This is a note to let you know that I've just added the patch titled
Revert "mm/filemap: avoid buffered read/write race to read inconsistent data"
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-mm-filemap-avoid-buffered-read-write-race-to-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d87bcb0965636a9b665231560ce147d06a7a18d8
Author: Baokun Li <libaokun1@xxxxxxxxxx>
Date: Wed Jan 24 22:28:56 2024 +0800
Revert "mm/filemap: avoid buffered read/write race to read inconsistent data"
[ Upstream commit 4b944f8ef99641d5af287c7d9df91d20ef5d3e88 ]
This reverts commit e2c27b803bb6 ("mm/filemap: avoid buffered read/write
race to read inconsistent data"). After making the i_size_read/write
helpers be smp_load_acquire/store_release(), it is already guaranteed that
changes to page contents are visible before we see increased inode size,
so the extra smp_rmb() in filemap_read() can be removed.
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240124142857.4146716-3-libaokun1@xxxxxxxxxx
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/mm/filemap.c b/mm/filemap.c
index e6c112f3a211f..cd028f3be6026 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2694,15 +2694,6 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
goto put_folios;
end_offset = min_t(loff_t, isize, iocb->ki_pos + iter->count);
- /*
- * Pairs with a barrier in
- * block_write_end()->mark_buffer_dirty() or other page
- * dirtying routines like iomap_write_end() to ensure
- * changes to page contents are visible before we see
- * increased inode size.
- */
- smp_rmb();
-
/*
* Once we start copying data, we don't want to be touching any
* cachelines that might be contended:
