On Sat, Jul 27, 2019 at 04:51:13PM +0800, Jia-Ju Bai wrote: > In insert_inline_extent(), the case that compressed_size > 0 > and compressed_pages = NULL cannot occur, otherwise a null-pointer > dereference may occur on line 215: > cpage = compressed_pages[i]; > > To warn this incorrect case, an assertion is added. > Thank Qu Wenruo and David Sterba for good advice. > > Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> > --- > fs/btrfs/inode.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 1af069a9a0c7..21d6e2dcc25f 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -178,6 +178,9 @@ static int insert_inline_extent(struct btrfs_trans_handle > *trans, > size_t cur_size = size; > unsigned long offset; > > + ASSERT((compressed_size > 0 && compressed_pages) || > + (compressed_size == 0 && !compressed_pages))
Thanks. I expect that the static checking tools can be instructed to understand that the condition has been checked and is not missing in the code below. ASSERT is conditinally a BUG() wrapper, otherwise a no-op. Btw, it's also good to check that the code compiles, the statement is missing semicolon.
