On Mon, 2018-05-28 at 12:02 +0200, Greg Kroah-Hartman wrote:
4.4-stable review patch. If anyone has any objections, please let me know.
From: Filipe Manana fdmanana@suse.com
[ Upstream commit 8434ec46c6e3232cebc25a910363b29f5c617820 ]
Should stable branches also get a backport of commit 4ee3fad34a9cc2cf33303dfbd0cf554248651c86? It looks like 4.4 and 4.9 would need a minor change (inode->root to BTRFS_I(inode)->root) but I don't know whether that's really sufficient.
Ben.
When logging an inode, at tree-log.c:copy_items(), if we call btrfs_next_leaf() at the loop which checks for the need to log holes, we need to make sure copy_items() returns the value 1 to its caller and not 0 (on success). This is because the path the caller passed was released and is now different from what is was before, and the caller expects a return value of 0 to mean both success and that the path has not changed, while a return value of 1 means both success and signals the caller that it can not reuse the path, it has to perform another tree search.
Even though this is a case that should not be triggered on normal circumstances or very rare at least, its consequences can be very unpredictable (especially when replaying a log tree).
Fixes: 16e7549f045d ("Btrfs: incompatible format change to remove hole extents") Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
fs/btrfs/tree-log.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3835,6 +3835,7 @@ fill_holes: ASSERT(ret == 0); src = src_path->nodes[0]; i = 0;
need_find_last_extent = true;} btrfs_item_key_to_cpu(src, &key, i);