[PATCH v2] xfs: fix memory leak on error in xfs_alloc_zone_info()

[Wilfred Mallawa <wilfred.opensource@gmail.com>]

From: Wilfred Mallawa <wilfred.mallawa@wdc.com>

Currently, the 0th index of the zi_used_bucket_bitmap array is not freed
on error due to the pre-decrement then evaluate semantic of the while
loop used in xfs_alloc_zone_info(). Fix it by allowing for the i == 0
case to be covered.

Fixes: 080d01c41d44 ("xfs: implement zoned garbage collection")
Cc: stable@vger.kernel.org
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
---
 fs/xfs/xfs_zone_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_zone_alloc.c b/fs/xfs/xfs_zone_alloc.c
index a851b98143c0..c64f9ab743a6 100644
--- a/fs/xfs/xfs_zone_alloc.c
+++ b/fs/xfs/xfs_zone_alloc.c
@@ -1217,7 +1217,7 @@ xfs_alloc_zone_info(
 	return zi;
 
 out_free_bitmaps:
-	while (--i > 0)
+	while (--i >= 0)
 		kvfree(zi->zi_used_bucket_bitmap[i]);
 	kfree(zi);
 	return NULL;
-- 
2.53.0