block: update string sizes for filename,backing_file,exact_filename
The string field entries 'filename', 'backing_file', and
'exact_filename' in the BlockDriverState struct are defined as 1024
bytes.
However, many places that use these values accept a maximum of PATH_MAX
bytes, so we have a mixture of 1024 byte and PATH_MAX byte allocations.
This patch makes the BlockDriverStruct field string sizes match usage.
This patch also does a few fixes related to the size that needs to
happen now:
* the block qapi driver is updated to use PATH_MAX bytes
* the qcow and qcow2 drivers have an additional safety check
* the block vvfat driver is updated to use PATH_MAX bytes
for the size of backing_file, for systems where PATH_MAX is < 1024
bytes.
* qemu-img uses PATH_MAX rather than 1024. These instances were not
changed to be dynamically allocated, however, as the extra
temporary 3K in stack usage for qemu-img does not seem worrisome.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 06a21dd..e264be9 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -339,13 +339,13 @@
* regarding this BDS's context */
QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
- char filename[1024];
- char backing_file[1024]; /* if non zero, the image is a diff of
- this file image */
+ char filename[PATH_MAX];
+ char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
+ this file image */
char backing_format[16]; /* if non-zero and backing_file exists */
QDict *full_open_options;
- char exact_filename[1024];
+ char exact_filename[PATH_MAX];
BlockDriverState *backing_hd;
BlockDriverState *file;
