Re: [PATCH RFC 14/16] scsi: sd: Add WRITE_ATOMIC_16 support

From: Bart Van Assche
Date: Wed May 03 2023 - 14:49:11 EST


On 5/3/23 11:38, John Garry wrote:
+static blk_status_t sd_setup_atomic_cmnd(struct scsi_cmnd *cmd,
+ sector_t lba, unsigned int nr_blocks,
+ unsigned char flags)
+{
+ cmd->cmd_len = 16;
+ cmd->cmnd[0] = WRITE_ATOMIC_16;
+ cmd->cmnd[1] = flags;
+ put_unaligned_be64(lba, &cmd->cmnd[2]);
+ cmd->cmnd[10] = 0;
+ cmd->cmnd[11] = 0;
+ put_unaligned_be16(nr_blocks, &cmd->cmnd[12]);
+ cmd->cmnd[14] = 0;
+ cmd->cmnd[15] = 0;
+
+ return BLK_STS_OK;
+}

A single space in front of the assignment operator please.

+
static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
{
struct request *rq = scsi_cmd_to_rq(cmd);
@@ -1149,6 +1166,7 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
unsigned int nr_blocks = sectors_to_logical(sdp, blk_rq_sectors(rq));
unsigned int mask = logical_to_sectors(sdp, 1) - 1;
bool write = rq_data_dir(rq) == WRITE;
+ bool atomic_write = !!(rq->cmd_flags & REQ_ATOMIC) && write;

Isn't the !! superfluous in the above expression? I have not yet seen any other kernel code where a flag test is used in a boolean expression and where !! occurs in front of the flag test.

Thanks,

Bart.