diff options
Diffstat (limited to 'fs/btrfs/ctree.h')
| -rw-r--r-- | fs/btrfs/ctree.h | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index c4b829806855..30fbbd7221a9 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -22,6 +22,7 @@ #include <linux/fs.h> #include <linux/workqueue.h> #include <linux/completion.h> +#include <asm/kmap_types.h> #include "bit-radix.h" #include "extent_map.h" @@ -431,15 +432,52 @@ struct btrfs_root { static inline u##bits btrfs_##name(struct extent_buffer *eb, \ type *s) \ { \ - __le##bits res; \ - read_eb_member(eb, s, 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 = (unsigned long)s + \ + 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, s, type, member, &res); \ + return le##bits##_to_cpu(res); \ + } \ } \ static inline void btrfs_set_##name(struct extent_buffer *eb, \ type *s, u##bits val) \ { \ - val = cpu_to_le##bits(val); \ - write_eb_member(eb, s, type, member, &val); \ + int err; \ + char *map_token; \ + char *kaddr; \ + unsigned long map_start; \ + unsigned long map_len; \ + unsigned long offset = (unsigned long)s + \ + 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, s, type, member, &val); \ + } \ } #define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits) \ |