diff options
| -rw-r--r-- | drivers/scsi/libiscsi.c | 49 | ||||
| -rw-r--r-- | include/scsi/libiscsi.h | 9 |
2 files changed, 39 insertions, 19 deletions
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index c1af2aa8e4e0..c723e60f02b0 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -1893,29 +1893,48 @@ EXPORT_SYMBOL_GPL(iscsi_host_free); * * This can be used by software iscsi_transports that allocate * a session per scsi host. + * + * Callers should set cmds_max to the largest total numer (mgmt + scsi) of + * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks + * for nop handling and login/logout requests. */ struct iscsi_cls_session * iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost, - uint16_t scsi_cmds_max, int cmd_task_size, + uint16_t cmds_max, int cmd_task_size, uint32_t initial_cmdsn, unsigned int id) { struct iscsi_session *session; struct iscsi_cls_session *cls_session; - int cmd_i, cmds_max; - + int cmd_i, scsi_cmds, total_cmds = cmds_max; /* - * The iscsi layer needs some tasks for nop handling and tmfs. + * The iscsi layer needs some tasks for nop handling and tmfs, + * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX + * + 1 command for scsi IO. */ - if (scsi_cmds_max < 1) - scsi_cmds_max = ISCSI_MGMT_CMDS_MAX; - if ((scsi_cmds_max + ISCSI_MGMT_CMDS_MAX) >= ISCSI_MGMT_ITT_OFFSET) { - printk(KERN_ERR "iscsi: invalid can_queue of %d. " - "can_queue must be less than %d.\n", - scsi_cmds_max, - ISCSI_MGMT_ITT_OFFSET - ISCSI_MGMT_CMDS_MAX); - scsi_cmds_max = ISCSI_DEF_XMIT_CMDS_MAX; + if (total_cmds < ISCSI_TOTAL_CMDS_MIN) { + printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue " + "must be a power of two that is at least %d.\n", + total_cmds, ISCSI_TOTAL_CMDS_MIN); + return NULL; + } + + if (total_cmds > ISCSI_TOTAL_CMDS_MAX) { + printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue " + "must be a power of 2 less than or equal to %d.\n", + cmds_max, ISCSI_TOTAL_CMDS_MAX); + total_cmds = ISCSI_TOTAL_CMDS_MAX; + } + + if (!is_power_of_2(total_cmds)) { + printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue " + "must be a power of 2.\n", total_cmds); + total_cmds = rounddown_pow_of_two(total_cmds); + if (total_cmds < ISCSI_TOTAL_CMDS_MIN) + return NULL; + printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n", + total_cmds); } - cmds_max = roundup_pow_of_two(scsi_cmds_max + ISCSI_MGMT_CMDS_MAX); + scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX; cls_session = iscsi_alloc_session(shost, iscsit, sizeof(struct iscsi_session)); @@ -1928,8 +1947,8 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost, session->fast_abort = 1; session->lu_reset_timeout = 15; session->abort_timeout = 10; - session->scsi_cmds_max = scsi_cmds_max; - session->cmds_max = cmds_max; + session->scsi_cmds_max = scsi_cmds; + session->cmds_max = total_cmds; session->queued_cmdsn = session->cmdsn = initial_cmdsn; session->exp_cmdsn = initial_cmdsn + 1; session->max_cmdsn = initial_cmdsn + 1; diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h index 21cfb1d5483f..5bf0187e7520 100644 --- a/include/scsi/libiscsi.h +++ b/include/scsi/libiscsi.h @@ -52,9 +52,7 @@ struct device; #endif #define ISCSI_DEF_XMIT_CMDS_MAX 128 /* must be power of 2 */ -#define ISCSI_MGMT_CMDS_MAX 16 /* must be power of 2 */ - -#define ISCSI_MGMT_ITT_OFFSET 0xa00 +#define ISCSI_MGMT_CMDS_MAX 15 #define ISCSI_DEF_CMD_PER_LUN 32 #define ISCSI_MAX_CMD_PER_LUN 128 @@ -72,7 +70,10 @@ enum { /* Connection suspend "bit" */ #define ISCSI_SUSPEND_BIT 1 -#define ISCSI_ITT_MASK (0xfff) +#define ISCSI_ITT_MASK (0x1fff) +#define ISCSI_TOTAL_CMDS_MAX 4096 +/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */ +#define ISCSI_TOTAL_CMDS_MIN 16 #define ISCSI_AGE_SHIFT 28 #define ISCSI_AGE_MASK (0xf << ISCSI_AGE_SHIFT) |