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Commit df68b8a7 authored by David Miller's avatar David Miller Committed by Chris Mason
Browse files

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: default avatarChris Mason <chris.mason@oracle.com>
parent 39b5637f

fs/btrfs/ctree.h

+6 −11
Original line number Diff line number Diff line
@@ -495,22 +495,17 @@ void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val); 
#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)		\

fs/btrfs/dir-item.c

+4 −8
Original line number Diff line number Diff line
@@ -71,8 +71,7 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, 


	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 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root 


	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 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, 
	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 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans, 


	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);

fs/btrfs/hash.c

+8 −9
Original line number Diff line number Diff line
@@ -76,19 +76,18 @@ static void str2hashbuf(const char *msg, int len, __u32 *buf, int num) 
		*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 @@ int btrfs_name_hash(const char *name, int len, u64 *hash_result) 
	}

	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;

}

fs/btrfs/hash.h

+1 −1
Original line number Diff line number Diff line
@@ -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

fs/btrfs/struct-funcs.c

+14 −16
Original line number Diff line number Diff line
@@ -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 @@ u##bits btrfs_##name(struct extent_buffer *eb, \ 
			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 @@ u##bits btrfs_##name(struct extent_buffer *eb, \ 
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 @@ void btrfs_set_##name(struct extent_buffer *eb, \ 
			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);	\

	}								\