Robert Evans fdc683e863 dnode_next_offset: backtrack if lower level does not match ... This changes the basic search algorithm from a single search up and down the tree to a full depth-first traversal to handle conditions where the tree matches at a higher level but not a lower level. Normally higher level blocks always point to matching blocks, but there are cases where this does not happen: 1. Racing block pointer updates from dbuf_write_ready. Before f664f1ee7f (#8946), both dbuf_write_ready and dnode_next_offset held dn_struct_rwlock which protected against pointer writes from concurrent syncs. This no longer applies, so sync context can f.e. clear or fill all L1->L0 BPs before the L2->L1 BP and higher BP's are updated. dnode_free_range in particular can reach this case and skip over L1 blocks that need to be dirtied. Later, sync will panic in free_children when trying to clear a non-dirty indirect block. This case was found with ztest. 2. txg > 0, non-hole case. This is #11196. Freeing blocks/dnodes breaks the assumption that a match at a higher level implies a match at a lower level when filtering txg > 0. Whenever some but not all L0 blocks are freed, the parent L1 block is rewritten. Its updated L2->L1 BP reflects a newer birth txg. Later when searching by txg, if the L1 block matches since the txg is newer, it is possible that none of the remaining L1->L0 BPs match if none have been updated. The same behavior is possible with dnode search at L0. This is reachable from dsl_destroy_head for synchronous freeing. When this happens open context fails to free objects leaving sync context stuck freeing potentially many objects. This is also reachable from traverse_pool for extreme rewind where it is theoretically possible that datasets not dirtied after txg are skipped if the MOS has high enough indirection to trigger this case. In both of these cases, without backtracking the search ends prematurely as ESRCH result implies no more matches in the entire object. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Akash B <akash-b@hpe.com> Signed-off-by: Robert Evans <evansr@google.com> Closes #16025 Closes #11196		2025-10-21 11:31:06 -07:00
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avl	Suppress Clang Static Analyzer false positive in the AVL tree code.	2023-03-08 13:51:21 -08:00
icp	Linux build: silence objtool warnings	2025-06-04 17:40:56 -07:00
lua	lua: add flex array field to TString type	2024-11-05 15:43:52 -08:00
nvpair	xdr: header cleanup	2024-04-29 13:50:05 -07:00
os	[zfs-2.2.9] Fix zpl_ctldir.c checkstyle	2025-10-20 14:56:20 -07:00
unicode	Illumos #15286: do_composition() needs sign awareness	2023-01-05 11:16:21 -08:00
zcommon	GCC 15: Fix unterminated-string-initialization (#17244)	2025-05-27 15:03:11 -07:00
zfs	dnode_next_offset: backtrack if lower level does not match	2025-10-21 11:31:06 -07:00
zstd	Resolve WS-2021-0184 vulnerability in zstd	2023-02-02 15:12:51 -08:00
.gitignore	FreeBSD: Ignore symlink to i386 includes	2022-08-02 16:34:23 -07:00
Kbuild.in	Linux build: always use objtool	2025-05-30 15:08:01 -07:00
Makefile.bsd	zfs_znode: lift common code to a single shared file	2024-11-15 10:15:01 -08:00
Makefile.in	Linux build: handle CONFIG_OBJTOOL_WERROR=y	2025-10-16 16:50:20 -07:00