From: Max Reitz <mreitz@redhat.com>
To: Alberto Garcia <berto@igalia.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Anton Nefedov <anton.nefedov@virtuozzo.com>,
qemu-block@nongnu.org,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
"Denis V . Lunev" <den@openvz.org>
Subject: Re: [RFC PATCH v3 21/27] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2()
Date: Fri, 21 Feb 2020 16:43:39 +0100 [thread overview]
Message-ID: <f0cd0326-5aba-0df5-6d27-ff42ce7aedbf@redhat.com> (raw)
In-Reply-To: <4e1c4c2994470119889e8f602b9c98f4d3457e8b.1577014346.git.berto@igalia.com>
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On 22.12.19 12:37, Alberto Garcia wrote:
> The L2 bitmap needs to be updated after each write to indicate what
> new subclusters are now allocated.
>
> This needs to happen even if the cluster was already allocated and the
> L2 entry was otherwise valid.
>
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
> block/qcow2-cluster.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
> index 0a40944667..ed291a4042 100644
> --- a/block/qcow2-cluster.c
> +++ b/block/qcow2-cluster.c
> @@ -986,6 +986,23 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
>
> set_l2_entry(s, l2_slice, l2_index + i, QCOW_OFLAG_COPIED |
> (cluster_offset + (i << s->cluster_bits)));
> +
> + /* Update bitmap with the subclusters that were just written */
> + if (has_subclusters(s)) {
> + unsigned written_from = m->cow_start.offset;
> + unsigned written_to = m->cow_end.offset + m->cow_end.nb_bytes ?:
> + m->nb_clusters << s->cluster_bits;
I suppose we could also calculate both at the beginning of the function
(I’m not sure whether the compiler can optimize these calculations to
happen only once if we don’t).
> + uint64_t l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index + i);
> + int sc;
> + for (sc = 0; sc < s->subclusters_per_cluster; sc++) {
> + int sc_off = i * s->cluster_size + sc * s->subcluster_size;
> + if (sc_off >= written_from && sc_off < written_to) {
> + l2_bitmap |= QCOW_OFLAG_SUB_ALLOC(sc);
> + l2_bitmap &= ~QCOW_OFLAG_SUB_ZERO(sc);
Works, but maybe a QCOW_OFLAG_SUB_MASK(sc) would be better for:
l2_bitmap &= ~QCOW_OFLAG_SUB_MASK(sc);
l2_bitmap |= QCOW_OFLAG_SUB_ALLOC(sc);
Nothing wrong though, so:
Reviewed-by: Max Reitz <mreitz@redhat.com>
> + }
> + }
> + set_l2_bitmap(s, l2_slice, l2_index + i, l2_bitmap);
> + }
> }
>
>
>
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next prev parent reply other threads:[~2020-02-21 15:45 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-22 11:36 [RFC PATCH v3 00/27] Add subcluster allocation to qcow2 Alberto Garcia
2019-12-22 11:36 ` [RFC PATCH v3 01/27] qcow2: Add calculate_l2_meta() Alberto Garcia
2020-02-20 13:28 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 02/27] qcow2: Split cluster_needs_cow() out of count_cow_clusters() Alberto Garcia
2020-02-20 13:32 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 03/27] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied() Alberto Garcia
2020-02-20 14:53 ` Eric Blake
2020-02-20 15:00 ` Max Reitz
2020-02-20 15:19 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 04/27] qcow2: Add get_l2_entry() and set_l2_entry() Alberto Garcia
2020-02-20 15:22 ` Eric Blake
2020-02-20 16:08 ` Alberto Garcia
2020-02-20 15:39 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 05/27] qcow2: Document the Extended L2 Entries feature Alberto Garcia
2020-02-20 14:28 ` Eric Blake
2020-02-20 14:49 ` Alberto Garcia
2020-02-20 15:16 ` Eric Blake
2020-02-26 16:57 ` Alberto Garcia
2020-02-20 14:33 ` Eric Blake
2020-02-20 16:10 ` Alberto Garcia
2020-02-20 15:54 ` Max Reitz
2020-02-20 16:02 ` Eric Blake
2020-02-20 16:04 ` Alberto Garcia
2019-12-22 11:36 ` [RFC PATCH v3 06/27] qcow2: Add dummy has_subclusters() function Alberto Garcia
2020-02-20 15:24 ` Eric Blake
2020-02-20 16:03 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 07/27] qcow2: Add subcluster-related fields to BDRVQcow2State Alberto Garcia
2020-02-20 15:28 ` Eric Blake
2020-02-20 16:34 ` Alberto Garcia
2020-02-20 16:48 ` Eric Blake
2020-02-21 13:14 ` Alberto Garcia
2020-02-20 16:15 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 08/27] qcow2: Add offset_to_sc_index() Alberto Garcia
2020-02-20 16:19 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 09/27] qcow2: Add l2_entry_size() Alberto Garcia
2020-02-20 16:24 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 10/27] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap() Alberto Garcia
2020-02-20 16:27 ` Max Reitz
2020-02-21 13:57 ` Alberto Garcia
2019-12-22 11:36 ` [RFC PATCH v3 11/27] qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type() Alberto Garcia
2020-02-20 17:21 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 12/27] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_* Alberto Garcia
2020-02-21 11:35 ` Max Reitz
2020-02-21 15:14 ` Alberto Garcia
2019-12-22 11:36 ` [RFC PATCH v3 13/27] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC Alberto Garcia
2020-02-21 12:02 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 14/27] qcow2: Add subcluster support to calculate_l2_meta() Alberto Garcia
2020-02-21 13:34 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 15/27] qcow2: Add subcluster support to qcow2_get_cluster_offset() Alberto Garcia
2020-02-21 14:21 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 16/27] qcow2: Add subcluster support to zero_in_l2_slice() Alberto Garcia
2020-02-21 14:37 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 17/27] qcow2: Add subcluster support to discard_in_l2_slice() Alberto Garcia
2020-02-21 14:45 ` Max Reitz
2019-12-22 11:36 ` [RFC PATCH v3 18/27] qcow2: Add subcluster support to check_refcounts_l2() Alberto Garcia
2020-02-21 14:47 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 19/27] qcow2: Add subcluster support to expand_zero_clusters_in_l1() Alberto Garcia
2020-02-21 14:57 ` Max Reitz
2020-02-26 17:19 ` Alberto Garcia
2020-02-27 9:17 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 20/27] qcow2: Fix offset calculation in handle_dependencies() Alberto Garcia
2020-02-21 15:01 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 21/27] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2() Alberto Garcia
2020-02-21 15:43 ` Max Reitz [this message]
2019-12-22 11:37 ` [RFC PATCH v3 22/27] qcow2: Clear the L2 bitmap when allocating a compressed cluster Alberto Garcia
2020-02-21 15:46 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 23/27] qcow2: Add subcluster support to handle_alloc_space() Alberto Garcia
2020-02-21 15:56 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 24/27] qcow2: Restrict qcow2_co_pwrite_zeroes() to full clusters only Alberto Garcia
2020-02-21 16:02 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 25/27] qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit Alberto Garcia
2020-02-20 14:12 ` Eric Blake
2020-02-20 14:16 ` Alberto Garcia
2020-02-21 16:44 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 26/27] qcow2: Add subcluster support to qcow2_measure() Alberto Garcia
2020-02-21 16:52 ` Max Reitz
2019-12-22 11:37 ` [RFC PATCH v3 27/27] iotests: Add tests for qcow2 images with extended L2 entries Alberto Garcia
2020-02-21 17:04 ` Max Reitz
2020-02-21 17:10 ` [RFC PATCH v3 00/27] Add subcluster allocation to qcow2 Max Reitz
2020-02-22 17:59 ` Alberto Garcia
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