From: Filipe Manana fdmanana@suse.com
commit e2c8e92d1140754073ad3799eb6620c76bab2078 upstream.
If an error happens while running dellaloc in COW mode for a range, we can end up calling extent_clear_unlock_delalloc() for a range that goes beyond our range's end offset by 1 byte, which affects 1 extra page. This results in clearing bits and doing page operations (such as a page unlock) outside our target range.
Fix that by calling extent_clear_unlock_delalloc() with an inclusive end offset, instead of an exclusive end offset, at cow_file_range().
Fixes: a315e68f6e8b30 ("Btrfs: fix invalid attempt to free reserved space on failure to cow range") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1142,7 +1142,7 @@ out_unlock: */ if (extent_reserved) { extent_clear_unlock_delalloc(inode, start, - start + cur_alloc_size, + start + cur_alloc_size - 1, locked_page, clear_bits, page_ops);