From 4631f39f058b98bfa3fd1d6ffb491fa9e70e3e81 Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Thu, 7 Apr 2022 10:57:13 -0600 Subject: md/raid5: Annotate functions that hold device_lock with __must_hold A handful of functions note the device_lock must be held with a comment but this is not comprehensive. Many other functions hold the lock when taken so add an __must_hold() to each call to annotate when the lock is held. This makes it a bit easier to analyse device_lock. Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu --- drivers/md/raid5.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 7c4f94c392ea..144ea077c2ed 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -79,18 +79,21 @@ static inline int stripe_hash_locks_hash(struct r5conf *conf, sector_t sect) } static inline void lock_device_hash_lock(struct r5conf *conf, int hash) + __acquires(&conf->device_lock) { spin_lock_irq(conf->hash_locks + hash); spin_lock(&conf->device_lock); } static inline void unlock_device_hash_lock(struct r5conf *conf, int hash) + __releases(&conf->device_lock) { spin_unlock(&conf->device_lock); spin_unlock_irq(conf->hash_locks + hash); } static inline void lock_all_device_hash_locks_irq(struct r5conf *conf) + __acquires(&conf->device_lock) { int i; spin_lock_irq(conf->hash_locks); @@ -100,6 +103,7 @@ static inline void lock_all_device_hash_locks_irq(struct r5conf *conf) } static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf) + __releases(&conf->device_lock) { int i; spin_unlock(&conf->device_lock); @@ -164,6 +168,7 @@ static bool stripe_is_lowprio(struct stripe_head *sh) } static void raid5_wakeup_stripe_thread(struct stripe_head *sh) + __must_hold(&sh->raid_conf->device_lock) { struct r5conf *conf = sh->raid_conf; struct r5worker_group *group; @@ -211,6 +216,7 @@ static void raid5_wakeup_stripe_thread(struct stripe_head *sh) static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh, struct list_head *temp_inactive_list) + __must_hold(&conf->device_lock) { int i; int injournal = 0; /* number of date pages with R5_InJournal */ @@ -296,6 +302,7 @@ static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh, static void __release_stripe(struct r5conf *conf, struct stripe_head *sh, struct list_head *temp_inactive_list) + __must_hold(&conf->device_lock) { if (atomic_dec_and_test(&sh->count)) do_release_stripe(conf, sh, temp_inactive_list); @@ -350,9 +357,9 @@ static void release_inactive_stripe_list(struct r5conf *conf, } } -/* should hold conf->device_lock already */ static int release_stripe_list(struct r5conf *conf, struct list_head *temp_inactive_list) + __must_hold(&conf->device_lock) { struct stripe_head *sh, *t; int count = 0; @@ -629,6 +636,10 @@ static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector, * This is because some failed devices may only affect one * of the two sections, and some non-in_sync devices may * be insync in the section most affected by failed devices. + * + * Most calls to this function hold &conf->device_lock. Calls + * in raid5_run() do not require the lock as no other threads + * have been started yet. */ int raid5_calc_degraded(struct r5conf *conf) { @@ -5275,6 +5286,7 @@ finish: } static void raid5_activate_delayed(struct r5conf *conf) + __must_hold(&conf->device_lock) { if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) { while (!list_empty(&conf->delayed_list)) { @@ -5292,9 +5304,9 @@ static void raid5_activate_delayed(struct r5conf *conf) } static void activate_bit_delay(struct r5conf *conf, - struct list_head *temp_inactive_list) + struct list_head *temp_inactive_list) + __must_hold(&conf->device_lock) { - /* device_lock is held */ struct list_head head; list_add(&head, &conf->bitmap_list); list_del_init(&conf->bitmap_list); @@ -5519,6 +5531,7 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio) * handle_list. */ static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group) + __must_hold(&conf->device_lock) { struct stripe_head *sh, *tmp; struct list_head *handle_list = NULL; @@ -6390,8 +6403,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio, static int handle_active_stripes(struct r5conf *conf, int group, struct r5worker *worker, struct list_head *temp_inactive_list) - __releases(&conf->device_lock) - __acquires(&conf->device_lock) + __must_hold(&conf->device_lock) { struct stripe_head *batch[MAX_STRIPE_BATCH], *sh; int i, batch_size = 0, hash; -- cgit v1.2.3