On 10/19/18 3:10 AM, Ming Lei wrote:
> On Thu, Oct 18, 2018 at 03:24:47PM -0600, Jens Axboe wrote:
>> We're only setting up the bounce bio sets if we happen
>> to need bouncing for regular HIGHMEM, not if we only need
>> it for ISA devices.
>>
>> Reported-by: Ondrej Zary <[email protected]>
>> Tested-by: Ondrej Zary <[email protected]>
>> Signed-off-by: Jens Axboe <[email protected]>
>>
>> diff --git a/block/bounce.c b/block/bounce.c
>> index b30071ac4ec6..1356a2f4aae2 100644
>> --- a/block/bounce.c
>> +++ b/block/bounce.c
>> @@ -31,6 +31,24 @@
>> static struct bio_set bounce_bio_set, bounce_bio_split;
>> static mempool_t page_pool, isa_page_pool;
>>
>> +static void init_bounce_bioset(void)
>> +{
>> + static bool bounce_bs_setup;
>> + int ret;
>> +
>> + if (bounce_bs_setup)
>> + return;
>> +
>> + ret = bioset_init(&bounce_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
>> + BUG_ON(ret);
>> + if (bioset_integrity_create(&bounce_bio_set, BIO_POOL_SIZE))
>> + BUG_ON(1);
>> +
>> + ret = bioset_init(&bounce_bio_split, BIO_POOL_SIZE, 0, 0);
>> + BUG_ON(ret);
>> + bounce_bs_setup = true;
>
> When initcall is run from do_basic_setup(), all CPUs and scheduler have been
> up,
> it is likely that init_emergency_pool() is run when one driver is calling
> blk_queue_bounce_limit() to start init_emergency_isa_pool().
>
> So the above code might be run twice.
Good point, it's actually not even safe right now with the mempool
setup. How about the below?
diff --git a/block/bounce.c b/block/bounce.c
index b30071ac4ec6..ec0d99995f5f 100644
--- a/block/bounce.c
+++ b/block/bounce.c
@@ -31,6 +31,24 @@
static struct bio_set bounce_bio_set, bounce_bio_split;
static mempool_t page_pool, isa_page_pool;
+static void init_bounce_bioset(void)
+{
+ static bool bounce_bs_setup;
+ int ret;
+
+ if (bounce_bs_setup)
+ return;
+
+ ret = bioset_init(&bounce_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
+ BUG_ON(ret);
+ if (bioset_integrity_create(&bounce_bio_set, BIO_POOL_SIZE))
+ BUG_ON(1);
+
+ ret = bioset_init(&bounce_bio_split, BIO_POOL_SIZE, 0, 0);
+ BUG_ON(ret);
+ bounce_bs_setup = true;
+}
+
#if defined(CONFIG_HIGHMEM)
static __init int init_emergency_pool(void)
{
@@ -44,14 +62,7 @@ static __init int init_emergency_pool(void)
BUG_ON(ret);
pr_info("pool size: %d pages\n", POOL_SIZE);
- ret = bioset_init(&bounce_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
- BUG_ON(ret);
- if (bioset_integrity_create(&bounce_bio_set, BIO_POOL_SIZE))
- BUG_ON(1);
-
- ret = bioset_init(&bounce_bio_split, BIO_POOL_SIZE, 0, 0);
- BUG_ON(ret);
-
+ init_bounce_bioset();
return 0;
}
@@ -86,6 +97,8 @@ static void *mempool_alloc_pages_isa(gfp_t gfp_mask, void
*data)
return mempool_alloc_pages(gfp_mask | GFP_DMA, data);
}
+static DEFINE_MUTEX(isa_mutex);
+
/*
* gets called "every" time someone init's a queue with BLK_BOUNCE_ISA
* as the max address, so check if the pool has already been created.
@@ -94,14 +107,20 @@ int init_emergency_isa_pool(void)
{
int ret;
- if (mempool_initialized(&isa_page_pool))
+ mutex_lock(&isa_mutex);
+
+ if (mempool_initialized(&isa_page_pool)) {
+ mutex_unlock(&isa_mutex);
return 0;
+ }
ret = mempool_init(&isa_page_pool, ISA_POOL_SIZE,
mempool_alloc_pages_isa,
mempool_free_pages, (void *) 0);
BUG_ON(ret);
pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE);
+ init_bounce_bioset();
+ mutex_unlock(&isa_mutex);
return 0;
}
--
Jens Axboe
