On 29/09/2023 18:54, Bart Van Assche wrote:
On 9/29/23 03:27, John Garry wrote:
+static void sd_config_atomic(struct scsi_disk *sdkp)
+{
+ unsigned int logical_block_size = sdkp->device->sector_size;
+ struct request_queue *q = sdkp->disk->queue;
+
+ if (sdkp->max_atomic) {
Please use the "return early" style here to keep the indentation
level in this function low.
ok, fine.
+ unsigned int max_atomic = max_t(unsigned int,
+ rounddown_pow_of_two(sdkp->max_atomic),
+ rounddown_pow_of_two(sdkp->max_atomic_with_boundary));
+ unsigned int unit_min = sdkp->atomic_granularity ?
+ rounddown_pow_of_two(sdkp->atomic_granularity) :
+ physical_block_size_sectors;
+ unsigned int unit_max = max_atomic;
+
+ if (sdkp->max_atomic_boundary)
+ unit_max = min_t(unsigned int, unit_max,
+ rounddown_pow_of_two(sdkp->max_atomic_boundary));
Why does "rounddown_pow_of_two()" occur in the above code?
I assume that you are talking about all the code above to calculate
atomic write values for the device.
The reason is that atomic write unit min and max are always a power-of-2
- see rules described earlier - as so that we why we rounddown to a
power-of-2.
Thanks,
John
