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;
}
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
