Btrfs: unaligned access fixes
Btrfs set/get macros lose type information needed to avoid
unaligned accesses on sparc64.
ere is a patch for the kernel bits which fixes most of the
unaligned accesses on sparc64.
btrfs_name_hash is modified to return the hash value instead
of getting a return location via a (potentially unaligned)
pointer.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 52144b0..086cb05 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -495,22 +495,17 @@
#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits) \
static inline u##bits btrfs_##name(struct extent_buffer *eb) \
{ \
- char *kaddr = kmap_atomic(eb->first_page, KM_USER0); \
- unsigned long offset = offsetof(type, member); \
- u##bits res; \
- __le##bits *tmp = (__le##bits *)(kaddr + offset); \
- res = le##bits##_to_cpu(*tmp); \
- kunmap_atomic(kaddr, KM_USER0); \
+ type *p = kmap_atomic(eb->first_page, KM_USER0); \
+ u##bits res = le##bits##_to_cpu(p->member); \
+ kunmap_atomic(p, KM_USER0); \
return res; \
} \
static inline void btrfs_set_##name(struct extent_buffer *eb, \
u##bits val) \
{ \
- char *kaddr = kmap_atomic(eb->first_page, KM_USER0); \
- unsigned long offset = offsetof(type, member); \
- __le##bits *tmp = (__le##bits *)(kaddr + offset); \
- *tmp = cpu_to_le##bits(val); \
- kunmap_atomic(kaddr, KM_USER0); \
+ type *p = kmap_atomic(eb->first_page, KM_USER0); \
+ p->member = cpu_to_le##bits(val); \
+ kunmap_atomic(p, KM_USER0); \
}
#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \