ALSA: rawmidi - Refactor rawmidi open/close codes

Refactor rawmidi open/close code messes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 194 insertions, 183 deletions

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 60f33e9412ad..473247c8e6d3 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -224,156 +224,143 @@ int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream)
         return 0;
 }
 
-int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
-                            int mode, struct snd_rawmidi_file * rfile)
+/* look for an available substream for the given stream direction;
+ * if a specific subdevice is given, try to assign it
+ */
+static int assign_substream(struct snd_rawmidi *rmidi, int subdevice,
+                            int stream, int mode,
+                            struct snd_rawmidi_substream **sub_ret)
 {
-        struct snd_rawmidi *rmidi;
-        struct list_head *list1, *list2;
-        struct snd_rawmidi_substream *sinput = NULL, *soutput = NULL;
-        struct snd_rawmidi_runtime *input = NULL, *output = NULL;
-        int err;
+        struct snd_rawmidi_substream *substream;
+        struct snd_rawmidi_str *s = &rmidi->streams[stream];
+        static unsigned int info_flags[2] = {
+                [SNDRV_RAWMIDI_STREAM_OUTPUT] = SNDRV_RAWMIDI_INFO_OUTPUT,
+                [SNDRV_RAWMIDI_STREAM_INPUT] = SNDRV_RAWMIDI_INFO_INPUT,
+        };
 
-        if (rfile)
-                rfile->input = rfile->output = NULL;
-        mutex_lock(&register_mutex);
-        rmidi = snd_rawmidi_search(card, device);
-        if (rmidi == NULL) {
-                mutex_unlock(&register_mutex);
-                return -ENODEV;
-        }
-        if (!try_module_get(rmidi->card->module)) {
-                mutex_unlock(&register_mutex);
+        if (!(rmidi->info_flags & info_flags[stream]))
                 return -ENXIO;
+        if (subdevice >= 0 && subdevice >= s->substream_count)
+                return -ENODEV;
+        if (s->substream_opened >= s->substream_count)
+                return -EAGAIN;
+
+        list_for_each_entry(substream, &s->substreams, list) {
+                if (substream->opened) {
+                        if (stream == SNDRV_RAWMIDI_STREAM_INPUT ||
+                            !(mode & SNDRV_RAWMIDI_LFLG_APPEND))
+                                continue;
+                }
+                if (subdevice < 0 || subdevice == substream->number) {
+                        *sub_ret = substream;
+                        return 0;
+                }
         }
-        mutex_unlock(&register_mutex);
+        return -EAGAIN;
+}
 
-        if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
-                mutex_lock(&rmidi->open_mutex);
+/* open and do ref-counting for the given substream */
+static int open_substream(struct snd_rawmidi *rmidi,
+                          struct snd_rawmidi_substream *substream,
+                          int mode)
+{
+        int err;
+
+        err = snd_rawmidi_runtime_create(substream);
+        if (err < 0)
+                return err;
+        err = substream->ops->open(substream);
+        if (err < 0)
+                return err;
+        substream->opened = 1;
+        if (substream->use_count++ == 0)
+                substream->active_sensing = 1;
+        if (mode & SNDRV_RAWMIDI_LFLG_APPEND)
+                substream->append = 1;
+        rmidi->streams[substream->stream].substream_opened++;
+        return 0;
+}
+
+static void close_substream(struct snd_rawmidi *rmidi,
+                            struct snd_rawmidi_substream *substream,
+                            int cleanup);
+
+static int rawmidi_open_priv(struct snd_rawmidi *rmidi, int subdevice, int mode,
+                             struct snd_rawmidi_file *rfile)
+{
+        struct snd_rawmidi_substream *sinput = NULL, *soutput = NULL;
+        int err;
+
+        rfile->input = rfile->output = NULL;
         if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
-                if (!(rmidi->info_flags & SNDRV_RAWMIDI_INFO_INPUT)) {
-                        err = -ENXIO;
-                        goto __error;
-                }
-                if (subdevice >= 0 && (unsigned int)subdevice >= rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_count) {
-                        err = -ENODEV;
-                        goto __error;
-                }
-                if (rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_opened >=
-                    rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_count) {
-                        err = -EAGAIN;
+                err = assign_substream(rmidi, subdevice,
+                                       SNDRV_RAWMIDI_STREAM_INPUT,
+                                       mode, &sinput);
+                if (err < 0)
                         goto __error;
-                }
         }
         if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
-                if (!(rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT)) {
-                        err = -ENXIO;
-                        goto __error;
-                }
-                if (subdevice >= 0 && (unsigned int)subdevice >= rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_count) {
-                        err = -ENODEV;
-                        goto __error;
-                }
-                if (rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_opened >=
-                    rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_count) {
-                        err = -EAGAIN;
+                err = assign_substream(rmidi, subdevice,
+                                       SNDRV_RAWMIDI_STREAM_OUTPUT,
+                                       mode, &soutput);
+                if (err < 0)
                         goto __error;
-                }
-        }
-        list1 = rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams.next;
-        while (1) {
-                if (list1 == &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substreams) {
-                        sinput = NULL;
-                        if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
-                                err = -EAGAIN;
-                                goto __error;
-                        }
-                        break;
-                }
-                sinput = list_entry(list1, struct snd_rawmidi_substream, list);
-                if ((mode & SNDRV_RAWMIDI_LFLG_INPUT) && sinput->opened)
-                        goto __nexti;
-                if (subdevice < 0 || (subdevice >= 0 && subdevice == sinput->number))
-                        break;
-              __nexti:
-                list1 = list1->next;
-        }
-        list2 = rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams.next;
-        while (1) {
-                if (list2 == &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substreams) {
-                        soutput = NULL;
-                        if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
-                                err = -EAGAIN;
-                                goto __error;
-                        }
-                        break;
-                }
-                soutput = list_entry(list2, struct snd_rawmidi_substream, list);
-                if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
-                        if (mode & SNDRV_RAWMIDI_LFLG_APPEND) {
-                                if (soutput->opened && !soutput->append)
-                                        goto __nexto;
-                        } else {
-                                if (soutput->opened)
-                                        goto __nexto;
-                        }
-                }
-                if (subdevice < 0 || (subdevice >= 0 && subdevice == soutput->number))
-                        break;
-              __nexto:
-                list2 = list2->next;
         }
-        if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
-                if ((err = snd_rawmidi_runtime_create(sinput)) < 0)
-                        goto __error;
-                input = sinput->runtime;
-                if ((err = sinput->ops->open(sinput)) < 0)
+
+        if (sinput) {
+                err = open_substream(rmidi, sinput, mode);
+                if (err < 0)
                         goto __error;
-                sinput->opened = 1;
-                rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_opened++;
-        } else {
-                sinput = NULL;
         }
-        if (mode & SNDRV_RAWMIDI_LFLG_OUTPUT) {
-                if (soutput->opened)
-                        goto __skip_output;
-                if ((err = snd_rawmidi_runtime_create(soutput)) < 0) {
-                        if (mode & SNDRV_RAWMIDI_LFLG_INPUT)
-                                sinput->ops->close(sinput);
-                        goto __error;
-                }
-                output = soutput->runtime;
-                if ((err = soutput->ops->open(soutput)) < 0) {
-                        if (mode & SNDRV_RAWMIDI_LFLG_INPUT)
-                                sinput->ops->close(sinput);
+        if (soutput) {
+                err = open_substream(rmidi, soutput, mode);
+                if (err < 0) {
+                        if (sinput)
+                                close_substream(rmidi, sinput, 0);
                         goto __error;
                 }
-              __skip_output:
-                soutput->opened = 1;
-                if (mode & SNDRV_RAWMIDI_LFLG_APPEND)
-                        soutput->append = 1;
-                if (soutput->use_count++ == 0)
-                        soutput->active_sensing = 1;
-                rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_opened++;
-        } else {
-                soutput = NULL;
-        }
-        if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
-                mutex_unlock(&rmidi->open_mutex);
-        if (rfile) {
-                rfile->rmidi = rmidi;
-                rfile->input = sinput;
-                rfile->output = soutput;
         }
+
+        rfile->rmidi = rmidi;
+        rfile->input = sinput;
+        rfile->output = soutput;
         return 0;
 
       __error:
-        if (input != NULL)
+        if (sinput && sinput->runtime)
                 snd_rawmidi_runtime_free(sinput);
-        if (output != NULL)
+        if (soutput && soutput->runtime)
                 snd_rawmidi_runtime_free(soutput);
-        if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
-                mutex_unlock(&rmidi->open_mutex);
-        module_put(rmidi->card->module);
+        return err;
+}
+
+/* called from sound/core/seq/seq_midi.c */
+int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
+                            int mode, struct snd_rawmidi_file * rfile)
+{
+        struct snd_rawmidi *rmidi;
+        int err;
+
+        if (snd_BUG_ON(!rfile))
+                return -EINVAL;
+
+        mutex_lock(&register_mutex);
+        rmidi = snd_rawmidi_search(card, device);
+        if (rmidi == NULL) {
+                mutex_unlock(&register_mutex);
+                return -ENODEV;
+        }
+        if (!try_module_get(rmidi->card->module)) {
+                mutex_unlock(&register_mutex);
+                return -ENXIO;
+        }
+        mutex_unlock(&register_mutex);
+
+        mutex_lock(&rmidi->open_mutex);
+        err = rawmidi_open_priv(rmidi, subdevice, mode, rfile);
+        mutex_unlock(&rmidi->open_mutex);
+        if (err < 0)
+                module_put(rmidi->card->module);
         return err;
 }
 
@@ -385,10 +372,13 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
         unsigned short fflags;
         int err;
         struct snd_rawmidi *rmidi;
-        struct snd_rawmidi_file *rawmidi_file;
+        struct snd_rawmidi_file *rawmidi_file = NULL;
         wait_queue_t wait;
         struct snd_ctl_file *kctl;
 
+        if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK)) 
+                return -EINVAL;         /* invalid combination */
+
         if (maj == snd_major) {
                 rmidi = snd_lookup_minor_data(iminor(inode),
                                               SNDRV_DEVICE_TYPE_RAWMIDI);
@@ -402,24 +392,25 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
 
         if (rmidi == NULL)
                 return -ENODEV;
-        if ((file->f_flags & O_APPEND) && !(file->f_flags & O_NONBLOCK)) 
-                return -EINVAL;         /* invalid combination */
+
+        if (!try_module_get(rmidi->card->module))
+                return -ENXIO;
+
+        mutex_lock(&rmidi->open_mutex);
         card = rmidi->card;
         err = snd_card_file_add(card, file);
         if (err < 0)
-                return -ENODEV;
+                goto __error_card;
         fflags = snd_rawmidi_file_flags(file);
         if ((file->f_flags & O_APPEND) || maj == SOUND_MAJOR) /* OSS emul? */
                 fflags |= SNDRV_RAWMIDI_LFLG_APPEND;
-        fflags |= SNDRV_RAWMIDI_LFLG_NOOPENLOCK;
         rawmidi_file = kmalloc(sizeof(*rawmidi_file), GFP_KERNEL);
         if (rawmidi_file == NULL) {
-                snd_card_file_remove(card, file);
-                return -ENOMEM;
+                err = -ENOMEM;
+                goto __error;
         }
         init_waitqueue_entry(&wait, current);
         add_wait_queue(&rmidi->open_wait, &wait);
-        mutex_lock(&rmidi->open_mutex);
         while (1) {
                 subdevice = -1;
                 read_lock(&card->ctl_files_rwlock);
@@ -431,8 +422,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
                         }
                 }
                 read_unlock(&card->ctl_files_rwlock);
-                err = snd_rawmidi_kernel_open(rmidi->card, rmidi->device,
-                                              subdevice, fflags, rawmidi_file);
+                err = rawmidi_open_priv(rmidi, subdevice, fflags, rawmidi_file);
                 if (err >= 0)
                         break;
                 if (err == -EAGAIN) {
@@ -451,67 +441,89 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file)
                         break;
                 }
         }
+        remove_wait_queue(&rmidi->open_wait, &wait);
+        if (err < 0) {
+                kfree(rawmidi_file);
+                goto __error;
+        }
 #ifdef CONFIG_SND_OSSEMUL
         if (rawmidi_file->input && rawmidi_file->input->runtime)
                 rawmidi_file->input->runtime->oss = (maj == SOUND_MAJOR);
         if (rawmidi_file->output && rawmidi_file->output->runtime)
                 rawmidi_file->output->runtime->oss = (maj == SOUND_MAJOR);
 #endif
-        remove_wait_queue(&rmidi->open_wait, &wait);
-        if (err >= 0) {
-                file->private_data = rawmidi_file;
-        } else {
-                snd_card_file_remove(card, file);
-                kfree(rawmidi_file);
-        }
+        file->private_data = rawmidi_file;
         mutex_unlock(&rmidi->open_mutex);
+        return 0;
+
+ __error:
+        snd_card_file_remove(card, file);
+ __error_card:
+        mutex_unlock(&rmidi->open_mutex);
+        module_put(rmidi->card->module);
         return err;
 }
 
-int snd_rawmidi_kernel_release(struct snd_rawmidi_file * rfile)
+static void close_substream(struct snd_rawmidi *rmidi,
+                            struct snd_rawmidi_substream *substream,
+                            int cleanup)
 {
-        struct snd_rawmidi *rmidi;
-        struct snd_rawmidi_substream *substream;
-        struct snd_rawmidi_runtime *runtime;
+        rmidi->streams[substream->stream].substream_opened--;
+        if (--substream->use_count)
+                return;
 
-        if (snd_BUG_ON(!rfile))
-                return -ENXIO;
-        rmidi = rfile->rmidi;
-        mutex_lock(&rmidi->open_mutex);
-        if (rfile->input != NULL) {
-                substream = rfile->input;
-                rfile->input = NULL;
-                runtime = substream->runtime;
-                snd_rawmidi_input_trigger(substream, 0);
-                substream->ops->close(substream);
-                if (runtime->private_free != NULL)
-                        runtime->private_free(substream);
-                snd_rawmidi_runtime_free(substream);
-                substream->opened = 0;
-                rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT].substream_opened--;
-        }
-        if (rfile->output != NULL) {
-                substream = rfile->output;
-                rfile->output = NULL;
-                if (--substream->use_count == 0) {
-                        runtime = substream->runtime;
+        if (cleanup) {
+                if (substream->stream == SNDRV_RAWMIDI_STREAM_INPUT)
+                        snd_rawmidi_input_trigger(substream, 0);
+                else {
                         if (substream->active_sensing) {
                                 unsigned char buf = 0xfe;
-                                /* sending single active sensing message to shut the device up */
+                                /* sending single active sensing message
+                                 * to shut the device up
+                                 */
                                 snd_rawmidi_kernel_write(substream, &buf, 1);
                         }
                         if (snd_rawmidi_drain_output(substream) == -ERESTARTSYS)
                                 snd_rawmidi_output_trigger(substream, 0);
-                        substream->ops->close(substream);
-                        if (runtime->private_free != NULL)
-                                runtime->private_free(substream);
-                        snd_rawmidi_runtime_free(substream);
-                        substream->opened = 0;
-                        substream->append = 0;
                 }
-                rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT].substream_opened--;
         }
+        substream->ops->close(substream);
+        if (substream->runtime->private_free)
+                substream->runtime->private_free(substream);
+        snd_rawmidi_runtime_free(substream);
+        substream->opened = 0;
+        substream->append = 0;
+}
+
+static void rawmidi_release_priv(struct snd_rawmidi_file *rfile)
+{
+        struct snd_rawmidi *rmidi;
+
+        rmidi = rfile->rmidi;
+        mutex_lock(&rmidi->open_mutex);
+        if (rfile->input) {
+                close_substream(rmidi, rfile->input, 1);
+                rfile->input = NULL;
+        }
+        if (rfile->output) {
+                close_substream(rmidi, rfile->output, 1);
+                rfile->output = NULL;
+        }
+        rfile->rmidi = NULL;
         mutex_unlock(&rmidi->open_mutex);
+        wake_up(&rmidi->open_wait);
+}
+
+/* called from sound/core/seq/seq_midi.c */
+int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile)
+{
+        struct snd_rawmidi *rmidi;
+
+        if (snd_BUG_ON(!rfile))
+                return -ENXIO;
+        
+        rmidi = rfile->rmidi;
+        rawmidi_release_priv(rfile);
         module_put(rmidi->card->module);
         return 0;
 }
@@ -520,15 +532,14 @@ static int snd_rawmidi_release(struct inode *inode, struct file *file)
 {
         struct snd_rawmidi_file *rfile;
         struct snd_rawmidi *rmidi;
-        int err;
 
         rfile = file->private_data;
-        err = snd_rawmidi_kernel_release(rfile);
         rmidi = rfile->rmidi;
-        wake_up(&rmidi->open_wait);
+        rawmidi_release_priv(rfile);
         kfree(rfile);
         snd_card_file_remove(rmidi->card, file);
-        return err;
+        module_put(rmidi->card->module);
+        return 0;
 }
 
 static int snd_rawmidi_info(struct snd_rawmidi_substream *substream,