Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-27 06:31:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

btrfs: introduce helper to grab an existing extent buffer from a page

Browse Source 
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>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2021-01-06 09:01:45 +08:00 committed by David Sterba
parent c0fab48095
commit c0f0a9e716
1 changed files with 30 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
fs/btrfs/extent_io.c
View File

@ -5247,6 +5247,29 @@ free_eb:
}
#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)
{
@ -5292,26 +5315,13 @@ 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);