Commit 6ca43ed8 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Mike Snitzer
Browse files

dm clone: replace spin_lock_irqsave with spin_lock_irq 



If we are in a place where it is known that interrupts are enabled,
functions spin_lock_irq/spin_unlock_irq should be used instead of
spin_lock_irqsave/spin_unlock_irqrestore.

spin_lock_irq and spin_unlock_irq are faster because they don't need to
push and pop the flags register.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarNikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent c1005322

drivers/md/dm-clone-metadata.c

+12 −17
Original line number Diff line number Diff line
@@ -712,7 +712,7 @@ static int __metadata_commit(struct dm_clone_metadata *cmd) 
static int __flush_dmap(struct dm_clone_metadata *cmd, struct dirty_map *dmap)

{

	int r;

	unsigned long word, flags;

	unsigned long word;



	word = 0;

	do {
@@ -736,9 +736,9 @@ static int __flush_dmap(struct dm_clone_metadata *cmd, struct dirty_map *dmap) 
		return r;



	/* Update the changed flag */

	spin_lock_irqsave(&cmd->bitmap_lock, flags);

	spin_lock_irq(&cmd->bitmap_lock);

	dmap->changed = 0;

	spin_unlock_irqrestore(&cmd->bitmap_lock, flags);

	spin_unlock_irq(&cmd->bitmap_lock);



	return 0;

}
@@ -746,7 +746,6 @@ static int __flush_dmap(struct dm_clone_metadata *cmd, struct dirty_map *dmap) 
int dm_clone_metadata_commit(struct dm_clone_metadata *cmd)

{

	int r = -EPERM;

	unsigned long flags;

	struct dirty_map *dmap, *next_dmap;



	down_write(&cmd->lock);
@@ -770,9 +769,9 @@ int dm_clone_metadata_commit(struct dm_clone_metadata *cmd) 
	}



	/* Swap dirty bitmaps */

	spin_lock_irqsave(&cmd->bitmap_lock, flags);

	spin_lock_irq(&cmd->bitmap_lock);

	cmd->current_dmap = next_dmap;

	spin_unlock_irqrestore(&cmd->bitmap_lock, flags);

	spin_unlock_irq(&cmd->bitmap_lock);



	/*

	 * No one is accessing the old dirty bitmap anymore, so we can flush
@@ -817,9 +816,9 @@ int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start, 
{

	int r = 0;

	struct dirty_map *dmap;

	unsigned long word, region_nr, flags;

	unsigned long word, region_nr;



	spin_lock_irqsave(&cmd->bitmap_lock, flags);

	spin_lock_irq(&cmd->bitmap_lock);



	if (cmd->read_only) {

		r = -EPERM;
@@ -836,7 +835,7 @@ int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start, 
		}

	}

out:

	spin_unlock_irqrestore(&cmd->bitmap_lock, flags);

	spin_unlock_irq(&cmd->bitmap_lock);



	return r;

}
@@ -903,13 +902,11 @@ out: 


void dm_clone_metadata_set_read_only(struct dm_clone_metadata *cmd)

{

	unsigned long flags;



	down_write(&cmd->lock);



	spin_lock_irqsave(&cmd->bitmap_lock, flags);

	spin_lock_irq(&cmd->bitmap_lock);

	cmd->read_only = 1;

	spin_unlock_irqrestore(&cmd->bitmap_lock, flags);

	spin_unlock_irq(&cmd->bitmap_lock);



	if (!cmd->fail_io)

		dm_bm_set_read_only(cmd->bm);
@@ -919,13 +916,11 @@ void dm_clone_metadata_set_read_only(struct dm_clone_metadata *cmd) 


void dm_clone_metadata_set_read_write(struct dm_clone_metadata *cmd)

{

	unsigned long flags;



	down_write(&cmd->lock);



	spin_lock_irqsave(&cmd->bitmap_lock, flags);

	spin_lock_irq(&cmd->bitmap_lock);

	cmd->read_only = 0;

	spin_unlock_irqrestore(&cmd->bitmap_lock, flags);

	spin_unlock_irq(&cmd->bitmap_lock);



	if (!cmd->fail_io)

		dm_bm_set_read_write(cmd->bm);

drivers/md/dm-clone-metadata.h

+3 −1
Original line number Diff line number Diff line
@@ -44,7 +44,9 @@ int dm_clone_set_region_hydrated(struct dm_clone_metadata *cmd, unsigned long re 
 * @start: Starting region number

 * @nr_regions: Number of regions in the range

 *

 * This function doesn't block, so it's safe to call it from interrupt context.

 * This function doesn't block, but since it uses spin_lock_irq()/spin_unlock_irq()

 * it's NOT safe to call it from any context where interrupts are disabled, e.g.,

 * from interrupt context.

 */

int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start,

			    unsigned long nr_regions);

drivers/md/dm-clone-target.c

+12 −16
Original line number Diff line number Diff line
@@ -332,8 +332,6 @@ static void submit_bios(struct bio_list *bios) 
 */

static void issue_bio(struct clone *clone, struct bio *bio)

{

	unsigned long flags;



	if (!bio_triggers_commit(clone, bio)) {

		generic_make_request(bio);

		return;
@@ -352,9 +350,9 @@ static void issue_bio(struct clone *clone, struct bio *bio) 
	 * Batch together any bios that trigger commits and then issue a single

	 * commit for them in process_deferred_flush_bios().

	 */

	spin_lock_irqsave(&clone->lock, flags);

	spin_lock_irq(&clone->lock);

	bio_list_add(&clone->deferred_flush_bios, bio);

	spin_unlock_irqrestore(&clone->lock, flags);

	spin_unlock_irq(&clone->lock);



	wake_worker(clone);

}
@@ -469,7 +467,7 @@ static void complete_discard_bio(struct clone *clone, struct bio *bio, bool succ 


static void process_discard_bio(struct clone *clone, struct bio *bio)

{

	unsigned long rs, re, flags;

	unsigned long rs, re;



	bio_region_range(clone, bio, &rs, &re);

	BUG_ON(re > clone->nr_regions);
@@ -501,9 +499,9 @@ static void process_discard_bio(struct clone *clone, struct bio *bio) 
	/*

	 * Defer discard processing.

	 */

	spin_lock_irqsave(&clone->lock, flags);

	spin_lock_irq(&clone->lock);

	bio_list_add(&clone->deferred_discard_bios, bio);

	spin_unlock_irqrestore(&clone->lock, flags);

	spin_unlock_irq(&clone->lock);



	wake_worker(clone);

}
@@ -1140,13 +1138,13 @@ static void process_deferred_discards(struct clone *clone) 
	int r = -EPERM;

	struct bio *bio;

	struct blk_plug plug;

	unsigned long rs, re, flags;

	unsigned long rs, re;

	struct bio_list discards = BIO_EMPTY_LIST;



	spin_lock_irqsave(&clone->lock, flags);

	spin_lock_irq(&clone->lock);

	bio_list_merge(&discards, &clone->deferred_discard_bios);

	bio_list_init(&clone->deferred_discard_bios);

	spin_unlock_irqrestore(&clone->lock, flags);

	spin_unlock_irq(&clone->lock);



	if (bio_list_empty(&discards))

		return;
@@ -1176,13 +1174,12 @@ out: 


static void process_deferred_bios(struct clone *clone)

{

	unsigned long flags;

	struct bio_list bios = BIO_EMPTY_LIST;



	spin_lock_irqsave(&clone->lock, flags);

	spin_lock_irq(&clone->lock);

	bio_list_merge(&bios, &clone->deferred_bios);

	bio_list_init(&clone->deferred_bios);

	spin_unlock_irqrestore(&clone->lock, flags);

	spin_unlock_irq(&clone->lock);



	if (bio_list_empty(&bios))

		return;
@@ -1193,7 +1190,6 @@ static void process_deferred_bios(struct clone *clone) 
static void process_deferred_flush_bios(struct clone *clone)

{

	struct bio *bio;

	unsigned long flags;

	struct bio_list bios = BIO_EMPTY_LIST;

	struct bio_list bio_completions = BIO_EMPTY_LIST;
@@ -1201,13 +1197,13 @@ static void process_deferred_flush_bios(struct clone *clone) 
	 * If there are any deferred flush bios, we must commit the metadata

	 * before issuing them or signaling their completion.

	 */

	spin_lock_irqsave(&clone->lock, flags);

	spin_lock_irq(&clone->lock);

	bio_list_merge(&bios, &clone->deferred_flush_bios);

	bio_list_init(&clone->deferred_flush_bios);



	bio_list_merge(&bio_completions, &clone->deferred_flush_completions);

	bio_list_init(&clone->deferred_flush_completions);

	spin_unlock_irqrestore(&clone->lock, flags);

	spin_unlock_irq(&clone->lock);



	if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) &&

	    !(dm_clone_changed_this_transaction(clone->cmd) && need_commit_due_to_time(clone)))

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