Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-22 Thread Alberto Garcia
On Wed 20 Nov 2019 07:44:57 PM CET, Kevin Wolf wrote: > When extending the size of an image that has a backing file larger than > its old size, make sure that the backing file data doesn't become > visible in the guest, but the added area is properly zeroed out. > > Consider the following scenario

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-22 Thread Alberto Garcia
On Thu 21 Nov 2019 03:33:31 PM CET, Kevin Wolf wrote: > For commit it's an image corruptor. For resize, I'll admit that it's > just wrong behaviour that is probably harmless in most cases, but it's > still wrong behaviour. It would be a corruptor in the same way as > commit if it allowed resizing

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Max Reitz
On 21.11.19 15:33, Kevin Wolf wrote: > Am 21.11.2019 um 13:21 hat Max Reitz geschrieben: >> On 21.11.19 12:34, Kevin Wolf wrote: >>> Am 21.11.2019 um 09:59 hat Max Reitz geschrieben: On 20.11.19 19:44, Kevin Wolf wrote: > When extending the size of an image that has a backing file larger

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Kevin Wolf
Am 21.11.2019 um 13:21 hat Max Reitz geschrieben: > On 21.11.19 12:34, Kevin Wolf wrote: > > Am 21.11.2019 um 09:59 hat Max Reitz geschrieben: > >> On 20.11.19 19:44, Kevin Wolf wrote: > >>> When extending the size of an image that has a backing file larger than > >>> its old size, make sure that

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Max Reitz
On 21.11.19 12:34, Kevin Wolf wrote: > Am 21.11.2019 um 09:59 hat Max Reitz geschrieben: >> On 20.11.19 19:44, Kevin Wolf wrote: >>> When extending the size of an image that has a backing file larger than >>> its old size, make sure that the backing file data doesn't become >>> visible in the

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Kevin Wolf
Am 21.11.2019 um 09:59 hat Max Reitz geschrieben: > On 20.11.19 19:44, Kevin Wolf wrote: > > When extending the size of an image that has a backing file larger than > > its old size, make sure that the backing file data doesn't become > > visible in the guest, but the added area is properly zeroed

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Kevin Wolf
Am 20.11.2019 um 22:15 hat Eric Blake geschrieben: > On 11/20/19 12:44 PM, Kevin Wolf wrote: > > When extending the size of an image that has a backing file larger than > > its old size, make sure that the backing file data doesn't become > > visible in the guest, but the added area is properly

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Vladimir Sementsov-Ogievskiy
21.11.2019 11:59, Max Reitz wrote: > On 20.11.19 19:44, Kevin Wolf wrote: >> When extending the size of an image that has a backing file larger than >> its old size, make sure that the backing file data doesn't become >> visible in the guest, but the added area is properly zeroed out. >> >>

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-21 Thread Max Reitz
On 20.11.19 19:44, Kevin Wolf wrote: > When extending the size of an image that has a backing file larger than > its old size, make sure that the backing file data doesn't become > visible in the guest, but the added area is properly zeroed out. > > Consider the following scenario where the

Re: [PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-20 Thread Eric Blake
On 11/20/19 12:44 PM, Kevin Wolf wrote: When extending the size of an image that has a backing file larger than its old size, make sure that the backing file data doesn't become visible in the guest, but the added area is properly zeroed out. Consider the following scenario where the overlay is

[PATCH v2 2/6] block: truncate: Don't make backing file data visible

2019-11-20 Thread Kevin Wolf
When extending the size of an image that has a backing file larger than its old size, make sure that the backing file data doesn't become visible in the guest, but the added area is properly zeroed out. Consider the following scenario where the overlay is shorter than its backing file: