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authorMax Reitz <mreitz@redhat.com>2014-11-26 17:20:26 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2015-01-13 11:47:56 +0000
commit9f07429e8873124c588847b0d499cb32b9410bdd (patch)
treef5de29af3815e86167edb769feddd6013ab32d12 /block.c
parent0a82855a1a819f3de49781d42728f485fbd64284 (diff)
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block: JSON filenames and relative backing files
When using a relative backing file name, qemu needs to know the directory of the top image file. For JSON filenames, such a directory cannot be easily determined (e.g. how do you determine the directory of a qcow2 BDS directly on top of a quorum BDS?). Therefore, do not allow relative filenames for the backing file of BDSs only having a JSON filename. Furthermore, BDS::exact_filename should be used whenever possible. If BDS::filename is not equal to BDS::exact_filename, the former will always be a JSON object. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r--block.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/block.c b/block.c
index 86f2faa..cf0867c 100644
--- a/block.c
+++ b/block.c
@@ -305,19 +305,28 @@ void path_combine(char *dest, int dest_size,
void bdrv_get_full_backing_filename_from_filename(const char *backed,
const char *backing,
- char *dest, size_t sz)
+ char *dest, size_t sz,
+ Error **errp)
{
- if (backing[0] == '\0' || path_has_protocol(backing)) {
+ if (backing[0] == '\0' || path_has_protocol(backing) ||
+ path_is_absolute(backing))
+ {
pstrcpy(dest, sz, backing);
+ } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
+ error_setg(errp, "Cannot use relative backing file names for '%s'",
+ backed);
} else {
path_combine(dest, sz, backed, backing);
}
}
-void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz)
+void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
+ Error **errp)
{
- bdrv_get_full_backing_filename_from_filename(bs->filename, bs->backing_file,
- dest, sz);
+ char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
+
+ bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
+ dest, sz, errp);
}
void bdrv_register(BlockDriver *bdrv)
@@ -1225,7 +1234,14 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
QDECREF(options);
goto free_exit;
} else {
- bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX);
+ bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX,
+ &local_err);
+ if (local_err) {
+ ret = -EINVAL;
+ error_propagate(errp, local_err);
+ QDECREF(options);
+ goto free_exit;
+ }
}
if (!bs->drv || !bs->drv->supports_backing) {