diff options
| author | Max Reitz <mreitz@redhat.com> | 2019-10-11 17:28:02 +0200 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2019-10-28 11:52:57 +0100 |
| commit | fcf9a6b7288154677f6ee9c5f345c4275170e97d (patch) | |
| tree | bf28894f61b5baffaba246f6883d6f5baa5936d7 /block/qcow2.h | |
| parent | ecf6c7c0c1e5e6883f0e245a7b47101b69dc8235 (diff) | |
qcow2: Keep unknown extra snapshot data
The qcow2 specification says to ignore unknown extra data fields in
snapshot table entries. Currently, we discard it whenever we update the
image, which is a bit different from "ignore".
This patch makes the qcow2 driver keep all unknown extra data fields
when updating an image's snapshot table.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-5-mreitz@redhat.com
[mreitz: Adjusted comments as proposed by Eric]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/qcow2.h')
| -rw-r--r-- | block/qcow2.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/block/qcow2.h b/block/qcow2.h index cc0d5eadd0..363681cfdc 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -61,6 +61,9 @@ * space for snapshot names and IDs */ #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) +/* Maximum amount of extra data per snapshot table entry to accept */ +#define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024 + /* Bitmap header extension constraints */ #define QCOW2_MAX_BITMAPS 65535 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS) @@ -181,6 +184,10 @@ typedef struct QCowSnapshot { uint32_t date_sec; uint32_t date_nsec; uint64_t vm_clock_nsec; + /* Size of all extra data, including QCowSnapshotExtraData if available */ + uint32_t extra_data_size; + /* Data beyond QCowSnapshotExtraData, if any */ + void *unknown_extra_data; } QCowSnapshot; struct Qcow2Cache; |