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scsi: tracing: Fix handling of TRANSFER LENGTH == 0 for READ(6) and WRITE(6)

According to SBC-2 a TRANSFER LENGTH field of zero means that 256 logical
blocks must be transferred. Make the SCSI tracing code follow SBC-2.

Fixes: bf81623542 ("[SCSI] add scsi trace core functions and put trace points")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Link: https://lore.kernel.org/r/20191105215553.185018-1-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
alistair/sunxi64-5.5-dsi
Bart Van Assche 2019-11-05 13:55:53 -08:00 committed by Martin K. Petersen
parent aff6ab9e72
commit f6b8540f40
1 changed files with 7 additions and 4 deletions

View File

@ -18,15 +18,18 @@ static const char *
scsi_trace_rw6(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
sector_t lba = 0, txlen = 0;
u32 lba = 0, txlen;
lba |= ((cdb[1] & 0x1F) << 16);
lba |= (cdb[2] << 8);
lba |= cdb[3];
txlen = cdb[4];
/*
* From SBC-2: a TRANSFER LENGTH field set to zero specifies that 256
* logical blocks shall be read (READ(6)) or written (WRITE(6)).
*/
txlen = cdb[4] ? cdb[4] : 256;
trace_seq_printf(p, "lba=%llu txlen=%llu",
(unsigned long long)lba, (unsigned long long)txlen);
trace_seq_printf(p, "lba=%u txlen=%u", lba, txlen);
trace_seq_putc(p, 0);
return ret;