Darrick J. Wong c0f399ff51 xfs: fix off-by-one error in xfs_btree_space_to_height ... Lately I've been stress-testing extreme-sized rmap btrees by using the (new) xfs_db bmap_inflate command to clone bmbt mappings billions of times and then using xfs_repair to build new rmap and refcount btrees. This of course is /much/ faster than actually FICLONEing a file billions of times. Unfortunately, xfs_repair fails in xfs_btree_bload_compute_geometry with EOVERFLOW, which indicates that xfs_mount.m_rmap_maxlevels is not sufficiently large for the test scenario. For a 1TB filesystem (~67 million AG blocks, 4 AGs) the btheight command reports: $ xfs_db -c 'btheight -n 4400801200 -w min rmapbt' /dev/sda rmapbt: worst case per 4096-byte block: 84 records (leaf) / 45 keyptrs (node) level 0: 4400801200 records, 52390491 blocks level 1: 52390491 records, 1164234 blocks level 2: 1164234 records, 25872 blocks level 3: 25872 records, 575 blocks level 4: 575 records, 13 blocks level 5: 13 records, 1 block 6 levels, 53581186 blocks total The AG is sufficiently large to build this rmap btree. Unfortunately, m_rmap_maxlevels is 5. Augmenting the loop in the space->height function to report height, node blocks, and blocks remaining produces this: ht 1 node_blocks 45 blockleft 67108863 ht 2 node_blocks 2025 blockleft 67108818 ht 3 node_blocks 91125 blockleft 67106793 ht 4 node_blocks 4100625 blockleft 67015668 final height: 5 The goal of this function is to compute the maximum height btree that can be stored in the given number of ondisk fsblocks. Starting with the top level of the tree, each iteration through the loop adds the fanout factor of the next level down until we run out of blocks. IOWs, maximum height is achieved by using the smallest fanout factor that can apply to that level. However, the loop setup is not correct. Top level btree blocks are allowed to contain fewer than minrecs items, so the computation is incorrect because the first time through the loop it should be using a fanout factor of 2. With this corrected, the above becomes: ht 1 node_blocks 2 blockleft 67108863 ht 2 node_blocks 90 blockleft 67108861 ht 3 node_blocks 4050 blockleft 67108771 ht 4 node_blocks 182250 blockleft 67104721 ht 5 node_blocks 8201250 blockleft 66922471 final height: 6 Fixes: 9ec691205e ("xfs: compute the maximum height of the rmap btree when reflink enabled") Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>		2023-01-03 10:23:07 -08:00
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xfs_ag.c
xfs_ag.h	xfs: create a predicate to verify per-AG extents	2022-10-31 08:58:20 -07:00
xfs_ag_resv.c
xfs_ag_resv.h
xfs_alloc.c	treewide: use get_random_u32_below() instead of deprecated function	2022-11-18 02:15:15 +01:00
xfs_alloc.h
xfs_alloc_btree.c
xfs_alloc_btree.h
xfs_attr.c
xfs_attr.h
xfs_attr_leaf.c	xfs: don't leak memory when attr fork loading fails	2022-07-20 16:40:39 -07:00
xfs_attr_leaf.h
xfs_attr_remote.c
xfs_attr_remote.h
xfs_attr_sf.h
xfs_bit.c
xfs_bit.h
xfs_bmap.c	xfs: invalidate xfs_bufs when allocating cow extents	2022-12-01 09:36:16 -08:00
xfs_bmap.h
xfs_bmap_btree.c
xfs_bmap_btree.h
xfs_btree.c	xfs: fix off-by-one error in xfs_btree_space_to_height	2023-01-03 10:23:07 -08:00
xfs_btree.h	xfs: get rid of assert from xfs_btree_islastblock	2022-12-01 09:36:16 -08:00
xfs_btree_staging.c
xfs_btree_staging.h
xfs_cksum.h
xfs_da_btree.c	xfs: trim the mapp array accordingly in xfs_da_grow_inode_int	2022-10-04 16:39:42 +11:00
xfs_da_btree.h
xfs_da_format.h
xfs_defer.c
xfs_defer.h
xfs_dir2.c	xfs: rearrange the logic and remove the broken comment for xfs_dir2_isxx	2022-10-04 16:39:58 +11:00
xfs_dir2.h	xfs: rearrange the logic and remove the broken comment for xfs_dir2_isxx	2022-10-04 16:39:58 +11:00
xfs_dir2_block.c
xfs_dir2_data.c
xfs_dir2_leaf.c	xfs: fix exception caused by unexpected illegal bestcount in leaf dir	2022-10-20 09:42:56 -07:00
xfs_dir2_node.c
xfs_dir2_priv.h
xfs_dir2_sf.c	xfs: Remove the unneeded result variable	2022-09-19 06:52:14 +10:00
xfs_dquot_buf.c
xfs_errortag.h	xfs: add debug knob to slow down write for fun	2022-11-28 17:54:49 -08:00
xfs_format.h	xfs: rename XFS_REFC_COW_START to _COWFLAG	2022-10-31 08:58:22 -07:00
xfs_fs.h
xfs_health.h
xfs_ialloc.c	treewide: use get_random_u32_below() instead of deprecated function	2022-11-18 02:15:15 +01:00
xfs_ialloc.h
xfs_ialloc_btree.c
xfs_ialloc_btree.h
xfs_iext_tree.c
xfs_inode_buf.c	xfs: make attr forks permanent	2022-07-14 09:46:37 -07:00
xfs_inode_buf.h
xfs_inode_fork.c	xfs: clean up "%Ld/%Lu" which doesn't meet C standard	2022-09-19 06:47:14 +10:00
xfs_inode_fork.h
xfs_log_format.h	xfs: refactor all the EFI/EFD log item sizeof logic	2022-10-31 08:58:20 -07:00
xfs_log_recover.h
xfs_log_rlimit.c
xfs_quota_defs.h
xfs_refcount.c	xfs: estimate post-merge refcounts correctly	2022-12-01 09:32:04 -08:00
xfs_refcount.h	xfs: rename XFS_REFC_COW_START to _COWFLAG	2022-10-31 08:58:22 -07:00
xfs_refcount_btree.c	xfs: track cow/shared record domains explicitly in xfs_refcount_irec	2022-10-31 08:58:21 -07:00
xfs_refcount_btree.h
xfs_rmap.c	xfs: create a predicate to verify per-AG extents	2022-10-31 08:58:20 -07:00
xfs_rmap.h
xfs_rmap_btree.c
xfs_rmap_btree.h
xfs_rtbitmap.c
xfs_sb.c	xfs: fix sb write verify for lazysbcount	2022-11-16 19:20:20 -08:00
xfs_sb.h
xfs_shared.h
xfs_symlink_remote.c
xfs_trans_inode.c
xfs_trans_resv.c	xfs: increase rename inode reservation	2022-10-26 13:02:24 -07:00
xfs_trans_resv.h
xfs_trans_space.h
xfs_types.c
xfs_types.h	xfs: report refcount domain in tracepoints	2022-10-31 08:58:21 -07:00