Re: [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-30 Thread Kevin Wolf
Am 28.04.2018 um 13:19 hat Max Reitz geschrieben: > On 2018-04-26 04:12, Eric Blake wrote: > > On 04/25/2018 10:08 AM, Max Reitz wrote: > > > >> > >>> Also, that does raise the question of whether you have more work to > >>> support write-zero requests with WRITE_UNCHANGED (which indeed sounds > >

Re: [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-28 Thread Max Reitz
On 2018-04-26 04:12, Eric Blake wrote: > On 04/25/2018 10:08 AM, Max Reitz wrote: > >> >>> Also, that does raise the question of whether you have more work to >>> support write-zero requests with WRITE_UNCHANGED (which indeed sounds >>> like something plausible to support). >> >> I'm afraid I don'

Re: [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-26 Thread Kevin Wolf
Am 26.04.2018 um 04:12 hat Eric Blake geschrieben: > On 04/25/2018 10:08 AM, Max Reitz wrote: > > > > >> Also, that does raise the question of whether you have more work to > >> support write-zero requests with WRITE_UNCHANGED (which indeed sounds > >> like something plausible to support). > > >

Re: [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-25 Thread Eric Blake
On 04/25/2018 10:08 AM, Max Reitz wrote: > >> Also, that does raise the question of whether you have more work to >> support write-zero requests with WRITE_UNCHANGED (which indeed sounds >> like something plausible to support). > > I'm afraid I don't quite understand the question. > BDRV_REQ_WRI

Re: [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-25 Thread Max Reitz
On 2018-04-25 16:33, Eric Blake wrote: > On 04/21/2018 08:29 AM, Max Reitz wrote: >> This flag signifies that a write request will not change the visible >> disk content. With this flag set, it is sufficient to have the >> BLK_PERM_WRITE_UNCHANGED permission instead of BLK_PERM_WRITE. >> >> Signed

Re: [Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-25 Thread Eric Blake
On 04/21/2018 08:29 AM, Max Reitz wrote: > This flag signifies that a write request will not change the visible > disk content. With this flag set, it is sufficient to have the > BLK_PERM_WRITE_UNCHANGED permission instead of BLK_PERM_WRITE. > > Signed-off-by: Max Reitz > Reviewed-by: Stefan Haj

[Qemu-devel] [PATCH v2 3/9] block: Add BDRV_REQ_WRITE_UNCHANGED flag

2018-04-21 Thread Max Reitz
This flag signifies that a write request will not change the visible disk content. With this flag set, it is sufficient to have the BLK_PERM_WRITE_UNCHANGED permission instead of BLK_PERM_WRITE. Signed-off-by: Max Reitz Reviewed-by: Stefan Hajnoczi Reviewed-by: Alberto Garcia --- include/bloc