syzbot

loop0: detected capacity change from 0 to 65534
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BUG: KCSAN: data-race in lbmIODone / lbmRead

write to 0xffff88803fc9c088 of 4 bytes by interrupt on cpu 1:
 lbmIODone+0x7b/0xc20 fs/jfs/jfs_logmgr.c:2193
 bio_endio+0x2d6/0x3a0 block/bio.c:1451
 req_bio_endio block/blk-core.c:265 [inline]
 blk_update_request+0x4f5/0xb40 block/blk-core.c:1456
 blk_mq_end_request+0x22/0x50 block/blk-mq.c:564
 lo_complete_rq+0xca/0x180 drivers/block/loop.c:497
 blk_complete_reqs block/blk-mq.c:576 [inline]
 blk_done_softirq+0x69/0x90 block/blk-mq.c:581
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:345
 run_ksoftirqd+0x13/0x20 kernel/softirq.c:652
 smpboot_thread_fn+0x34f/0x520 kernel/smpboot.c:165
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff88803fc9c088 of 4 bytes by task 17398 on cpu 0:
 lbmRead+0x2a7/0x370 fs/jfs/jfs_logmgr.c:2001
 lmLogInit+0x51b/0xe40 fs/jfs/jfs_logmgr.c:1298
 open_inline_log fs/jfs/jfs_logmgr.c:1183 [inline]
 lmLogOpen+0x2f1/0xa30 fs/jfs/jfs_logmgr.c:1077
 jfs_mount_rw+0x7e/0x320 fs/jfs/jfs_mount.c:260
 jfs_fill_super+0x3a5/0x710 fs/jfs/super.c:570
 mount_bdev+0x1e8/0x290 fs/super.c:1367
 jfs_do_mount+0x2d/0x40 fs/jfs/super.c:675
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:592
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1497
 do_new_mount fs/namespace.c:2903 [inline]
 path_mount+0x11b9/0x1c00 fs/namespace.c:3233
 do_mount fs/namespace.c:3246 [inline]
 __do_sys_mount fs/namespace.c:3454 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3431
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3431
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17398 Comm: syz-executor.0 Tainted: G        W         5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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