From 742ecf3ce1acdbcd0bc936178e1eaf346a0fd376 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 27 Feb 2024 09:52:53 +0100 Subject: [PATCH] ALSA: core: Use guard() for locking We can simplify the code gracefully with new guard() macro and co for automatic cleanup of locks. Only the code refactoring, and no functional changes. Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20240227085306.9764-12-tiwai@suse.de --- sound/core/init.c | 199 +++++++++++++++++++---------------------- sound/core/sound.c | 28 +++--- sound/core/sound_oss.c | 17 ++-- 3 files changed, 107 insertions(+), 137 deletions(-) diff --git a/sound/core/init.c b/sound/core/init.c index 22c0d217b860..4ed5037d8693 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -284,30 +284,31 @@ static int snd_card_init(struct snd_card *card, struct device *parent, if (xid) strscpy(card->id, xid, sizeof(card->id)); err = 0; - mutex_lock(&snd_card_mutex); - if (idx < 0) /* first check the matching module-name slot */ - idx = get_slot_from_bitmask(idx, module_slot_match, module); - if (idx < 0) /* if not matched, assign an empty slot */ - idx = get_slot_from_bitmask(idx, check_empty_slot, module); - if (idx < 0) - err = -ENODEV; - else if (idx < snd_ecards_limit) { - if (test_bit(idx, snd_cards_lock)) - err = -EBUSY; /* invalid */ - } else if (idx >= SNDRV_CARDS) - err = -ENODEV; + scoped_guard(mutex, &snd_card_mutex) { + if (idx < 0) /* first check the matching module-name slot */ + idx = get_slot_from_bitmask(idx, module_slot_match, module); + if (idx < 0) /* if not matched, assign an empty slot */ + idx = get_slot_from_bitmask(idx, check_empty_slot, module); + if (idx < 0) + err = -ENODEV; + else if (idx < snd_ecards_limit) { + if (test_bit(idx, snd_cards_lock)) + err = -EBUSY; /* invalid */ + } else if (idx >= SNDRV_CARDS) + err = -ENODEV; + if (!err) { + set_bit(idx, snd_cards_lock); /* lock it */ + if (idx >= snd_ecards_limit) + snd_ecards_limit = idx + 1; /* increase the limit */ + } + } if (err < 0) { - mutex_unlock(&snd_card_mutex); dev_err(parent, "cannot find the slot for index %d (range 0-%i), error: %d\n", - idx, snd_ecards_limit - 1, err); + idx, snd_ecards_limit - 1, err); if (!card->managed) kfree(card); /* manually free here, as no destructor called */ return err; } - set_bit(idx, snd_cards_lock); /* lock it */ - if (idx >= snd_ecards_limit) - snd_ecards_limit = idx + 1; /* increase the limit */ - mutex_unlock(&snd_card_mutex); card->dev = parent; card->number = idx; #ifdef MODULE @@ -386,11 +387,10 @@ struct snd_card *snd_card_ref(int idx) { struct snd_card *card; - mutex_lock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); card = snd_cards[idx]; if (card) get_device(&card->card_dev); - mutex_unlock(&snd_card_mutex); return card; } EXPORT_SYMBOL_GPL(snd_card_ref); @@ -398,12 +398,8 @@ EXPORT_SYMBOL_GPL(snd_card_ref); /* return non-zero if a card is already locked */ int snd_card_locked(int card) { - int locked; - - mutex_lock(&snd_card_mutex); - locked = test_bit(card, snd_cards_lock); - mutex_unlock(&snd_card_mutex); - return locked; + guard(mutex)(&snd_card_mutex); + return test_bit(card, snd_cards_lock); } static loff_t snd_disconnect_llseek(struct file *file, loff_t offset, int orig) @@ -427,15 +423,15 @@ static int snd_disconnect_release(struct inode *inode, struct file *file) { struct snd_monitor_file *df = NULL, *_df; - spin_lock(&shutdown_lock); - list_for_each_entry(_df, &shutdown_files, shutdown_list) { - if (_df->file == file) { - df = _df; - list_del_init(&df->shutdown_list); - break; + scoped_guard(spinlock, &shutdown_lock) { + list_for_each_entry(_df, &shutdown_files, shutdown_list) { + if (_df->file == file) { + df = _df; + list_del_init(&df->shutdown_list); + break; + } } } - spin_unlock(&shutdown_lock); if (likely(df)) { if ((file->f_flags & FASYNC) && df->disconnected_f_op->fasync) @@ -501,27 +497,24 @@ void snd_card_disconnect(struct snd_card *card) if (!card) return; - spin_lock(&card->files_lock); - if (card->shutdown) { - spin_unlock(&card->files_lock); - return; + scoped_guard(spinlock, &card->files_lock) { + if (card->shutdown) + return; + card->shutdown = 1; + + /* replace file->f_op with special dummy operations */ + list_for_each_entry(mfile, &card->files_list, list) { + /* it's critical part, use endless loop */ + /* we have no room to fail */ + mfile->disconnected_f_op = mfile->file->f_op; + + scoped_guard(spinlock, &shutdown_lock) + list_add(&mfile->shutdown_list, &shutdown_files); + + mfile->file->f_op = &snd_shutdown_f_ops; + fops_get(mfile->file->f_op); + } } - card->shutdown = 1; - - /* replace file->f_op with special dummy operations */ - list_for_each_entry(mfile, &card->files_list, list) { - /* it's critical part, use endless loop */ - /* we have no room to fail */ - mfile->disconnected_f_op = mfile->file->f_op; - - spin_lock(&shutdown_lock); - list_add(&mfile->shutdown_list, &shutdown_files); - spin_unlock(&shutdown_lock); - - mfile->file->f_op = &snd_shutdown_f_ops; - fops_get(mfile->file->f_op); - } - spin_unlock(&card->files_lock); /* notify all connected devices about disconnection */ /* at this point, they cannot respond to any calls except release() */ @@ -544,10 +537,10 @@ void snd_card_disconnect(struct snd_card *card) } /* disable fops (user space) operations for ALSA API */ - mutex_lock(&snd_card_mutex); - snd_cards[card->number] = NULL; - clear_bit(card->number, snd_cards_lock); - mutex_unlock(&snd_card_mutex); + scoped_guard(mutex, &snd_card_mutex) { + snd_cards[card->number] = NULL; + clear_bit(card->number, snd_cards_lock); + } #ifdef CONFIG_PM wake_up(&card->power_sleep); @@ -569,11 +562,10 @@ void snd_card_disconnect_sync(struct snd_card *card) { snd_card_disconnect(card); - spin_lock_irq(&card->files_lock); + guard(spinlock_irq)(&card->files_lock); wait_event_lock_irq(card->remove_sleep, list_empty(&card->files_list), card->files_lock); - spin_unlock_irq(&card->files_lock); } EXPORT_SYMBOL_GPL(snd_card_disconnect_sync); @@ -767,9 +759,8 @@ void snd_card_set_id(struct snd_card *card, const char *nid) /* check if user specified own card->id */ if (card->id[0] != '\0') return; - mutex_lock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); snd_card_set_id_no_lock(card, nid, nid); - mutex_unlock(&snd_card_mutex); } EXPORT_SYMBOL(snd_card_set_id); @@ -797,14 +788,11 @@ static ssize_t id_store(struct device *dev, struct device_attribute *attr, } memcpy(buf1, buf, copy); buf1[copy] = '\0'; - mutex_lock(&snd_card_mutex); - if (!card_id_ok(NULL, buf1)) { - mutex_unlock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); + if (!card_id_ok(NULL, buf1)) return -EEXIST; - } strcpy(card->id, buf1); snd_info_card_id_change(card); - mutex_unlock(&snd_card_mutex); return count; } @@ -897,26 +885,27 @@ int snd_card_register(struct snd_card *card) err = snd_device_register_all(card); if (err < 0) return err; - mutex_lock(&snd_card_mutex); - if (snd_cards[card->number]) { - /* already registered */ - mutex_unlock(&snd_card_mutex); - return snd_info_card_register(card); /* register pending info */ + scoped_guard(mutex, &snd_card_mutex) { + if (snd_cards[card->number]) { + /* already registered */ + return snd_info_card_register(card); /* register pending info */ + } + if (*card->id) { + /* make a unique id name from the given string */ + char tmpid[sizeof(card->id)]; + + memcpy(tmpid, card->id, sizeof(card->id)); + snd_card_set_id_no_lock(card, tmpid, tmpid); + } else { + /* create an id from either shortname or longname */ + const char *src; + + src = *card->shortname ? card->shortname : card->longname; + snd_card_set_id_no_lock(card, src, + retrieve_id_from_card_name(src)); + } + snd_cards[card->number] = card; } - if (*card->id) { - /* make a unique id name from the given string */ - char tmpid[sizeof(card->id)]; - memcpy(tmpid, card->id, sizeof(card->id)); - snd_card_set_id_no_lock(card, tmpid, tmpid); - } else { - /* create an id from either shortname or longname */ - const char *src; - src = *card->shortname ? card->shortname : card->longname; - snd_card_set_id_no_lock(card, src, - retrieve_id_from_card_name(src)); - } - snd_cards[card->number] = card; - mutex_unlock(&snd_card_mutex); err = snd_info_card_register(card); if (err < 0) return err; @@ -937,7 +926,7 @@ static void snd_card_info_read(struct snd_info_entry *entry, struct snd_card *card; for (idx = count = 0; idx < SNDRV_CARDS; idx++) { - mutex_lock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); card = snd_cards[idx]; if (card) { count++; @@ -949,7 +938,6 @@ static void snd_card_info_read(struct snd_info_entry *entry, snd_iprintf(buffer, " %s\n", card->longname); } - mutex_unlock(&snd_card_mutex); } if (!count) snd_iprintf(buffer, "--- no soundcards ---\n"); @@ -962,13 +950,12 @@ void snd_card_info_read_oss(struct snd_info_buffer *buffer) struct snd_card *card; for (idx = count = 0; idx < SNDRV_CARDS; idx++) { - mutex_lock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); card = snd_cards[idx]; if (card) { count++; snd_iprintf(buffer, "%s\n", card->longname); } - mutex_unlock(&snd_card_mutex); } if (!count) { snd_iprintf(buffer, "--- no soundcards ---\n"); @@ -985,12 +972,11 @@ static void snd_card_module_info_read(struct snd_info_entry *entry, struct snd_card *card; for (idx = 0; idx < SNDRV_CARDS; idx++) { - mutex_lock(&snd_card_mutex); + guard(mutex)(&snd_card_mutex); card = snd_cards[idx]; if (card) snd_iprintf(buffer, "%2i %s\n", idx, card->module->name); - mutex_unlock(&snd_card_mutex); } } #endif @@ -1072,15 +1058,13 @@ int snd_card_file_add(struct snd_card *card, struct file *file) mfile->file = file; mfile->disconnected_f_op = NULL; INIT_LIST_HEAD(&mfile->shutdown_list); - spin_lock(&card->files_lock); + guard(spinlock)(&card->files_lock); if (card->shutdown) { - spin_unlock(&card->files_lock); kfree(mfile); return -ENODEV; } list_add(&mfile->list, &card->files_list); get_device(&card->card_dev); - spin_unlock(&card->files_lock); return 0; } EXPORT_SYMBOL(snd_card_file_add); @@ -1102,22 +1086,21 @@ int snd_card_file_remove(struct snd_card *card, struct file *file) { struct snd_monitor_file *mfile, *found = NULL; - spin_lock(&card->files_lock); - list_for_each_entry(mfile, &card->files_list, list) { - if (mfile->file == file) { - list_del(&mfile->list); - spin_lock(&shutdown_lock); - list_del(&mfile->shutdown_list); - spin_unlock(&shutdown_lock); - if (mfile->disconnected_f_op) - fops_put(mfile->disconnected_f_op); - found = mfile; - break; + scoped_guard(spinlock, &card->files_lock) { + list_for_each_entry(mfile, &card->files_list, list) { + if (mfile->file == file) { + list_del(&mfile->list); + scoped_guard(spinlock, &shutdown_lock) + list_del(&mfile->shutdown_list); + if (mfile->disconnected_f_op) + fops_put(mfile->disconnected_f_op); + found = mfile; + break; + } } + if (list_empty(&card->files_list)) + wake_up_all(&card->remove_sleep); } - if (list_empty(&card->files_list)) - wake_up_all(&card->remove_sleep); - spin_unlock(&card->files_lock); if (!found) { dev_err(card->dev, "card file remove problem (%p)\n", file); return -ENOENT; diff --git a/sound/core/sound.c b/sound/core/sound.c index df5571d98629..b9db9aa0bfcb 100644 --- a/sound/core/sound.c +++ b/sound/core/sound.c @@ -103,7 +103,7 @@ void *snd_lookup_minor_data(unsigned int minor, int type) if (minor >= ARRAY_SIZE(snd_minors)) return NULL; - mutex_lock(&sound_mutex); + guard(mutex)(&sound_mutex); mreg = snd_minors[minor]; if (mreg && mreg->type == type) { private_data = mreg->private_data; @@ -111,7 +111,6 @@ void *snd_lookup_minor_data(unsigned int minor, int type) get_device(&mreg->card_ptr->card_dev); } else private_data = NULL; - mutex_unlock(&sound_mutex); return private_data; } EXPORT_SYMBOL(snd_lookup_minor_data); @@ -150,17 +149,15 @@ static int snd_open(struct inode *inode, struct file *file) if (minor >= ARRAY_SIZE(snd_minors)) return -ENODEV; - mutex_lock(&sound_mutex); - mptr = snd_minors[minor]; - if (mptr == NULL) { - mptr = autoload_device(minor); - if (!mptr) { - mutex_unlock(&sound_mutex); - return -ENODEV; + scoped_guard(mutex, &sound_mutex) { + mptr = snd_minors[minor]; + if (mptr == NULL) { + mptr = autoload_device(minor); + if (!mptr) + return -ENODEV; } + new_fops = fops_get(mptr->f_ops); } - new_fops = fops_get(mptr->f_ops); - mutex_unlock(&sound_mutex); if (!new_fops) return -ENODEV; replace_fops(file, new_fops); @@ -269,7 +266,7 @@ int snd_register_device(int type, struct snd_card *card, int dev, preg->f_ops = f_ops; preg->private_data = private_data; preg->card_ptr = card; - mutex_lock(&sound_mutex); + guard(mutex)(&sound_mutex); minor = snd_find_free_minor(type, card, dev); if (minor < 0) { err = minor; @@ -284,7 +281,6 @@ int snd_register_device(int type, struct snd_card *card, int dev, snd_minors[minor] = preg; error: - mutex_unlock(&sound_mutex); if (err < 0) kfree(preg); return err; @@ -305,7 +301,7 @@ int snd_unregister_device(struct device *dev) int minor; struct snd_minor *preg; - mutex_lock(&sound_mutex); + guard(mutex)(&sound_mutex); for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) { preg = snd_minors[minor]; if (preg && preg->dev == dev) { @@ -315,7 +311,6 @@ int snd_unregister_device(struct device *dev) break; } } - mutex_unlock(&sound_mutex); if (minor >= ARRAY_SIZE(snd_minors)) return -ENOENT; return 0; @@ -355,7 +350,7 @@ static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_bu int minor; struct snd_minor *mptr; - mutex_lock(&sound_mutex); + guard(mutex)(&sound_mutex); for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { mptr = snd_minors[minor]; if (!mptr) @@ -373,7 +368,6 @@ static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_bu snd_iprintf(buffer, "%3i: : %s\n", minor, snd_device_type_name(mptr->type)); } - mutex_unlock(&sound_mutex); } int __init snd_minor_info_init(void) diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c index 2751bf2ff61b..d65cc6fee2e6 100644 --- a/sound/core/sound_oss.c +++ b/sound/core/sound_oss.c @@ -29,7 +29,7 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type) if (minor >= ARRAY_SIZE(snd_oss_minors)) return NULL; - mutex_lock(&sound_oss_mutex); + guard(mutex)(&sound_oss_mutex); mreg = snd_oss_minors[minor]; if (mreg && mreg->type == type) { private_data = mreg->private_data; @@ -37,7 +37,6 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type) get_device(&mreg->card_ptr->card_dev); } else private_data = NULL; - mutex_unlock(&sound_oss_mutex); return private_data; } EXPORT_SYMBOL(snd_lookup_oss_minor_data); @@ -106,7 +105,7 @@ int snd_register_oss_device(int type, struct snd_card *card, int dev, preg->f_ops = f_ops; preg->private_data = private_data; preg->card_ptr = card; - mutex_lock(&sound_oss_mutex); + guard(mutex)(&sound_oss_mutex); snd_oss_minors[minor] = preg; minor_unit = SNDRV_MINOR_OSS_DEVICE(minor); switch (minor_unit) { @@ -130,7 +129,6 @@ int snd_register_oss_device(int type, struct snd_card *card, int dev, goto __end; snd_oss_minors[track2] = preg; } - mutex_unlock(&sound_oss_mutex); return 0; __end: @@ -139,7 +137,6 @@ int snd_register_oss_device(int type, struct snd_card *card, int dev, if (register1 >= 0) unregister_sound_special(register1); snd_oss_minors[minor] = NULL; - mutex_unlock(&sound_oss_mutex); kfree(preg); return -EBUSY; } @@ -156,12 +153,10 @@ int snd_unregister_oss_device(int type, struct snd_card *card, int dev) return 0; if (minor < 0) return minor; - mutex_lock(&sound_oss_mutex); + guard(mutex)(&sound_oss_mutex); mptr = snd_oss_minors[minor]; - if (mptr == NULL) { - mutex_unlock(&sound_oss_mutex); + if (mptr == NULL) return -ENOENT; - } switch (SNDRV_MINOR_OSS_DEVICE(minor)) { case SNDRV_MINOR_OSS_PCM: track2 = SNDRV_MINOR_OSS(cidx, SNDRV_MINOR_OSS_AUDIO); @@ -176,7 +171,6 @@ int snd_unregister_oss_device(int type, struct snd_card *card, int dev) if (track2 >= 0) snd_oss_minors[track2] = NULL; snd_oss_minors[minor] = NULL; - mutex_unlock(&sound_oss_mutex); /* call unregister_sound_special() outside sound_oss_mutex; * otherwise may deadlock, as it can trigger the release of a card @@ -220,7 +214,7 @@ static void snd_minor_info_oss_read(struct snd_info_entry *entry, int minor; struct snd_minor *mptr; - mutex_lock(&sound_oss_mutex); + guard(mutex)(&sound_oss_mutex); for (minor = 0; minor < SNDRV_OSS_MINORS; ++minor) { mptr = snd_oss_minors[minor]; if (!mptr) @@ -233,7 +227,6 @@ static void snd_minor_info_oss_read(struct snd_info_entry *entry, snd_iprintf(buffer, "%3i: : %s\n", minor, snd_oss_device_type_name(mptr->type)); } - mutex_unlock(&sound_oss_mutex); }