Re: [syzbot] [reiserfs?] possible deadlock in super_lock

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in fs_bdev_sync

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6681 at fs/super.c:1464 fs_bdev_sync+0x138/0x168 fs/super.c:1464
Modules linked in:
CPU: 0 PID: 6681 Comm: syz-executor.4 Not tainted 6.6.0-rc5-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : fs_bdev_sync+0x138/0x168 fs/super.c:1464
lr : fs_bdev_sync+0x138/0x168 fs/super.c:1464
sp : ffff800097637a70
x29: ffff800097637a70 x28: ffff0000d6699bc0 x27: 0000000000000003
x26: dfff800000000000 x25: ffff700012ec6f58 x24: ffff800097637ac0
x23: 0000000000001261 x22: dfff800000000000 x21: 0000000000000001
x20: 0000000000000000 x19: ffff0000c657c000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008031d534 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 00000000c0101282
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff0000d6699bc0 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000040 x4 : ffffffffffffffff x3 : 0000000000000000
x2 : 0000000000000015 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 fs_bdev_sync+0x138/0x168 fs/super.c:1464
 blkdev_flushbuf block/ioctl.c:371 [inline]
 blkdev_common_ioctl+0x838/0x286c block/ioctl.c:500
 blkdev_ioctl+0x35c/0xae4 block/ioctl.c:622
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:857
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 116
hardirqs last  enabled at (115): [<ffff8000809cd760>] kasan_quarantine_put+0x1a0/0x1c8 mm/kasan/quarantine.c:240
hardirqs last disabled at (116): [<ffff80008a630728>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:436
softirqs last  enabled at (92): [<ffff800080033cf4>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (90): [<ffff800080033cc0>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---


Tested on:

commit:         94f6f055 Linux 6.6-rc5
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=129ec4e9680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1b8c825e0d5f3f72
dashboard link: https://syzkaller.appspot.com/bug?extid=062317ea1d0a6d5e29e7
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=156813ee680000