[ALSA] Add O_APPEND flag support to PCM
Added O_APPEND flag support to PCM to enable shared substreams
among multiple processes. This mechanism is used by dmix and
dsnoop plugins.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 7b5729c..36d6765 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1284,13 +1284,16 @@
/*
* prepare ioctl
*/
-static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream, int state)
+/* we use the second argument for updating f_flags */
+static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream,
+ int f_flags)
{
struct snd_pcm_runtime *runtime = substream->runtime;
if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
return -EBADFD;
if (snd_pcm_running(substream))
return -EBUSY;
+ substream->f_flags = f_flags;
return 0;
}
@@ -1319,17 +1322,26 @@
/**
* snd_pcm_prepare
* @substream: the PCM substream instance
+ * @file: file to refer f_flags
*
* Prepare the PCM substream to be triggerable.
*/
-static int snd_pcm_prepare(struct snd_pcm_substream *substream)
+static int snd_pcm_prepare(struct snd_pcm_substream *substream,
+ struct file *file)
{
int res;
struct snd_card *card = substream->pcm->card;
+ int f_flags;
+
+ if (file)
+ f_flags = file->f_flags;
+ else
+ f_flags = substream->f_flags;
snd_power_lock(card);
if ((res = snd_power_wait(card, SNDRV_CTL_POWER_D0)) >= 0)
- res = snd_pcm_action_nonatomic(&snd_pcm_action_prepare, substream, 0);
+ res = snd_pcm_action_nonatomic(&snd_pcm_action_prepare,
+ substream, f_flags);
snd_power_unlock(card);
return res;
}
@@ -1340,7 +1352,7 @@
static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream, int state)
{
- if (substream->ffile->f_flags & O_NONBLOCK)
+ if (substream->f_flags & O_NONBLOCK)
return -EAGAIN;
substream->runtime->trigger_master = substream;
return 0;
@@ -2015,6 +2027,10 @@
void snd_pcm_release_substream(struct snd_pcm_substream *substream)
{
+ substream->ref_count--;
+ if (substream->ref_count > 0)
+ return;
+
snd_pcm_drop(substream);
if (substream->hw_opened) {
if (substream->ops->hw_free != NULL)
@@ -2041,6 +2057,11 @@
err = snd_pcm_attach_substream(pcm, stream, file, &substream);
if (err < 0)
return err;
+ if (substream->ref_count > 1) {
+ *rsubstream = substream;
+ return 0;
+ }
+
substream->no_mmap_ctrl = 0;
err = snd_pcm_hw_constraints_init(substream);
if (err < 0) {
@@ -2086,17 +2107,20 @@
if (err < 0)
return err;
- pcm_file = kzalloc(sizeof(*pcm_file), GFP_KERNEL);
- if (pcm_file == NULL) {
- snd_pcm_release_substream(substream);
- return -ENOMEM;
+ if (substream->ref_count > 1)
+ pcm_file = substream->file;
+ else {
+ pcm_file = kzalloc(sizeof(*pcm_file), GFP_KERNEL);
+ if (pcm_file == NULL) {
+ snd_pcm_release_substream(substream);
+ return -ENOMEM;
+ }
+ str = substream->pstr;
+ substream->file = pcm_file;
+ substream->pcm_release = pcm_release_private;
+ pcm_file->substream = substream;
+ snd_pcm_add_file(str, pcm_file);
}
- str = substream->pstr;
- substream->file = pcm_file;
- substream->pcm_release = pcm_release_private;
- pcm_file->substream = substream;
- snd_pcm_add_file(str, pcm_file);
-
file->private_data = pcm_file;
*rpcm_file = pcm_file;
return 0;
@@ -2506,7 +2530,8 @@
return 0;
}
-static int snd_pcm_common_ioctl1(struct snd_pcm_substream *substream,
+static int snd_pcm_common_ioctl1(struct file *file,
+ struct snd_pcm_substream *substream,
unsigned int cmd, void __user *arg)
{
snd_assert(substream != NULL, return -ENXIO);
@@ -2531,7 +2556,7 @@
case SNDRV_PCM_IOCTL_CHANNEL_INFO:
return snd_pcm_channel_info_user(substream, arg);
case SNDRV_PCM_IOCTL_PREPARE:
- return snd_pcm_prepare(substream);
+ return snd_pcm_prepare(substream, file);
case SNDRV_PCM_IOCTL_RESET:
return snd_pcm_reset(substream);
case SNDRV_PCM_IOCTL_START:
@@ -2573,7 +2598,8 @@
return -ENOTTY;
}
-static int snd_pcm_playback_ioctl1(struct snd_pcm_substream *substream,
+static int snd_pcm_playback_ioctl1(struct file *file,
+ struct snd_pcm_substream *substream,
unsigned int cmd, void __user *arg)
{
snd_assert(substream != NULL, return -ENXIO);
@@ -2649,10 +2675,11 @@
return result < 0 ? result : 0;
}
}
- return snd_pcm_common_ioctl1(substream, cmd, arg);
+ return snd_pcm_common_ioctl1(file, substream, cmd, arg);
}
-static int snd_pcm_capture_ioctl1(struct snd_pcm_substream *substream,
+static int snd_pcm_capture_ioctl1(struct file *file,
+ struct snd_pcm_substream *substream,
unsigned int cmd, void __user *arg)
{
snd_assert(substream != NULL, return -ENXIO);
@@ -2728,7 +2755,7 @@
return result < 0 ? result : 0;
}
}
- return snd_pcm_common_ioctl1(substream, cmd, arg);
+ return snd_pcm_common_ioctl1(file, substream, cmd, arg);
}
static long snd_pcm_playback_ioctl(struct file *file, unsigned int cmd,
@@ -2741,7 +2768,8 @@
if (((cmd >> 8) & 0xff) != 'A')
return -ENOTTY;
- return snd_pcm_playback_ioctl1(pcm_file->substream, cmd, (void __user *)arg);
+ return snd_pcm_playback_ioctl1(file, pcm_file->substream, cmd,
+ (void __user *)arg);
}
static long snd_pcm_capture_ioctl(struct file *file, unsigned int cmd,
@@ -2754,7 +2782,8 @@
if (((cmd >> 8) & 0xff) != 'A')
return -ENOTTY;
- return snd_pcm_capture_ioctl1(pcm_file->substream, cmd, (void __user *)arg);
+ return snd_pcm_capture_ioctl1(file, pcm_file->substream, cmd,
+ (void __user *)arg);
}
int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream,
@@ -2766,12 +2795,12 @@
fs = snd_enter_user();
switch (substream->stream) {
case SNDRV_PCM_STREAM_PLAYBACK:
- result = snd_pcm_playback_ioctl1(substream,
- cmd, (void __user *)arg);
+ result = snd_pcm_playback_ioctl1(NULL, substream, cmd,
+ (void __user *)arg);
break;
case SNDRV_PCM_STREAM_CAPTURE:
- result = snd_pcm_capture_ioctl1(substream,
- cmd, (void __user *)arg);
+ result = snd_pcm_capture_ioctl1(NULL, substream, cmd,
+ (void __user *)arg);
break;
default:
result = -EINVAL;