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Date:   Mon, 24 Jul 2023 16:39:32 +1000
From:   Dave Chinner <david@fromorbit.com>
To:     Nitesh Shetty <nj.shetty@samsung.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>, hch@lst.de,
        gost.dev@samsung.com, Anuj Gupta <anuj20.g@samsung.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fs/read_write: Enable copy_file_range for block device.
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References: <CGME20230724060655epcas5p24f21ce77480885c746b9b86d27585492@epcas5p2.samsung.com>
 <20230724060336.8939-1-nj.shetty@samsung.com>
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On Mon, Jul 24, 2023 at 11:33:36AM +0530, Nitesh Shetty wrote:
> From: Anuj Gupta <anuj20.g@samsung.com>
> 
> Change generic_copy_file_checks to use ->f_mapping->host for both inode_in
> and inode_out. Allow block device in generic_file_rw_checks.

Why? copy_file_range() is for copying a range of a regular file to
another regular file - why do we want to support block devices for
somethign that is clearly intended for copying data files?

Also, the copy_file_range man page states:

ERRORS
.....
    EINVAL Either fd_in or fd_out is not a regular file.
.....

If we are changing the behavioru of copy_file_range (why?), then man
page updates need to be done as well, documenting the change, which
kernel versions only support regular files, etc.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com