Re: [PATCH 03/11] mm: Protect operations adding pages to page cache with invalidate_lock

On Wed 12-05-21 15:20:44, Matthew Wilcox wrote:

On Wed, May 12, 2021 at 03:46:11PM +0200, Jan Kara wrote:

quoted

diff --git a/mm/truncate.c b/mm/truncate.c
index 57a618c4a0d6..93bde2741e0e 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c

@@ -415,7 +415,7 @@ EXPORT_SYMBOL(truncate_inode_pages_range);
  * @mapping: mapping to truncate
  * @lstart: offset from which to truncate
  *
- * Called under (and serialised by) inode->i_rwsem.
+ * Called under (and serialised by) inode->i_rwsem and inode->i_mapping_rwsem.

mapping->invalidate_lock, surely?

Right, thanks for noticing. 

And could we ask lockdep to assert this for us instead of just a comment?

That's the plan but currently it would trip for filesystems unaware of
invalidate_lock. Once all filesystems are converted I plan to transform the
comments into actual asserts. In this series I aim at fixing the data
corruption issues, I plan the cleanups for later...

								Honza

-- 
Jan Kara [off-list ref]
SUSE Labs, CR