[FALSE ALERT]
There is a false alert when compiling btrfs-progs using gcc 12.2.1:
$ make D=1
kernel-shared/print-tree.c: In function 'print_sys_chunk_array':
kernel-shared/print-tree.c:1797:9: warning: 'buf' may be used uninitialized [-Wmaybe-uninitialized]
1797 | write_extent_buffer(buf, sb, 0, sizeof(*sb));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ./kernel-shared/ctree.h:27,
from kernel-shared/print-tree.c:24:
./kernel-shared/extent_io.h:148:6: note: by argument 1 of type 'const struct extent_buffer *' to 'write_extent_buffer' declared here
148 | void write_extent_buffer(const struct extent_buffer *eb, const void *src,
| ^~~~~~~~~~~~~~~~~~~
[CAUSE]
This is a false alert, the uninitialized part of buf will not be
utilized at all during write_extent_buffer().
[FIX]
Instead of allocating such ad-hoc buffer, go a more formal way by
calling alloc_dummy_extent_buffer(), which would properly set all
the members.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
6c7a6dba95