6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chao Yu <chao@xxxxxxxxxx>
commit 5079e1c0c879311668b77075de3e701869804adf upstream.
generic/082 reports a bug as below:
__schedule+0x332/0xf60
schedule+0x6f/0xf0
schedule_timeout+0x23b/0x2a0
wait_for_completion+0x8f/0x140
f2fs_issue_checkpoint+0xfe/0x1b0
f2fs_sync_fs+0x9d/0xb0
sync_filesystem+0x87/0xb0
dquot_load_quota_sb+0x41b/0x460
dquot_load_quota_inode+0xa5/0x130
dquot_quota_on+0x4b/0x60
f2fs_quota_on+0xe3/0x1b0
do_quotactl+0x483/0x700
__x64_sys_quotactl+0x15c/0x310
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
The root casue is race case as below:
Thread A Kworker IRQ
- write()
: write data to quota.user file
- writepages
- f2fs_submit_page_write
- __is_cp_guaranteed return false
- inc_page_count(F2FS_WB_DATA)
- submit_bio
- quotactl(Q_QUOTAON)
- f2fs_quota_on
- dquot_quota_on
- dquot_load_quota_inode
- vfs_setup_quota_inode
: inode->i_flags |= S_NOQUOTA
- f2fs_write_end_io
- __is_cp_guaranteed return true
- dec_page_count(F2FS_WB_CP_DATA)
- dquot_load_quota_sb
- f2fs_sync_fs
- f2fs_issue_checkpoint
- do_checkpoint
- f2fs_wait_on_all_pages(F2FS_WB_CP_DATA)
: loop due to F2FS_WB_CP_DATA count is negative
Calling filemap_fdatawrite() and filemap_fdatawait() to keep all data
clean before quota file setup.
Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sergio González Collado <sergio.collado@xxxxxxxxx>
Reported-by: syzbot+d0ab8746c920a592aeab@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/f2fs/super.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2824,15 +2824,26 @@ static int f2fs_quota_on(struct super_bl
return -EBUSY;
}
+ if (path->dentry->d_sb != sb)
+ return -EXDEV;
+
err = f2fs_quota_sync(sb, type);
if (err)
return err;
- err = dquot_quota_on(sb, type, format_id, path);
+ inode = d_inode(path->dentry);
+
+ err = filemap_fdatawrite(inode->i_mapping);
if (err)
return err;
- inode = d_inode(path->dentry);
+ err = filemap_fdatawait(inode->i_mapping);
+ if (err)
+ return err;
+
+ err = dquot_quota_on(sb, type, format_id, path);
+ if (err)
+ return err;
inode_lock(inode);
F2FS_I(inode)->i_flags |= F2FS_NOATIME_FL | F2FS_IMMUTABLE_FL;
