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) \
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 5247a9a..7a73dc5 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -71,8 +71,7 @@
key.objectid = dir;
btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
- ret = btrfs_name_hash(name, name_len, &key.offset);
- BUG_ON(ret);
+ key.offset = btrfs_name_hash(name, name_len);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
@@ -125,8 +124,7 @@
key.objectid = dir;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
- ret = btrfs_name_hash(name, name_len, &key.offset);
- BUG_ON(ret);
+ key.offset = btrfs_name_hash(name, name_len);
path = btrfs_alloc_path();
data_size = sizeof(*dir_item) + name_len;
dir_item = insert_with_overflow(trans, root, path, &key, data_size,
@@ -199,8 +197,7 @@
key.objectid = dir;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
- ret = btrfs_name_hash(name, name_len, &key.offset);
- BUG_ON(ret);
+ key.offset = btrfs_name_hash(name, name_len);
ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
if (ret < 0)
@@ -261,8 +258,7 @@
key.objectid = dir;
btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
- ret = btrfs_name_hash(name, name_len, &key.offset);
- BUG_ON(ret);
+ key.offset = btrfs_name_hash(name, name_len);
ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
if (ret < 0)
return ERR_PTR(ret);
diff --git a/fs/btrfs/hash.c b/fs/btrfs/hash.c
index e5c7690..d5252f5 100644
--- a/fs/btrfs/hash.c
+++ b/fs/btrfs/hash.c
@@ -76,19 +76,18 @@
*buf++ = pad;
}
-int btrfs_name_hash(const char *name, int len, u64 *hash_result)
+u64 btrfs_name_hash(const char *name, int len)
{
__u32 hash;
__u32 minor_hash = 0;
const char *p;
__u32 in[8], buf[2];
+ u64 hash_result;
if (len == 1 && *name == '.') {
- *hash_result = 1;
- return 0;
+ return 1;
} else if (len == 2 && name[0] == '.' && name[1] == '.') {
- *hash_result = 2;
- return 0;
+ return 2;
}
/* Initialize the default seed for the hash checksum functions */
@@ -106,8 +105,8 @@
}
hash = buf[0];
minor_hash = buf[1];
- *hash_result = buf[0];
- *hash_result <<= 32;
- *hash_result |= buf[1];
- return 0;
+ hash_result = buf[0];
+ hash_result <<= 32;
+ hash_result |= buf[1];
+ return hash_result;
}
diff --git a/fs/btrfs/hash.h b/fs/btrfs/hash.h
index d3be026..868ee17 100644
--- a/fs/btrfs/hash.h
+++ b/fs/btrfs/hash.h
@@ -18,5 +18,5 @@
#ifndef __HASH__
#define __HASH__
-int btrfs_name_hash(const char *name, int len, u64 *hash_result);
+u64 btrfs_name_hash(const char *name, int len);
#endif
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index c5715a6..ad03a32 100644
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -21,16 +21,15 @@
u##bits btrfs_##name(struct extent_buffer *eb, \
type *s) \
{ \
- unsigned long offset = (unsigned long)s + \
- offsetof(type, member); \
- __le##bits *tmp; \
+ unsigned long part_offset = (unsigned long)s; \
+ unsigned long offset = part_offset + offsetof(type, member); \
+ type *p; \
/* ugly, but we want the fast path here */ \
if (eb->map_token && offset >= eb->map_start && \
offset + sizeof(((type *)0)->member) <= eb->map_start + \
eb->map_len) { \
- tmp = (__le##bits *)(eb->kaddr + offset - \
- eb->map_start); \
- return le##bits##_to_cpu(*tmp); \
+ p = (type *)(eb->kaddr + part_offset - eb->map_start); \
+ return le##bits##_to_cpu(p->member); \
} \
{ \
int err; \
@@ -48,8 +47,8 @@
read_eb_member(eb, s, type, member, &res); \
return le##bits##_to_cpu(res); \
} \
- tmp = (__le##bits *)(kaddr + offset - map_start); \
- res = le##bits##_to_cpu(*tmp); \
+ p = (type *)(kaddr + part_offset - map_start); \
+ res = le##bits##_to_cpu(p->member); \
if (unmap_on_exit) \
unmap_extent_buffer(eb, map_token, KM_USER1); \
return res; \
@@ -58,16 +57,15 @@
void btrfs_set_##name(struct extent_buffer *eb, \
type *s, u##bits val) \
{ \
- unsigned long offset = (unsigned long)s + \
- offsetof(type, member); \
- __le##bits *tmp; \
+ unsigned long part_offset = (unsigned long)s; \
+ unsigned long offset = part_offset + offsetof(type, member); \
+ type *p; \
/* ugly, but we want the fast path here */ \
if (eb->map_token && offset >= eb->map_start && \
offset + sizeof(((type *)0)->member) <= eb->map_start + \
eb->map_len) { \
- tmp = (__le##bits *)(eb->kaddr + offset - \
- eb->map_start); \
- *tmp = cpu_to_le##bits(val); \
+ p = (type *)(eb->kaddr + part_offset - eb->map_start); \
+ p->member = cpu_to_le##bits(val); \
return; \
} \
{ \
@@ -86,8 +84,8 @@
write_eb_member(eb, s, type, member, &val); \
return; \
} \
- tmp = (__le##bits *)(kaddr + offset - map_start); \
- *tmp = cpu_to_le##bits(val); \
+ p = (type *)(kaddr + part_offset - map_start); \
+ p->member = cpu_to_le##bits(val); \
if (unmap_on_exit) \
unmap_extent_buffer(eb, map_token, KM_USER1); \
} \