From: Jan Kara <jack@suse.cz>
To: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: linux-fsdevel@vger.kernel.org, jack@suse.com, hch@infradead.org,
linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org,
linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
axboe@kernel.dk, linux-api@vger.kernel.org,
adam.manzanares@wdc.com, viro@zeniv.linux.org.uk,
Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 02/10] fs: Introduce filemap_range_has_page()
Date: Thu, 25 May 2017 10:25:32 +0200 [thread overview]
Message-ID: <20170525082532.GC28950@quack2.suse.cz> (raw)
In-Reply-To: <20170524164150.9492-3-rgoldwyn@suse.de>
On Wed 24-05-17 11:41:42, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
>
> filemap_range_has_page() return true if the file's mapping has
> a page within the range mentioned. This function will be used
> to check if a write() call will cause a writeback of previous
> writes.
>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> include/linux/fs.h | 2 ++
> mm/filemap.c | 33 +++++++++++++++++++++++++++++++++
> 2 files changed, 35 insertions(+)
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index f53867140f43..dc0ab585cd56 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2517,6 +2517,8 @@ extern int filemap_fdatawait(struct address_space *);
> extern void filemap_fdatawait_keep_errors(struct address_space *);
> extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
> loff_t lend);
> +extern int filemap_range_has_page(struct address_space *, loff_t lstart,
> + loff_t lend);
> extern int filemap_write_and_wait(struct address_space *mapping);
> extern int filemap_write_and_wait_range(struct address_space *mapping,
> loff_t lstart, loff_t lend);
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 6f1be573a5e6..87aba7698584 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -376,6 +376,39 @@ int filemap_flush(struct address_space *mapping)
> }
> EXPORT_SYMBOL(filemap_flush);
>
> +/**
> + * filemap_range_has_page - check if a page exists in range.
> + * @mapping: address space structure to wait for
> + * @start_byte: offset in bytes where the range starts
> + * @end_byte: offset in bytes where the range ends (inclusive)
> + *
> + * Find at least one page in the range supplied, usually used to check if
> + * direct writing in this range will trigger a writeback.
> + */
> +int filemap_range_has_page(struct address_space *mapping,
> + loff_t start_byte, loff_t end_byte)
> +{
> + pgoff_t index = start_byte >> PAGE_SHIFT;
> + pgoff_t end = end_byte >> PAGE_SHIFT;
> + struct pagevec pvec;
> + int ret;
> +
> + if (end_byte < start_byte)
> + return 0;
> +
> + if (mapping->nrpages == 0)
> + return 0;
> +
> + pagevec_init(&pvec, 0);
> + ret = pagevec_lookup(&pvec, mapping, index, 1);
> + if (!ret)
> + return 0;
> + ret = (pvec.pages[0]->index <= end);
> + pagevec_release(&pvec);
> + return ret;
> +}
> +EXPORT_SYMBOL(filemap_range_has_page);
> +
> static int __filemap_fdatawait_range(struct address_space *mapping,
> loff_t start_byte, loff_t end_byte)
> {
> --
> 2.12.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2017-05-25 8:25 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-24 16:41 [PATCH 0/10 v9] No wait AIO Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 01/10] fs: Separate out kiocb flags setup based on RWF_* flags Goldwyn Rodrigues
2017-05-25 8:16 ` Jan Kara
2017-05-24 16:41 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-05-25 8:25 ` Jan Kara [this message]
[not found] ` <20170524164150.9492-1-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-05-24 16:41 ` [PATCH 03/10] fs: Use RWF_* flags for AIO operations Goldwyn Rodrigues
2017-05-25 8:27 ` Jan Kara
2017-05-24 16:41 ` [PATCH 05/10] fs: return if direct write will trigger writeback Goldwyn Rodrigues
2017-05-25 8:32 ` Jan Kara
2017-05-28 9:27 ` [PATCH 0/10 v9] No wait AIO Christoph Hellwig
2017-05-29 2:38 ` Goldwyn Rodrigues
2017-05-29 8:32 ` Christoph Hellwig
2017-05-24 16:41 ` [PATCH 04/10] fs: Introduce RWF_NOWAIT Goldwyn Rodrigues
2017-05-25 8:30 ` Jan Kara
2017-05-24 16:41 ` [PATCH 06/10] fs: Introduce IOMAP_NOWAIT Goldwyn Rodrigues
2017-05-25 8:33 ` Jan Kara
2017-05-24 16:41 ` [PATCH 07/10] fs: return on congested block device Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 08/10] ext4: nowait aio support Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 09/10] xfs: " Goldwyn Rodrigues
2017-05-24 16:49 ` Darrick J. Wong
[not found] ` <20170524164150.9492-10-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-05-28 9:31 ` Christoph Hellwig
2017-05-29 2:38 ` Goldwyn Rodrigues
2017-05-29 8:21 ` Jan Kara
2017-05-29 8:33 ` Christoph Hellwig
[not found] ` <20170529083338.GC1899-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2017-05-30 16:13 ` Goldwyn Rodrigues
2017-05-31 8:51 ` Jan Kara
2017-05-24 16:41 ` [PATCH 10/10] btrfs: " Goldwyn Rodrigues
-- strict thread matches above, loose matches on Subject: below --
2017-06-15 15:59 [PATCH 0/10 v12] No wait AIO Goldwyn Rodrigues
2017-06-15 15:59 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
[not found] ` <20170615160002.17233-3-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-06-15 18:25 ` Andrew Morton
2017-06-06 11:19 [PATCH 0/10 v11] No wait AIO Goldwyn Rodrigues
2017-06-06 11:19 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-06-05 5:35 [PATCH 0/10 v10] No wait AIO Goldwyn Rodrigues
2017-06-05 5:35 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-05-11 19:17 [PATCH 0/10 v8] No wait AIO Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
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