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From:   David Howells <dhowells@redhat.com>
In-Reply-To: <20220316131723.111553-5-jefflexu@linux.alibaba.com>
References: <20220316131723.111553-5-jefflexu@linux.alibaba.com> <20220316131723.111553-1-jefflexu@linux.alibaba.com>
To:     Jeffle Xu <jefflexu@linux.alibaba.com>
Cc:     dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org,
        chao@kernel.org, linux-erofs@lists.ozlabs.org,
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Subject: Re: [PATCH v5 04/22] cachefiles: notify user daemon with anon_fd when looking up cookie
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Date:   Mon, 21 Mar 2022 14:01:34 +0000
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Jeffle Xu <jefflexu@linux.alibaba.com> wrote:

> +	read_lock(&cache->reqs_lock);
> +
> +	/* recheck dead state under lock */
> +	if (test_bit(CACHEFILES_DEAD, &cache->flags)) {
> +		read_unlock(&cache->reqs_lock);
> +		ret =3D -EIO;
> +		goto out;
> +	}
> +
> +	xa_lock(xa);
> +	ret =3D __xa_alloc(xa, &id, req, xa_limit_32b, GFP_KERNEL);

You're holding a spinlock.  You can't use GFP_KERNEL.

> +static int cachefiles_ondemand_cinit(struct cachefiles_cache *cache, ch=
ar *args)
> +{
> ...
> +	tmp =3D kstrdup(args, GFP_KERNEL);

No need to copy the string.  The caller already did that and added a NUL f=
or
good measure.

I would probably move most of the functions added in this patch to
fs/cachefiles/ondemand.c.

David