quota: Silence lockdep on quota_on

Commit d01730d74d2b0155da50d44555001706294014f7 didn't completely fix
the problem since we still take dqio_mutex and i_mutex in the wrong
order. Move taking of i_mutex further down (luckily it's needed only
for updating inode flags) below where dqio_mutex is taken.

Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 70f36c0..38f7bd5 100644 (file)
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2043,7 +2043,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
                invalidate_bdev(sb->s_bdev);
        }
        mutex_lock(&dqopt->dqonoff_mutex);
-       mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
        if (sb_has_quota_loaded(sb, type)) {
                error = -EBUSY;
                goto out_lock;
@@ -2054,9 +2053,11 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
                 * possible) Also nobody should write to the file - we use
                 * special IO operations which ignore the immutable bit. */
                down_write(&dqopt->dqptr_sem);
+               mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
                oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE |
                                             S_NOQUOTA);
                inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE;
+               mutex_unlock(&inode->i_mutex);
                up_write(&dqopt->dqptr_sem);
                sb->dq_op->drop(inode);
        }
@@ -2080,7 +2081,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
                goto out_file_init;
        }
        mutex_unlock(&dqopt->dqio_mutex);
-       mutex_unlock(&inode->i_mutex);
        spin_lock(&dq_state_lock);
        dqopt->flags |= dquot_state_flag(flags, type);
        spin_unlock(&dq_state_lock);
@@ -2096,13 +2096,14 @@ out_file_init:
 out_lock:
        if (oldflags != -1) {
                down_write(&dqopt->dqptr_sem);
+               mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
                /* Set the flags back (in the case of accidental quotaon()
                 * on a wrong file we don't want to mess up the flags) */
                inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE);
                inode->i_flags |= oldflags;
+               mutex_unlock(&inode->i_mutex);
                up_write(&dqopt->dqptr_sem);
        }
-       mutex_unlock(&inode->i_mutex);
        mutex_unlock(&dqopt->dqonoff_mutex);
 out_fmt:
        put_quota_format(fmt);