btrfs: fix off-by-one chunk length calculation at contains_pending_ex…

…tent()

At contains_pending_extent() the value of the end offset of a chunk we
found in the device's allocation state io tree is inclusive, so when
we calculate the length we pass to the in_range() macro, we must sum
1 to the expression "physical_end - physical_offset".

In practice the wrong calculation should be harmless as chunks sizes
are never 1 byte and we should never have 1 byte ranges of unallocated
space. Nevertheless fix the wrong calculation.

Reported-by: Alex Lyakas <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/CAOcd+r30e-f4R-5x-S7sV22RJPe7+pgwherA6xqN2_qe7o4XTg@mail.gmail.com/
Fixes: 1c11b63 ("btrfs: replace pending/pinned chunks lists with io tree")
CC: [email protected] # 6.1+
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>

fs/btrfs/volumes.c

@@ -1406,7 +1406,7 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
 
 		if (in_range(physical_start, *start, len) ||
 		    in_range(*start, physical_start,
-			     physical_end - physical_start)) {
+			     physical_end + 1 - physical_start)) {
 			*start = physical_end + 1;
 			return true;
 		}