From df68b8a7ad4a18c9e63f1c12015a59c3b7031adb Mon Sep 17 00:00:00 2001 From: David Miller Date: Fri, 15 Feb 2008 10:40:52 -0500 Subject: 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 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 @@ 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) \ 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 @@ 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); 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 @@ 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; } 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 @@ 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); \ } \ -- cgit v0.10.2