6.14-stable review patch. If anyone has any objections, please let me know.
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From: Luis Chamberlain mcgrof@kernel.org
[ Upstream commit 425fbcd62d2e1330e64d8d3bf89e554830ba997f ]
You can use lsblk to query for a block device block device block size:
lsblk -o MIN-IO /dev/nvme0n1 MIN-IO 4096
The min-io is the minimum IO the block device prefers for optimal performance. In turn we map this to the block device block size. The current block size exposed even for block devices with an LBA format of 16k is 4k. Likewise devices which support 4k LBA format but have a larger Indirection Unit of 16k have an exposed block size of 4k.
This incurs read-modify-writes on direct IO against devices with a min-io larger than the page size. To fix this, use the block device min io, which is the minimal optimal IO the device prefers.
With this we now get:
lsblk -o MIN-IO /dev/nvme0n1 MIN-IO 16384
And so userspace gets the appropriate information it needs for optimal performance. This is verified with blkalgn against mkfs against a device with LBA format of 4k but an NPWG of 16k (min io size)
mkfs.xfs -f -b size=16k /dev/nvme3n1 blkalgn -d nvme3n1 --ops Write
Block size : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 0 | | 512 -> 1023 : 0 | | 1024 -> 2047 : 0 | | 2048 -> 4095 : 0 | | 4096 -> 8191 : 0 | | 8192 -> 16383 : 0 | | 16384 -> 32767 : 66 |****************************************| 32768 -> 65535 : 0 | | 65536 -> 131071 : 0 | | 131072 -> 262143 : 2 |* | Block size: 14 - 66 Block size: 17 - 2
Algn size : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 0 | | 512 -> 1023 : 0 | | 1024 -> 2047 : 0 | | 2048 -> 4095 : 0 | | 4096 -> 8191 : 0 | | 8192 -> 16383 : 0 | | 16384 -> 32767 : 66 |****************************************| 32768 -> 65535 : 0 | | 65536 -> 131071 : 0 | | 131072 -> 262143 : 2 |* | Algn size: 14 - 66 Algn size: 17 - 2
Reviewed-by: Hannes Reinecke hare@suse.de Signed-off-by: Luis Chamberlain mcgrof@kernel.org Link: https://lore.kernel.org/r/20250221223823.1680616-9-mcgrof@kernel.org Reviewed-by: John Garry john.g.garry@oracle.com Signed-off-by: Christian Brauner brauner@kernel.org Stable-dep-of: 5f33b5226c9d ("block: don't autoload drivers on stat") Signed-off-by: Sasha Levin sashal@kernel.org --- block/bdev.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/block/bdev.c b/block/bdev.c index 9d73a8fbf7f99..8453f6a795d9a 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -1274,9 +1274,6 @@ void bdev_statx(struct path *path, struct kstat *stat, struct inode *backing_inode; struct block_device *bdev;
- if (!(request_mask & (STATX_DIOALIGN | STATX_WRITE_ATOMIC))) - return; - backing_inode = d_backing_inode(path->dentry);
/* @@ -1303,6 +1300,8 @@ void bdev_statx(struct path *path, struct kstat *stat, queue_atomic_write_unit_max_bytes(bd_queue)); }
+ stat->blksize = bdev_io_min(bdev); + blkdev_put_no_open(bdev); }