xfs: introduce rmap btree definitions
Originally-From: Dave Chinner <dchinner@redhat.com>
Add new per-ag rmap btree definitions to the per-ag structures. The
rmap btree will sit in the empty slots on disk after the free space
btrees, and hence form a part of the array of space management
btrees. This requires the definition of the btree to be contiguous
with the free space btrees.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index adb204d..74f4d3d 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -455,6 +455,7 @@
}
#define XFS_SB_FEAT_RO_COMPAT_FINOBT (1 << 0) /* free inode btree */
+#define XFS_SB_FEAT_RO_COMPAT_RMAPBT (1 << 1) /* reverse map btree */
#define XFS_SB_FEAT_RO_COMPAT_ALL \
(XFS_SB_FEAT_RO_COMPAT_FINOBT)
#define XFS_SB_FEAT_RO_COMPAT_UNKNOWN ~XFS_SB_FEAT_RO_COMPAT_ALL
@@ -538,6 +539,12 @@
(sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID);
}
+static inline bool xfs_sb_version_hasrmapbt(struct xfs_sb *sbp)
+{
+ return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
+ (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT);
+}
+
/*
* end of superblock version macros
*/
@@ -598,10 +605,10 @@
#define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
/*
- * Btree number 0 is bno, 1 is cnt. This value gives the size of the
+ * Btree number 0 is bno, 1 is cnt, 2 is rmap. This value gives the size of the
* arrays below.
*/
-#define XFS_BTNUM_AGF ((int)XFS_BTNUM_CNTi + 1)
+#define XFS_BTNUM_AGF ((int)XFS_BTNUM_RMAPi + 1)
/*
* The second word of agf_levels in the first a.g. overlaps the EFS
@@ -618,12 +625,10 @@
__be32 agf_seqno; /* sequence # starting from 0 */
__be32 agf_length; /* size in blocks of a.g. */
/*
- * Freespace information
+ * Freespace and rmap information
*/
__be32 agf_roots[XFS_BTNUM_AGF]; /* root blocks */
- __be32 agf_spare0; /* spare field */
__be32 agf_levels[XFS_BTNUM_AGF]; /* btree levels */
- __be32 agf_spare1; /* spare field */
__be32 agf_flfirst; /* first freelist block's index */
__be32 agf_fllast; /* last freelist block's index */
@@ -1308,6 +1313,13 @@
#define XFS_FIBT_BLOCK(mp) ((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
/*
+ * Reverse mapping btree format definitions
+ *
+ * There is a btree for the reverse map per allocation group
+ */
+#define XFS_RMAP_CRC_MAGIC 0x524d4233 /* 'RMB3' */
+
+/*
* The first data block of an AG depends on whether the filesystem was formatted
* with the finobt feature. If so, account for the finobt reserved root btree
* block.