Commit 4c175af2 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: check that bc_nlevels never overflows 



Warn if we ever bump nlevels higher than the allowed maximum cursor
height.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChandan Babu R <chandan.babu@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 1ba6fd34

fs/xfs/libxfs/xfs_btree.c

+2 −0
Original line number Diff line number Diff line
@@ -2933,6 +2933,7 @@ xfs_btree_new_iroot( 
	be16_add_cpu(&block->bb_level, 1);

	xfs_btree_set_numrecs(block, 1);

	cur->bc_nlevels++;

	ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);

	cur->bc_ptrs[level + 1] = 1;



	kp = xfs_btree_key_addr(cur, 1, block);
@@ -3096,6 +3097,7 @@ xfs_btree_new_root( 
	xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);

	cur->bc_ptrs[cur->bc_nlevels] = nptr;

	cur->bc_nlevels++;

	ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);

	*stat = 1;

	return 0;

error0:

fs/xfs/libxfs/xfs_btree_staging.c

+2 −0
Original line number Diff line number Diff line
@@ -703,6 +703,7 @@ xfs_btree_bload_compute_geometry( 
			 * block-based btree level.

			 */

			cur->bc_nlevels++;

			ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);

			xfs_btree_bload_level_geometry(cur, bbl, level,

					nr_this_level, &avg_per_block,

					&level_blocks, &dontcare64);
@@ -718,6 +719,7 @@ xfs_btree_bload_compute_geometry( 


			/* Otherwise, we need another level of btree. */

			cur->bc_nlevels++;

			ASSERT(cur->bc_nlevels <= XFS_BTREE_MAXLEVELS);

		}



		nr_blocks += level_blocks;