btrfs-progs: reorganize extent_buffer and fix alignment of data
Reported by UBSAN, the checksum code tries to access unaligned data that
come from the extent_buffer.
struct extent_buffer {
struct cache_extent cache_node; /* 0 48 */
u64 start; /* 48 8 */
u64 dev_bytenr; /* 56 8 */
/* --- cacheline 1 boundary (64 bytes) --- */
u32 len; /* 64 4 */
/* XXX 4 bytes hole, try to pack */
struct extent_io_tree * tree; /* 72 8 */
struct list_head lru; /* 80 16 */
struct list_head recow; /* 96 16 */
int refs; /* 112 4 */
u32 flags; /* 116 4 */
int fd; /* 120 4 */
char data[0]; /* 124 0 */
/* size: 128, cachelines: 2, members: 11 */
/* sum members: 120, holes: 1, sum holes: 4 */
/* padding: 4 */
};
Add explicit alignment to data.
Reported-by: Lukas Lueg <lukas.lueg@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=156471
Signed-off-by: David Sterba <dsterba@suse.com>
da64ae3a0f