On 10/16/2012 08:44 AM, Jeff Cody wrote: > Currently, bdrv_find_backing_image compares bs->backing_file with > what is passed in as a backing_file name. Mismatches may occur, > however, when bs->backing_file and backing_file are both not
Reads better as s/both not/not both/.
> absolute or relative.
>
> Use path_combine() to make sure any relative backing filenames are
> relative to the current image filename being searched, and then use
> realpath() to make all comparisons based on absolute filenames.
>
> This also changes bdrv_find_backing_image to no longer be recursive,
> but iterative.
>
> Signed-off-by: Jeff Cody <jc...@redhat.com>
> ---
> block.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 58 insertions(+), 6 deletions(-)
> - if (!bs->drv) {
> + char *filename_full = NULL;
> + char *backing_file_full = NULL;
> + char *filename_tmp = NULL;
> + int is_protocol = 0;
Any reason you didn't use bool here?
> + BlockDriverState *curr_bs = NULL;
> + BlockDriverState *retval = NULL;
> +
> + if (!bs || !bs->drv || !backing_file) {
> return NULL;
> }
>
> - if (bs->backing_hd) {
> - if (strcmp(bs->backing_file, backing_file) == 0) {
> - return bs->backing_hd;
> + filename_full = g_malloc(sizeof(char) * PATH_MAX);
sizeof(char) is guaranteed to be 1; this can be simplified to
g_malloc(PATH_MAX).
> + backing_file_full = g_malloc(sizeof(char) * PATH_MAX);
> + filename_tmp = g_malloc(sizeof(char) * PATH_MAX);
> + if (!filename_full || !backing_file_full || !filename_tmp) {
> + goto error;
> + }
Dead 'if', since g_malloc() is guaranteed to succeed.
> +
> + is_protocol = path_has_protocol(backing_file);
> +
> + for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
> +
> + /* If either of the filename paths is actually a protocol, then
> + * compare unmodified paths; otherwise make paths relative */
> + if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
> + if (strcmp(backing_file, curr_bs->backing_file) == 0) {
I guess we are guaranteed that if is_protocol and path_has_protocol()
give different answers, then the strcmp() will fail?
--
Eric Blake ebl...@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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