KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup

KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent (4)
Status: auto-closed as invalid on 2021/02/22 02:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 279d, last: 279d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent (3)	2	400d	408d	0/22	auto-closed as invalid on 2020/10/24 21:16
upstream	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent (2)	1	552d	552d	0/22	auto-closed as invalid on 2020/06/18 13:13
upstream	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent	1	639d	639d	0/22	auto-closed as invalid on 2020/04/03 02:12

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent

write to 0xffff888016b91bb0 of 8 bytes by task 6899 on cpu 0:
 ext4_es_set_referenced fs/ext4/extents_status.h:194 [inline]
 ext4_es_lookup_extent+0x2f7/0x500 fs/ext4/extents_status.c:968
 ext4_map_blocks+0x105/0xfc0 fs/ext4/inode.c:529
 mpage_map_one_extent+0x10d/0x390 fs/ext4/inode.c:2396
 mpage_map_and_submit_extent fs/ext4/inode.c:2449 [inline]
 ext4_writepages+0xa51/0x1e50 fs/ext4/inode.c:2801
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:422
 __filemap_fdatawrite mm/filemap.c:430 [inline]
 filemap_flush+0x1f/0x30 mm/filemap.c:457
 ext4_alloc_da_blocks+0x4a/0x100 fs/ext4/inode.c:3165
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:142
 __fput+0x24b/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x16b/0x1a0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888016b91bb0 of 8 bytes by task 6900 on cpu 1:
 ext4_es_type fs/ext4/extents_status.h:159 [inline]
 ext4_es_is_delayed+0x12/0x20 fs/ext4/extents_status.h:174
 __es_find_extent_range+0x1d5/0x330 fs/ext4/extents_status.c:285
 ext4_es_find_extent_range+0x8a/0x200 fs/ext4/extents_status.c:320
 ext4_ext_put_gap_in_cache fs/ext4/extents.c:2237 [inline]
 ext4_ext_map_blocks+0xb96/0x1fc0 fs/ext4/extents.c:4143
 ext4_da_map_blocks fs/ext4/inode.c:1758 [inline]
 ext4_da_get_block_prep+0x428/0x9a0 fs/ext4/inode.c:1835
 ext4_block_write_begin+0x414/0xc00 fs/ext4/inode.c:1077
 ext4_da_write_begin+0x50a/0xaf0 fs/ext4/inode.c:3016
 generic_perform_write+0x196/0x3a0 mm/filemap.c:3408
 ext4_buffered_write_iter+0x2e5/0x3d0 fs/ext4/file.c:270
 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x42a/0x780 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:933
 splice_direct_to_actor+0x345/0x650 fs/splice.c:888
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5db/0xca0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6900 Comm: syz-executor.4 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/01/18 02:10	upstream	0da0a8a0a0e1	fd103621	.config	log	report			info	KCSAN: data-race in ext4_es_is_delayed / ext4_es_lookup_extent