Compiler is throwing out this false positive warning in the following
function flow. Apparently, %parent and %p are initialized in tree_search_for_insert().
__set_extent_bit()
state = tree_search_for_insert(tree, start, &p, &parent);
insert_state_fast(tree, prealloc, p, parent, bits, changeset);
rb_link_node(&state->rb_node, parent, node);
Compile warnings:
In file included from ./common/extent-cache.h:23,
from kernel-shared/ctree.h:26,
from kernel-shared/extent-io-tree.c:4:
kernel-shared/extent-io-tree.c: In function ‘__set_extent_bit’:
./kernel-lib/rbtree.h:80:28: warning: ‘parent’ may be used uninitialized in this function [-Wmaybe-uninitialized]
node->__rb_parent_color = (unsigned long)parent;
^~~~~~~~~~~~~~~~~~~~~
kernel-shared/extent-io-tree.c:996:18: note: ‘parent’ was declared here
struct rb_node *parent;
^~~~~~
In file included from ./common/extent-cache.h:23,
from kernel-shared/ctree.h:26,
from kernel-shared/extent-io-tree.c:4:
./kernel-lib/rbtree.h:83:11: warning: ‘p’ may be used uninitialized in this function [-Wmaybe-uninitialized]
*rb_link = node;
~~~~~~~~~^~~~~~
kernel-shared/extent-io-tree.c:995:19: note: ‘p’ was declared here
struct rb_node **p;
Fix:
Initialize to NULL, as in the kernel.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
f16be8eeb7