Re: [PATCH 3/4] aacraid: use blk_mq_rq_busy_iter() for traversing outstanding commands

[Hannes Reinecke <hare@suse.de>]

On 11/1/19 4:34 PM, Bart Van Assche wrote:
> On 11/1/19 4:18 AM, Hannes Reinecke wrote:
>> +static bool synchronize_busy_iter(struct request *req, void *data, 
>> bool reserved)
>> +{
>> +    struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
>> +    struct synchronize_busy_data *busy_data = data;
>> +
>> +    if (busy_data->sdev == cmd->device &&
>> +        cmd->SCp.phase == AAC_OWNER_FIRMWARE) {
>> +        u64 cmnd_lba;
>> +        u32 cmnd_count;
>> +
>> +        if (cmd->cmnd[0] == WRITE_6) {
>> +            cmnd_lba = ((cmd->cmnd[1] & 0x1F) << 16) |
>> +                (cmd->cmnd[2] << 8) |
>> +                cmd->cmnd[3];
>> +            cmnd_count = cmd->cmnd[4];
>> +            if (cmnd_count == 0)
>> +                cmnd_count = 256;
>> +        } else if (cmd->cmnd[0] == WRITE_16) {
>> +            cmnd_lba = ((u64)cmd->cmnd[2] << 56) |
>> +                ((u64)cmd->cmnd[3] << 48) |
>> +                ((u64)cmd->cmnd[4] << 40) |
>> +                ((u64)cmd->cmnd[5] << 32) |
>> +                ((u64)cmd->cmnd[6] << 24) |
>> +                (cmd->cmnd[7] << 16) |
>> +                (cmd->cmnd[8] << 8) |
>> +                cmd->cmnd[9];
>> +            cmnd_count = (cmd->cmnd[10] << 24) |
>> +                (cmd->cmnd[11] << 16) |
>> +                (cmd->cmnd[12] << 8) |
>> +                cmd->cmnd[13];
>> +        } else if (cmd->cmnd[0] == WRITE_12) {
>> +            cmnd_lba = ((u64)cmd->cmnd[2] << 24) |
>> +                (cmd->cmnd[3] << 16) |
>> +                (cmd->cmnd[4] << 8) |
>> +                cmd->cmnd[5];
>> +            cmnd_count = (cmd->cmnd[6] << 24) |
>> +                (cmd->cmnd[7] << 16) |
>> +                (cmd->cmnd[8] << 8) |
>> +                cmd->cmnd[9];
>> +        } else if (cmd->cmnd[0] == WRITE_10) {
>> +            cmnd_lba = ((u64)cmd->cmnd[2] << 24) |
>> +                (cmd->cmnd[3] << 16) |
>> +                (cmd->cmnd[4] << 8) |
>> +                cmd->cmnd[5];
>> +            cmnd_count = (cmd->cmnd[7] << 8) |
>> +                cmd->cmnd[8];
>> +        } else
>> +            return true;
> 
> The above code looks very similar to the code in scsi_trace.c. Although 
> SCSI LLDs shouldn't parse CDBs, there are a few SCSI LLDs that do this. 
> Would it be worth it to introduce a function in the SCSI core that 
> extracts the most important fields from a CDB (LBA, data buffer size, ...)?
> 
Possibly.
I'll see what I can come up with.

But in either case I'd rather do this as a separate patchset.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                              +49 911 74053 688
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