From: Nikolay Borisov <nborisov@suse.com>
To: dsterba@suse.cz, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 5/6] btrfs: Read stripe len directly in btrfs_rmap_block
Date: Wed, 15 Jan 2020 12:52:12 +0200 [thread overview]
Message-ID: <00859c46-cbdd-19f8-b57c-18e7670afa3c@suse.com> (raw)
In-Reply-To: <20200114165411.GG3929@twin.jikos.cz>
On 14.01.20 г. 18:54 ч., David Sterba wrote:
> On Tue, Nov 19, 2019 at 02:05:54PM +0200, Nikolay Borisov wrote:
>> extent_map::orig_block_len contains the size of a physical stripe when
>> it's used to describe block groups. So get the size directly in
>> btrfs_rmap_block rather than open-coding the calculations. No
>> functional changes.
>>
>> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
>> ---
>> fs/btrfs/block-group.c | 11 +++--------
>> 1 file changed, 3 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
>> index c3b1f304bc70..2ab4d9cb598a 100644
>> --- a/fs/btrfs/block-group.c
>> +++ b/fs/btrfs/block-group.c
>> @@ -1546,17 +1546,12 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
>> return -EIO;
>>
>> map = em->map_lookup;
>> - data_stripe_length = em->len;
>> + data_stripe_length = em->orig_block_len;
>> io_stripe_size = map->stripe_len;
>>
>> - if (map->type & BTRFS_BLOCK_GROUP_RAID10)
>> - data_stripe_length = div_u64(data_stripe_length, map->num_stripes / map->sub_stripes);
>> - else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
>> - data_stripe_length = div_u64(data_stripe_length, map->num_stripes);
>> - else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
>> - data_stripe_length = div_u64(data_stripe_length, nr_data_stripes(map));
>> + /* For raid5/6 adjust to a full IO stripe length */
>> + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
>> io_stripe_size = map->stripe_len * nr_data_stripes(map);
>
> I'm not convinced this is 'no functional change' so will merge only
> patches 1-4 for now as I have reviewed them and want to add them to
> misc-next before the 5.6 freeze.
>
THe easiest way to convince yourself is to work out the maths happening
in __btrfs_alloc_chunk, since orig_block_len for chunks is set there.
next prev parent reply other threads:[~2020-01-15 10:52 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 12:05 [PATCH 0/6] Cleanup super block stripe exclusion code Nikolay Borisov
2019-11-19 12:05 ` [PATCH 1/6] btrfs: Move and unexport btrfs_rmap_block Nikolay Borisov
2019-11-26 15:53 ` David Sterba
2019-12-10 17:57 ` [PATCH v2] " Nikolay Borisov
2020-01-02 15:21 ` David Sterba
2019-11-19 12:05 ` [PATCH 2/6] btrfs: selftests: Add support for dummy devices Nikolay Borisov
2019-11-19 12:05 ` [PATCH 3/6] btrfs: Add self-tests for btrfs_rmap_block Nikolay Borisov
2019-11-26 16:04 ` David Sterba
2019-12-10 18:00 ` [PATCH v2] " Nikolay Borisov
2020-01-02 15:40 ` David Sterba
2020-01-10 14:46 ` Nikolay Borisov
2020-01-14 16:51 ` David Sterba
2019-11-19 12:05 ` [PATCH 4/6] btrfs: Refactor btrfs_rmap_block to improve readability Nikolay Borisov
2019-11-19 12:05 ` [PATCH 5/6] btrfs: Read stripe len directly in btrfs_rmap_block Nikolay Borisov
2020-01-14 16:54 ` David Sterba
2020-01-15 10:52 ` Nikolay Borisov [this message]
2019-11-19 12:05 ` [PATCH 6/6] btrfs: Remove dead code exclude_super_stripes Nikolay Borisov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=00859c46-cbdd-19f8-b57c-18e7670afa3c@suse.com \
--to=nborisov@suse.com \
--cc=dsterba@suse.cz \
--cc=linux-btrfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).