[PATCH v2 03/18] btrfs: file: update comment for btrfs_dirty_pages()

[Qu Wenruo <wqu@suse.com>]

The original comment is from the initial merge, which has several
problems:
- No holes check any more
- No inline decision is made

Update the out-of-date comment with more correct one.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/file.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 0e41459b8de6..a29b50208eee 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -453,12 +453,15 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
 }
 
 /*
- * after copy_from_user, pages need to be dirtied and we need to make
- * sure holes are created between the current EOF and the start of
- * any next extents (if required).
- *
- * this also makes the decision about creating an inline extent vs
- * doing real data extents, marking pages dirty and delalloc as required.
+ * After btrfs_copy_from_user(), update the following things for delalloc:
+ * - DELALLOC extent io tree bits
+ *   Later btrfs_run_delalloc_range() relies on this bit to determine the
+ *   writeback range.
+ * - Page status
+ *   Including basic status like Dirty and Uptodate, and btrfs specific bit
+ *   like Checked (for cow fixup)
+ * - Inode size update
+ *   If needed
  */
 int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
 		      size_t num_pages, loff_t pos, size_t write_bytes,
-- 
2.29.2