diff options
Diffstat (limited to 'fs/btrfs/struct-funcs.c')
| -rw-r--r-- | fs/btrfs/struct-funcs.c | 73 |
1 files changed, 61 insertions, 12 deletions
diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c index 4c13b737f568..73f7987143df 100644 --- a/fs/btrfs/struct-funcs.c +++ b/fs/btrfs/struct-funcs.c @@ -33,6 +33,8 @@ static inline void put_unaligned_le8(u8 val, void *p) * * The extent buffer api is used to do the page spanning work required to * have a metadata blocksize different from the page size. + * + * There are 2 variants defined, one with a token pointer and one without. */ #define DEFINE_BTRFS_SETGET_BITS(bits) \ @@ -50,8 +52,10 @@ u##bits btrfs_get_token_##bits(const struct extent_buffer *eb, \ int size = sizeof(u##bits); \ u##bits res; \ \ - if (token && token->kaddr && token->offset <= offset && \ - token->eb == eb && \ + ASSERT(token); \ + ASSERT(token->eb == eb); \ + \ + if (token->kaddr && token->offset <= offset && \ (token->offset + PAGE_SIZE >= offset + size)) { \ kaddr = token->kaddr; \ p = kaddr + part_offset - token->offset; \ @@ -68,11 +72,33 @@ u##bits btrfs_get_token_##bits(const struct extent_buffer *eb, \ } \ p = kaddr + part_offset - map_start; \ res = get_unaligned_le##bits(p + off); \ - if (token) { \ - token->kaddr = kaddr; \ - token->offset = map_start; \ - token->eb = eb; \ + token->kaddr = kaddr; \ + token->offset = map_start; \ + return res; \ +} \ +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; \ + \ + 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); \ } \ + p = kaddr + part_offset - map_start; \ + res = get_unaligned_le##bits(p + off); \ return res; \ } \ void btrfs_set_token_##bits(struct extent_buffer *eb, \ @@ -89,8 +115,10 @@ void btrfs_set_token_##bits(struct extent_buffer *eb, \ unsigned long map_len; \ int size = sizeof(u##bits); \ \ - if (token && token->kaddr && token->offset <= offset && \ - token->eb == eb && \ + ASSERT(token); \ + ASSERT(token->eb == eb); \ + \ + if (token->kaddr && token->offset <= offset && \ (token->offset + PAGE_SIZE >= offset + size)) { \ kaddr = token->kaddr; \ p = kaddr + part_offset - token->offset; \ @@ -108,11 +136,32 @@ void btrfs_set_token_##bits(struct extent_buffer *eb, \ } \ p = kaddr + part_offset - map_start; \ put_unaligned_le##bits(val, p + off); \ - if (token) { \ - token->kaddr = kaddr; \ - token->offset = map_start; \ - token->eb = eb; \ + token->kaddr = kaddr; \ + token->offset = map_start; \ +} \ +void btrfs_set_##bits(struct extent_buffer *eb, void *ptr, \ + unsigned long off, u##bits val) \ +{ \ + 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); \ + \ + err = map_private_extent_buffer(eb, offset, size, \ + &kaddr, &map_start, &map_len); \ + if (err) { \ + __le##bits val2; \ + \ + val2 = cpu_to_le##bits(val); \ + write_extent_buffer(eb, &val2, offset, size); \ + return; \ } \ + p = kaddr + part_offset - map_start; \ + put_unaligned_le##bits(val, p + off); \ } DEFINE_BTRFS_SETGET_BITS(8) |