| Message ID | 20180416165849.28864-3-mreitz@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Apr 16, 2018 at 06:58:42PM +0200, Max Reitz wrote: > Currently we never actually check whether the WRITE_UNCHANGED > permission has been taken for unchanging writes. But the one check that > is commented out checks both WRITE and WRITE_UNCHANGED; and considering > that WRITE_UNCHANGED is already documented as being weaker then WRITE, s/then/than/ Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
On Mon 16 Apr 2018 06:58:42 PM CEST, Max Reitz wrote: > Currently we never actually check whether the WRITE_UNCHANGED > permission has been taken for unchanging writes. But the one check that > is commented out checks both WRITE and WRITE_UNCHANGED; and considering > that WRITE_UNCHANGED is already documented as being weaker then WRITE, > we should probably explicitly document WRITE to include WRITE_UNCHANGED. > > Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> s/then/than/ as Stefan mentioned. Berto
On 2018-04-20 14:04, Alberto Garcia wrote: > On Mon 16 Apr 2018 06:58:42 PM CEST, Max Reitz wrote: >> Currently we never actually check whether the WRITE_UNCHANGED >> permission has been taken for unchanging writes. But the one check that >> is commented out checks both WRITE and WRITE_UNCHANGED; and considering >> that WRITE_UNCHANGED is already documented as being weaker then WRITE, >> we should probably explicitly document WRITE to include WRITE_UNCHANGED. >> >> Signed-off-by: Max Reitz <mreitz@redhat.com> > > Reviewed-by: Alberto Garcia <berto@igalia.com> > > s/then/than/ as Stefan mentioned. Yep, will fix. Thanks for reviewing! Max
diff --git a/include/block/block.h b/include/block/block.h index cdec3639a3..397b5e8d44 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -205,6 +205,9 @@ enum { * This permission (which is weaker than BLK_PERM_WRITE) is both enough and * required for writes to the block node when the caller promises that * the visible disk content doesn't change. + * + * As the BLK_PERM_WRITE permission is strictly stronger, either is + * sufficient to perform an unchanging write. */ BLK_PERM_WRITE_UNCHANGED = 0x04,
Currently we never actually check whether the WRITE_UNCHANGED permission has been taken for unchanging writes. But the one check that is commented out checks both WRITE and WRITE_UNCHANGED; and considering that WRITE_UNCHANGED is already documented as being weaker then WRITE, we should probably explicitly document WRITE to include WRITE_UNCHANGED. Signed-off-by: Max Reitz <mreitz@redhat.com> --- include/block/block.h | 3 +++ 1 file changed, 3 insertions(+)