[v5.15] possible deadlock in ext4_evict_inode (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 574362648507 Linux 5.15.151
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14f59b82180000
kernel config: https://syzkaller.appspot.com/x/.config?x=6c9a42d9e3519ca9
dashboard link: https://syzkaller.appspot.com/bug?extid=b86b556e2f73dd217d29
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f00d4062000b/disk-57436264.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3a74c2b6ca62/vmlinux-57436264.xz
kernel image: https://storage.googleapis.com/syzbot-assets/93bd706dc219/bzImage-57436264.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b86b55...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.15.151-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/25866 is trying to acquire lock:
ffff8880219c0650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1787 [inline]
ffff8880219c0650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1904 [inline]
ffff8880219c0650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x375/0x1100 fs/ext4/inode.c:243

but task is already holding lock:
ffff8880219c2bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x314/0x12f0 fs/ext4/migrate.c:438

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&sbi->s_writepages_rwsem){++++}-{0:0}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
ext4_writepages+0x1f6/0x3d10 fs/ext4/inode.c:2677
do_writepages+0x481/0x730 mm/page-writeback.c:2364
filemap_fdatawrite_wbc+0x1d6/0x230 mm/filemap.c:400
__filemap_fdatawrite_range mm/filemap.c:433 [inline]
filemap_write_and_wait_range+0x19e/0x280 mm/filemap.c:704
__iomap_dio_rw+0x897/0x1f40 fs/iomap/direct-io.c:557
iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:672
ext4_dio_read_iter fs/ext4/file.c:77 [inline]
ext4_file_read_iter+0x530/0x6c0 fs/ext4/file.c:128
call_read_iter include/linux/fs.h:2142 [inline]
generic_file_splice_read+0x4ad/0x790 fs/splice.c:311
do_splice_to fs/splice.c:796 [inline]
splice_direct_to_actor+0x448/0xc10 fs/splice.c:870
do_splice_direct+0x285/0x3d0 fs/splice.c:979
do_sendfile+0x625/0xff0 fs/read_write.c:1249
__do_sys_sendfile64 fs/read_write.c:1317 [inline]
__se_sys_sendfile64+0x178/0x1e0 fs/read_write.c:1303
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #2 (&sb->s_type->i_mutex_key#9){++++}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
down_read+0x45/0x2e0 kernel/locking/rwsem.c:1488
inode_lock_shared include/linux/fs.h:799 [inline]
ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3152
bmap+0xa1/0xd0 fs/inode.c:1756
jbd2_journal_bmap fs/jbd2/journal.c:980 [inline]
__jbd2_journal_erase fs/jbd2/journal.c:1790 [inline]
jbd2_journal_flush+0x7a2/0xc90 fs/jbd2/journal.c:2496
ext4_ioctl_checkpoint fs/ext4/ioctl.c:849 [inline]
__ext4_ioctl fs/ext4/ioctl.c:1267 [inline]
ext4_ioctl+0x3249/0x5b80 fs/ext4/ioctl.c:1276
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #1 (&journal->j_checkpoint_mutex){+.+.}-{3:3}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
mutex_lock_io_nested+0x45/0x60 kernel/locking/mutex.c:777
__jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:71
add_transaction_credits+0x950/0xc00 fs/jbd2/transaction.c:299
start_this_handle+0x747/0x1570 fs/jbd2/transaction.c:423
jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:521
__ext4_journal_start_sb+0x175/0x370 fs/ext4/ext4_jbd2.c:105
__ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
ext4_evict_inode+0x7dd/0x1100 fs/ext4/inode.c:254
evict+0x2a4/0x620 fs/inode.c:587
do_unlinkat+0x508/0x950 fs/namei.c:4355
__do_sys_unlink fs/namei.c:4396 [inline]
__se_sys_unlink fs/namei.c:4394 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4394
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb

-> #0 (sb_internal){.+.+}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
__sb_start_write include/linux/fs.h:1787 [inline]
sb_start_intwrite include/linux/fs.h:1904 [inline]
ext4_evict_inode+0x375/0x1100 fs/ext4/inode.c:243
evict+0x2a4/0x620 fs/inode.c:587
ext4_ext_migrate+0x100b/0x12f0 fs/ext4/migrate.c:588
__ext4_ioctl fs/ext4/ioctl.c:1028 [inline]
ext4_ioctl+0x1935/0x5b80 fs/ext4/ioctl.c:1276
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb

other info that might help us debug this:

Chain exists of:
sb_internal --> &sb->s_type->i_mutex_key#9 --> &sbi->s_writepages_rwsem

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&sbi->s_writepages_rwsem);
lock(&sb->s_type->i_mutex_key#9);
lock(&sbi->s_writepages_rwsem);
lock(sb_internal);

*** DEADLOCK ***

3 locks held by syz-executor.3/25866:
#0: ffff8880219c0460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:421
#1: ffff8880316edda8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
#1: ffff8880316edda8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: __ext4_ioctl fs/ext4/ioctl.c:1027 [inline]
#1: ffff8880316edda8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_ioctl+0x192d/0x5b80 fs/ext4/ioctl.c:1276
#2: ffff8880219c2bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x314/0x12f0 fs/ext4/migrate.c:438

stack backtrace:
CPU: 0 PID: 25866 Comm: syz-executor.3 Not tainted 5.15.151-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
__sb_start_write include/linux/fs.h:1787 [inline]
sb_start_intwrite include/linux/fs.h:1904 [inline]
ext4_evict_inode+0x375/0x1100 fs/ext4/inode.c:243
evict+0x2a4/0x620 fs/inode.c:587
ext4_ext_migrate+0x100b/0x12f0 fs/ext4/migrate.c:588
__ext4_ioctl fs/ext4/ioctl.c:1028 [inline]
ext4_ioctl+0x1935/0x5b80 fs/ext4/ioctl.c:1276
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fdbd9e18da9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdbd83990c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdbd9f46f80 RCX: 00007fdbd9e18da9
RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000003
RBP: 00007fdbd9e6547a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fdbd9f46f80 R15: 00007fff5a2a4208
</TASK>


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