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Date: Tue, 23 May 2017 01:39:32 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org, david@sigma-star.at,
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Subject: Re: [PATCH 5/6] ubifs: Implement export_operations
Message-ID: <20170523083932.GC4107@infradead.org>
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> +static struct inode *ubifs_nfs_get_inode(struct super_block *sb, uint64_t ino,
> +					 uint32_t generation)
> +{
> +	return ubifs_iget(sb, ino);
> +}

You need to maintain and check an inode generation counter for this
to be safe.