From 33122cde2f27e8a6ff8c3e791152c62948dd24dd Mon Sep 17 00:00:00 2001 From: Jeffrey Cody Date: Tue, 21 Feb 2017 16:29:56 +0100 Subject: [PATCH 1/4] block: check full backing filename when searching protocol filenames RH-Author: Jeffrey Cody Message-id: <9cfa02a61bc34480a6f58532ed92eb851db91eeb.1487694132.git.jcody@redhat.com> Patchwork-id: 73958 O-Subject: [RHEV-7.3.z qemu-kvm-rhev 1/3] block: check full backing filename when searching protocol filenames Bugzilla: 1425125 RH-Acked-by: John Snow RH-Acked-by: Laurent Vivier RH-Acked-by: Stefan Hajnoczi In bdrv_find_backing_image(), if we are searching an image for a backing file that contains a protocol, we currently only compare unmodified paths. However, some management software will change the backing filename to be a relative filename in a path. QEMU is able to handle this fine, because internally it will use path_combine to put together the full protocol URI. However, this can lead to an inability to match an image during a QAPI command that needs to use bdrv_find_backing_image() to find the image, when it is searched by the full URI. When searching for a protocol filename, if the straight comparison fails, this patch will also compare against the full backing filename to see if that is a match. Signed-off-by: Jeff Cody Message-id: c2d025adca8a2b665189e6f4cf080f44126d0b6b.1485392617.git.jcody@redhat.com Reviewed-by: Max Reitz Signed-off-by: Max Reitz (cherry picked from commit 418661e0324c1c419552cf24bd4447292e884bdd) Signed-off-by: Miroslav Rezanina --- block.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/block.c b/block.c index 75afea5..de52900 100644 --- a/block.c +++ b/block.c @@ -3126,6 +3126,7 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, int is_protocol = 0; BlockDriverState *curr_bs = NULL; BlockDriverState *retval = NULL; + Error *local_error = NULL; if (!bs || !bs->drv || !backing_file) { return NULL; @@ -3146,6 +3147,18 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, retval = curr_bs->backing->bs; break; } + /* Also check against the full backing filename for the image */ + bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX, + &local_error); + if (local_error == NULL) { + if (strcmp(backing_file, backing_file_full) == 0) { + retval = curr_bs->backing->bs; + break; + } + } else { + error_free(local_error); + local_error = NULL; + } } else { /* If not an absolute filename path, make it relative to the current * image's filename path */ -- 1.8.3.1