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ca8b201f28
As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:
Chain exists of:
&sbi->cp_rwsem --> fs_reclaim --> sb_internal#2
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(sb_internal#2);
lock(fs_reclaim);
lock(sb_internal#2);
rlock(&sbi->cp_rwsem);
*** DEADLOCK ***
3 locks held by kswapd0/73:
#0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
#0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
#1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
#1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
#2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890
stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
evict+0x504/0x9c0 fs/inode.c:810
f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
evict+0x504/0x9c0 fs/inode.c:810
dispose_list fs/inode.c:852 [inline]
prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
super_cache_scan+0x39b/0x4b0 fs/super.c:224
do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
shrink_slab_memcg mm/shrinker.c:550 [inline]
shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
shrink_many mm/vmscan.c:5016 [inline]
lru_gen_shrink_node mm/vmscan.c:5094 [inline]
shrink_node+0x315d/0x3780 mm/vmscan.c:6081
kswapd_shrink_node mm/vmscan.c:6941 [inline]
balance_pgdat mm/vmscan.c:7124 [inline]
kswapd+0x147c/0x2800 mm/vmscan.c:7389
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
The root cause is deadlock among four locks as below:
kswapd
- fs_reclaim --- Lock A
- shrink_one
- evict
- f2fs_evict_inode
- sb_start_intwrite --- Lock B
- iput
- evict
- f2fs_evict_inode
- sb_start_intwrite --- Lock B
- f2fs_truncate
- f2fs_truncate_blocks
- f2fs_do_truncate_blocks
- f2fs_lock_op --- Lock C
ioctl
- f2fs_ioc_commit_atomic_write
- f2fs_lock_op --- Lock C
- __f2fs_commit_atomic_write
- __replace_atomic_write_block
- f2fs_get_dnode_of_data
- __get_node_folio
- f2fs_check_nid_range
- f2fs_handle_error
- f2fs_record_errors
- f2fs_down_write --- Lock D
open
- do_open
- do_truncate
- security_inode_need_killpriv
- f2fs_getxattr
- lookup_all_xattrs
- f2fs_handle_error
- f2fs_record_errors
- f2fs_down_write --- Lock D
- f2fs_commit_super
- read_mapping_folio
- filemap_alloc_folio_noprof
- prepare_alloc_pages
- fs_reclaim_acquire --- Lock A
In order to avoid such deadlock, we need to avoid grabbing sb_lock in
f2fs_handle_error(), so, let's use asynchronous method instead:
- remove f2fs_handle_error() implementation
- rename f2fs_handle_error_async() to f2fs_handle_error()
- spread f2fs_handle_error()
Fixes:
|
||
|---|---|---|
| .. | ||
| 9p | ||
| adfs | ||
| affs | ||
| afs | ||
| autofs | ||
| befs | ||
| bfs | ||
| btrfs | ||
| cachefiles | ||
| ceph | ||
| coda | ||
| configfs | ||
| cramfs | ||
| crypto | ||
| debugfs | ||
| devpts | ||
| dlm | ||
| ecryptfs | ||
| efivarfs | ||
| efs | ||
| erofs | ||
| exfat | ||
| exportfs | ||
| ext2 | ||
| ext4 | ||
| f2fs | ||
| fat | ||
| freevxfs | ||
| fuse | ||
| gfs2 | ||
| hfs | ||
| hfsplus | ||
| hostfs | ||
| hpfs | ||
| hugetlbfs | ||
| iomap | ||
| isofs | ||
| jbd2 | ||
| jffs2 | ||
| jfs | ||
| kernfs | ||
| lockd | ||
| minix | ||
| netfs | ||
| nfs | ||
| nfs_common | ||
| nfsd | ||
| nilfs2 | ||
| nls | ||
| notify | ||
| ntfs3 | ||
| ocfs2 | ||
| omfs | ||
| openpromfs | ||
| orangefs | ||
| overlayfs | ||
| proc | ||
| pstore | ||
| qnx4 | ||
| qnx6 | ||
| quota | ||
| ramfs | ||
| resctrl | ||
| romfs | ||
| smb | ||
| squashfs | ||
| sysfs | ||
| tests | ||
| tracefs | ||
| ubifs | ||
| udf | ||
| ufs | ||
| unicode | ||
| vboxsf | ||
| verity | ||
| xfs | ||
| zonefs | ||
| aio.c | ||
| anon_inodes.c | ||
| attr.c | ||
| backing-file.c | ||
| bad_inode.c | ||
| binfmt_elf_fdpic.c | ||
| binfmt_elf.c | ||
| binfmt_flat.c | ||
| binfmt_misc.c | ||
| binfmt_script.c | ||
| bpf_fs_kfuncs.c | ||
| buffer.c | ||
| char_dev.c | ||
| compat_binfmt_elf.c | ||
| coredump.c | ||
| d_path.c | ||
| dax.c | ||
| dcache.c | ||
| direct-io.c | ||
| drop_caches.c | ||
| eventfd.c | ||
| eventpoll.c | ||
| exec.c | ||
| fcntl.c | ||
| fhandle.c | ||
| file_attr.c | ||
| file_table.c | ||
| file.c | ||
| filesystems.c | ||
| fs_context.c | ||
| fs_parser.c | ||
| fs_pin.c | ||
| fs_struct.c | ||
| fs_types.c | ||
| fs-writeback.c | ||
| fsopen.c | ||
| init.c | ||
| inode.c | ||
| internal.h | ||
| ioctl.c | ||
| Kconfig | ||
| Kconfig.binfmt | ||
| kernel_read_file.c | ||
| libfs.c | ||
| locks.c | ||
| Makefile | ||
| mbcache.c | ||
| mnt_idmapping.c | ||
| mount.h | ||
| mpage.c | ||
| namei.c | ||
| namespace.c | ||
| nsfs.c | ||
| open.c | ||
| pidfs.c | ||
| pipe.c | ||
| pnode.c | ||
| pnode.h | ||
| posix_acl.c | ||
| proc_namespace.c | ||
| read_write.c | ||
| readdir.c | ||
| remap_range.c | ||
| select.c | ||
| seq_file.c | ||
| signalfd.c | ||
| splice.c | ||
| stack.c | ||
| stat.c | ||
| statfs.c | ||
| super.c | ||
| sync.c | ||
| sysctls.c | ||
| timerfd.c | ||
| userfaultfd.c | ||
| utimes.c | ||
| xattr.c | ||