On Wed, Apr 16 2008 at 5:09 +0300, FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote:
> On Tue, 15 Apr 2008 15:34:47 +0300
> Boaz Harrosh <bharrosh@xxxxxxxxxxx> wrote:
>
>> Add support for variable-length, extended, and vendor specific
>> CDBs to scsi-ml. It is now possible for initiators and ULD's
>> to issue these types of commands. LLDs need not change much.
>> All they need is to raise the .max_cmd_len to the longest command
>> they support (see iscsi patch).
>>
>> - clean-up some code paths that did not expect commands to be
>> larger than 16, and change cmd_len members' type to short as
>> char is not enough.
>>
>> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
>> ---
>> block/scsi_ioctl.c | 5 ++---
>> drivers/scsi/constants.c | 10 +++-------
>> drivers/scsi/scsi.c | 22 +++++++++++-----------
>> drivers/scsi/scsi_lib.c | 8 ++++++--
>> include/scsi/scsi.h | 40 +++++++++++++++++++++++++++++++++-------
>> include/scsi/scsi_cmnd.h | 2 +-
>> include/scsi/scsi_host.h | 8 +++-----
>> 7 files changed, 59 insertions(+), 36 deletions(-)
>>
>> diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
>> index a2c3a93..aaf07e4 100644
>> --- a/block/scsi_ioctl.c
>> +++ b/block/scsi_ioctl.c
>> @@ -33,13 +33,12 @@
>> #include <scsi/scsi_cmnd.h>
>>
>> /* Command group 3 is reserved and should never be used. */
>> -const unsigned char scsi_command_size[8] =
>> +const unsigned char scsi_command_size_tbl[8] =
>> {
>> 6, 10, 10, 12,
>> 16, 12, 10, 10
>> };
>> -
>> -EXPORT_SYMBOL(scsi_command_size);
>> +EXPORT_SYMBOL(scsi_command_size_tbl);
>>
>> #include <scsi/sg.h>
>>
>> diff --git a/drivers/scsi/constants.c b/drivers/scsi/constants.c
>> index 403a7f2..9785d73 100644
>> --- a/drivers/scsi/constants.c
>> +++ b/drivers/scsi/constants.c
>> @@ -28,7 +28,6 @@
>> #define SERVICE_ACTION_OUT_12 0xa9
>> #define SERVICE_ACTION_IN_16 0x9e
>> #define SERVICE_ACTION_OUT_16 0x9f
>> -#define VARIABLE_LENGTH_CMD 0x7f
>>
>>
>>
>> @@ -210,7 +209,7 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
>> cdb0 = cdbp[0];
>> switch(cdb0) {
>> case VARIABLE_LENGTH_CMD:
>> - len = cdbp[7] + 8;
>> + len = scsi_varlen_cdb_length(cdbp);
>> if (len < 10) {
>> printk("short variable length command, "
>> "len=%d ext_len=%d", len, cdb_len);
>> @@ -300,7 +299,7 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
>> cdb0 = cdbp[0];
>> switch(cdb0) {
>> case VARIABLE_LENGTH_CMD:
>> - len = cdbp[7] + 8;
>> + len = scsi_varlen_cdb_length(cdbp);
>> if (len < 10) {
>> printk("short opcode=0x%x command, len=%d "
>> "ext_len=%d", cdb0, len, cdb_len);
>> @@ -335,10 +334,7 @@ void __scsi_print_command(unsigned char *cdb)
>> int k, len;
>>
>> print_opcode_name(cdb, 0);
>> - if (VARIABLE_LENGTH_CMD == cdb[0])
>> - len = cdb[7] + 8;
>> - else
>> - len = COMMAND_SIZE(cdb[0]);
>> + len = scsi_command_size(cdb);
>> /* print out all bytes in cdb */
>> for (k = 0; k < len; ++k)
>> printk(" %02x", cdb[k]);
>> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
>> index f6980bd..3dabecb 100644
>> --- a/drivers/scsi/scsi.c
>> +++ b/drivers/scsi/scsi.c
>> @@ -79,15 +79,6 @@ static void scsi_done(struct scsi_cmnd *cmd);
>> #define MIN_RESET_PERIOD (15*HZ)
>>
>> /*
>> - * Macro to determine the size of SCSI command. This macro takes vendor
>> - * unique commands into account. SCSI commands in groups 6 and 7 are
>> - * vendor unique and we will depend upon the command length being
>> - * supplied correctly in cmd_len.
>> - */
>> -#define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
>> - COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
>> -
>> -/*
>> * Note - the initial logging level can be set here to log events at boot time.
>> * After the system is up, you may enable logging via the /proc interface.
>> */
>> @@ -620,6 +611,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
>> unsigned long flags = 0;
>> unsigned long timeout;
>> int rtn = 0;
>> + unsigned cmd_len;
>>
>> /* check if the device is still usable */
>> if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
>> @@ -701,9 +693,17 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
>> * Before we queue this command, check if the command
>> * length exceeds what the host adapter can handle.
>> */
>> - if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
>> + cmd_len = cmd->cmd_len;
>> + if (!cmd_len) {
>> + BUG_ON(cmd->cmnd[0] == VARIABLE_LENGTH_CMD);
>> + cmd_len = COMMAND_SIZE((cmd)->cmnd[0]);
>> + }
>
> Hmm, how can cmd->cmd_len be zero here?
>
With FS_PC commands this is zero here. Because ULD prepare the command
only after prep_fn.
>
>> + if (cmd_len > cmd->device->host->max_cmd_len) {
>> SCSI_LOG_MLQUEUE(3,
>> - printk("queuecommand : command too long.\n"));
>> + printk("queuecommand : command too long. "
>> + "cdb_size=%d host->max_cmd_len=%d\n",
>> + cmd->cmd_len, cmd->device->host->max_cmd_len));
>> cmd->result = (DID_ABORT << 16);
>
> Why can't we just do:
>
> if (scsi_command_size(cmd->cmnd) > cmd->device->host->max_cmd_len) {
>
Because we can't. If ULD gave us length then we only use that, and we do
not assume we know anything about the command. scsi_command_size() only
knows about scsi commands and not all scsi commands at that, not all
versions and dialects of scsi. The commit log of this patch sayes:
"support for variable-length, extended, and vendor specific"
This code here enables that.
>
>> scsi_done(cmd);
>> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
>> index 325270b..e621505 100644
>> --- a/drivers/scsi/scsi_lib.c
>> +++ b/drivers/scsi/scsi_lib.c
>> @@ -195,6 +195,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
>>
>> req->cmd_len = COMMAND_SIZE(cmd[0]);
>> memcpy(req->cmd, cmd, req->cmd_len);
>> +
>
> Please don't put a new line at a place unrelated with this patch.
>
Ooops left over from the rebasing sorry.
>
>> req->sense = sense;
>> req->sense_len = 0;
>> req->retries = retries;
>> @@ -445,7 +446,7 @@ static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
>> scsi_set_resid(cmd, 0);
>> memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
>> if (cmd->cmd_len == 0)
>> - cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
>> + cmd->cmd_len = scsi_command_size(cmd->cmnd);
>> }
>>
>> void scsi_device_unbusy(struct scsi_device *sdev)
>> @@ -1130,13 +1131,16 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
>> }
>>
>> cmd->cmd_len = req->cmd_len;
>> + if (!cmd->cmd_len)
>> + cmd->cmd_len = scsi_command_size(cmd->cmnd);
>> +
>
> how can cmd->cmd_len be zero here? SG_IO path sets up req->cmd_len
> properly for PC commands.
>
It is either that or BUG_ON(), I would say that a simple thing like that
I would let the Initiator get lazy if it wants to.
>
>> if (!req->data_len)
>> cmd->sc_data_direction = DMA_NONE;
>> else if (rq_data_dir(req) == WRITE)
>> cmd->sc_data_direction = DMA_TO_DEVICE;
>> else
>> cmd->sc_data_direction = DMA_FROM_DEVICE;
>> -
>> +
>> cmd->transfersize = req->data_len;
>> cmd->allowed = req->retries;
>> cmd->timeout_per_command = req->timeout;
>> diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
>> index 1f74bcd..32742c4 100644
>> --- a/include/scsi/scsi.h
>> +++ b/include/scsi/scsi.h
>> @@ -30,13 +30,6 @@
>> #endif
>>
>> /*
>> - * SCSI command lengths
>> - */
>> -
>> -extern const unsigned char scsi_command_size[8];
>> -#define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
>> -
>> -/*
>> * Special value for scanning to specify scanning or rescanning of all
>> * possible channels, (target) ids, or luns on a given shost.
>> */
>> @@ -109,6 +102,7 @@ extern const unsigned char scsi_command_size[8];
>> #define MODE_SENSE_10 0x5a
>> #define PERSISTENT_RESERVE_IN 0x5e
>> #define PERSISTENT_RESERVE_OUT 0x5f
>> +#define VARIABLE_LENGTH_CMD 0x7f
>> #define REPORT_LUNS 0xa0
>> #define MAINTENANCE_IN 0xa3
>> #define MOVE_MEDIUM 0xa5
>> @@ -136,6 +130,38 @@ extern const unsigned char scsi_command_size[8];
>> #define ATA_12 0xa1 /* 12-byte pass-thru */
>>
>> /*
>> + * SCSI command lengths
>> + */
>> +
>> +#define SCSI_MAX_VARLEN_CDB_SIZE 260
>> +
>> +/* defined in T10 SCSI Primary Commands-2 (SPC2) */
>> +struct scsi_varlen_cdb_hdr {
>> + u8 opcode; /* opcode always == VARIABLE_LENGTH_CMD */
>> + u8 control;
>> + u8 misc[5];
>> + u8 additional_cdb_length; /* total cdb length - 8 */
>> + __be16 service_action;
>> + /* service specific data follows */
>> +};
>> +
>> +static inline unsigned
>> +scsi_varlen_cdb_length(const void *hdr)
>> +{
>> + return ((struct scsi_varlen_cdb_hdr *)hdr)->additional_cdb_length + 8;
>> +}
>> +
>> +extern const unsigned char scsi_command_size_tbl[8];
>> +#define COMMAND_SIZE(opcode) scsi_command_size_tbl[((opcode) >> 5) & 7]
>> +
>> +static inline unsigned
>> +scsi_command_size(const unsigned char *cmnd)
>> +{
>> + return (cmnd[0] == VARIABLE_LENGTH_CMD) ?
>> + scsi_varlen_cdb_length(cmnd) : COMMAND_SIZE(cmnd[0]);
>> +}
>> +
>> +/*
>> * SCSI Architecture Model (SAM) Status codes. Taken from SAM-3 draft
>> * T10/1561-D Revision 4 Draft dated 7th November 2002.
>> */
>> diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
>> index dea73e5..f4dacb1 100644
>> --- a/include/scsi/scsi_cmnd.h
>> +++ b/include/scsi/scsi_cmnd.h
>> @@ -78,7 +78,7 @@ struct scsi_cmnd {
>> int allowed;
>> int timeout_per_command;
>>
>> - unsigned char cmd_len;
>> + unsigned short cmd_len;
>> enum dma_data_direction sc_data_direction;
>>
>> /* These elements define the operation we are about to perform */
>> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
>> index 4913286..31f1bfd 100644
>> --- a/include/scsi/scsi_host.h
>> +++ b/include/scsi/scsi_host.h
>> @@ -573,13 +573,11 @@ struct Scsi_Host {
>> /*
>> * The maximum length of SCSI commands that this host can accept.
>> * Probably 12 for most host adapters, but could be 16 for others.
>> + * or 260 if the driver supports variable length cdbs.
>> * For drivers that don't set this field, a value of 12 is
>> - * assumed. I am leaving this as a number rather than a bit
>> - * because you never know what subsequent SCSI standards might do
>> - * (i.e. could there be a 20 byte or a 24-byte command a few years
>> - * down the road?).
>> + * assumed.
>> */
>> - unsigned char max_cmd_len;
>> + unsigned short max_cmd_len;
>>
>> int this_id;
>> int can_queue;
>> --
>> 1.5.3.3
>>
>>
>> --
As a reply to this mail I'll send a patch without the extra space.
Boaz
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