Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <55e2bef1-e8b5-3475-21df-487bddb47f5b@roeck-us.net>
Date:   Mon, 13 Feb 2023 14:51:06 -0800
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Subject: Re: [PATCH v13 03/12] splice: Do splice read from a buffered file
 without using ITER_PIPE
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To:     David Howells <dhowells@redhat.com>
Cc:     Jens Axboe <axboe@kernel.dk>, Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        David Hildenbrand <david@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>, linux-fsdevel@vger.kernel.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Christoph Hellwig <hch@lst.de>,
        John Hubbard <jhubbard@nvidia.com>
References: <20230213180632.GA368628@roeck-us.net>
 <20230209102954.528942-1-dhowells@redhat.com>
 <20230209102954.528942-4-dhowells@redhat.com>
 <2416073.1676328192@warthog.procyon.org.uk>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <2416073.1676328192@warthog.procyon.org.uk>
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On 2/13/23 14:43, David Howells wrote:
> Guenter Roeck <linux@roeck-us.net> wrote:
> 
>> [    4.660118] PC is at 0x0
>> [    4.660248] LR is at filemap_read_folio+0x17/0x4e
> 
> Do you know what the filesystem is that's being read from?
> 
> I think the problem is that there are a few filesystems/drivers that call
> generic_file_splice_read() but don't have a ->read_folio().  Now most of these
> can be made to call direct_splice_read() instead, leaving just coda, overlayfs
> and shmem.
> 
> Coda and overlayfs can be made to pass the request down a layer.  I'm about to
> look into shmem.
> 

Both are initrd.

Guenter