| Message ID | 20171026075947.9597-1-mreitz@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | qemu-img.1: Image invalidation on qemu-img commit | expand |
On Thu, Oct 26, 2017 at 09:59:47AM +0200, Max Reitz wrote: > qemu-img commit invalidates all images between base and top. This > should be mentioned in the man page. > > Suggested-by: Ping Li <pingl@redhat.com> > Signed-off-by: Max Reitz <mreitz@redhat.com> > --- > qemu-img.texi | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/qemu-img.texi b/qemu-img.texi > index ee5c5940d3..fdcf120f36 100644 > --- a/qemu-img.texi > +++ b/qemu-img.texi > @@ -274,11 +274,10 @@ If the backing chain of the given image file @var{filename} has more than one > layer, the backing file into which the changes will be committed may be > specified as @var{base} (which has to be part of @var{filename}'s backing > chain). If @var{base} is not specified, the immediate backing file of the top > -image (which is @var{filename}) will be used. For reasons of consistency, > -explicitly specifying @var{base} will always imply @code{-d} (since emptying an > -image after committing to an indirect backing file would lead to different data > -being read from the image due to content in the intermediate backing chain > -overruling the commit target). > +image (which is @var{filename}) will be used. Note that after a commit operation > +all images between @var{base} and the top image will be invalid and may return > +garbage data when read. For this reason, @code{-b} implies @code{-d} (so that > +the top image stays valid). > > @item compare [-f @var{fmt}] [-F @var{fmt}] [-T @var{src_cache}] [-p] [-s] [-q] @var{filename1} @var{filename2} > > -- > 2.13.6 > > Reviewed-by: Jeff Cody <jcody@redhat.com>
Am 26.10.2017 um 09:59 hat Max Reitz geschrieben: > qemu-img commit invalidates all images between base and top. This > should be mentioned in the man page. > > Suggested-by: Ping Li <pingl@redhat.com> > Signed-off-by: Max Reitz <mreitz@redhat.com> Thanks, applied to the block branch. Kevin
diff --git a/qemu-img.texi b/qemu-img.texi index ee5c5940d3..fdcf120f36 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -274,11 +274,10 @@ If the backing chain of the given image file @var{filename} has more than one layer, the backing file into which the changes will be committed may be specified as @var{base} (which has to be part of @var{filename}'s backing chain). If @var{base} is not specified, the immediate backing file of the top -image (which is @var{filename}) will be used. For reasons of consistency, -explicitly specifying @var{base} will always imply @code{-d} (since emptying an -image after committing to an indirect backing file would lead to different data -being read from the image due to content in the intermediate backing chain -overruling the commit target). +image (which is @var{filename}) will be used. Note that after a commit operation +all images between @var{base} and the top image will be invalid and may return +garbage data when read. For this reason, @code{-b} implies @code{-d} (so that +the top image stays valid). @item compare [-f @var{fmt}] [-F @var{fmt}] [-T @var{src_cache}] [-p] [-s] [-q] @var{filename1} @var{filename2}
qemu-img commit invalidates all images between base and top. This should be mentioned in the man page. Suggested-by: Ping Li <pingl@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> --- qemu-img.texi | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)