[syzbot] possible deadlock in fs_reclaim_acquire (4)

From: syzbot
Date: Tue Dec 06 2022 - 11:18:09 EST


Hello,

syzbot found the following issue on:

HEAD commit: a4412fdd49dc error-injection: Add prompt for function erro..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1418c55b880000
kernel config: https://syzkaller.appspot.com/x/.config?x=4aa2a38f1d88bd1c
dashboard link: https://syzkaller.appspot.com/bug?extid=9b9bbfea68487857fb9c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9b9bbfea68487857fb9c@xxxxxxxxxxxxxxxxxxxxxxxxx

======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc7-syzkaller-00123-ga4412fdd49dc #0 Not tainted
------------------------------------------------------
klogd/3144 is trying to acquire lock:
ffff88801ef6d090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0x100 fs/reiserfs/lock.c:27

but task is already holding lock:
ffffffff8c6c9a40 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4755 [inline]
ffffffff8c6c9a40 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4780 [inline]
ffffffff8c6c9a40 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x808/0x23d0 mm/page_alloc.c:5186

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:4682 [inline]
fs_reclaim_acquire+0x11d/0x160 mm/page_alloc.c:4696
might_alloc include/linux/sched/mm.h:271 [inline]
slab_pre_alloc_hook mm/slab.h:710 [inline]
slab_alloc_node mm/slab.c:3241 [inline]
slab_alloc mm/slab.c:3265 [inline]
__kmem_cache_alloc_lru mm/slab.c:3442 [inline]
kmem_cache_alloc_lru+0x3e/0x7b0 mm/slab.c:3468
__d_alloc+0x32/0x980 fs/dcache.c:1769
d_alloc_anon fs/dcache.c:1868 [inline]
d_make_root+0x49/0x110 fs/dcache.c:2069
reiserfs_fill_super+0x12eb/0x2e90 fs/reiserfs/super.c:2083
mount_bdev+0x351/0x410 fs/super.c:1401
legacy_get_tree+0x109/0x220 fs/fs_context.c:610
vfs_get_tree+0x8d/0x2f0 fs/super.c:1531
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x132a/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x283/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&sbi->lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
lock_acquire kernel/locking/lockdep.c:5668 [inline]
lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747
reiserfs_write_lock+0x79/0x100 fs/reiserfs/lock.c:27
reiserfs_dirty_inode+0xd2/0x260 fs/reiserfs/super.c:704
__mark_inode_dirty+0x247/0x11e0 fs/fs-writeback.c:2408
mark_inode_dirty_sync include/linux/fs.h:2480 [inline]
iput.part.0+0x57/0x880 fs/inode.c:1770
iput+0x5c/0x80 fs/inode.c:1763
dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401
__dentry_kill+0x3c0/0x640 fs/dcache.c:607
shrink_dentry_list+0x240/0x800 fs/dcache.c:1201
prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282
super_cache_scan+0x33a/0x590 fs/super.c:104
do_shrink_slab+0x464/0xce0 mm/vmscan.c:842
shrink_slab_memcg mm/vmscan.c:911 [inline]
shrink_slab+0x388/0x660 mm/vmscan.c:990
shrink_node_memcgs mm/vmscan.c:6112 [inline]
shrink_node+0x93d/0x1f30 mm/vmscan.c:6141
shrink_zones mm/vmscan.c:6379 [inline]
do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:6441
try_to_free_pages+0x2e5/0x960 mm/vmscan.c:6676
__perform_reclaim mm/page_alloc.c:4758 [inline]
__alloc_pages_direct_reclaim mm/page_alloc.c:4780 [inline]
__alloc_pages_slowpath.constprop.0+0x8b6/0x23d0 mm/page_alloc.c:5186
__alloc_pages+0x4aa/0x5b0 mm/page_alloc.c:5571
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285
folio_alloc+0x20/0x70 mm/mempolicy.c:2295
filemap_alloc_folio+0x30a/0x3a0 mm/filemap.c:971
__filemap_get_folio+0x32c/0xd90 mm/filemap.c:1965
filemap_fault+0x15aa/0x2400 mm/filemap.c:3145
__do_fault+0x107/0x600 mm/memory.c:4203
do_read_fault mm/memory.c:4554 [inline]
do_fault mm/memory.c:4683 [inline]
handle_pte_fault mm/memory.c:4955 [inline]
__handle_mm_fault+0x2184/0x3a40 mm/memory.c:5097
handle_mm_fault+0x1cc/0x780 mm/memory.c:5218
do_user_addr_fault+0x475/0x1210 arch/x86/mm/fault.c:1428
handle_page_fault arch/x86/mm/fault.c:1519 [inline]
exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1575
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(&sbi->lock);
lock(fs_reclaim);
lock(&sbi->lock);

*** DEADLOCK ***

4 locks held by klogd/3144:
#0: ffff8880210a28a0 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
#0: ffff8880210a28a0 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_fault+0x1564/0x2400 mm/filemap.c:3142
#1: ffffffff8c6c9a40 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4755 [inline]
#1: ffffffff8c6c9a40 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4780 [inline]
#1: ffffffff8c6c9a40 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x808/0x23d0 mm/page_alloc.c:5186
#2: ffffffff8c688470 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab_memcg mm/vmscan.c:884 [inline]
#2: ffffffff8c688470 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x2a0/0x660 mm/vmscan.c:990
#3: ffff88801c1200e0 (&type->s_umount_key#63){++++}-{3:3}, at: trylock_super fs/super.c:415 [inline]
#3: ffff88801c1200e0 (&type->s_umount_key#63){++++}-{3:3}, at: super_cache_scan+0x70/0x590 fs/super.c:79

stack backtrace:
CPU: 2 PID: 3144 Comm: klogd Not tainted 6.1.0-rc7-syzkaller-00123-ga4412fdd49dc #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain kernel/locking/lockdep.c:3831 [inline]
__lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
lock_acquire kernel/locking/lockdep.c:5668 [inline]
lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747
reiserfs_write_lock+0x79/0x100 fs/reiserfs/lock.c:27
reiserfs_dirty_inode+0xd2/0x260 fs/reiserfs/super.c:704
__mark_inode_dirty+0x247/0x11e0 fs/fs-writeback.c:2408
mark_inode_dirty_sync include/linux/fs.h:2480 [inline]
iput.part.0+0x57/0x880 fs/inode.c:1770
iput+0x5c/0x80 fs/inode.c:1763
dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401
__dentry_kill+0x3c0/0x640 fs/dcache.c:607
shrink_dentry_list+0x240/0x800 fs/dcache.c:1201
prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282
super_cache_scan+0x33a/0x590 fs/super.c:104
do_shrink_slab+0x464/0xce0 mm/vmscan.c:842
shrink_slab_memcg mm/vmscan.c:911 [inline]
shrink_slab+0x388/0x660 mm/vmscan.c:990
shrink_node_memcgs mm/vmscan.c:6112 [inline]
shrink_node+0x93d/0x1f30 mm/vmscan.c:6141
shrink_zones mm/vmscan.c:6379 [inline]
do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:6441
try_to_free_pages+0x2e5/0x960 mm/vmscan.c:6676
__perform_reclaim mm/page_alloc.c:4758 [inline]
__alloc_pages_direct_reclaim mm/page_alloc.c:4780 [inline]
__alloc_pages_slowpath.constprop.0+0x8b6/0x23d0 mm/page_alloc.c:5186
__alloc_pages+0x4aa/0x5b0 mm/page_alloc.c:5571
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2285
folio_alloc+0x20/0x70 mm/mempolicy.c:2295
filemap_alloc_folio+0x30a/0x3a0 mm/filemap.c:971
__filemap_get_folio+0x32c/0xd90 mm/filemap.c:1965
filemap_fault+0x15aa/0x2400 mm/filemap.c:3145
__do_fault+0x107/0x600 mm/memory.c:4203
do_read_fault mm/memory.c:4554 [inline]
do_fault mm/memory.c:4683 [inline]
handle_pte_fault mm/memory.c:4955 [inline]
__handle_mm_fault+0x2184/0x3a40 mm/memory.c:5097
handle_mm_fault+0x1cc/0x780 mm/memory.c:5218
do_user_addr_fault+0x475/0x1210 arch/x86/mm/fault.c:1428
handle_page_fault arch/x86/mm/fault.c:1519 [inline]
exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1575
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7fb9df1a0df1
Code: Unable to access opcode bytes at 0x7fb9df1a0dc7.
RSP: 002b:00007ffd6af99d40 EFLAGS: 00010206
RAX: 0000000000000003 RBX: 0000000000000000 RCX: 0000000000000006
RDX: 00007fb9df2626c6 RSI: 00007fb9df26423e RDI: 00007fb9df2626c6
RBP: 0000559d3192c2e4 R08: 0000000000000001 R09: 00007ffd6af99e5f
R10: 0000000000000000 R11: 0000559d3192c2e4 R12: 00000000ffffffff
R13: 0000000000000000 R14: 00007fb9df26423e R15: 0000000000000000
</TASK>


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