From: Daniel Wagner <dwagner@suse.de>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, jlayton@kernel.org, hch@infradead.org
Subject: Re: [PATCH 4/8] mm/fs: Add a_ops->readahead
Date: Mon, 13 Jan 2020 19:22:42 +0100 [thread overview]
Message-ID: <20200113182242.byzbv5frzyymbddi@beryllium.lan> (raw)
In-Reply-To: <20200113153746.26654-5-willy@infradead.org>
Hi,
On Mon, Jan 13, 2020 at 07:37:42AM -0800, Matthew Wilcox wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
>
> This will replace ->readpages with a saner interface:
> - No return type (errors are ignored for read ahead anyway)
> - Pages are already in the page cache when ->readpages is called
> - Pages are passed in a pagevec instead of a linked list
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> Documentation/filesystems/locking.rst | 8 +++++-
> Documentation/filesystems/vfs.rst | 9 ++++++
> include/linux/fs.h | 3 ++
> mm/readahead.c | 40 ++++++++++++++++++++++++++-
> 4 files changed, 58 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
> index 5057e4d9dcd1..1e2f1186fd1a 100644
> --- a/Documentation/filesystems/locking.rst
> +++ b/Documentation/filesystems/locking.rst
> @@ -239,6 +239,8 @@ prototypes::
> int (*readpage)(struct file *, struct page *);
> int (*writepages)(struct address_space *, struct writeback_control *);
> int (*set_page_dirty)(struct page *page);
> + int (*readahead)(struct file *, struct address_space *,
> + struct pagevec *, pgoff_t index);
Shouldn't this be no return type? Just trying to map your commit
message to the code.
> int (*readpages)(struct file *filp, struct address_space *mapping,
> struct list_head *pages, unsigned nr_pages);
> int (*write_begin)(struct file *, struct address_space *mapping,
> @@ -271,7 +273,8 @@ writepage: yes, unlocks (see below)
> readpage: yes, unlocks
> writepages:
> set_page_dirty no
> -readpages:
> +readpages: no
> +readahead: yes, unlocks
> write_begin: locks the page exclusive
> write_end: yes, unlocks exclusive
> bmap:
> @@ -298,6 +301,9 @@ completion.
> ->readpages() populates the pagecache with the passed pages and starts
> I/O against them. They come unlocked upon I/O completion.
>
> +->readahead() starts I/O against the pages. They come unlocked upon
> +I/O completion.
> +
> ->writepage() is used for two purposes: for "memory cleansing" and for
> "sync". These are quite different operations and the behaviour may differ
> depending upon the mode.
> diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
> index 7d4d09dd5e6d..63d0f0dbbf9c 100644
> --- a/Documentation/filesystems/vfs.rst
> +++ b/Documentation/filesystems/vfs.rst
> @@ -706,6 +706,8 @@ cache in your filesystem. The following members are defined:
> int (*readpage)(struct file *, struct page *);
> int (*writepages)(struct address_space *, struct writeback_control *);
> int (*set_page_dirty)(struct page *page);
> + int (*readahead)(struct file *, struct address_space *,
> + struct pagevec *, pgoff_t index);
Same here?
Maybe I just miss the point, in the case, sorry for the noise.
Thanks,
Daniel
next prev parent reply other threads:[~2020-01-13 18:22 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-13 15:37 [RFC 0/8] Replacing the readpages a_op Matthew Wilcox
2020-01-13 15:37 ` [PATCH 1/8] pagevec: Add an iterator Matthew Wilcox
2020-01-13 15:37 ` [PATCH 2/8] mm: Fix the return type of __do_page_cache_readahead Matthew Wilcox
2020-01-13 15:37 ` [PATCH 3/8] mm: Use a pagevec for readahead Matthew Wilcox
2020-01-13 15:37 ` [PATCH 4/8] mm/fs: Add a_ops->readahead Matthew Wilcox
2020-01-13 18:22 ` Daniel Wagner [this message]
2020-01-13 19:17 ` Matthew Wilcox
2020-01-13 15:37 ` [PATCH 5/8] iomap,xfs: Convert from readpages to readahead Matthew Wilcox
2020-01-13 15:37 ` [PATCH 6/8] cifs: " Matthew Wilcox
2020-01-13 15:37 ` [PATCH 7/8] mm: Remove add_to_page_cache_locked Matthew Wilcox
2020-01-13 15:37 ` [PATCH 8/8] mm: Unify all add_to_page_cache variants Matthew Wilcox
2020-01-13 16:42 ` [RFC 0/8] Replacing the readpages a_op Chris Mason
2020-01-13 17:40 ` Matthew Wilcox
2020-01-13 18:00 ` Chris Mason
2020-01-13 21:58 ` Matthew Wilcox
2020-01-13 22:00 ` Jens Axboe
2020-01-13 22:10 ` Matthew Wilcox
2020-01-13 22:14 ` Jens Axboe
2020-01-13 22:27 ` Matthew Wilcox
2020-01-13 22:30 ` Jens Axboe
2020-01-13 22:34 ` Chris Mason
2020-01-14 1:01 ` Matthew Wilcox
2020-01-14 1:07 ` Chris Mason
2020-01-13 17:54 ` Matthew Wilcox
2020-01-13 22:19 ` Jens Axboe
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