| Message ID | 20250128142250.163901-1-Kai.Makisara@kolumbus.fi |
|---|---|
| Headers | show |
| Series | scsi: scsi_debug: Add more tape support | expand |
On 1/28/25 6:22 AM, Kai Mäkisara wrote: > +#define SDEBUG_READ_BLOCK_LIMITS_ARR_SZ 6 Isn't enum or 'static const' preferred for declaring constants that are only used inside a single function? > + unsigned char arr[SDEBUG_READ_BLOCK_LIMITS_ARR_SZ]; > + > + memset(arr, 0, SDEBUG_READ_BLOCK_LIMITS_ARR_SZ); The above two statements can be combined in a single statement: u8 arr[SDEBUG_READ_BLOCK_LIMITS_ARR_SZ] = { }; Thanks, Bart.
These changes to the scsi_debug driver have been made to support testing of the st driver. This is a RFC to see if there is interest to add this to the kernel scsi_debug driver. Currently, the scsi_debug driver can create tape devices and the st driver attaches to those. Nothing much can be done with the tape devices because scsi_debug does not have support for the tape-specific commands and features. These patches add some more tape support to the scsi_debug driver. The end result is simulated drives with a tape having two partitions (i.e., partitioning can't be changed). The tape partitions are implemented as fixed number of 8-byte units (partition zero 100 000 units and partition one 1000 units). The first four bytes of a unit contains the type of the unit (data block, filemark or end-of-data mark). If the units is a data block, the first four bytes contain the block length and the remaining four bytes the first four bytes of written data. This allows the user to use tags to see that the read block is what it was supposed to be. The following SCSI operations are added or modified: LOCATE - added MODE SELECT - modified to allow use without page(s) (just header and block descriptor) - store density and block size MODE SENSE - modified to allow use without page(s) (just header and block descriptor) - set density and block size - partition page added READ BLOCK LIMITS - added READ POSITION - added READ - added tape support for READ (6) REWIND - modified to set the tape position SPACE - added START STOP (LOAD) - modified to return New Medium Unit Attention if tape loaded (not according to the standard, but enables testing this UA) WRITE - added tape support for WRITE (6) WRITE FILEMARKS - added Kai Mäkisara (6): scsi: scsi_debug: First fixes for tapes scsi: scsi_debug: Add READ BLOCK LIMITS and modify LOAD for tapes scsi: scsi_debug: Add tape write support with block lengths and 4 bytes of data scsi: scsi_debug: Add read support and update locate for tapes scsi: scsi_debug: Add compression mode page for tapes scsi: scsi_debug: Reset tape setting at device reset drivers/scsi/scsi_debug.c | 630 +++++++++++++++++++++++++++++++++++++- 1 file changed, 618 insertions(+), 12 deletions(-)