[dm-devel] [PATCH 1/4] block: add zone open, close and finish support

[Chaitanya Kulkarni]

On 6/24/19 12:43 PM, Bart Van Assche wrote:
> On 6/21/19 6:07 AM, Matias Bjørling wrote:
>> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
>> index 95202f80676c..067ef9242275 100644
>> --- a/include/linux/blk_types.h
>> +++ b/include/linux/blk_types.h
>> @@ -284,13 +284,20 @@ enum req_opf {
>>    	REQ_OP_DISCARD		= 3,
>>    	/* securely erase sectors */
>>    	REQ_OP_SECURE_ERASE	= 5,
>> -	/* reset a zone write pointer */
>> -	REQ_OP_ZONE_RESET	= 6,
>>    	/* write the same sector many times */
>>    	REQ_OP_WRITE_SAME	= 7,
>>    	/* write the zero filled sector many times */
>>    	REQ_OP_WRITE_ZEROES	= 9,
>>    
>> +	/* reset a zone write pointer */
>> +	REQ_OP_ZONE_RESET	= 16,
>> +	/* Open zone(s) */
>> +	REQ_OP_ZONE_OPEN	= 17,
>> +	/* Close zone(s) */
>> +	REQ_OP_ZONE_CLOSE	= 18,
>> +	/* Finish zone(s) */
>> +	REQ_OP_ZONE_FINISH	= 19,
>> +
>>    	/* SCSI passthrough using struct scsi_request */
>>    	REQ_OP_SCSI_IN		= 32,
>>    	REQ_OP_SCSI_OUT		= 33,
>> @@ -375,6 +382,22 @@ static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
>>    	bio->bi_opf = op | op_flags;
>>    }
> 
> Are the new operation types ever passed to op_is_write()? The definition
> of that function is as follows:
> 
May be we should change numbering since blktrace also relies on the 
having on_is_write() without looking at the rq_ops().

197  * Data direction bit lookup
  198  */
  199 static const u32 ddir_act[2] = { BLK_TC_ACT(BLK_TC_READ),
  200                                  BLK_TC_ACT(BLK_TC_WRITE) };  <----
  201
  202 #define BLK_TC_RAHEAD           BLK_TC_AHEAD
  203 #define BLK_TC_PREFLUSH         BLK_TC_FLUSH
  204
  205 /* The ilog2() calls fall out because they're constant */
  206 #define MASK_TC_BIT(rw, __name) ((rw & REQ_ ## __name) << \
  207           (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - __REQ_ ## 
__name))
  208
  209 /*
  210  * The worker for the various blk_add_trace*() types. Fills out a
  211  * blk_io_trace structure and places it in a per-cpu subbuffer.
  212  */
  213 static void __blk_add_trace(struct blk_trace *bt, sector_t sector, 
int bytes,
  214                      int op, int op_flags, u32 what, int error, 
int pdu_len,
  215                      void *pdu_data, union kernfs_node_id *cgid)
  216 {
  217         struct task_struct *tsk = current;
  218         struct ring_buffer_event *event = NULL;
  219         struct ring_buffer *buffer = NULL;
  220         struct blk_io_trace *t;
  221         unsigned long flags = 0;
  222         unsigned long *sequence;
  223         pid_t pid;
  224         int cpu, pc = 0;
  225         bool blk_tracer = blk_tracer_enabled;
  226         ssize_t cgid_len = cgid ? sizeof(*cgid) : 0;
  227
  228         if (unlikely(bt->trace_state != Blktrace_running && 
!blk_tracer))
  229                 return;
  230
  231         what |= ddir_act[op_is_write(op) ? WRITE : READ];  <--- 


> static inline bool op_is_write(unsigned int op)
> {
> 	return (op & 1);
> }
>