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Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitm
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex |
Date: |
Tue, 27 Jun 2017 15:58:15 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 |
On 27/06/2017 15:51, Vladimir Sementsov-Ogievskiy wrote:
>>>
>>> bdrv_create_dirty_bitmap(...)
>>>
>>> bdrv_dirty_bitmaps_lock(bs)
>>>
>>> bitmap = bdrv_find_dirty_bitmap(bs, name)
>>>
>>> <some changes>
>>>
>>> bdrv_dirty_bitmaps_unlock(bs)
>>>
>>> - because we can't now trust the pointer returned by
>>> bdrv_create_dirty_bitmap, as it releases bitmap lock before return.
>> If you have the big QEMU lock (you do if you are in the QEMU monitor),
>> you are protected from changes to the list of bitmaps.
>>
>> Paolo
>
> but you wrote "Writing to the list requires the BQL _and_ the
> dirty_bitmap_mutex".
>
> should it be BQL only?
bdrv_dirty_bitmaps_lock/unlock is (should be) called by the functions
that write to the list. I hope I can post the patch today already.
Paolo
- [Qemu-devel] [PATCH 14/19] block: introduce dirty_bitmap_mutex, (continued)
- [Qemu-devel] [PATCH 14/19] block: introduce dirty_bitmap_mutex, Paolo Bonzini, 2017/06/05
- [Qemu-devel] [PATCH 17/19] block: introduce block_account_one_io, Paolo Bonzini, 2017/06/05
- [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/05
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/26
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/26
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex,
Paolo Bonzini <=
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Vladimir Sementsov-Ogievskiy, 2017/06/27
- Re: [Qemu-devel] [PATCH 16/19] block: protect modification of dirty bitmaps with a mutex, Paolo Bonzini, 2017/06/27
[Qemu-devel] [PATCH 15/19] migration/block: reset dirty bitmap before reading, Paolo Bonzini, 2017/06/05
[Qemu-devel] [PATCH 18/19] block: split BlockAcctStats creation and setup, Paolo Bonzini, 2017/06/05