From: Qu Wenruo <wqu@suse.com>
To: linux-btrfs@vger.kernel.org
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Subject: [PATCH v3 06/22] btrfs: extent_io: introduce a helper to grab an existing extent buffer from a page
Date: Wed, 6 Jan 2021 09:01:45 +0800 [thread overview]
Message-ID: <20210106010201.37864-7-wqu@suse.com> (raw)
In-Reply-To: <20210106010201.37864-1-wqu@suse.com>
This patch will extract the code to grab an extent buffer from a page
into a helper, grab_extent_buffer_from_page().
This reduces one indent level, and provides the work place for later
expansion for subapge support.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/extent_io.c | 51 +++++++++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a2a9c2148e91..d60f1837f8fb 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5248,6 +5248,30 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
}
#endif
+static struct extent_buffer *grab_extent_buffer(struct page *page)
+{
+ struct extent_buffer *exists;
+
+ /* Page not yet attached to an extent buffer */
+ if (!PagePrivate(page))
+ return NULL;
+
+ /*
+ * We could have already allocated an eb for this page
+ * and attached one so lets see if we can get a ref on
+ * the existing eb, and if we can we know it's good and
+ * we can just return that one, else we know we can just
+ * overwrite page->private.
+ */
+ exists = (struct extent_buffer *)page->private;
+ if (atomic_inc_not_zero(&exists->refs))
+ return exists;
+
+ WARN_ON(PageDirty(page));
+ detach_page_private(page);
+ return NULL;
+}
+
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start, u64 owner_root, int level)
{
@@ -5293,26 +5317,13 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
}
spin_lock(&mapping->private_lock);
- if (PagePrivate(p)) {
- /*
- * We could have already allocated an eb for this page
- * and attached one so lets see if we can get a ref on
- * the existing eb, and if we can we know it's good and
- * we can just return that one, else we know we can just
- * overwrite page->private.
- */
- exists = (struct extent_buffer *)p->private;
- if (atomic_inc_not_zero(&exists->refs)) {
- spin_unlock(&mapping->private_lock);
- unlock_page(p);
- put_page(p);
- mark_extent_buffer_accessed(exists, p);
- goto free_eb;
- }
- exists = NULL;
-
- WARN_ON(PageDirty(p));
- detach_page_private(p);
+ exists = grab_extent_buffer(p);
+ if (exists) {
+ spin_unlock(&mapping->private_lock);
+ unlock_page(p);
+ put_page(p);
+ mark_extent_buffer_accessed(exists, p);
+ goto free_eb;
}
attach_extent_buffer_page(eb, p);
spin_unlock(&mapping->private_lock);
--
2.29.2
next prev parent reply other threads:[~2021-01-06 1:03 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 1:01 [PATCH v3 00/22] btrfs: add read-only support for subpage sector size Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 01/22] btrfs: extent_io: rename @offset parameter to @disk_bytenr for submit_extent_page() Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 02/22] btrfs: extent_io: refactor __extent_writepage_io() to improve readability Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 03/22] btrfs: file: update comment for btrfs_dirty_pages() Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 04/22] btrfs: extent_io: update locked page dirty/writeback/error bits in __process_pages_contig() Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 05/22] btrfs: extent_io: merge PAGE_CLEAR_DIRTY and PAGE_SET_WRITEBACK into PAGE_START_WRITEBACK Qu Wenruo
2021-01-06 1:01 ` Qu Wenruo [this message]
2021-01-12 15:08 ` [PATCH v3 06/22] btrfs: extent_io: introduce a helper to grab an existing extent buffer from a page David Sterba
2021-01-06 1:01 ` [PATCH v3 07/22] btrfs: extent_io: introduce the skeleton of btrfs_subpage structure Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 08/22] btrfs: extent_io: make attach_extent_buffer_page() to handle subpage case Qu Wenruo
2021-01-06 6:54 ` Qu Wenruo
2021-01-07 1:35 ` Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 09/22] btrfs: extent_io: make grab_extent_buffer_from_page() " Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 10/22] btrfs: extent_io: support subpage for extent buffer page release Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 11/22] btrfs: extent_io: attach private to dummy extent buffer pages Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 12/22] btrfs: subpage: introduce helper for subpage uptodate status Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 13/22] btrfs: subpage: introduce helper for subpage error status Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 14/22] btrfs: extent_io: make set/clear_extent_buffer_uptodate() to support subpage size Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 15/22] btrfs: extent_io: make btrfs_clone_extent_buffer() to be subpage compatible Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 16/22] btrfs: extent_io: implement try_release_extent_buffer() for subpage metadata support Qu Wenruo
2021-01-06 8:24 ` Qu Wenruo
2021-01-06 8:43 ` Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 17/22] btrfs: extent_io: introduce read_extent_buffer_subpage() Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 18/22] btrfs: extent_io: make endio_readpage_update_page_status() to handle subpage case Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 19/22] btrfs: disk-io: introduce subpage metadata validation check Qu Wenruo
2021-01-06 1:01 ` [PATCH v3 20/22] btrfs: introduce btrfs_subpage for data inodes Qu Wenruo
2021-01-06 5:04 ` kernel test robot
2021-01-06 5:32 ` Qu Wenruo
2021-01-06 6:48 ` Rong Chen
2021-01-09 9:53 ` kernel test robot
2021-01-06 1:02 ` [PATCH v3 21/22] btrfs: integrate page status update for read path into begin/end_page_read() Qu Wenruo
2021-01-06 1:02 ` [PATCH v3 22/22] btrfs: allow RO mount of 4K sector size fs on 64K page system Qu Wenruo
2021-01-12 15:14 ` [PATCH v3 00/22] btrfs: add read-only support for subpage sector size David Sterba
2021-01-13 5:06 ` Qu Wenruo
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