On Friday 19 October 2018 18:35:00 Jens Axboe wrote:
> 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 <linux@xxxxxxxxxxxxxxxxxxxx>
> >> Tested-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
> >> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> >>
> >> 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;
> }
>
Works for me.
--
Ondrej Zary
