From d7d7920a7f6614e32ebdae205e108ccc2d85d9af Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 15 Oct 2020 13:03:30 +0200 Subject: [PATCH] ext4: Detect already used quota file early [ Upstream commit e0770e91424f694b461141cbc99adf6b23006b60 ] When we try to use file already used as a quota file again (for the same or different quota type), strange things can happen. At the very least lockdep annotations may be wrong but also inode flags may be wrongly set / reset. When the file is used for two quota types at once we can even corrupt the file and likely crash the kernel. Catch all these cases by checking whether passed file is already used as quota file and bail early in that case. This fixes occasional generic/219 failure due to lockdep complaint. Reviewed-by: Andreas Dilger Reported-by: Ritesh Harjani Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20201015110330.28716-1-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/super.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 4aae7e3e89a12..2603537b1f66b 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5856,6 +5856,11 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id, /* Quotafile not on the same filesystem? */ if (path->dentry->d_sb != sb) return -EXDEV; + + /* Quota already enabled for this file? */ + if (IS_NOQUOTA(d_inode(path->dentry))) + return -EBUSY; + /* Journaling quota? */ if (EXT4_SB(sb)->s_qf_names[type]) { /* Quotafile not in fs root? */