#define OCFS2_CLEAR_INCOMPAT_FEATURE(sb,mask) \
OCFS2_SB(sb)->s_feature_incompat &= ~(mask)
-#define OCFS2_FEATURE_COMPAT_SUPP 0
+#define OCFS2_FEATURE_COMPAT_SUPP OCFS2_FEATURE_COMPAT_BACKUP_SB
#define OCFS2_FEATURE_INCOMPAT_SUPP OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT
#define OCFS2_FEATURE_RO_COMPAT_SUPP 0
/* Support for sparse allocation in b-trees */
#define OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC 0x0010
+/*
+ * backup superblock flag is used to indicate that this volume
+ * has backup superblocks.
+ */
+#define OCFS2_FEATURE_COMPAT_BACKUP_SB 0x0001
+
+/* The byte offset of the first backup block will be 1G.
+ * The following will be 4G, 16G, 64G, 256G and 1T.
+ */
+#define OCFS2_BACKUP_SB_START 1 << 30
+
+/* the max backup superblock nums */
+#define OCFS2_MAX_BACKUP_SUPERBLOCKS 6
+
/*
* Flags on ocfs2_dinode.i_flags
*/
return size / sizeof(struct ocfs2_truncate_rec);
}
+
+static inline u64 ocfs2_backup_super_blkno(struct super_block *sb, int index)
+{
+ u64 offset = OCFS2_BACKUP_SB_START;
+
+ if (index >= 0 && index < OCFS2_MAX_BACKUP_SUPERBLOCKS) {
+ offset <<= (2 * index);
+ offset /= sb->s_blocksize;
+ return offset;
+ }
+
+ return 0;
+
+}
#else
static inline int ocfs2_fast_symlink_chars(int blocksize)
{
return size / sizeof(struct ocfs2_truncate_rec);
}
+
+static inline uint64_t ocfs2_backup_super_blkno(int blocksize, int index)
+{
+ uint64_t offset = OCFS2_BACKUP_SB_START;
+
+ if (index >= 0 && index < OCFS2_MAX_BACKUP_SUPERBLOCKS) {
+ offset <<= (2 * index);
+ offset /= blocksize;
+ return offset;
+ }
+
+ return 0;
+}
#endif /* __KERNEL__ */