linux-kernel - Re: [PATCH 11/11] block: don't check for BIO_MAX_PAGES in blk_bio_segment

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CACVXFVMkX6X36=3mU7cXmbLA6HLASvk402DWL772=d7ihWNhMw@mail.gmail.com>
Date:   Fri, 21 Apr 2017 23:48:59 +0800
From:   Ming Lei <tom.leiming@...il.com>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     NeilBrown <neilb@...e.com>, Jens Axboe <axboe@...nel.dk>,
        linux-block <linux-block@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 11/11] block: don't check for BIO_MAX_PAGES in blk_bio_segment_split()

On Fri, Apr 21, 2017 at 7:34 PM, Christoph Hellwig <hch@...radead.org> wrote:
> On Thu, Apr 20, 2017 at 03:38:50PM +1000, NeilBrown wrote:
>> blk_bio_segment_split() makes sure bios have no more than
>> BIO_MAX_PAGES entries in the bi_io_vec.
>> This was done because bio_clone_bioset() (when given a
>> mempool bioset) could not handle larger io_vecs.
>>
>> No driver uses bio_clone_bioset() any more, they all
>> use bio_clone_fast() if anything, and bio_clone_fast()
>> doesn't clone the bi_io_vec.
>
> Hmm.  From Jens tree:
>
> drivers/lightnvm/pblk-read.c:           int_bio = bio_clone_bioset(bio, GFP_KERNEL, fs_bio_set);
> drivers/md/raid1.c:                             mbio = bio_clone_bioset_partial(bio, GFP_NOIO,
> drivers/md/raid1.c:                             mbio = bio_clone_bioset_partial(bio, GFP_NOIO,

Btrfs use bio_clone_bioset() too:

     fs/btrfs/extent_io.c:2703:      new = bio_clone_bioset(bio,
gfp_mask, btrfs_bioset);

Thanks,
Ming Lei