVAL); - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); val = (int)SNDSTAT_PID(sndstat_dev); - mtx_unlock(&sndstat_lock); err = sysctl_handle_int(oidp, &val, 0, req); if (err == 0 && req->newptr != NULL && val == 0) { - mtx_lock(&sndstat_lock); SNDSTAT_FLUSH(); SNDSTAT_PID_SET(sndstat_dev, 0); - mtx_unlock(&sndstat_lock); } + sx_unlock(&sndstat_lock); return (err); } SYSCTL_PROC(_hw_snd, OID_AUTO, sndstat_pid, CTLTYPE_INT | CTLFLAG_RW, @@ -119,12 +118,10 @@ sysctl_hw_sndverbose(SYSCTL_HANDLER_ARGS verbose = snd_verbose; error = sysctl_handle_int(oidp, &verbose, 0, req); if (error == 0 && req->newptr != NULL) { - mtx_lock(&sndstat_lock); if (verbose < 0 || verbose > 4) error = EINVAL; else snd_verbose = verbose; - mtx_unlock(&sndstat_lock); } return error; } @@ -137,20 +134,19 @@ sndstat_open(struct cdev *i_dev, int fla if (sndstat_dev == NULL || i_dev != sndstat_dev) return EBADF; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); if (SNDSTAT_PID(i_dev) != 0) { - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return EBUSY; } SNDSTAT_PID_SET(i_dev, td->td_proc->p_pid); - mtx_unlock(&sndstat_lock); if (sbuf_new(&sndstat_sbuf, NULL, 4096, SBUF_AUTOEXTEND) == NULL) { - mtx_lock(&sndstat_lock); SNDSTAT_PID_SET(i_dev, 0); - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return ENXIO; } sndstat_bufptr = 0; + sx_unlock(&sndstat_lock); return 0; } @@ -160,16 +156,16 @@ sndstat_close(struct cdev *i_dev, int fl if (sndstat_dev == NULL || i_dev != sndstat_dev) return EBADF; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); if (SNDSTAT_PID(i_dev) == 0) { - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return EBADF; } SNDSTAT_FLUSH(); SNDSTAT_PID_SET(i_dev, 0); - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return 0; } @@ -182,20 +178,18 @@ sndstat_read(struct cdev *i_dev, struct if (sndstat_dev == NULL || i_dev != sndstat_dev) return EBADF; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); if (SNDSTAT_PID(i_dev) != buf->uio_td->td_proc->p_pid || sndstat_bufptr == -1) { - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return EBADF; } - mtx_unlock(&sndstat_lock); if (sndstat_bufptr == 0) { err = (sndstat_prepare(&sndstat_sbuf) > 0) ? 0 : ENOMEM; if (err) { - mtx_lock(&sndstat_lock); SNDSTAT_FLUSH(); - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return err; } } @@ -203,6 +197,7 @@ sndstat_read(struct cdev *i_dev, struct l = min(buf->uio_resid, sbuf_len(&sndstat_sbuf) - sndstat_bufptr); err = (l > 0)? uiomove(sbuf_data(&sndstat_sbuf) + sndstat_bufptr, l, buf) : 0; sndstat_bufptr += l; + sx_unlock(&sndstat_lock); return err; } @@ -228,13 +223,13 @@ sndstat_acquire(struct thread *td) if (sndstat_dev == NULL) return EBADF; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); if (SNDSTAT_PID(sndstat_dev) != 0) { - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return EBUSY; } SNDSTAT_PID_SET(sndstat_dev, td->td_proc->p_pid); - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return 0; } @@ -244,13 +239,13 @@ sndstat_release(struct thread *td) if (sndstat_dev == NULL) return EBADF; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); if (SNDSTAT_PID(sndstat_dev) != td->td_proc->p_pid) { - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return EBADF; } SNDSTAT_PID_SET(sndstat_dev, 0); - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return 0; } @@ -284,12 +279,12 @@ sndstat_register(device_t dev, char *str ent->unit = unit; ent->handler = handler; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); SLIST_INSERT_HEAD(&sndstat_devlist, ent, link); if (type == SS_TYPE_MODULE) sndstat_files++; sndstat_maxunit = (unit > sndstat_maxunit)? unit : sndstat_maxunit; - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return 0; } @@ -305,17 +300,17 @@ sndstat_unregister(device_t dev) { struct sndstat_entry *ent; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); SLIST_FOREACH(ent, &sndstat_devlist, link) { if (ent->dev == dev) { SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link); - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); free(ent, M_DEVBUF); return 0; } } - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return ENXIO; } @@ -325,18 +320,18 @@ sndstat_unregisterfile(char *str) { struct sndstat_entry *ent; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); SLIST_FOREACH(ent, &sndstat_devlist, link) { if (ent->dev == NULL && ent->str == str) { SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link); sndstat_files--; - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); free(ent, M_DEVBUF); return 0; } } - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return ENXIO; } @@ -399,7 +394,7 @@ sndstat_init(void) { if (sndstat_dev != NULL) return EINVAL; - mtx_init(&sndstat_lock, "sndstat", "sndstat lock", MTX_DEF); + sx_init(&sndstat_lock, "sndstat lock"); sndstat_dev = make_dev(&sndstat_cdevsw, SND_DEV_STATUS, UID_ROOT, GID_WHEEL, 0444, "sndstat"); return 0; @@ -411,20 +406,20 @@ sndstat_uninit(void) if (sndstat_dev == NULL) return EINVAL; - mtx_lock(&sndstat_lock); + sx_xlock(&sndstat_lock); if (SNDSTAT_PID(sndstat_dev) != curthread->td_proc->p_pid) { - mtx_unlock(&sndstat_lock); + sx_unlock(&sndstat_lock); return EBUSY; } - SNDSTAT_FLUSH(); - - mtx_unlock(&sndstat_lock); - + /* XXXPHO: use destroy_dev_sched() */ destroy_dev(sndstat_dev); sndstat_dev = NULL; - mtx_destroy(&sndstat_lock); + SNDSTAT_FLUSH(); + + sx_unlock(&sndstat_lock); + sx_destroy(&sndstat_lock); return 0; }
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