Commit d7e97117 authored Apr 24, 2012 by Jan Kara

quota: Fix double lock in add_dquot_ref() with CONFIG_QUOTA_DEBUG



When CONFIG_QUOTA_DEBUG is enabled we call inode_get_rsv_space() from
add_dquot_ref() while holding i_lock. But inode_get_rsv_space() is trying
to get i_lock as well resulting in double lock.

Fix the problem by moving inode_get_rsv_space() call out of i_lock.

Reported-and-analyzed-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>

parent fd2cbd4d

fs/quota/dquot.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -907,14 +907,14 @@ static void add_dquot_ref(struct super_block *sb, int type)
		spin_unlock(&inode->i_lock);
		continue;
		}
		#ifdef CONFIG_QUOTA_DEBUG
		if (unlikely(inode_get_rsv_space(inode) > 0))
		reserved = 1;
		#endif
		__iget(inode);
		spin_unlock(&inode->i_lock);
		spin_unlock(&inode_sb_list_lock);

		#ifdef CONFIG_QUOTA_DEBUG
		if (unlikely(inode_get_rsv_space(inode) > 0))
		reserved = 1;
		#endif
		iput(old_inode);
		__dquot_initialize(inode, type);

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