The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 964edf66bf9ab70cb387b27946c0aef7b94c4d1b Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Sun, 21 May 2017 22:31:23 -0400
Subject: [PATCH] ext4: clear lockdep subtype for quota files on quota off
Quota files have special ranking of i_data_sem lock. We inform lockdep
about it when turning on quotas however when turning quotas off, we
don't clear the lockdep subclass from i_data_sem lock and thus when the
inode gets later reused for a normal file or directory, lockdep gets
confused and complains about possible deadlocks. Fix the problem by
resetting lockdep subclass of i_data_sem on quota off.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: daf647d2dd58cec59570d7698a45b98e580f2076
Reported-and-tested-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0b177da9ea82..8f05c72bc4ec 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -848,14 +848,9 @@ static inline void ext4_quota_off_umount(struct super_block *sb)
{
int type;
- if (ext4_has_feature_quota(sb)) {
- dquot_disable(sb, -1,
- DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
- } else {
- /* Use our quota_off function to clear inode flags etc. */
- for (type = 0; type < EXT4_MAXQUOTAS; type++)
- ext4_quota_off(sb, type);
- }
+ /* Use our quota_off function to clear inode flags etc. */
+ for (type = 0; type < EXT4_MAXQUOTAS; type++)
+ ext4_quota_off(sb, type);
}
#else
static inline void ext4_quota_off_umount(struct super_block *sb)
@@ -5485,7 +5480,7 @@ static int ext4_quota_off(struct super_block *sb, int type)
goto out;
err = dquot_quota_off(sb, type);
- if (err)
+ if (err || ext4_has_feature_quota(sb))
goto out_put;
inode_lock(inode);
@@ -5505,6 +5500,7 @@ static int ext4_quota_off(struct super_block *sb, int type)
out_unlock:
inode_unlock(inode);
out_put:
+ lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
iput(inode);
return err;
out: