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Date:   Thu, 20 Jul 2023 14:09:10 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Dave Chinner <david@fromorbit.com>, Hannes Reinecke <hare@suse.de>,
        Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
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Subject: Re: [PATCH 16/17] block: use iomap for writes to block devices
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References: <20230424054926.26927-1-hch@lst.de> <20230424054926.26927-17-hch@lst.de> <b96b397e-2f5e-7910-3bb3-7405d0e293a7@suse.de> <ZG09wR4WOI8zDxJK@dread.disaster.area> <ZG4SGYOogQtEZrll@casper.infradead.org>
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On Wed, May 24, 2023 at 02:33:13PM +0100, Matthew Wilcox wrote:
> As you can see, do_page_cache_ra() does limit readahead to i_size.
> Is ractl->mapping->host the correct way to find the inode?  I always
> get confused.

As far as I can tell it is the right inode, the indirection through
file->f_mapping ensures it actually points to the backing inode.