On 2017-12-14 05:57 PM, Bart Van Assche wrote:
On Wed, 2017-12-13 at 20:40 -0500, Douglas Gilbert wrote:
+ {0, 0x7f, 0x11, F_SA_HIGH | F_D_OUT | FF_MEDIA_IO, resp_write_scat,
+ NULL, {32, 0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x11, 0xf8,
+ 0, 0xff, 0xff, 0x0, 0x0} }, /* WRITE SCATTERED(32) */
I know this is consistent with other command declarations in the scsi_debug
driver, but it seems weird to me to report to the initiator that only some
bits of the ADDITIONAL CDB LENGTH fields are supported (0x18)? From SPC-5:
The CDB USAGE DATA field contains information about the CDB for the command
being queried. The first byte of the CDB USAGE DATA field shall contain the
operation code for the command being queried. If the command being queried
contains a service action, then that service action code shall be placed in
the CDB USAGE DATA field in the same location as the SERVICE ACTION field of
the command CDB. All other bytes of the CDB USAGE DATA field shall contain a
usage map for bits in the CDB for the command being queried.
Given the opcode and service action for WRITE SCATTERED(32), if the
ADDITIONAL CDB LENGTH is other than 0x18, then the command is in error.
The mask with the best coverage on that is 0x18. It will catch any
bits set that are clear in the corresponding mask position but not catch
bits that are clear where the mask is set. So 0x19 will get caught as
invalid but 0x10 won't.
Attached is some output from a Seagate SAS SSD using the sg_opcodes
utility. Note that the 5 variable length cdb_s are all 32 bytes long
and have a mask of 0x18 for the ADDITIONAL CDB LENGTH.
+ lrdp = kzalloc(lbdof_blen, GFP_ATOMIC);
+ if (lrdp == NULL) {
+ mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
+ INSUFF_RES_ASCQ);
+ return illegal_condition_result;
+ }
It seems weird to me to report a fatal error to the initiator if a memory
allocation fails? I think other SCSI LLDs return SCSI_MLQUEUE_HOST_BUSY if a
memory allocation fails.
The scsi_debug driver plays the role of SCSI initiator and target
connected via a virtual transport. If the underlying OS reports a
resource error than I believe it is the implementer's choice whether
to treat it as a initiator error or a target (logical unit) error.
I chose the latter because the failure is in code that is roughly
equivalent to the device server (inside a LU inside a target).
The scsi_debug driver reports SCSI_MLQUEUE_HOST_BUSY in other contexts,
both real out-of-resources situations and via error injection.
Doug Gilbert
SEAGATE ST200FM0073 CB02
Peripheral device type: disk
Opcode Service CDB Name
(hex) action(h) size
-----------------------------------------------
00 6 Test Unit Ready
cdb usage: 00 00 00 00 00 00
01 6 Rezero Unit
cdb usage: 01 00 01 00 ff 00
03 6 Request Sense
cdb usage: 03 e1 00 00 ff 00
04 6 Format Unit
cdb usage: 04 ff 00 ff ff 00
07 6 Reassign Blocks
cdb usage: 07 03 00 00 00 00
08 6 Read(6)
cdb usage: 08 1f ff ff ff 00
0a 6 Write(6)
cdb usage: 0a 1f ff ff ff 00
0b 6 Seek(6)
cdb usage: 0b 1f ff ff 00 00
12 6 Inquiry
cdb usage: 12 e1 ff ff ff 00
15 6 Mode select(6)
cdb usage: 15 11 00 00 ff 00
16 6 Reserve(6)
cdb usage: 16 1e ff ff ff 00
17 6 Release(6)
cdb usage: 17 1e ff 00 00 00
1a 6 Mode sense(6)
cdb usage: 1a 08 ff ff ff 00
1b 6 Start stop unit
cdb usage: 1b 01 00 0f f5 00
1c 6 Receive diagnostic results
cdb usage: 1c 01 ff ff ff 00
1d 6 Send diagnostic
cdb usage: 1d f7 00 ff ff 00
25 10 Read capacity(10)
cdb usage: 25 00 7f ff ff ff 00 00 01 00
28 10 Read(10)
cdb usage: 28 fa ff ff ff ff 00 ff ff 00
2a 10 Write(10)
cdb usage: 2a fa ff ff ff ff 00 ff ff 00
2b 10 Seek(10)
cdb usage: 2b 00 ff ff ff ff 00 00 00 00
2e 10 Write and verify(10)
cdb usage: 2e f2 ff ff ff ff 00 ff ff 00
2f 10 Verify(10)
cdb usage: 2f f2 ff ff ff ff 00 ff ff 00
35 10 Synchronize cache(10)
cdb usage: 35 06 ff ff ff ff 00 ff ff 00
37 10 Read defect data(10)
cdb usage: 37 00 1f 00 00 00 00 ff ff 00
3b 0 10 Write buffer, combined header and data [or multiple modes]
cdb usage: 3b 00 ff ff ff ff ff ff ff 00
3b 2 10 Write buffer, data
cdb usage: 3b 02 ff ff ff ff ff ff ff 00
3b 4 10 Write buffer, download microcode and activate
cdb usage: 3b 04 ff ff ff ff ff ff ff 00
3b 5 10 Write buffer, download microcode, save, and activate
cdb usage: 3b 05 ff ff ff ff ff ff ff 00
3b 6 10 Write buffer, download microcode with offsets and activate
cdb usage: 3b 06 ff ff ff ff ff ff ff 00
3b 7 10 Write buffer, download microcode with offsets, save, and activate
cdb usage: 3b 07 ff ff ff ff ff ff ff 00
3b a 10 Write buffer, write data to echo buffer
cdb usage: 3b 0a ff ff ff ff ff ff ff 00
3b d 10 Write buffer, download microcode with offsets, select activation events, save and defer activate
cdb usage: 3b 0d ff ff ff ff ff ff ff 00
3b e 10 Write buffer, download microcode with offsets, save and defer activate
cdb usage: 3b 0e ff ff ff ff ff ff ff 00
3b f 10 Write buffer, activate deferred microcode
cdb usage: 3b 0f ff ff ff ff ff ff ff 00
3b 1a 10 Write buffer, enable expander comms protocol and echo buffer
cdb usage: 3b 1a ff ff ff ff ff ff ff 00
3b 1c 10 Write buffer, download application client error history
cdb usage: 3b 1c ff ff ff ff ff ff ff 00
3c 0 10 Read buffer, combined header and data [or multiple modes]
cdb usage: 3c 00 ff ff ff ff ff ff ff 00
3c 2 10 Read buffer, data
cdb usage: 3c 02 ff ff ff ff ff ff ff 00
3c 3 10 Read buffer, descriptor
cdb usage: 3c 03 ff ff ff ff ff ff ff 00
3c a 10 Read buffer, read data from echo buffer
cdb usage: 3c 0a ff ff ff ff ff ff ff 00
3c b 10 Read buffer, echo buffer descriptor
cdb usage: 3c 0b ff ff ff ff ff ff ff 00
3c 1c 10 Read buffer, error history
cdb usage: 3c 1c ff ff ff ff ff ff ff 00
3e 10 Read long(10)
cdb usage: 3e 06 ff ff ff ff 00 ff ff 00
3f 10 Write long(10)
cdb usage: 3f e0 ff ff ff ff 00 ff ff 00
41 10 Write same(10)
cdb usage: 41 e2 ff ff ff ff 00 ff ff 00
42 10 Unmap
cdb usage: 42 00 00 00 00 00 1f ff ff 00
48 2 10 Sanitize, block erase
cdb usage: 48 02 00 00 00 00 00 ff ff 00
48 3 10 Sanitize, cryptographic erase
cdb usage: 48 83 00 00 00 00 00 ff ff 00
48 1f 10 Sanitize, exit failure mode
cdb usage: 48 9f 00 00 00 00 00 ff ff 00
4c 10 Log select
cdb usage: 4c 03 c0 00 00 00 00 ff ff 00
4d 10 Log sense
cdb usage: 4d 03 ff 00 00 ff ff ff ff 00
55 10 Mode select(10)
cdb usage: 55 11 00 00 00 00 00 ff ff 00
56 10 Reserve(10)
cdb usage: 56 12 ff 00 00 00 00 ff ff 00
57 10 Release(10)
cdb usage: 57 12 00 00 00 00 00 ff ff 00
5a 10 Mode sense(10)
cdb usage: 5a 18 ff ff 00 00 00 ff ff 00
5e 0 10 Persistent reserve in, read keys
cdb usage: 5e 00 00 00 00 00 00 ff ff 00
5e 1 10 Persistent reserve in, read reservation
cdb usage: 5e 01 00 00 00 00 00 ff ff 00
5e 2 10 Persistent reserve in, report capabilities
cdb usage: 5e 02 00 00 00 00 00 ff ff 00
5e 3 10 Persistent reserve in, read full status
cdb usage: 5e 03 00 00 00 00 00 ff ff 00
5f 0 10 Persistent reserve out, register
cdb usage: 5f 00 ff 00 00 00 00 ff ff 00
5f 1 10 Persistent reserve out, reserve
cdb usage: 5f 01 ff 00 00 00 00 ff ff 00
5f 2 10 Persistent reserve out, release
cdb usage: 5f 02 ff 00 00 00 00 ff ff 00
5f 3 10 Persistent reserve out, clear
cdb usage: 5f 03 ff 00 00 00 00 ff ff 00
5f 4 10 Persistent reserve out, preempt
cdb usage: 5f 04 ff 00 00 00 00 ff ff 00
5f 5 10 Persistent reserve out, preempt and abort
cdb usage: 5f 05 ff 00 00 00 00 ff ff 00
5f 6 10 Persistent reserve out, register and ignore existing key
cdb usage: 5f 06 ff 00 00 00 00 ff ff 00
5f 7 10 Persistent reserve out, register and move
cdb usage: 5f 07 ff 00 00 00 00 ff ff 00
7f 9 32 Read(32)
cdb usage: 7f 09 00 00 00 00 1f 18 00 ff fa 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
7f a 32 Verify(32)
cdb usage: 7f 0a 00 00 00 00 1f 18 00 ff f2 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
7f b 32 Write(32)
cdb usage: 7f 0b 00 00 00 00 1f 18 00 ff fa 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
7f c 32 Write an verify(32)
cdb usage: 7f 0c 00 00 00 00 1f 18 00 ff f2 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
7f d 32 Write same(32)
cdb usage: 7f 0d 00 00 00 00 1f 18 00 ff fe 00 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
88 16 Read(16)
cdb usage: 88 fa ff ff ff ff ff ff ff ff 00 00 ff ff 00 00
8a 16 Write(16)
cdb usage: 8a fa ff ff ff ff ff ff ff ff 00 00 ff ff 00 00
8e 16 Write and verify(16)
cdb usage: 8e f2 ff ff ff ff ff ff ff ff 00 00 ff ff 00 00
8f 16 Verify(16)
cdb usage: 8f f2 ff ff ff ff ff ff ff ff 00 00 ff ff 00 00
91 16 Synchronize cache(16)
cdb usage: 91 06 ff ff ff ff ff ff ff ff 00 00 ff ff 00 00
93 16 Write same(16)
cdb usage: 93 ea ff ff ff ff ff ff ff ff ff ff ff ff 00 00
9e 10 16 Read capacity(16)
cdb usage: 9e 10 ff ff ff ff ff ff ff ff 00 00 ff ff 01 00
9e 11 16 Read long(16)
cdb usage: 9e 11 ff ff ff ff ff ff ff ff 00 00 ff ff 03 00
9f 11 16 Write long(16)
cdb usage: 9f f1 ff ff ff ff ff ff ff ff 00 00 ff ff 00 00
a0 12 Report luns
cdb usage: a0 e0 00 00 00 00 ff ff ff ff 00 00
a2 12 Security protocol in
cdb usage: a2 ff ff ff ff ff ff ff ff ff 00 00
a3 5 12 Report identifying information
cdb usage: a3 05 00 00 00 00 ff ff ff ff 00 00
a3 c 12 Report supported operation codes
cdb usage: a3 0c 07 ff ff ff ff ff ff ff 00 00
a3 d 12 Report supported task management functions
cdb usage: a3 0d 07 ff ff ff ff ff ff ff 00 00
a4 6 12 Set identifying information
cdb usage: a4 06 00 00 00 00 ff ff ff ff 00 00
a4 f 12 Set timestamp
cdb usage: a4 0f 00 00 00 00 ff ff ff ff 00 00
b5 12 Security protocol out
cdb usage: b5 ff ff ff ff ff ff ff ff ff 00 00
b7 12 Read defect data(12)
cdb usage: b7 1f 00 00 00 00 ff ff ff ff 00 00
e0 10 Vendor specific [0xe0]
cdb usage: e0 ff ff ff ff 00 ff ff 00 00
e1 10 Vendor specific [0xe1]
cdb usage: e1 ff ff ff ff 03 ff ff 00 00
e2 10 Vendor specific [0xe2]
cdb usage: e2 ff ff ff ff 00 ff ff 00 00
e6 10 Vendor specific [0xe6]
cdb usage: e6 ff 1f ff ff ff ff ff ff 00
f7 10 Vendor specific [0xf7]
cdb usage: f7 fe ff ff ff ff fe ff ff 00
