diff options
Diffstat (limited to 'fs/btrfs/ctree.h')
| -rw-r--r-- | fs/btrfs/ctree.h | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 30fbbd7221a9..aed08618aca6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -483,15 +483,50 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ #define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits) \ static inline u##bits btrfs_##name(struct extent_buffer *eb) \ { \ - __le##bits res; \ - read_eb_member(eb, NULL, type, member, &res); \ - return le##bits##_to_cpu(res); \ + int err; \ + char *map_token; \ + char *kaddr; \ + unsigned long map_start; \ + unsigned long map_len; \ + unsigned long offset = offsetof(type, member); \ + err = map_extent_buffer(eb, offset, \ + sizeof(((type *)0)->member), \ + &map_token, &kaddr, \ + &map_start, &map_len, KM_USER0); \ + if (!err) { \ + __le##bits *tmp = (__le##bits *)(kaddr + offset - \ + map_start); \ + u##bits res = le##bits##_to_cpu(*tmp); \ + unmap_extent_buffer(eb, map_token, KM_USER0); \ + return res; \ + } else { \ + __le##bits res; \ + read_eb_member(eb, NULL, type, member, &res); \ + return le##bits##_to_cpu(res); \ + } \ } \ static inline void btrfs_set_##name(struct extent_buffer *eb, \ u##bits val) \ { \ - val = cpu_to_le##bits(val); \ - write_eb_member(eb, NULL, type, member, &val); \ + int err; \ + char *map_token; \ + char *kaddr; \ + unsigned long map_start; \ + unsigned long map_len; \ + unsigned long offset = offsetof(type, member); \ + err = map_extent_buffer(eb, offset, \ + sizeof(((type *)0)->member), \ + &map_token, &kaddr, \ + &map_start, &map_len, KM_USER0); \ + if (!err) { \ + __le##bits *tmp = (__le##bits *)(kaddr + offset - \ + map_start); \ + *tmp = cpu_to_le##bits(val); \ + unmap_extent_buffer(eb, map_token, KM_USER0); \ + } else { \ + val = cpu_to_le##bits(val); \ + write_eb_member(eb, NULL, type, member, &val); \ + } \ } #define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \ |