Documentation/ABI/stable/sysfs-block states:
What: /sys/block/<disk>/queue/discard_granularity
[...]
A discard_granularity of 0 means that the device does not support
discard functionality.
but this got broken when sorting out the block limits updates. Fix this
by setting the discard_granularity limit to zero when the combined
max_discard_sectors is zero.
Fixes: 3c407dc723bb ("block: default the discard granularity to sector size")
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/blk-settings.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index a000daafbfb4..20f8b207d5e8 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -336,12 +336,19 @@ int blk_validate_limits(struct queue_limits *lim)
lim->max_discard_sectors =
min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors);
+ /*
+ * When discard is not supported, discard_granularity should be reported
+ * as 0 to userspace.
+ */
+ if (lim->max_discard_sectors)
+ lim->discard_granularity =
+ max(lim->discard_granularity, lim->physical_block_size);
+ else
+ lim->discard_granularity = 0;
+
if (!lim->max_discard_segments)
lim->max_discard_segments = 1;
- if (lim->discard_granularity < lim->physical_block_size)
- lim->discard_granularity = lim->physical_block_size;
-
/*
* By default there is no limit on the segment boundary alignment,
* but if there is one it can't be smaller than the page size as
--
2.47.2
