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Date:   Thu, 29 Oct 2020 17:45:35 +0100
From:   David Sterba <dsterba@suse.cz>
To:     Anand Jain <anand.jain@oracle.com>
Cc:     linux-btrfs@vger.kernel.org, Josef Bacik <josef@toxicpanda.com>
Subject: Re: [PATCH v10 3/3] btrfs: create read policy sysfs attribute, pid
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References: <cover.1603884513.git.anand.jain@oracle.com>
 <52a41497534bdaa301adc57d61ea3632ab65f2c6.1603884513.git.anand.jain@oracle.com>
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On Wed, Oct 28, 2020 at 09:14:47PM +0800, Anand Jain wrote:
> +static ssize_t btrfs_read_policy_store(struct kobject *kobj,
> +				       struct kobj_attribute *a,
> +				       const char *buf, size_t len)
> +{
> +	int i;
> +	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
> +
> +	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
> +		if (btrfs_strmatch(buf, btrfs_read_policy_name[i])) {

Does sysfs guarantee that the buf is nul terminated string or that it
contains a null at all? Because if not, the skip_space step of strmatch
could run out of the buffer.