xfs: use interval query for rmap alloc operations on shared files

When it's possible for reverse mappings to overlap (data fork extents
of files on reflink filesystems), use the interval query function to
find the left neighbor of an extent we're trying to add; and be
careful to use the lookup functions to update the neighbors and/or
add new extents.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_rmap.h

@@ -206,4 +206,11 @@ int xfs_rmap_finish_one(struct xfs_trans *tp, enum xfs_rmap_intent_type type,
 		xfs_fsblock_t startblock, xfs_filblks_t blockcount,
 		xfs_exntst_t state, struct xfs_btree_cur **pcur);
 
+int xfs_rmap_find_left_neighbor(struct xfs_btree_cur *cur, xfs_agblock_t bno,
+		uint64_t owner, uint64_t offset, unsigned int flags,
+		struct xfs_rmap_irec *irec, int	*stat);
+int xfs_rmap_lookup_le_range(struct xfs_btree_cur *cur, xfs_agblock_t bno,
+		uint64_t owner, uint64_t offset, unsigned int flags,
+		struct xfs_rmap_irec *irec, int	*stat);
+
 #endif	/* __XFS_RMAP_H__ */

fs/xfs/xfs_rmap_item.c

@@ -484,9 +484,15 @@ xfs_rui_recover(
 		case XFS_RMAP_EXTENT_MAP:
 			type = XFS_RMAP_MAP;
 			break;
+		case XFS_RMAP_EXTENT_MAP_SHARED:
+			type = XFS_RMAP_MAP_SHARED;
+			break;
 		case XFS_RMAP_EXTENT_UNMAP:
 			type = XFS_RMAP_UNMAP;
 			break;
+		case XFS_RMAP_EXTENT_UNMAP_SHARED:
+			type = XFS_RMAP_UNMAP_SHARED;
+			break;
 		case XFS_RMAP_EXTENT_CONVERT:
 			type = XFS_RMAP_CONVERT;
 			break;

fs/xfs/xfs_trace.h

@@ -2588,6 +2588,11 @@ DEFINE_RMAPBT_EVENT(xfs_rmap_delete);
 DEFINE_AG_ERROR_EVENT(xfs_rmap_insert_error);
 DEFINE_AG_ERROR_EVENT(xfs_rmap_delete_error);
 DEFINE_AG_ERROR_EVENT(xfs_rmap_update_error);
+
+DEFINE_RMAPBT_EVENT(xfs_rmap_find_left_neighbor_candidate);
+DEFINE_RMAPBT_EVENT(xfs_rmap_find_left_neighbor_query);
+DEFINE_RMAPBT_EVENT(xfs_rmap_lookup_le_range_candidate);
+DEFINE_RMAPBT_EVENT(xfs_rmap_lookup_le_range);
 DEFINE_RMAPBT_EVENT(xfs_rmap_lookup_le_range_result);
 DEFINE_RMAPBT_EVENT(xfs_rmap_find_right_neighbor_result);
 DEFINE_RMAPBT_EVENT(xfs_rmap_find_left_neighbor_result);