linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Qu Wenruo <wqu@suse.com>
To: linux-btrfs@vger.kernel.org
Subject: [PATCH v2 07/19] btrfs: update num_extent_pages() to support subpage sized extent buffer
Date: Tue, 15 Sep 2020 13:35:20 +0800	[thread overview]
Message-ID: <20200915053532.63279-8-wqu@suse.com> (raw)
In-Reply-To: <20200915053532.63279-1-wqu@suse.com>

For subpage sized extent buffer, we have ensured no extent buffer will
cross page boundary, thus we would only need one page for any extent
buffer.

This patch will update the function num_extent_pages() to handle such
case.
Now num_extent_pages() would return 1 instead of for subpage sized
extent buffer.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/extent_io.h | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index d511890702cc..61556d6e9363 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -229,8 +229,15 @@ void wait_on_extent_buffer_writeback(struct extent_buffer *eb);
 
 static inline int num_extent_pages(const struct extent_buffer *eb)
 {
-	return (round_up(eb->start + eb->len, PAGE_SIZE) >> PAGE_SHIFT) -
-	       (eb->start >> PAGE_SHIFT);
+	/*
+	 * For sectorsize == PAGE_SIZE case, since eb is always aligned to
+	 * sectorsize, it's just (eb->len / PAGE_SIZE) >> PAGE_SHIFT.
+	 *
+	 * For sectorsize < PAGE_SIZE case, we only want to support 64K
+	 * PAGE_SIZE, and ensured all tree blocks won't cross page boundary.
+	 * So in that case we always got 1 page.
+	 */
+	return (round_up(eb->len, PAGE_SIZE) >> PAGE_SHIFT);
 }
 
 static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
-- 
2.28.0


  parent reply	other threads:[~2020-09-15  5:36 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15  5:35 [PATCH v2 00/19] btrfs: add read-only support for subpage sector size Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 01/19] btrfs: extent-io-tests: remove invalid tests Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 02/19] btrfs: remove the unnecessary parameter @start and @len for check_data_csum() Qu Wenruo
2020-09-15  8:39   ` Johannes Thumshirn
2020-09-15  5:35 ` [PATCH v2 03/19] btrfs: calculate inline extent buffer page size based on page size Qu Wenruo
2020-09-15  8:35   ` Nikolay Borisov
2020-09-15 10:05     ` Qu Wenruo
2020-09-15  8:40   ` Johannes Thumshirn
2020-09-15  5:35 ` [PATCH v2 04/19] btrfs: remove the open-code to read disk-key Qu Wenruo
2020-09-15  8:36   ` Nikolay Borisov
2020-09-15  8:40   ` Johannes Thumshirn
2020-09-16 16:01   ` David Sterba
2020-09-17  8:02     ` Qu Wenruo
2020-09-17 12:37       ` David Sterba
2020-09-17 13:15         ` Qu Wenruo
2020-09-17 22:41           ` David Sterba
2020-09-17 23:26             ` Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 05/19] btrfs: make btrfs_fs_info::buffer_radix to take sector size devided values Qu Wenruo
2020-09-15  8:27   ` Johannes Thumshirn
2020-09-15 10:04     ` Qu Wenruo
2020-09-15 10:12       ` Johannes Thumshirn
2020-09-15 17:40   ` kernel test robot
2020-09-15  5:35 ` [PATCH v2 06/19] btrfs: don't allow tree block to cross page boundary for subpage support Qu Wenruo
2020-09-15  8:37   ` Nikolay Borisov
2020-09-15 10:06     ` Qu Wenruo
2020-09-15  8:44   ` Johannes Thumshirn
2020-09-15  5:35 ` Qu Wenruo [this message]
2020-09-15  8:42   ` [PATCH v2 07/19] btrfs: update num_extent_pages() to support subpage sized extent buffer Johannes Thumshirn
2020-09-15 10:07     ` Qu Wenruo
2020-09-15 10:12       ` Johannes Thumshirn
2020-09-15 10:07     ` Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 08/19] btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 09/19] btrfs: make csum_tree_block() handle sectorsize smaller than page size Qu Wenruo
2020-09-15  8:47   ` Johannes Thumshirn
2020-09-15  5:35 ` [PATCH v2 10/19] btrfs: add assert_spin_locked() for attach_extent_buffer_page() Qu Wenruo
2020-09-15  8:52   ` Johannes Thumshirn
2020-09-15  5:35 ` [PATCH v2 11/19] btrfs: extract the extent buffer verification from btree_readpage_end_io_hook() Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 12/19] btrfs: extent_io: only require sector size alignment for page read Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 13/19] btrfs: make btrfs_readpage_end_io_hook() follow sector size Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 14/19] btrfs: make btree inode io_tree has its special owner Qu Wenruo
2020-09-16  9:28   ` Johannes Thumshirn
2020-09-16 16:06   ` David Sterba
2020-09-17  0:02     ` Qu Wenruo
2020-09-17 12:50       ` David Sterba
2020-09-18  8:18         ` Qu Wenruo
2020-09-22 14:06           ` David Sterba
2020-09-22 14:14   ` David Sterba
2020-09-15  5:35 ` [PATCH v2 15/19] btrfs: don't set extent_io_tree bits for btree inode at endio time Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 16/19] btrfs: use extent_io_tree to handle subpage extent buffer allocation Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 17/19] btrfs: implement subpage metadata read and its endio function Qu Wenruo
2020-09-16  8:47   ` kernel test robot
2020-09-15  5:35 ` [PATCH v2 18/19] btrfs: implement btree_readpage() and try_release_extent_buffer() for subpage Qu Wenruo
2020-09-15  5:35 ` [PATCH v2 19/19] btrfs: allow RO mount of 4K sector size fs on 64K page system Qu Wenruo
2020-09-16  1:35 ` [PATCH v2 00/19] btrfs: add read-only support for subpage sector size Qu Wenruo
2020-09-16 16:18 ` Neal Gompa
2020-09-17  0:03   ` Qu Wenruo
2020-09-17  0:13     ` Neal Gompa
2020-09-17  0:24       ` Qu Wenruo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200915053532.63279-8-wqu@suse.com \
    --to=wqu@suse.com \
    --cc=linux-btrfs@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).