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 <[email protected]> Signed-off-by: Qu Wenruo <[email protected]> --- 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
