6.13-stable review patch. If anyone has any objections, please let me know.
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From: John Garry john.g.garry@oracle.com
[ 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@lst.de Signed-off-by: John Garry john.g.garry@oracle.com Reviewed-by: Martin K. Petersen martin.petersen@oracle.com Link: https://lore.kernel.org/r/20250109114000.2299896-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- 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; }