[FALSE ALERT]
With clang 15.0.7, there is a false alert on uninitialized value in
ctree.c:
kernel-shared/ctree.c:3418:13: warning: variable 'offset' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
} else if (ret < 0) {
^~~~~~~
kernel-shared/ctree.c:3428:41: note: uninitialized use occurs here
write_extent_buffer(eb, &subvol_id_le, offset, sizeof(subvol_id_le));
^~~~~~
kernel-shared/ctree.c:3418:9: note: remove the 'if' if its condition is always true
} else if (ret < 0) {
^~~~~~~~~~~~~
kernel-shared/ctree.c:3380:22: note: initialize the variable 'offset' to silence this warning
unsigned long offset;
^
= 0
kernel-shared/ctree.c:3418:13: warning: variable 'eb' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
} else if (ret < 0) {
^~~~~~~
kernel-shared/ctree.c:3429:26: note: uninitialized use occurs here
btrfs_mark_buffer_dirty(eb);
^~
kernel-shared/ctree.c:3418:9: note: remove the 'if' if its condition is always true
} else if (ret < 0) {
^~~~~~~~~~~~~
kernel-shared/ctree.c:3378:26: note: initialize the variable 'eb' to silence this warning
struct extent_buffer *eb;
^
= NULL
[CAUSE]
The original code is handling the return value from
btrfs_insert_empty_item() like this:
ret = btrfs_insert_empty_item();
if (ret >= 0) {
/* Do something for it. */
} else if (ret == -EEXIST) {
/* Do something else. */
} else if (ret < 0) {
/* Error handling. */
}
But the problem is, the last one check is always true if we can reach
there.
Thus clang is providing the hint to remove the if () check.
[FIX]
Normally we prefer to do error handling first, so move the error
handling first so we don't need the if () else if () chain.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
e2806fd624