On 12/10/20 1:38 AM, Qu Wenruo wrote:
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 | 52 +++++++++++++++++++++++++++-----------------
1 file changed, 32 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 612fe60b367e..6350c2687c7e 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5251,6 +5251,32 @@ struct extent_buffer *alloc_test_extent_buffer(struct
btrfs_fs_info *fs_info,
}
#endif
+static struct extent_buffer *grab_extent_buffer_from_page(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)) {
+ mark_extent_buffer_accessed(exists, page);
+ 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)
{
@@ -5296,26 +5322,12 @@ 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_from_page(p);
+ if (exists) {
+ spin_unlock(&mapping->private_lock);
+ unlock_page(p);
+ put_page(p);
Put the mark_extent_buffer_accessed() here. Thanks,
Josef
