From: Eric Blake <eblake@redhat.com>
To: Alberto Garcia <berto@igalia.com>, qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-block@nongnu.org, Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH v5 28/31] qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit
Date: Wed, 6 May 2020 13:09:07 -0500 [thread overview]
Message-ID: <926a34f4-c629-fe8e-ed5a-b655b68d1265@redhat.com> (raw)
In-Reply-To: <f8d2bb7d22fd228816e5caed6640af36a63cdddc.1588699789.git.berto@igalia.com>
On 5/5/20 12:38 PM, Alberto Garcia wrote:
> Now that the implementation of subclusters is complete we can finally
> add the necessary options to create and read images with this feature,
> which we call "extended L2 entries".
>
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
What you have looks good, but I didn't notice anything affecting amend.
The simplest option: amend can reject attempts to toggle the extended L2
option (the zstd compression patches take that path). More complicated
is actually supporting it (in either direction, turning it on or off),
which requires rewriting ALL L2 tables in the entry (including any in
internal snapshots), which could be quite time-intensive, and where you
must be careful to stage things so that failures during partial
conversion merely leave leaked clusters rather than a header pointing to
a half-converted state. Either way, one of the iotests should probably
add coverage on what happens when you attempt to amend the bit on or off.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
next prev parent reply other threads:[~2020-05-06 18:10 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 17:38 [PATCH v5 00/31] Add subcluster allocation to qcow2 Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 01/31] qcow2: Make Qcow2AioTask store the full host offset Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 02/31] qcow2: Convert qcow2_get_cluster_offset() into qcow2_get_host_offset() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 03/31] qcow2: Add calculate_l2_meta() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 04/31] qcow2: Split cluster_needs_cow() out of count_cow_clusters() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 05/31] qcow2: Process QCOW2_CLUSTER_ZERO_ALLOC clusters in handle_copied() Alberto Garcia
2020-05-05 19:23 ` Eric Blake
2020-05-05 17:38 ` [PATCH v5 06/31] qcow2: Add get_l2_entry() and set_l2_entry() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 07/31] qcow2: Document the Extended L2 Entries feature Alberto Garcia
2020-05-05 19:35 ` Eric Blake
2020-05-06 15:02 ` Alberto Garcia
2020-05-06 15:24 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 08/31] qcow2: Add dummy has_subclusters() function Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 09/31] qcow2: Add subcluster-related fields to BDRVQcow2State Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 10/31] qcow2: Add offset_to_sc_index() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 11/31] qcow2: Add offset_into_subcluster() and size_to_subclusters() Alberto Garcia
2020-05-05 19:42 ` Eric Blake
2020-05-06 10:18 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 12/31] qcow2: Add l2_entry_size() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 13/31] qcow2: Update get/set_l2_entry() and add get/set_l2_bitmap() Alberto Garcia
2020-05-05 20:04 ` Eric Blake
2020-05-06 12:06 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 14/31] qcow2: Add QCow2SubclusterType and qcow2_get_subcluster_type() Alberto Garcia
2020-05-05 21:08 ` Eric Blake
2020-05-05 17:38 ` [PATCH v5 15/31] qcow2: Add qcow2_cluster_is_allocated() Alberto Garcia
2020-05-05 21:10 ` Eric Blake
2020-05-05 17:38 ` [PATCH v5 16/31] qcow2: Add cluster type parameter to qcow2_get_host_offset() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 17/31] qcow2: Replace QCOW2_CLUSTER_* with QCOW2_SUBCLUSTER_* Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 18/31] qcow2: Handle QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 19/31] qcow2: Add subcluster support to calculate_l2_meta() Alberto Garcia
2020-05-05 21:59 ` Eric Blake
2020-05-06 17:14 ` Alberto Garcia
2020-05-06 17:39 ` Eric Blake
2020-05-07 15:34 ` Alberto Garcia
2020-05-07 15:50 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 20/31] qcow2: Add subcluster support to qcow2_get_host_offset() Alberto Garcia
2020-05-06 17:55 ` Eric Blake
2020-05-08 11:44 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 21/31] qcow2: Add subcluster support to zero_in_l2_slice() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 22/31] qcow2: Add subcluster support to discard_in_l2_slice() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 23/31] qcow2: Add subcluster support to check_refcounts_l2() Alberto Garcia
2020-05-06 17:58 ` Eric Blake
2020-05-05 17:38 ` [PATCH v5 24/31] qcow2: Update L2 bitmap in qcow2_alloc_cluster_link_l2() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 25/31] qcow2: Clear the L2 bitmap when allocating a compressed cluster Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 26/31] qcow2: Add subcluster support to handle_alloc_space() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 27/31] qcow2: Add subcluster support to qcow2_co_pwrite_zeroes() Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 28/31] qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit Alberto Garcia
2020-05-06 18:09 ` Eric Blake [this message]
2020-05-07 14:37 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 29/31] qcow2: Assert that expand_zero_clusters_in_l1() does not support subclusters Alberto Garcia
2020-05-06 18:11 ` Eric Blake
2020-05-05 17:38 ` [PATCH v5 30/31] qcow2: Add subcluster support to qcow2_measure() Alberto Garcia
2020-05-06 18:13 ` Eric Blake
2020-05-07 15:16 ` Alberto Garcia
2020-05-05 17:38 ` [PATCH v5 31/31] iotests: Add tests for qcow2 images with extended L2 entries Alberto Garcia
2020-05-20 9:35 ` [PATCH v5 00/31] Add subcluster allocation to qcow2 Derek Su
2020-05-20 9:50 ` Alberto Garcia
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