linux-kernel - Re: IO errors after "block: remove bio_get_nr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <62de5f2365e58309503720ec3ad2fafd@lycos.com>
Date:	Tue, 22 Dec 2015 10:52:37 +0500
From:	"Artem S. Tashkinov" <t.artem@...os.com>
To:	Kent Overstreet <kent.overstreet@...il.com>
Cc:	Junichi Nomura <j-nomura@...jp.nec.com>, Tejun Heo <tj@...nel.org>,
	"Artem S. Tashkinov" <t.artem@...lcity.com>,
	Christoph Hellwig <hch@....de>,
	Ming Lin <ming.l@....samsung.com>, Jens Axboe <axboe@...com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Steven Whitehouse <swhiteho@...hat.com>,
	IDE-ML <linux-ide@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Ming Lei <tom.leiming@...il.com>
Subject: Re: IO errors after "block: remove bio_get_nr_vecs()"

On 2015-12-22 10:38, Kent Overstreet wrote:
> On Tue, Dec 22, 2015 at 05:26:12AM +0000, Junichi Nomura wrote:
>> On 12/22/15 12:59, Kent Overstreet wrote:
>> > reproduced it with 32 bit pae:
>> >
>> >> 1. Exclude memory above 4G line with boot param "max_addr=4G".
>> >
>> > doesn't work - max_addr=1G doesn't work either
>> >
>> >> 2. Disable highmem with "highmem=0".
>> >
>> > works!
>> >
>> >> 3. Try booting 64bit kernel.
>> >
>> > works
>> 
>> blk_queue_bio() does split then bounce, which makes the segment
>> counting based on pages before bouncing and could go wrong.
>> 
>> What do you think of a patch like this?
> 
> Artem, can you give this patch a try?


This patch ostensibly fixes the issue - at least I cannot immediately 
reproduce it. You can count me in as "Tested-by: Artem S. Tashkinov"

> 
>> 
>> --
>> Jun'ichi Nomura, NEC Corporation
>> 
>> diff --git a/block/blk-core.c b/block/blk-core.c
>> index 5131993b..1d1c3c7 100644
>> --- a/block/blk-core.c
>> +++ b/block/blk-core.c
>> @@ -1689,8 +1689,6 @@ static blk_qc_t blk_queue_bio(struct 
>> request_queue *q, struct bio *bio)
>>  	struct request *req;
>>  	unsigned int request_count = 0;
>> 
>> -	blk_queue_split(q, &bio, q->bio_split);
>> -
>>  	/*
>>  	 * low level driver can indicate that it wants pages above a
>>  	 * certain limit bounced to low memory (ie for highmem, or even
>> @@ -1698,6 +1696,8 @@ static blk_qc_t blk_queue_bio(struct 
>> request_queue *q, struct bio *bio)
>>  	 */
>>  	blk_queue_bounce(q, &bio);
>> 
>> +	blk_queue_split(q, &bio, q->bio_split);
>> +
>>  	if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
>>  		bio->bi_error = -EIO;
>>  		bio_endio(bio);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/