From: Paolo Bonzini <pbonzini@redhat.com>
To: Max Reitz <mreitz@redhat.com>, qemu-devel@nongnu.org
Cc: kwolf@redhat.com, qemu-block@nongnu.org
Subject: Re: [PATCH v3 3/7] block: add max_hw_transfer to BlockLimits
Date: Wed, 16 Jun 2021 15:18:49 +0200 [thread overview]
Message-ID: <a684c31d-9da3-9e75-89c0-c68997760108@redhat.com> (raw)
In-Reply-To: <cb030dc0-ee6f-4c0b-723d-4197c51f8a61@redhat.com>
On 15/06/21 18:18, Max Reitz wrote:
>> }
>> +/* Returns the maximum hardware transfer length, in bytes; guaranteed
>> nonzero */
>> +uint64_t blk_get_max_hw_transfer(BlockBackend *blk)
>> +{
>> + BlockDriverState *bs = blk_bs(blk);
>> + uint64_t max = INT_MAX;
>> +
>> + if (bs) {
>> + max = MIN_NON_ZERO(bs->bl.max_hw_transfer, bs->bl.max_transfer);
>> + }
>> + return max;
>
> Both `max_hw_transfer` and `max_transfer` can be 0, so this could return
> 0, contrary to what the comment above promises.
>
> Should `max` be initialized to 0 with a `MIN_NON_ZERO(max, INT_MAX)`
> here (like `blk_get_max_transfer()` does it)?
Yes, something to that effect.
> (As for the rest, I think aligning to the request alignment makes sense,
> but then again we don’t do that for max_transfer either, so... this at
> least wouldn’t be a new bug.
Ok, will do. I will also add a new patch to align max_transfer to the
request alignment.
> Regarding the comment, checkpatch complains about it, so it should be
> fixed so that /* is on its own line.
That makes it different from every other comment in block_int.h though.
Is it okay to fix all of them in a follow-up?
Paolo
> Speaking of checkpatch, now that I ran it, it also complains about the
> new line in bdrv_merge_limits() exceeding 80 characters, so that should
> be fixed, too.)
next prev parent reply other threads:[~2021-06-16 13:19 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 13:37 [PATCH v3 0/7] block: file-posix queue Paolo Bonzini
2021-06-03 13:37 ` [PATCH v3 1/7] file-posix: fix max_iov for /dev/sg devices Paolo Bonzini
2021-06-07 5:39 ` Vladimir Sementsov-Ogievskiy
2021-06-07 6:16 ` Vladimir Sementsov-Ogievskiy
2021-06-07 7:23 ` Vladimir Sementsov-Ogievskiy
2021-06-15 15:58 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 2/7] scsi-generic: pass max_segments via max_iov field in BlockLimits Paolo Bonzini
2021-06-15 16:06 ` Max Reitz
2021-06-15 16:20 ` Max Reitz
2021-06-15 17:41 ` Paolo Bonzini
2021-06-03 13:37 ` [PATCH v3 3/7] block: add max_hw_transfer to BlockLimits Paolo Bonzini
2021-06-03 17:33 ` Eric Blake
2021-06-04 7:21 ` Paolo Bonzini
2021-06-15 16:18 ` Max Reitz
2021-06-16 13:18 ` Paolo Bonzini [this message]
2021-06-16 13:46 ` Max Reitz
2021-06-17 9:59 ` Paolo Bonzini
2021-06-03 13:37 ` [PATCH v3 4/7] file-posix: try BLKSECTGET on block devices too, do not round to power of 2 Paolo Bonzini
2021-06-15 16:32 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 5/7] block: feature detection for host block support Paolo Bonzini
2021-06-15 16:40 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 6/7] block: check for sys/disk.h Paolo Bonzini
2021-06-15 16:42 ` Max Reitz
2021-06-03 13:37 ` [PATCH v3 7/7] block: detect DKIOCGETBLOCKCOUNT/SIZE before use Paolo Bonzini
2021-06-15 16:50 ` Max Reitz
2021-06-15 16:57 ` Daniel P. Berrangé
2021-06-07 13:52 ` [PATCH v3 0/7] block: file-posix queue Maxim Levitsky
2021-06-10 13:40 ` Paolo Bonzini
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