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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 55C8w8KlkiyCkUuEFR8e/puPcRaItbgFvicU24qsjo6+hCK96KR9PXjFhK9ki/gRU1NNO3JhbKhXTeYTZj8LJZG7lJC3n2R+U+278aguTDKwNRfn3VEsXVvWfZcPS19qJ++PQ10xEIN14KT9XTDxP51LVk0g8fx5tPmBSOF9JKUnEtguyxI4fveyp7C09fYuduwtCPrFe1X6Oi0QTsJe+fw2ySO3D56lJNxbHoExNRp47bXSCWvYO/lbDem2Ukqw34Oguph9xGRh+4UMXOcKKEAqVfFBpPH3+X/egc1inRr6JVrrOxGLX82RLfl0sYhVMDFLDmjMu2fzYafr3CaC0/yERITtBRUT4KqmYsnidupJo+ZwMjY4wMBVtKG+reeH5SZwYmq1L3TZOJ4+6/sdnLbe5i7rV9qRUiNLVRMGS9+/yEq88vTghDfT/BKKh78Y X-ExternalRecipientOutboundConnectors: 0bc7f26d-0264-416e-a6fc-8352af79c58f X-OriginatorOrg: virtuozzo.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Oct 2026 10:28:49.3095 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 0c38cacf-92be-4bcd-e242-08df341516f5 X-MS-Exchange-CrossTenant-Id: 0bc7f26d-0264-416e-a6fc-8352af79c58f X-MS-Exchange-CrossTenant-AuthSource: MI3PEPF00008484.eurprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: Internet X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM9PR08MB5923 > Whenever option discard-no-unref=3Don is enabled, we bypass refcount > machinery and unconditionally punch hole in the data on 'discard' and > 'write -z -u' paths. However, when this same cluster is also referenced > by an internal snapshot, such operations lead to problems. The active L2 > table is copied before it is changed, so the snapshot metadata stays > correct, but the host range under it is punched out and the snapshot reads > zeroes there afterwards. qemu-img check finds nothing wrong. >=20 > Fix this by guarding the 'keep_reference' flag by the presence of the > QCOW_OFLAG_COPIED bit. I.e. only proceed with unconditional data > punching if we own this cluster exclusively. >=20 > Fixes: 42a2890a76f4 ("qcow2: add discard-no-unref option") > Signed-off-by: Andrey Drobyshev Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.vzint.dev/#/patchset/2026102710261= 8.798471-1-andrey.drobyshev@virtuozzo.com?part=3D1