diff options
Diffstat (limited to 'fs/ocfs2/ocfs2_fs.h')
| -rw-r--r-- | fs/ocfs2/ocfs2_fs.h | 53 |
1 files changed, 46 insertions, 7 deletions
diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h index d61a1521b10..448aa8d11a9 100644 --- a/fs/ocfs2/ocfs2_fs.h +++ b/fs/ocfs2/ocfs2_fs.h @@ -165,6 +165,9 @@ /* Refcount tree support */ #define OCFS2_FEATURE_INCOMPAT_REFCOUNT_TREE 0x1000 +/* Discontigous block groups */ +#define OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG 0x2000 + /* * backup superblock flag is used to indicate that this volume * has backup superblocks. @@ -832,6 +835,13 @@ struct ocfs2_dx_leaf { }; /* + * Largest bitmap for a block (suballocator) group in bytes. This limit + * does not affect cluster groups (global allocator). Cluster group + * bitmaps run to the end of the block. + */ +#define OCFS2_MAX_BG_BITMAP_SIZE 256 + +/* * On disk allocator group structure for OCFS2 */ struct ocfs2_group_desc @@ -852,7 +862,29 @@ struct ocfs2_group_desc __le64 bg_blkno; /* Offset on disk, in blocks */ /*30*/ struct ocfs2_block_check bg_check; /* Error checking */ __le64 bg_reserved2; -/*40*/ __u8 bg_bitmap[0]; +/*40*/ union { + __u8 bg_bitmap[0]; + struct { + /* + * Block groups may be discontiguous when + * OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG is set. + * The extents of a discontigous block group are + * stored in bg_list. It is a flat list. + * l_tree_depth must always be zero. A + * discontiguous group is signified by a non-zero + * bg_list->l_next_free_rec. Only block groups + * can be discontiguous; Cluster groups cannot. + * We've never made a block group with more than + * 2048 blocks (256 bytes of bg_bitmap). This + * codifies that limit so that we can fit bg_list. + * bg_size of a discontiguous block group will + * be 256 to match bg_bitmap_filler. + */ + __u8 bg_bitmap_filler[OCFS2_MAX_BG_BITMAP_SIZE]; +/*140*/ struct ocfs2_extent_list bg_list; + }; + }; +/* Actual on-disk size is one block */ }; struct ocfs2_refcount_rec { @@ -1276,12 +1308,16 @@ static inline u16 ocfs2_local_alloc_size(struct super_block *sb) return size; } -static inline int ocfs2_group_bitmap_size(struct super_block *sb) +static inline int ocfs2_group_bitmap_size(struct super_block *sb, + int suballocator) { int size; - size = sb->s_blocksize - - offsetof(struct ocfs2_group_desc, bg_bitmap); + if (suballocator) + size = OCFS2_MAX_BG_BITMAP_SIZE; + else + size = sb->s_blocksize - + offsetof(struct ocfs2_group_desc, bg_bitmap); return size; } @@ -1404,12 +1440,15 @@ static inline int ocfs2_local_alloc_size(int blocksize) return size; } -static inline int ocfs2_group_bitmap_size(int blocksize) +static inline int ocfs2_group_bitmap_size(int blocksize, int suballocator) { int size; - size = blocksize - - offsetof(struct ocfs2_group_desc, bg_bitmap); + if (suballocator) + size = OCFS2_MAX_BG_BITMAP_SIZE; + else + size = blocksize - + offsetof(struct ocfs2_group_desc, bg_bitmap); return size; } |