From: Eric Blake <eblake@redhat.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>,
"Vladimir Sementsov-Ogievskiy" <vsementsov@virtuozzo.com>,
qemu-block@nongnu.org
Cc: kwolf@redhat.com, fam@euphon.net, integration@gluster.org,
sheepdog@lists.wpkg.org, ronniesahlberg@gmail.com,
pavel.dovgaluk@ispras.ru, sw@weilnetz.de, pl@kamp.de,
qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org,
stefanha@redhat.com, namei.unix@gmail.com, pbonzini@redhat.com
Subject: Re: [PATCH v2 01/17] block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes
Date: Mon, 27 Apr 2020 09:12:12 -0500 [thread overview]
Message-ID: <9f7404a1-8336-0b5f-ff4c-14749b7a33b5@redhat.com> (raw)
In-Reply-To: <4618c626-b757-f83a-d231-ef08eef9311d@redhat.com>
On 4/27/20 5:05 AM, Philippe Mathieu-Daudé wrote:
> On 4/27/20 10:23 AM, Vladimir Sementsov-Ogievskiy wrote:
>> The function is called from 64bit io handlers, and bytes is just passed
>> to throttle_account() which is 64bit too (unsigned though). So, let's
>> convert intermediate argument to 64bit too.
>
> What is the meaning of negative bytes in this function?
An error. It is more for consistency, in that we really cannot access
more than 63 bits of size information (off_t is signed, and network
protocols don't magically add a 64th bit to that underlying inherent
limitation of files and block devices).
It may be worth adding assert(bytes >= 0), if that makes it easier to
prove we are only dealing with positive lengths.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
next prev parent reply other threads:[~2020-04-27 14:13 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-27 8:23 [PATCH v2 00/17] 64bit block-layer Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 01/17] block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes Vladimir Sementsov-Ogievskiy
2020-04-27 10:05 ` Philippe Mathieu-Daudé
2020-04-27 14:12 ` Eric Blake [this message]
2020-04-28 22:09 ` Eric Blake
2020-04-29 5:05 ` Vladimir Sementsov-Ogievskiy
2020-04-29 12:53 ` Eric Blake
2020-04-27 8:23 ` [PATCH v2 02/17] block: use int64_t as bytes type in tracked requests Vladimir Sementsov-Ogievskiy
2020-04-27 10:11 ` Philippe Mathieu-Daudé
2020-04-27 11:26 ` Vladimir Sementsov-Ogievskiy
2020-04-27 11:40 ` Philippe Mathieu-Daudé
2020-04-27 11:26 ` Vladimir Sementsov-Ogievskiy
2020-04-29 15:50 ` Eric Blake
2020-04-30 8:21 ` Vladimir Sementsov-Ogievskiy
2020-04-30 8:33 ` Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 03/17] block/io: use int64_t bytes parameter in bdrv_check_byte_request() Vladimir Sementsov-Ogievskiy
2020-04-29 19:27 ` Eric Blake
2020-04-30 5:15 ` Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 04/17] block/io: use int64_t bytes in driver wrappers Vladimir Sementsov-Ogievskiy
2020-04-29 20:27 ` Eric Blake
2020-04-27 8:23 ` [PATCH v2 05/17] block/io: support int64_t bytes in bdrv_co_do_pwrite_zeroes() Vladimir Sementsov-Ogievskiy
2020-04-29 21:14 ` Eric Blake
2020-04-27 8:23 ` [PATCH v2 06/17] block/io: support int64_t bytes in bdrv_aligned_pwritev() Vladimir Sementsov-Ogievskiy
2020-04-29 22:04 ` Eric Blake
2020-04-30 5:25 ` Vladimir Sementsov-Ogievskiy
2020-04-30 5:30 ` Vladimir Sementsov-Ogievskiy
2020-04-30 5:37 ` Vladimir Sementsov-Ogievskiy
2020-04-30 9:26 ` Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 07/17] block/io: support int64_t bytes in bdrv_co_do_copy_on_readv() Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 08/17] block/io: support int64_t bytes in bdrv_aligned_preadv() Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 09/17] block/io: support int64_t bytes in bdrv_co_p{read, write}v_part() Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 10/17] block/io: support int64_t bytes in read/write wrappers Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 11/17] block/io: use int64_t bytes in copy_range Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 12/17] block/block-backend: convert blk io path to use int64_t parameters Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 13/17] block: use int64_t instead of uint64_t in driver read handlers Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 14/17] block: use int64_t instead of uint64_t in driver write handlers Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 15/17] block: use int64_t instead of uint64_t in copy_range driver handlers Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 16/17] block: use int64_t instead of int in driver write_zeroes handlers Vladimir Sementsov-Ogievskiy
2020-04-27 8:23 ` [PATCH v2 17/17] block: use int64_t instead of int in driver discard handlers Vladimir Sementsov-Ogievskiy
2020-04-27 9:30 ` [PATCH v2 00/17] 64bit block-layer no-reply
2020-04-27 10:02 ` no-reply
2020-04-27 10:08 ` no-reply
2020-04-27 14:17 ` Vladimir Sementsov-Ogievskiy
2020-04-28 21:33 ` Eric Blake
2020-04-29 5:24 ` Vladimir Sementsov-Ogievskiy
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