| Message ID | f5a69a4a7e74370375959ecf08744cb485f168e0.1402683788.git.jcody@redhat.com |
|---|---|
| State | New |
| Headers | show |
The Friday 13 Jun 2014 à 14:52:31 (-0400), Jeff Cody wrote : > This simplifies the function bdrv_find_overlay(). With this change, > bdrv_find_base() is just a subset of usage of bdrv_find_overlay(), > so this also takes advantage of that. > > Reviewed-by: Eric Blake <eblake@redhat.com> > Signed-off-by: Jeff Cody <jcody@redhat.com> > --- > block.c | 45 ++++++++++----------------------------------- > 1 file changed, 10 insertions(+), 35 deletions(-) > > diff --git a/block.c b/block.c > index f9ea1b4..83996e3 100644 > --- a/block.c > +++ b/block.c > @@ -2569,32 +2569,23 @@ int bdrv_change_backing_file(BlockDriverState *bs, > * > * Returns NULL if bs is not found in active's image chain, > * or if active == bs. > + * > + * Returns the bottommost base image if bs == NULL. > */ > BlockDriverState *bdrv_find_overlay(BlockDriverState *active, > BlockDriverState *bs) > { > - BlockDriverState *overlay = NULL; > - BlockDriverState *intermediate; > - > - assert(active != NULL); > - assert(bs != NULL); > - > - /* if bs is the same as active, then by definition it has no overlay > - */ > - if (active == bs) { > - return NULL; > + while (active && bs != active->backing_hd) { > + active = active->backing_hd; > } > > - intermediate = active; > - while (intermediate->backing_hd) { > - if (intermediate->backing_hd == bs) { > - overlay = intermediate; > - break; > - } > - intermediate = intermediate->backing_hd; > - } > + return active; > +} > > - return overlay; > +/* Given a BDS, searches for the base layer. */ > +BlockDriverState *bdrv_find_base(BlockDriverState *bs) > +{ > + return bdrv_find_overlay(bs, NULL); > } > > typedef struct BlkIntermediateStates { > @@ -4376,22 +4367,6 @@ int bdrv_get_backing_file_depth(BlockDriverState *bs) > return 1 + bdrv_get_backing_file_depth(bs->backing_hd); > } > > -BlockDriverState *bdrv_find_base(BlockDriverState *bs) > -{ > - BlockDriverState *curr_bs = NULL; > - > - if (!bs) { > - return NULL; > - } > - > - curr_bs = bs; > - > - while (curr_bs->backing_hd) { > - curr_bs = curr_bs->backing_hd; > - } > - return curr_bs; > -} > - > /**************************************************************/ > /* async I/Os */ > > -- > 1.8.3.1 > > That is a neat simplification. Reviewed-by: Benoit Canet <benoit@irqsave.net>
diff --git a/block.c b/block.c index f9ea1b4..83996e3 100644 --- a/block.c +++ b/block.c @@ -2569,32 +2569,23 @@ int bdrv_change_backing_file(BlockDriverState *bs, * * Returns NULL if bs is not found in active's image chain, * or if active == bs. + * + * Returns the bottommost base image if bs == NULL. */ BlockDriverState *bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs) { - BlockDriverState *overlay = NULL; - BlockDriverState *intermediate; - - assert(active != NULL); - assert(bs != NULL); - - /* if bs is the same as active, then by definition it has no overlay - */ - if (active == bs) { - return NULL; + while (active && bs != active->backing_hd) { + active = active->backing_hd; } - intermediate = active; - while (intermediate->backing_hd) { - if (intermediate->backing_hd == bs) { - overlay = intermediate; - break; - } - intermediate = intermediate->backing_hd; - } + return active; +} - return overlay; +/* Given a BDS, searches for the base layer. */ +BlockDriverState *bdrv_find_base(BlockDriverState *bs) +{ + return bdrv_find_overlay(bs, NULL); } typedef struct BlkIntermediateStates { @@ -4376,22 +4367,6 @@ int bdrv_get_backing_file_depth(BlockDriverState *bs) return 1 + bdrv_get_backing_file_depth(bs->backing_hd); } -BlockDriverState *bdrv_find_base(BlockDriverState *bs) -{ - BlockDriverState *curr_bs = NULL; - - if (!bs) { - return NULL; - } - - curr_bs = bs; - - while (curr_bs->backing_hd) { - curr_bs = curr_bs->backing_hd; - } - return curr_bs; -} - /**************************************************************/ /* async I/Os */