Re: [PATCH v4 1/3] fs: allow per-device dax status checking for filesystems

Dave Jiang
2018-02-15T17:58:54Z

On 02/15/2018 10:52 AM, Christoph Hellwig wrote:
>> /**
>> - * __bdev_dax_supported() - Check if the device supports dax for filesystem
>> + * bdev_dax_supported() - Check if the device supports dax for filesystem
>> * @sb: The superblock of the device
>> + * @bdev: block device to check
>> * @blocksize: The block size of the device
>> *
>> * This is a library function for filesystems to check if the block device
>> @@ -82,9 +83,9 @@ EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
>> *
>> * Return: negative errno if unsupported, 0 if supported.
>> */
>> -int __bdev_dax_supported(struct super_block *sb, int blocksize)
>> +int bdev_dax_supported(struct super_block *sb, struct block_device *bdev,
>> + int blocksize)
>> {
>> - struct block_device *bdev = sb->s_bdev;
>> struct dax_device *dax_dev;
>> pgoff_t pgoff;
>> int err, id;
>
> This now only uses sb for sb->s_id. It might be better to use bdevname
> to print the device name and don't bother passing a sb at all.
>

I think Darrick wanted to keep the API the same for non-XFS users. I'm
ok with dropping the passed in sb if Darrick has no objections.