[PATCH v4 1/5] block: Add extra checks in blk_validate_atomic_write_limits()

[John Garry <john.g.garry@oracle.com>]

It is so far expected that the limits passed are valid.

In future atomic writes will be supported for stacked block devices, and
calculating the limits there will be complicated, so add extra sanity
checks to ensure that the values are always valid.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 block/blk-settings.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 7d6b296997c2..44e1148986b3 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -178,9 +178,26 @@ static void blk_validate_atomic_write_limits(struct queue_limits *lim)
 	if (!lim->atomic_write_hw_max)
 		goto unsupported;
 
+	if (WARN_ON_ONCE(!is_power_of_2(lim->atomic_write_hw_unit_min)))
+		goto unsupported;
+
+	if (WARN_ON_ONCE(!is_power_of_2(lim->atomic_write_hw_unit_max)))
+		goto unsupported;
+
+	if (WARN_ON_ONCE(lim->atomic_write_hw_unit_min >
+			 lim->atomic_write_hw_unit_max))
+		goto unsupported;
+
+	if (WARN_ON_ONCE(lim->atomic_write_hw_unit_max >
+			 lim->atomic_write_hw_max))
+		goto unsupported;
+
 	boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT;
 
 	if (boundary_sectors) {
+		if (WARN_ON_ONCE(lim->atomic_write_hw_max >
+				 lim->atomic_write_hw_boundary))
+			goto unsupported;
 		/*
 		 * A feature of boundary support is that it disallows bios to
 		 * be merged which would result in a merged request which
-- 
2.31.1