Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
12.03.2021 18:52, Max Reitz wrote: On 12.03.21 16:24, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 18:10, Max Reitz wrote: On 12.03.21 13:46, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09,

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Max Reitz
On 12.03.21 16:24, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 18:10, Max Reitz wrote: On 12.03.21 13:46, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote:

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
12.03.2021 17:58, Max Reitz wrote: On 12.03.21 13:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
12.03.2021 18:10, Max Reitz wrote: On 12.03.21 13:46, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35,

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Max Reitz
On 12.03.21 13:46, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote:

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Max Reitz
On 12.03.21 13:42, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote:

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Max Reitz
On 12.03.21 13:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
12.03.2021 15:32, Vladimir Sementsov-Ogievskiy wrote: 12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
12.03.2021 14:17, Max Reitz wrote: On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded (refcount becomes 0) and reused during data write. In this

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Max Reitz
On 12.03.21 10:09, Vladimir Sementsov-Ogievskiy wrote: 11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded (refcount becomes 0) and reused during data write. In this case data write may pollute another

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-12 Thread Vladimir Sementsov-Ogievskiy
11.03.2021 22:58, Max Reitz wrote: On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded (refcount becomes 0) and reused during data write. In this case data write may pollute another cluster (recently allocated) or even metadata. I was

Re: [PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-11 Thread Max Reitz
On 05.03.21 18:35, Vladimir Sementsov-Ogievskiy wrote: There is a bug in qcow2: host cluster can be discarded (refcount becomes 0) and reused during data write. In this case data write may pollute another cluster (recently allocated) or even metadata. I was about to ask whether we couldn’t

[PATCH v3 3/6] block/qcow2: introduce inflight writes counters: fix discard

2021-03-05 Thread Vladimir Sementsov-Ogievskiy
There is a bug in qcow2: host cluster can be discarded (refcount becomes 0) and reused during data write. In this case data write may pollute another cluster (recently allocated) or even metadata. To fix the issue let's track inflight writes to host cluster in the hash table and consider new