Re: [REVIEW 1 of 4] Clean up i_flags handling

[Christoph Hellwig <hch@infradead.org>]

> +/*
> + * i_flags helper functions
> + */
> +static inline void
> +__xfs_iflags_set(xfs_inode_t *ip, unsigned short flags)
> +{
> +	ip->i_flags |= flags;
> +}
> +
> +static inline void
> +xfs_iflags_set(xfs_inode_t *ip, unsigned short flags)
> +{
> +	spin_lock(&ip->i_flags_lock);
> +	__xfs_iflags_set(ip, flags);
> +	spin_unlock(&ip->i_flags_lock);
> +}

This is not actually 

> +
> +static inline void
> +xfs_iflags_clear(xfs_inode_t *ip, unsigned short flags)
> +{
> +	spin_lock(&ip->i_flags_lock);
> +	ip->i_flags &= ~flags;
> +	spin_unlock(&ip->i_flags_lock);
> +}
> +
> +static inline int
> +__xfs_iflags_test(xfs_inode_t *ip, unsigned short flags)
> +{
> +	return (ip->i_flags & flags);
> +}
> +
> +static inline int
> +xfs_iflags_test(xfs_inode_t *ip, unsigned short flags)
> +{
> +	int ret;
> +	spin_lock(&ip->i_flags_lock);
> +	ret = __xfs_iflags_test(ip, flags);
> +	spin_unlock(&ip->i_flags_lock);
> +	return ret;

This is not actually guaranteed to work on machiens with very weak
memory ordering.  Please use the *_bit routines from bitops.h instead.