bcachefs: Use DECLARE_FLEX_ARRAY() helper and fix multiple -Warray-bounds warnings

Transform zero-length array `s` into a proper flexible-array
member in `struct snapshot_table` via the DECLARE_FLEX_ARRAY()
helper; and fix tons of the following -Warray-bounds warnings:

fs/bcachefs/snapshot.h:36:21: warning: array subscript <unknown> is outside array bounds of 'struct snapshot_t[0]' [-Warray-bounds=]
fs/bcachefs/snapshot.h:36:21: warning: array subscript <unknown> is outside array bounds of 'struct snapshot_t[0]' [-Warray-bounds=]
fs/bcachefs/snapshot.c:135:70: warning: array subscript <unknown> is outside array bounds of 'struct snapshot_t[0]' [-Warray-bounds=]
fs/bcachefs/snapshot.h:36:21: warning: array subscript <unknown> is outside array bounds of 'struct snapshot_t[0]' [-Warray-bounds=]
fs/bcachefs/snapshot.h:36:21: warning: array subscript <unknown> is outside array bounds of 'struct snapshot_t[0]' [-Warray-bounds=]
fs/bcachefs/snapshot.h:36:21: warning: array subscript <unknown> is outside array bounds of 'struct snapshot_t[0]' [-Warray-bounds=]

This helps with the ongoing efforts to globally enable -Warray-bounds.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/subvolume_types.h b/fs/bcachefs/subvolume_types.h
index 86833445af205643b81bd08b3b204005c7bee071..2d2e66a4e4681ee5ba6ba18666d135ab961a2cbf 100644 (file)
--- a/fs/bcachefs/subvolume_types.h
+++ b/fs/bcachefs/subvolume_types.h
@@ -20,7 +20,7 @@ struct snapshot_t {
 };
 
 struct snapshot_table {
-       struct snapshot_t       s[0];
+       DECLARE_FLEX_ARRAY(struct snapshot_t, s);
 };
 
 typedef struct {