[PATCH AUTOSEL 4.19 142/146] f2fs: fix to flush all dirty inodes recovered in readonly fs

Sasha Levin
2018-10-31T23:41:58Z

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 1378752b9921e60749eaf18ec6c47b33f9001abb ]

generic/417 reported as blow:

------------[ cut here ]------------
kernel BUG at /home/yuchao/git/devf2fs/inode.c:695!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 21697 Comm: umount Tainted: G W O 4.18.0-rc2+ #39
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: f2fs_evict_inode+0x556/0x580 [f2fs]
Call Trace:
? _raw_spin_unlock+0x2c/0x50
evict+0xa8/0x170
dispose_list+0x34/0x40
evict_inodes+0x118/0x120
generic_shutdown_super+0x41/0x100
? rcu_read_lock_sched_held+0x97/0xa0
kill_block_super+0x22/0x50
kill_f2fs_super+0x6f/0x80 [f2fs]
deactivate_locked_super+0x3d/0x70
deactivate_super+0x40/0x60
cleanup_mnt+0x39/0x70
__cleanup_mnt+0x10/0x20
task_work_run+0x81/0xa0
exit_to_usermode_loop+0x59/0xa7
do_fast_syscall_32+0x1f5/0x22c
entry_SYSENTER_32+0x53/0x86
EIP: f2fs_evict_inode+0x556/0x580 [f2fs]

It can simply reproduced with scripts:

Enable quota feature during mkfs.

Testcase1:
1. mkfs.f2fs /dev/zram0
2. mount -t f2fs /dev/zram0 /mnt/f2fs
3. xfs_io -f /mnt/f2fs/file -c "pwrite 0 4k" -c "fsync"
4. godown /mnt/f2fs
5. umount /mnt/f2fs
6. mount -t f2fs -o ro /dev/zram0 /mnt/f2fs
7. umount /mnt/f2fs

Testcase2:
1. mkfs.f2fs /dev/zram0
2. mount -t f2fs /dev/zram0 /mnt/f2fs
3. touch /mnt/f2fs/file
4. create process[pid = x] do:
a) open /mnt/f2fs/file;
b) unlink /mnt/f2fs/file
5. godown -f /mnt/f2fs
6. kill process[pid = x]
7. umount /mnt/f2fs
8. mount -t f2fs -o ro /dev/zram0 /mnt/f2fs
9. umount /mnt/f2fs

The reason is: during recovery, i_{c,m}time of inode will be updated, then
the inode can be set dirty w/o being tracked in sbi->inode_list[DIRTY_META]
global list, so later write_checkpoint will not flush such dirty inode into
node page.

Once umount is called, sync_filesystem() in generic_shutdown_super() will
skip syncng dirty inodes due to sb_rdonly check, leaving dirty inodes
there.

To solve this issue, during umount, add remove SB_RDONLY flag in
sb->s_flags, to make sure sync_filesystem() will not be skipped.

Signed-off-by: Chao Yu <yuchao0@huawei.com>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/checkpoint.c | 2 ++
fs/f2fs/f2fs.h | 1 +
fs/f2fs/recovery.c | 14 +++++++++-----
fs/f2fs/super.c | 3 +++
4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index e8b6b89bddb8..59d0472013f4 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -696,6 +696,8 @@ int f2fs_recover_orphan_inodes(struct f2fs_sb_info *sbi)
/* clear Orphan Flag */
clear_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG);
out:
+ set_sbi_flag(sbi, SBI_IS_RECOVERED);
+
#ifdef CONFIG_QUOTA
/* Turn quotas off */
if (quota_enabled)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e146e6c443e8..ecb735142276 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1089,6 +1089,7 @@ enum {
SBI_NEED_SB_WRITE, /* need to recover superblock */
SBI_NEED_CP, /* need to checkpoint */
SBI_IS_SHUTDOWN, /* shutdown by ioctl */
+ SBI_IS_RECOVERED, /* recovered orphan/data */
};

enum {
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 12a3293bcbc9..9a8579fb3a30 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -698,11 +698,15 @@ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
/* let's drop all the directory inodes for clean checkpoint */
destroy_fsync_dnodes(&dir_list);

- if (!err && need_writecp) {
- struct cp_control cpc = {
- .reason = CP_RECOVERY,
- };
- err = f2fs_write_checkpoint(sbi, &cpc);
+ if (need_writecp) {
+ set_sbi_flag(sbi, SBI_IS_RECOVERED);
+
+ if (!err) {
+ struct cp_control cpc = {
+ .reason = CP_RECOVERY,
+ };
+ err = f2fs_write_checkpoint(sbi, &cpc);
+ }
}

kmem_cache_destroy(fsync_entry_slab);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index d0d016f21307..287c9fe9fff9 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3188,6 +3188,9 @@ static void kill_f2fs_super(struct super_block *sb)
};
f2fs_write_checkpoint(sbi, &cpc);
}
+
+ if (is_sbi_flag_set(sbi, SBI_IS_RECOVERED) && f2fs_readonly(sb))
+ sb->s_flags &= ~SB_RDONLY;
}
kill_block_super(sb);
}
--
2.17.1