From: Mikulas Patocka <mpatocka@redhat.com>
Date: Fri, 4 Oct 2019 10:17:37 -0400
Subject: [PATCH] dm clone: replace spin_lock_irqsave with spin_lock_irq
Git-commit: 6ca43ed8376a51afec790dd484a51804ade4352a
Patch-mainline: v5.5-rc1
References: bsc#1175995,jsc#SLE-15608
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: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/md/dm-clone-metadata.c | 29 ++++++++++++-----------------
drivers/md/dm-clone-metadata.h | 4 +++-
drivers/md/dm-clone-target.c | 28 ++++++++++++----------------
3 files changed, 27 insertions(+), 34 deletions(-)
diff --git a/drivers/md/dm-clone-metadata.c b/drivers/md/dm-clone-metadata.c
index 6bc8c1d1c351..08c552e5e41b 100644
--- a/drivers/md/dm-clone-metadata.c
+++ b/drivers/md/dm-clone-metadata.c
@@ -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 @@ int dm_clone_metadata_abort(struct dm_clone_metadata *cmd)
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);
diff --git a/drivers/md/dm-clone-metadata.h b/drivers/md/dm-clone-metadata.h
index 434bff08508b..3fe50a781c11 100644
--- a/drivers/md/dm-clone-metadata.h
+++ b/drivers/md/dm-clone-metadata.h
@@ -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);
diff --git a/drivers/md/dm-clone-target.c b/drivers/md/dm-clone-target.c
index 4ca8f1977222..f7d1070a4d40 100644
--- a/drivers/md/dm-clone-target.c
+++ b/drivers/md/dm-clone-target.c
@@ -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 @@ static void process_deferred_discards(struct clone *clone)
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)))
--
2.16.4