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- Convert sx lock to plain mutex. Since the access of /dev/sndstat
  is pretty much exclusive and protected by toggling sndstat_isopen,
  plain mutex is more than enough.
- Enable SBUF_AUTOEXTEND to avoid buffer truncation.
This commit is contained in:
Ariff Abdullah 2007-03-16 17:13:12 +00:00
parent 81be5d6d94
commit dd83f3b6cf
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=167640
1 changed files with 48 additions and 36 deletions
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84
sys/dev/sound/pcm/sndstat.c
View file

@ -61,7 +61,7 @@ struct sndstat_entry {
};
#ifdef USING_MUTEX
static struct sx sndstat_lock;
static struct mtx sndstat_lock;
#endif
static struct sbuf sndstat_sbuf;
static struct cdev *sndstat_dev = 0;
@ -72,6 +72,11 @@ static int sndstat_files = 0;
static SLIST_HEAD(, sndstat_entry) sndstat_devlist = SLIST_HEAD_INITIALIZER(none);
#ifdef SND_DEBUG
SYSCTL_INT(_hw_snd, OID_AUTO, sndstat_isopen, CTLFLAG_RW,
&sndstat_isopen, 1, "sndstat emergency exit");
#endif
int snd_verbose = 1;
#ifdef USING_MUTEX
TUNABLE_INT("hw.snd.verbose", &snd_verbose);
@ -89,12 +94,12 @@ sysctl_hw_sndverbose(SYSCTL_HANDLER_ARGS)
verbose = snd_verbose;
error = sysctl_handle_int(oidp, &verbose, sizeof(verbose), req);
if (error == 0 && req->newptr != NULL) {
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (verbose < 0 || verbose > 4)
error = EINVAL;
else
snd_verbose = verbose;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
}
return error;
}
@ -106,14 +111,14 @@ sndstat_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
{
int error;
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (sndstat_isopen) {
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return EBUSY;
}
sndstat_isopen = 1;
sx_xunlock(&sndstat_lock);
if (sbuf_new(&sndstat_sbuf, NULL, 4096, 0) == NULL) {
mtx_unlock(&sndstat_lock);
if (sbuf_new(&sndstat_sbuf, NULL, 4096, SBUF_AUTOEXTEND) == NULL) {
error = ENXIO;
goto out;
}
@ -121,9 +126,9 @@ sndstat_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
error = (sndstat_prepare(&sndstat_sbuf) > 0) ? 0 : ENOMEM;
out:
if (error) {
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
sndstat_isopen = 0;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
}
return (error);
}
@ -131,15 +136,19 @@ sndstat_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
static int
sndstat_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
{
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (!sndstat_isopen) {
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return EBADF;
}
sbuf_delete(&sndstat_sbuf);
sndstat_isopen = 0;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
sbuf_delete(&sndstat_sbuf);
mtx_lock(&sndstat_lock);
sndstat_isopen = 0;
mtx_unlock(&sndstat_lock);
return 0;
}
@ -148,16 +157,17 @@ sndstat_read(struct cdev *i_dev, struct uio *buf, int flag)
{
int l, err;
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (!sndstat_isopen) {
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return EBADF;
}
mtx_unlock(&sndstat_lock);
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_xunlock(&sndstat_lock);
return err;
}
@ -179,26 +189,26 @@ sndstat_find(int type, int unit)
int
sndstat_acquire(void)
{
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (sndstat_isopen) {
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return EBUSY;
}
sndstat_isopen = 1;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return 0;
}
int
sndstat_release(void)
{
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (!sndstat_isopen) {
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return EBADF;
}
sndstat_isopen = 0;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return 0;
}
@ -232,12 +242,12 @@ sndstat_register(device_t dev, char *str, sndstat_handler handler)
ent->unit = unit;
ent->handler = handler;
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
SLIST_INSERT_HEAD(&sndstat_devlist, ent, link);
if (type == SS_TYPE_MODULE)
sndstat_files++;
sndstat_maxunit = (unit > sndstat_maxunit)? unit : sndstat_maxunit;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return 0;
}
@ -253,17 +263,17 @@ sndstat_unregister(device_t dev)
{
struct sndstat_entry *ent;
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
SLIST_FOREACH(ent, &sndstat_devlist, link) {
if (ent->dev == dev) {
SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link);
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
free(ent, M_DEVBUF);
return 0;
}
}
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return ENXIO;
}
@ -273,18 +283,18 @@ sndstat_unregisterfile(char *str)
{
struct sndstat_entry *ent;
sx_xlock(&sndstat_lock);
mtx_lock(&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--;
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
free(ent, M_DEVBUF);
return 0;
}
}
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return ENXIO;
}
@ -339,7 +349,7 @@ sndstat_prepare(struct sbuf *s)
static int
sndstat_init(void)
{
sx_init(&sndstat_lock, "sndstat");
mtx_init(&sndstat_lock, "sndstat", "sndstat lock", MTX_DEF);
sndstat_dev = make_dev(&sndstat_cdevsw, SND_DEV_STATUS, UID_ROOT, GID_WHEEL, 0444, "sndstat");
return (sndstat_dev != 0)? 0 : ENXIO;
@ -348,18 +358,20 @@ sndstat_init(void)
static int
sndstat_uninit(void)
{
sx_xlock(&sndstat_lock);
mtx_lock(&sndstat_lock);
if (sndstat_isopen) {
sx_xunlock(&sndstat_lock);
mtx_unlock(&sndstat_lock);
return EBUSY;
}
sndstat_isopen = 1;
mtx_unlock(&sndstat_lock);
if (sndstat_dev)
destroy_dev(sndstat_dev);
sndstat_dev = 0;
sx_xunlock(&sndstat_lock);
sx_destroy(&sndstat_lock);
mtx_destroy(&sndstat_lock);
return 0;
}