diff options
Diffstat (limited to 'fs/btrfs/struct-funcs.c')
| -rw-r--r-- | fs/btrfs/struct-funcs.c | 29 |
1 files changed, 10 insertions, 19 deletions
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c index 68c02997e60d..e6d2bd019444 100644 --- a/fs/btrfs/struct-funcs.c +++ b/fs/btrfs/struct-funcs.c @@ -99,28 +99,19 @@ u##bits btrfs_get_token_##bits(struct btrfs_map_token *token, \ u##bits btrfs_get_##bits(const struct extent_buffer *eb, \ const void *ptr, unsigned long off) \ { \ - unsigned long part_offset = (unsigned long)ptr; \ - unsigned long offset = part_offset + off; \ - void *p; \ - int err; \ - char *kaddr; \ - unsigned long map_start; \ - unsigned long map_len; \ - int size = sizeof(u##bits); \ - u##bits res; \ + const unsigned long member_offset = (unsigned long)ptr + off; \ + const unsigned long oip = offset_in_page(member_offset); \ + const int size = sizeof(u##bits); \ + __le##bits leres; \ \ ASSERT(check_setget_bounds(eb, ptr, off, size)); \ - err = map_private_extent_buffer(eb, offset, size, \ - &kaddr, &map_start, &map_len); \ - if (err) { \ - __le##bits leres; \ - \ - read_extent_buffer(eb, &leres, offset, size); \ - return le##bits##_to_cpu(leres); \ + if (oip + size <= PAGE_SIZE) { \ + const unsigned long idx = member_offset >> PAGE_SHIFT; \ + const char *kaddr = page_address(eb->pages[idx]); \ + return get_unaligned_le##bits(kaddr + oip); \ } \ - p = kaddr + part_offset - map_start; \ - res = get_unaligned_le##bits(p + off); \ - return res; \ + read_extent_buffer(eb, &leres, member_offset, size); \ + return le##bits##_to_cpu(leres); \ } \ void btrfs_set_token_##bits(struct btrfs_map_token *token, \ const void *ptr, unsigned long off, \ |