Commit 4631f39f authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Song Liu
Browse files

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: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarSong Liu <song@kernel.org>
parent 4f4ee2bf

drivers/md/raid5.c

+17 −5
Original line number Diff line number Diff line
@@ -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 @@ static void handle_stripe(struct stripe_head *sh) 
}



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)) {
@@ -5293,8 +5305,8 @@ static void raid5_activate_delayed(struct r5conf *conf) 


static void activate_bit_delay(struct r5conf *conf,

		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;