linux/include/scsi/scsi.h
Mike Christie a4dfaa6f2e [SCSI] scsi: add transport host byte errors (v3)
Currently, if there is a transport problem the iscsi drivers will return
outstanding commands (commands being exeucted by the driver/fw/hw) with
DID_BUS_BUSY and block the session so no new commands can be queued.
Commands that are caught between the failure handling and blocking are
failed with DID_IMM_RETRY or one of the scsi ml queuecommand return values.
When the recovery_timeout fires, the iscsi drivers then fail IO with
DID_NO_CONNECT.

For fcp, some drivers will fail some outstanding IO (disk but possibly not
tape) with DID_BUS_BUSY or DID_ERROR or some other value that causes a retry
and hits the scsi_error.c failfast check, block the rport, and commands
caught in the race are failed with DID_IMM_RETRY. Other drivers, may
hold onto all IO and wait for the terminate_rport_io or dev_loss_tmo_callbk
to be called.

The following patches attempt to unify what upper layers will see drivers
like multipath can make a good guess. This relies on drivers being
hooked into their transport class.

This first patch just defines two new host byte errors so drivers can
return the same value for when a rport/session is blocked and for
when the fast_io_fail_tmo fires.

The idea is that if the LLD/class detects a problem and is going to block
a rport/session, then if the LLD wants or must return the command to scsi-ml,
then it can return it with DID_TRANSPORT_DISRUPTED. This will requeue
the IO into the same scsi queue it came from, until the fast io fail timer
fires and the class decides what to do.

When using multipath and the fast_io_fail_tmo fires then the class
can fail commands with DID_TRANSPORT_FAILFAST or drivers can use
DID_TRANSPORT_FAILFAST in their terminate_rport_io callbacks or
the equivlent in iscsi if we ever implement more advanced recovery methods.
A LLD, like lpfc, could continue to return DID_ERROR and then it will hit
the normal failfast path, so drivers do not have fully be ported to
work better. The point of the patches is that upper layers will
not see a failure that could be recovered from while the rport/session is
blocked until fast_io_fail_tmo/recovery_timeout fires.

V3
Remove some comments.
V2
Fixed patch/diff errors and renamed DID_TRANSPORT_BLOCKED to
DID_TRANSPORT_DISRUPTED.
V1
initial patch.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-13 09:28:48 -04:00

537 lines
16 KiB
C

/*
* This header file contains public constants and structures used by
* the scsi code for linux.
*
* For documentation on the OPCODES, MESSAGES, and SENSE values,
* please consult the SCSI standard.
*/
#ifndef _SCSI_SCSI_H
#define _SCSI_SCSI_H
#include <linux/types.h>
#include <scsi/scsi_cmnd.h>
/*
* The maximum number of SG segments that we will put inside a
* scatterlist (unless chaining is used). Should ideally fit inside a
* single page, to avoid a higher order allocation. We could define this
* to SG_MAX_SINGLE_ALLOC to pack correctly at the highest order. The
* minimum value is 32
*/
#define SCSI_MAX_SG_SEGMENTS 128
/*
* Like SCSI_MAX_SG_SEGMENTS, but for archs that have sg chaining. This limit
* is totally arbitrary, a setting of 2048 will get you at least 8mb ios.
*/
#ifdef ARCH_HAS_SG_CHAIN
#define SCSI_MAX_SG_CHAIN_SEGMENTS 2048
#else
#define SCSI_MAX_SG_CHAIN_SEGMENTS SCSI_MAX_SG_SEGMENTS
#endif
/*
* Special value for scanning to specify scanning or rescanning of all
* possible channels, (target) ids, or luns on a given shost.
*/
#define SCAN_WILD_CARD ~0
/*
* SCSI opcodes
*/
#define TEST_UNIT_READY 0x00
#define REZERO_UNIT 0x01
#define REQUEST_SENSE 0x03
#define FORMAT_UNIT 0x04
#define READ_BLOCK_LIMITS 0x05
#define REASSIGN_BLOCKS 0x07
#define INITIALIZE_ELEMENT_STATUS 0x07
#define READ_6 0x08
#define WRITE_6 0x0a
#define SEEK_6 0x0b
#define READ_REVERSE 0x0f
#define WRITE_FILEMARKS 0x10
#define SPACE 0x11
#define INQUIRY 0x12
#define RECOVER_BUFFERED_DATA 0x14
#define MODE_SELECT 0x15
#define RESERVE 0x16
#define RELEASE 0x17
#define COPY 0x18
#define ERASE 0x19
#define MODE_SENSE 0x1a
#define START_STOP 0x1b
#define RECEIVE_DIAGNOSTIC 0x1c
#define SEND_DIAGNOSTIC 0x1d
#define ALLOW_MEDIUM_REMOVAL 0x1e
#define SET_WINDOW 0x24
#define READ_CAPACITY 0x25
#define READ_10 0x28
#define WRITE_10 0x2a
#define SEEK_10 0x2b
#define POSITION_TO_ELEMENT 0x2b
#define WRITE_VERIFY 0x2e
#define VERIFY 0x2f
#define SEARCH_HIGH 0x30
#define SEARCH_EQUAL 0x31
#define SEARCH_LOW 0x32
#define SET_LIMITS 0x33
#define PRE_FETCH 0x34
#define READ_POSITION 0x34
#define SYNCHRONIZE_CACHE 0x35
#define LOCK_UNLOCK_CACHE 0x36
#define READ_DEFECT_DATA 0x37
#define MEDIUM_SCAN 0x38
#define COMPARE 0x39
#define COPY_VERIFY 0x3a
#define WRITE_BUFFER 0x3b
#define READ_BUFFER 0x3c
#define UPDATE_BLOCK 0x3d
#define READ_LONG 0x3e
#define WRITE_LONG 0x3f
#define CHANGE_DEFINITION 0x40
#define WRITE_SAME 0x41
#define READ_TOC 0x43
#define LOG_SELECT 0x4c
#define LOG_SENSE 0x4d
#define XDWRITEREAD_10 0x53
#define MODE_SELECT_10 0x55
#define RESERVE_10 0x56
#define RELEASE_10 0x57
#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 MAINTENANCE_OUT 0xa4
#define MOVE_MEDIUM 0xa5
#define EXCHANGE_MEDIUM 0xa6
#define READ_12 0xa8
#define WRITE_12 0xaa
#define WRITE_VERIFY_12 0xae
#define SEARCH_HIGH_12 0xb0
#define SEARCH_EQUAL_12 0xb1
#define SEARCH_LOW_12 0xb2
#define READ_ELEMENT_STATUS 0xb8
#define SEND_VOLUME_TAG 0xb6
#define WRITE_LONG_2 0xea
#define READ_16 0x88
#define WRITE_16 0x8a
#define VERIFY_16 0x8f
#define SERVICE_ACTION_IN 0x9e
/* values for service action in */
#define SAI_READ_CAPACITY_16 0x10
/* values for maintenance in */
#define MI_REPORT_TARGET_PGS 0x0a
/* values for maintenance out */
#define MO_SET_TARGET_PGS 0x0a
/* Values for T10/04-262r7 */
#define ATA_16 0x85 /* 16-byte pass-thru */
#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.
*/
#define SAM_STAT_GOOD 0x00
#define SAM_STAT_CHECK_CONDITION 0x02
#define SAM_STAT_CONDITION_MET 0x04
#define SAM_STAT_BUSY 0x08
#define SAM_STAT_INTERMEDIATE 0x10
#define SAM_STAT_INTERMEDIATE_CONDITION_MET 0x14
#define SAM_STAT_RESERVATION_CONFLICT 0x18
#define SAM_STAT_COMMAND_TERMINATED 0x22 /* obsolete in SAM-3 */
#define SAM_STAT_TASK_SET_FULL 0x28
#define SAM_STAT_ACA_ACTIVE 0x30
#define SAM_STAT_TASK_ABORTED 0x40
/** scsi_status_is_good - check the status return.
*
* @status: the status passed up from the driver (including host and
* driver components)
*
* This returns true for known good conditions that may be treated as
* command completed normally
*/
static inline int scsi_status_is_good(int status)
{
/*
* FIXME: bit0 is listed as reserved in SCSI-2, but is
* significant in SCSI-3. For now, we follow the SCSI-2
* behaviour and ignore reserved bits.
*/
status &= 0xfe;
return ((status == SAM_STAT_GOOD) ||
(status == SAM_STAT_INTERMEDIATE) ||
(status == SAM_STAT_INTERMEDIATE_CONDITION_MET) ||
/* FIXME: this is obsolete in SAM-3 */
(status == SAM_STAT_COMMAND_TERMINATED));
}
/*
* Status codes. These are deprecated as they are shifted 1 bit right
* from those found in the SCSI standards. This causes confusion for
* applications that are ported to several OSes. Prefer SAM Status codes
* above.
*/
#define GOOD 0x00
#define CHECK_CONDITION 0x01
#define CONDITION_GOOD 0x02
#define BUSY 0x04
#define INTERMEDIATE_GOOD 0x08
#define INTERMEDIATE_C_GOOD 0x0a
#define RESERVATION_CONFLICT 0x0c
#define COMMAND_TERMINATED 0x11
#define QUEUE_FULL 0x14
#define ACA_ACTIVE 0x18
#define TASK_ABORTED 0x20
#define STATUS_MASK 0xfe
/*
* SENSE KEYS
*/
#define NO_SENSE 0x00
#define RECOVERED_ERROR 0x01
#define NOT_READY 0x02
#define MEDIUM_ERROR 0x03
#define HARDWARE_ERROR 0x04
#define ILLEGAL_REQUEST 0x05
#define UNIT_ATTENTION 0x06
#define DATA_PROTECT 0x07
#define BLANK_CHECK 0x08
#define COPY_ABORTED 0x0a
#define ABORTED_COMMAND 0x0b
#define VOLUME_OVERFLOW 0x0d
#define MISCOMPARE 0x0e
/*
* DEVICE TYPES
* Please keep them in 0x%02x format for $MODALIAS to work
*/
#define TYPE_DISK 0x00
#define TYPE_TAPE 0x01
#define TYPE_PRINTER 0x02
#define TYPE_PROCESSOR 0x03 /* HP scanners use this */
#define TYPE_WORM 0x04 /* Treated as ROM by our system */
#define TYPE_ROM 0x05
#define TYPE_SCANNER 0x06
#define TYPE_MOD 0x07 /* Magneto-optical disk -
* - treated as TYPE_DISK */
#define TYPE_MEDIUM_CHANGER 0x08
#define TYPE_COMM 0x09 /* Communications device */
#define TYPE_RAID 0x0c
#define TYPE_ENCLOSURE 0x0d /* Enclosure Services Device */
#define TYPE_RBC 0x0e
#define TYPE_NO_LUN 0x7f
/* SCSI protocols; these are taken from SPC-3 section 7.5 */
enum scsi_protocol {
SCSI_PROTOCOL_FCP = 0, /* Fibre Channel */
SCSI_PROTOCOL_SPI = 1, /* parallel SCSI */
SCSI_PROTOCOL_SSA = 2, /* Serial Storage Architecture - Obsolete */
SCSI_PROTOCOL_SBP = 3, /* firewire */
SCSI_PROTOCOL_SRP = 4, /* Infiniband RDMA */
SCSI_PROTOCOL_ISCSI = 5,
SCSI_PROTOCOL_SAS = 6,
SCSI_PROTOCOL_ADT = 7, /* Media Changers */
SCSI_PROTOCOL_ATA = 8,
SCSI_PROTOCOL_UNSPEC = 0xf, /* No specific protocol */
};
/* Returns a human-readable name for the device */
extern const char * scsi_device_type(unsigned type);
/*
* standard mode-select header prepended to all mode-select commands
*/
struct ccs_modesel_head {
__u8 _r1; /* reserved */
__u8 medium; /* device-specific medium type */
__u8 _r2; /* reserved */
__u8 block_desc_length; /* block descriptor length */
__u8 density; /* device-specific density code */
__u8 number_blocks_hi; /* number of blocks in this block desc */
__u8 number_blocks_med;
__u8 number_blocks_lo;
__u8 _r3;
__u8 block_length_hi; /* block length for blocks in this desc */
__u8 block_length_med;
__u8 block_length_lo;
};
/*
* ScsiLun: 8 byte LUN.
*/
struct scsi_lun {
__u8 scsi_lun[8];
};
/*
* The Well Known LUNS (SAM-3) in our int representation of a LUN
*/
#define SCSI_W_LUN_BASE 0xc100
#define SCSI_W_LUN_REPORT_LUNS (SCSI_W_LUN_BASE + 1)
#define SCSI_W_LUN_ACCESS_CONTROL (SCSI_W_LUN_BASE + 2)
#define SCSI_W_LUN_TARGET_LOG_PAGE (SCSI_W_LUN_BASE + 3)
static inline int scsi_is_wlun(unsigned int lun)
{
return (lun & 0xff00) == SCSI_W_LUN_BASE;
}
/*
* MESSAGE CODES
*/
#define COMMAND_COMPLETE 0x00
#define EXTENDED_MESSAGE 0x01
#define EXTENDED_MODIFY_DATA_POINTER 0x00
#define EXTENDED_SDTR 0x01
#define EXTENDED_EXTENDED_IDENTIFY 0x02 /* SCSI-I only */
#define EXTENDED_WDTR 0x03
#define EXTENDED_PPR 0x04
#define EXTENDED_MODIFY_BIDI_DATA_PTR 0x05
#define SAVE_POINTERS 0x02
#define RESTORE_POINTERS 0x03
#define DISCONNECT 0x04
#define INITIATOR_ERROR 0x05
#define ABORT_TASK_SET 0x06
#define MESSAGE_REJECT 0x07
#define NOP 0x08
#define MSG_PARITY_ERROR 0x09
#define LINKED_CMD_COMPLETE 0x0a
#define LINKED_FLG_CMD_COMPLETE 0x0b
#define TARGET_RESET 0x0c
#define ABORT_TASK 0x0d
#define CLEAR_TASK_SET 0x0e
#define INITIATE_RECOVERY 0x0f /* SCSI-II only */
#define RELEASE_RECOVERY 0x10 /* SCSI-II only */
#define CLEAR_ACA 0x16
#define LOGICAL_UNIT_RESET 0x17
#define SIMPLE_QUEUE_TAG 0x20
#define HEAD_OF_QUEUE_TAG 0x21
#define ORDERED_QUEUE_TAG 0x22
#define IGNORE_WIDE_RESIDUE 0x23
#define ACA 0x24
#define QAS_REQUEST 0x55
/* Old SCSI2 names, don't use in new code */
#define BUS_DEVICE_RESET TARGET_RESET
#define ABORT ABORT_TASK_SET
/*
* Host byte codes
*/
#define DID_OK 0x00 /* NO error */
#define DID_NO_CONNECT 0x01 /* Couldn't connect before timeout period */
#define DID_BUS_BUSY 0x02 /* BUS stayed busy through time out period */
#define DID_TIME_OUT 0x03 /* TIMED OUT for other reason */
#define DID_BAD_TARGET 0x04 /* BAD target. */
#define DID_ABORT 0x05 /* Told to abort for some other reason */
#define DID_PARITY 0x06 /* Parity error */
#define DID_ERROR 0x07 /* Internal error */
#define DID_RESET 0x08 /* Reset by somebody. */
#define DID_BAD_INTR 0x09 /* Got an interrupt we weren't expecting. */
#define DID_PASSTHROUGH 0x0a /* Force command past mid-layer */
#define DID_SOFT_ERROR 0x0b /* The low level driver just wish a retry */
#define DID_IMM_RETRY 0x0c /* Retry without decrementing retry count */
#define DID_REQUEUE 0x0d /* Requeue command (no immediate retry) also
* without decrementing the retry count */
#define DID_TRANSPORT_DISRUPTED 0x0e /* Transport error disrupted execution
* and the driver blocked the port to
* recover the link. Transport class will
* retry or fail IO */
#define DID_TRANSPORT_FAILFAST 0x0f /* Transport class fastfailed the io */
#define DRIVER_OK 0x00 /* Driver status */
/*
* These indicate the error that occurred, and what is available.
*/
#define DRIVER_BUSY 0x01
#define DRIVER_SOFT 0x02
#define DRIVER_MEDIA 0x03
#define DRIVER_ERROR 0x04
#define DRIVER_INVALID 0x05
#define DRIVER_TIMEOUT 0x06
#define DRIVER_HARD 0x07
#define DRIVER_SENSE 0x08
#define SUGGEST_RETRY 0x10
#define SUGGEST_ABORT 0x20
#define SUGGEST_REMAP 0x30
#define SUGGEST_DIE 0x40
#define SUGGEST_SENSE 0x80
#define SUGGEST_IS_OK 0xff
#define DRIVER_MASK 0x0f
#define SUGGEST_MASK 0xf0
/*
* Internal return values.
*/
#define NEEDS_RETRY 0x2001
#define SUCCESS 0x2002
#define FAILED 0x2003
#define QUEUED 0x2004
#define SOFT_ERROR 0x2005
#define ADD_TO_MLQUEUE 0x2006
#define TIMEOUT_ERROR 0x2007
#define SCSI_RETURN_NOT_HANDLED 0x2008
/*
* Midlevel queue return values.
*/
#define SCSI_MLQUEUE_HOST_BUSY 0x1055
#define SCSI_MLQUEUE_DEVICE_BUSY 0x1056
#define SCSI_MLQUEUE_EH_RETRY 0x1057
#define SCSI_MLQUEUE_TARGET_BUSY 0x1058
/*
* Use these to separate status msg and our bytes
*
* These are set by:
*
* status byte = set from target device
* msg_byte = return status from host adapter itself.
* host_byte = set by low-level driver to indicate status.
* driver_byte = set by mid-level.
*/
#define status_byte(result) (((result) >> 1) & 0x7f)
#define msg_byte(result) (((result) >> 8) & 0xff)
#define host_byte(result) (((result) >> 16) & 0xff)
#define driver_byte(result) (((result) >> 24) & 0xff)
#define suggestion(result) (driver_byte(result) & SUGGEST_MASK)
static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
{
cmd->result |= status << 8;
}
static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
{
cmd->result |= status << 16;
}
static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
{
cmd->result |= status << 24;
}
#define sense_class(sense) (((sense) >> 4) & 0x7)
#define sense_error(sense) ((sense) & 0xf)
#define sense_valid(sense) ((sense) & 0x80);
/*
* default timeouts
*/
#define FORMAT_UNIT_TIMEOUT (2 * 60 * 60 * HZ)
#define START_STOP_TIMEOUT (60 * HZ)
#define MOVE_MEDIUM_TIMEOUT (5 * 60 * HZ)
#define READ_ELEMENT_STATUS_TIMEOUT (5 * 60 * HZ)
#define READ_DEFECT_DATA_TIMEOUT (60 * HZ )
#define IDENTIFY_BASE 0x80
#define IDENTIFY(can_disconnect, lun) (IDENTIFY_BASE |\
((can_disconnect) ? 0x40 : 0) |\
((lun) & 0x07))
/*
* struct scsi_device::scsi_level values. For SCSI devices other than those
* prior to SCSI-2 (i.e. over 12 years old) this value is (resp[2] + 1)
* where "resp" is a byte array of the response to an INQUIRY. The scsi_level
* variable is visible to the user via sysfs.
*/
#define SCSI_UNKNOWN 0
#define SCSI_1 1
#define SCSI_1_CCS 2
#define SCSI_2 3
#define SCSI_3 4 /* SPC */
#define SCSI_SPC_2 5
#define SCSI_SPC_3 6
/*
* INQ PERIPHERAL QUALIFIERS
*/
#define SCSI_INQ_PQ_CON 0x00
#define SCSI_INQ_PQ_NOT_CON 0x01
#define SCSI_INQ_PQ_NOT_CAP 0x03
/*
* Here are some scsi specific ioctl commands which are sometimes useful.
*
* Note that include/linux/cdrom.h also defines IOCTL 0x5300 - 0x5395
*/
/* Used to obtain PUN and LUN info. Conflicts with CDROMAUDIOBUFSIZ */
#define SCSI_IOCTL_GET_IDLUN 0x5382
/* 0x5383 and 0x5384 were used for SCSI_IOCTL_TAGGED_{ENABLE,DISABLE} */
/* Used to obtain the host number of a device. */
#define SCSI_IOCTL_PROBE_HOST 0x5385
/* Used to obtain the bus number for a device */
#define SCSI_IOCTL_GET_BUS_NUMBER 0x5386
/* Used to obtain the PCI location of a device */
#define SCSI_IOCTL_GET_PCI 0x5387
/* Pull a u32 out of a SCSI message (using BE SCSI conventions) */
static inline __u32 scsi_to_u32(__u8 *ptr)
{
return (ptr[0]<<24) + (ptr[1]<<16) + (ptr[2]<<8) + ptr[3];
}
#endif /* _SCSI_SCSI_H */