6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: John Garry <john.g.garry@xxxxxxxxxx>
[ Upstream commit 6564862d646e7d630929ba1ff330740bb215bdac ]
For stacking atomic writes, ensure that the start sector is aligned with
the device atomic write unit min and any boundary. Otherwise, we may
permit misaligned atomic writes.
Rework bdev_can_atomic_write() into a common helper to resuse the
alignment check. There also use atomic_write_hw_unit_min, which is more
proper (than atomic_write_unit_min).
Fixes: d7f36dc446e89 ("block: Support atomic writes limits for stacked devices")
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250109114000.2299896-2-john.g.garry@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
block/blk-settings.c | 7 +++++--
include/linux/blkdev.h | 21 ++++++++++++---------
2 files changed, 17 insertions(+), 11 deletions(-)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index b017637d9e735..64f2e67238d77 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -608,7 +608,7 @@ static bool blk_stack_atomic_writes_head(struct queue_limits *t,
}
static void blk_stack_atomic_writes_limits(struct queue_limits *t,
- struct queue_limits *b)
+ struct queue_limits *b, sector_t start)
{
if (!(t->features & BLK_FEAT_ATOMIC_WRITES_STACKED))
goto unsupported;
@@ -616,6 +616,9 @@ static void blk_stack_atomic_writes_limits(struct queue_limits *t,
if (!b->atomic_write_unit_min)
goto unsupported;
+ if (!blk_atomic_write_start_sect_aligned(start, b))
+ goto unsupported;
+
/*
* If atomic_write_hw_max is set, we have already stacked 1x bottom
* device, so check for compliance.
@@ -798,7 +801,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
t->zone_write_granularity = 0;
t->max_zone_append_sectors = 0;
}
- blk_stack_atomic_writes_limits(t, b);
+ blk_stack_atomic_writes_limits(t, b, start);
return ret;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e0ce4d6913cde..495813277597f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1701,6 +1701,15 @@ struct io_comp_batch {
void (*complete)(struct io_comp_batch *);
};
+static inline bool blk_atomic_write_start_sect_aligned(sector_t sector,
+ struct queue_limits *limits)
+{
+ unsigned int alignment = max(limits->atomic_write_hw_unit_min,
+ limits->atomic_write_hw_boundary);
+
+ return IS_ALIGNED(sector, alignment >> SECTOR_SHIFT);
+}
+
static inline bool bdev_can_atomic_write(struct block_device *bdev)
{
struct request_queue *bd_queue = bdev->bd_queue;
@@ -1709,15 +1718,9 @@ static inline bool bdev_can_atomic_write(struct block_device *bdev)
if (!limits->atomic_write_unit_min)
return false;
- if (bdev_is_partition(bdev)) {
- sector_t bd_start_sect = bdev->bd_start_sect;
- unsigned int alignment =
- max(limits->atomic_write_unit_min,
- limits->atomic_write_hw_boundary);
-
- if (!IS_ALIGNED(bd_start_sect, alignment >> SECTOR_SHIFT))
- return false;
- }
+ if (bdev_is_partition(bdev))
+ return blk_atomic_write_start_sect_aligned(bdev->bd_start_sect,
+ limits);
return true;
}
--
2.39.5
