From: Josef Bacik <josef@toxicpanda.com>
To: Nikolay Borisov <nborisov@suse.com>, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 03/10] btrfs: Simplify metadata pages reading
Date: Thu, 10 Sep 2020 10:56:44 -0400 [thread overview]
Message-ID: <09182e67-e5d4-cb10-a55c-537c4fbf9155@toxicpanda.com> (raw)
In-Reply-To: <20200909094914.29721-4-nborisov@suse.com>
On 9/9/20 5:49 AM, Nikolay Borisov wrote:
> Metadata pages currently use __do_readpage to read metadata pages,
> unfortunately this function is also used to deal with ordinary data
> pages. This makes the metadata pages reading code to go through multiple
> hoops in order to adhere to __do_readpage invariants. Most of these are
> necessary for data pages which could be compressed. For metadata it's
> enough to simply build a bio and submit it.
>
> To this effect simply call submit_extent_page directly from
> read_extent_buffer_pages which is the only callpath used to populate
> extent_buffers with data. This in turn enables further cleanups.
>
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
> fs/btrfs/extent_io.c | 18 ++++++------------
> 1 file changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index ac92c0ab1402..1789a7931312 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -5575,20 +5575,14 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num)
> }
>
> ClearPageError(page);
> - err = __extent_read_full_page(page,
> - btree_get_extent, &bio,
> - mirror_num, &bio_flags,
> - REQ_META);
> + err = submit_extent_page(REQ_OP_READ | REQ_META, NULL,
> + page, page_offset(page), PAGE_SIZE, 0,
> + &bio, end_bio_extent_readpage,
> + mirror_num, 0, 0, false);
> if (err) {
> ret = err;
> - /*
> - * We use &bio in above __extent_read_full_page,
> - * so we ensure that if it returns error, the
> - * current page fails to add itself to bio and
> - * it's been unlocked.
> - *
> - * We must dec io_pages by ourselves.
> - */
I'd rather change the comment to indicate that we failed to submit the bio, thus
the page is our responsibility to clean up, and thus we need to do the
error/unlock and io_pages dance. Thanks,
Josef
next prev parent reply other threads:[~2020-09-10 14:57 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-09 9:49 [PATCH 00/10] Cleanup metadata page reading path Nikolay Borisov
2020-09-09 9:49 ` [PATCH 01/10] btrfs: Remove btree_readpage Nikolay Borisov
2020-09-09 10:37 ` Johannes Thumshirn
2020-09-09 11:13 ` Qu Wenruo
2020-09-09 9:49 ` [PATCH 02/10] btrfs: Remove pg_offset from btrfs_get_extent Nikolay Borisov
2020-09-09 10:40 ` Johannes Thumshirn
2020-09-09 11:15 ` Qu Wenruo
2020-09-09 9:49 ` [PATCH 03/10] btrfs: Simplify metadata pages reading Nikolay Borisov
2020-09-09 11:20 ` Qu Wenruo
2020-09-14 8:08 ` Nikolay Borisov
2020-09-14 8:22 ` Qu Wenruo
2020-09-10 14:56 ` Josef Bacik [this message]
2020-09-09 9:49 ` [PATCH 04/10] btrfs: Remove btree_get_extent Nikolay Borisov
2020-09-10 14:57 ` Josef Bacik
2020-09-09 9:49 ` [PATCH 05/10] btrfs: Remove btrfs_get_extent indirection from __do_readpage Nikolay Borisov
2020-09-09 11:24 ` Qu Wenruo
2020-09-09 11:56 ` Nikolay Borisov
2020-09-09 9:49 ` [PATCH 06/10] btrfs: Remove mirror_num argument from extent_read_full_page Nikolay Borisov
2020-09-10 14:58 ` Josef Bacik
2020-09-09 9:49 ` [PATCH 07/10] btrfs: Promote extent_read_full_page to btrfs_readpage Nikolay Borisov
2020-09-10 15:01 ` Josef Bacik
2020-09-09 9:49 ` [PATCH 08/10] btrfs: Sink mirror_num argument in extent_read_full_page Nikolay Borisov
2020-09-10 15:02 ` Josef Bacik
2020-09-09 9:49 ` [PATCH 09/10] btrfs: Sink read_flags argument into extent_read_full_page Nikolay Borisov
2020-09-10 15:03 ` Josef Bacik
2020-09-09 9:49 ` [PATCH 10/10] btrfs: Sink mirror_num argument in __do_readpage Nikolay Borisov
2020-09-10 15:04 ` Josef Bacik
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