Re: bioset changes in 4.18 broke aha1542

[Jens Axboe]

On 10/18/18 2:22 PM, Ondrej Zary wrote:
> On Thursday 18 October 2018 22:10:31 Jens Axboe wrote:
>> On 10/18/18 2:04 PM, Ondrej Zary wrote:
>>> On Thursday 18 October 2018 21:59:09 Jens Axboe wrote:
>>>> On 10/18/18 1:55 PM, Ondrej Zary wrote:
>>>>> On Thursday 18 October 2018 20:58:57 Jens Axboe wrote:
>>>>>> On 10/18/18 12:34 PM, Ondrej Zary wrote:
>>>>>>> Hello,
>>>>>>> aha1542 works fine in 4.17 but crashes in 4.18. It's hard to bisect because
>>>>>>> of many commits that don't compile.
>>>>>>> # only skipped commits left to test
>>>>>>> # possible first bad commit: [52190f8abe7f2bf2b4e5f9760cbcc1427ca2136b] fs: convert block_dev.c to bioset_init()
>>>>>>> # possible first bad commit: [a47a28b74a5c7c27bf621276b85ad6c124651236] target: convert to bioset_init()/mempool_init()
>>>>>>> # possible first bad commit: [6f1c819c219f7841079f0f43ab62727a55b0d849] dm: convert to bioset_init()/mempool_init()
>>>>>>> # possible first bad commit: [afeee514ce7f4cab605beedd03be71ebaf0c5fc8] md: convert to bioset_init()/mempool_init()
>>>>>>> # possible first bad commit: [d19936a26658a7a53edd5619d631ee2c2c3151a2] bcache: convert to bioset_init()/mempool_init()
>>>>>>> # possible first bad commit: [b906bbb6997785d9ea0bd3f5585537afa6257c43] lightnvm: convert to bioset_init()/mempool_init()
>>>>>>>
>>>>>>> Testing manually, a47a28b74a5c7c27bf621276b85ad6c124651236 works.
>>>>>>> 52190f8abe7f2bf2b4e5f9760cbcc1427ca2136b does not compile
>>>>>>> 8ac9f7c1fd1d342e82ddf078425423b050652ba0 does not compile
>>>>>>> e292d7bc63c8f2adb3dfda27910e805f1b6557f9 does not compile
>>>>>>> dad08527525f9a8ac9c7f278864c65f94bc5e9b3 does not compile
>>>>>>> 943cf9f3ca16133dbd00f9a4cbfea46512fcb0e8 works
>>>>>>> ..
>>>>>>> fedc3abe7bd2dcc4c80bcf3cff8708a3908d8219 works
>>>>>>> 04c4950d5b373ba712d928592e05e73510785bca crashes
>>>>>>
>>>>>> It looks like the ISA bioset pool isn't being initialized. You should
>>>>>> have messages like this in your dmesg:
>>>>>>
>>>>>> isa pool size: 16 pages
>>>>>>
>>>>>> (which you do), but also something on the bioset section. Do you have
>>>>>> this one:
>>>>>>
>>>>>> pool size: 64 pages
>>>>>>
>>>>>> as well?
>>>>>>
>>>>>
>>>>> No, it's not there.
>>>>
>>>> Can you attach your .config? I'm guessing CONFIG_HIGHMEM* isn't set.
>>>>
>>>
>>> It is.
>>
>> Puzzled... Does this work?
>>
>>
>> diff --git a/block/bounce.c b/block/bounce.c
>> index b30071ac4ec6..49564a1bfd22 100644
>> --- a/block/bounce.c
>> +++ b/block/bounce.c
>> @@ -35,10 +35,6 @@ static mempool_t page_pool, isa_page_pool;
>>  static __init int init_emergency_pool(void)
>>  {
>>  	int ret;
>> -#if defined(CONFIG_HIGHMEM) && !defined(CONFIG_MEMORY_HOTPLUG)
>> -	if (max_pfn <= max_low_pfn)
>> -		return 0;
>> -#endif
>>  
>>  	ret = mempool_init_page_pool(&page_pool, POOL_SIZE, 0);
>>  	BUG_ON(ret);
>>
> 
> Yes, it does! 
> bounce: pool size: 64 pages
> and aha1542 works.
> 
> Also added printks for pfn:
> max_pfn=65520, max_low_pfn=65520

This should be a better fix, though I'm still puzzled why we need
it now. Can you test this one?


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 __init 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;
 }
 
@@ -102,6 +113,7 @@ int init_emergency_isa_pool(void)
 	BUG_ON(ret);
 
 	pr_info("isa pool size: %d pages\n", ISA_POOL_SIZE);
+	init_bounce_bioset();
 	return 0;
 }
 

-- 
Jens Axboe