| Message ID | 943d55a006aab912af62bbb89833a48baba2d69c.1421768887.git.jcody@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 01/20/2015 12:31 PM, Jeff Cody wrote: > The backing_filename string in mirror_run() is only used to check > for a NULL string, so we don't need to allocate 1024 bytes (or, later, > PATH_MAX bytes), when we only need to copy the first 2 characters. > > We technically only need 1 byte, as we are just checking for NULL, but > since backing_filename[] is populated by bdrv_get_backing_filename(), a > string size of 1 will always only return '\0'; > > Signed-off-by: Jeff Cody <jcody@redhat.com> > --- > block/mirror.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/block/mirror.c b/block/mirror.c > index 9019d1b..4056164 100644 > --- a/block/mirror.c > +++ b/block/mirror.c > @@ -378,7 +378,8 @@ static void coroutine_fn mirror_run(void *opaque) > int64_t sector_num, end, sectors_per_chunk, length; > uint64_t last_pause_ns; > BlockDriverInfo bdi; > - char backing_filename[1024]; > + char backing_filename[2]; /* we only need 2 characters because we are only > + checking for a NULL string */ > int ret = 0; > int n; > > Reviewed-by: John Snow <jsnow@redhat.com>
On Tue, Jan 20, 2015 at 12:31:32PM -0500, Jeff Cody wrote: > The backing_filename string in mirror_run() is only used to check > for a NULL string, so we don't need to allocate 1024 bytes (or, later, > PATH_MAX bytes), when we only need to copy the first 2 characters. > > We technically only need 1 byte, as we are just checking for NULL, but > since backing_filename[] is populated by bdrv_get_backing_filename(), a > string size of 1 will always only return '\0'; > > Signed-off-by: Jeff Cody <jcody@redhat.com> > --- > block/mirror.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/block/mirror.c b/block/mirror.c index 9019d1b..4056164 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -378,7 +378,8 @@ static void coroutine_fn mirror_run(void *opaque) int64_t sector_num, end, sectors_per_chunk, length; uint64_t last_pause_ns; BlockDriverInfo bdi; - char backing_filename[1024]; + char backing_filename[2]; /* we only need 2 characters because we are only + checking for a NULL string */ int ret = 0; int n;
The backing_filename string in mirror_run() is only used to check for a NULL string, so we don't need to allocate 1024 bytes (or, later, PATH_MAX bytes), when we only need to copy the first 2 characters. We technically only need 1 byte, as we are just checking for NULL, but since backing_filename[] is populated by bdrv_get_backing_filename(), a string size of 1 will always only return '\0'; Signed-off-by: Jeff Cody <jcody@redhat.com> --- block/mirror.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)