[openib-general][patch review] srp: fmr implementation,
Roland Dreier
rdreier at cisco.com
Fri May 5 13:27:23 PDT 2006
I'm testing the patch below, which I think does the right thing for
aborts and device resets. What do you think?
diff-tree 70e37d747deddb32d3b3560b42c5fd26a6118967 (from ebdb3a3d034fdea7c296f96fb0b07093ff75a989)
Author: Roland Dreier <rolandd at cisco.com>
Date: Fri May 5 13:26:13 2006 -0700
IB/srp: Fix tracking of pending requests during error handling
Signed-off-by: Roland Dreier <rolandd at cisco.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 5bb5574..c32ce43 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -409,6 +409,34 @@ static int srp_connect_target(struct srp
}
}
+static void srp_unmap_data(struct scsi_cmnd *scmnd,
+ struct srp_target_port *target,
+ struct srp_request *req)
+{
+ struct scatterlist *scat;
+ int nents;
+
+ if (!scmnd->request_buffer ||
+ (scmnd->sc_data_direction != DMA_TO_DEVICE &&
+ scmnd->sc_data_direction != DMA_FROM_DEVICE))
+ return;
+
+ /*
+ * This handling of non-SG commands can be killed when the
+ * SCSI midlayer no longer generates non-SG commands.
+ */
+ if (likely(scmnd->use_sg)) {
+ nents = scmnd->use_sg;
+ scat = scmnd->request_buffer;
+ } else {
+ nents = 1;
+ scat = &req->fake_sg;
+ }
+
+ dma_unmap_sg(target->srp_host->dev->dma_device, scat, nents,
+ scmnd->sc_data_direction);
+}
+
static int srp_reconnect_target(struct srp_target_port *target)
{
struct ib_cm_id *new_cm_id;
@@ -455,16 +483,16 @@ static int srp_reconnect_target(struct s
list_for_each_entry(req, &target->req_queue, list) {
req->scmnd->result = DID_RESET << 16;
req->scmnd->scsi_done(req->scmnd);
+ srp_unmap_data(req->scmnd, target, req);
}
target->rx_head = 0;
target->tx_head = 0;
target->tx_tail = 0;
- target->req_head = 0;
- for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
- target->req_ring[i].next = i + 1;
- target->req_ring[SRP_SQ_SIZE - 1].next = -1;
+ INIT_LIST_HEAD(&target->free_reqs);
INIT_LIST_HEAD(&target->req_queue);
+ for (i = 0; i < SRP_SQ_SIZE; ++i)
+ list_add_tail(&target->req_ring[i].list, &target->free_reqs);
ret = srp_connect_target(target);
if (ret)
@@ -589,40 +617,10 @@ static int srp_map_data(struct scsi_cmnd
return len;
}
-static void srp_unmap_data(struct scsi_cmnd *scmnd,
- struct srp_target_port *target,
- struct srp_request *req)
-{
- struct scatterlist *scat;
- int nents;
-
- if (!scmnd->request_buffer ||
- (scmnd->sc_data_direction != DMA_TO_DEVICE &&
- scmnd->sc_data_direction != DMA_FROM_DEVICE))
- return;
-
- /*
- * This handling of non-SG commands can be killed when the
- * SCSI midlayer no longer generates non-SG commands.
- */
- if (likely(scmnd->use_sg)) {
- nents = scmnd->use_sg;
- scat = scmnd->request_buffer;
- } else {
- nents = 1;
- scat = &req->fake_sg;
- }
-
- dma_unmap_sg(target->srp_host->dev->dma_device, scat, nents,
- scmnd->sc_data_direction);
-}
-
-static void srp_remove_req(struct srp_target_port *target, struct srp_request *req,
- int index)
+static void srp_remove_req(struct srp_target_port *target, struct srp_request *req)
{
- list_del(&req->list);
- req->next = target->req_head;
- target->req_head = index;
+ srp_unmap_data(req->scmnd, target, req);
+ list_move_tail(&req->list, &target->free_reqs);
}
static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp)
@@ -647,7 +645,7 @@ static void srp_process_rsp(struct srp_t
req->tsk_status = rsp->data[3];
complete(&req->done);
} else {
- scmnd = req->scmnd;
+ scmnd = req->scmnd;
if (!scmnd)
printk(KERN_ERR "Null scmnd for RSP w/tag %016llx\n",
(unsigned long long) rsp->tag);
@@ -665,14 +663,11 @@ static void srp_process_rsp(struct srp_t
else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
scmnd->resid = be32_to_cpu(rsp->data_in_res_cnt);
- srp_unmap_data(scmnd, target, req);
-
if (!req->tsk_mgmt) {
- req->scmnd = NULL;
scmnd->host_scribble = (void *) -1L;
scmnd->scsi_done(scmnd);
- srp_remove_req(target, req, rsp->tag & ~SRP_TAG_TSK_MGMT);
+ srp_remove_req(target, req);
} else
req->cmd_done = 1;
}
@@ -859,7 +854,6 @@ static int srp_queuecommand(struct scsi_
struct srp_request *req;
struct srp_iu *iu;
struct srp_cmd *cmd;
- long req_index;
int len;
if (target->state == SRP_TARGET_CONNECTING)
@@ -879,22 +873,20 @@ static int srp_queuecommand(struct scsi_
dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
SRP_MAX_IU_LEN, DMA_TO_DEVICE);
- req_index = target->req_head;
+ req = list_entry(target->free_reqs.next, struct srp_request, list);
scmnd->scsi_done = done;
scmnd->result = 0;
- scmnd->host_scribble = (void *) req_index;
+ scmnd->host_scribble = (void *) (long) req->index;
cmd = iu->buf;
memset(cmd, 0, sizeof *cmd);
cmd->opcode = SRP_CMD;
cmd->lun = cpu_to_be64((u64) scmnd->device->lun << 48);
- cmd->tag = req_index;
+ cmd->tag = req->index;
memcpy(cmd->cdb, scmnd->cmnd, scmnd->cmd_len);
- req = &target->req_ring[req_index];
-
req->scmnd = scmnd;
req->cmd = iu;
req->cmd_done = 0;
@@ -919,8 +911,7 @@ static int srp_queuecommand(struct scsi_
goto err_unmap;
}
- target->req_head = req->next;
- list_add_tail(&req->list, &target->req_queue);
+ list_move_tail(&req->list, &target->req_queue);
return 0;
@@ -1143,30 +1134,20 @@ static int srp_cm_handler(struct ib_cm_i
return 0;
}
-static int srp_send_tsk_mgmt(struct scsi_cmnd *scmnd, u8 func)
+static int srp_send_tsk_mgmt(struct srp_target_port *target,
+ struct srp_request *req, u8 func)
{
- struct srp_target_port *target = host_to_target(scmnd->device->host);
- struct srp_request *req;
struct srp_iu *iu;
struct srp_tsk_mgmt *tsk_mgmt;
- int req_index;
- int ret = FAILED;
spin_lock_irq(target->scsi_host->host_lock);
if (target->state == SRP_TARGET_DEAD ||
target->state == SRP_TARGET_REMOVED) {
- scmnd->result = DID_BAD_TARGET << 16;
+ req->scmnd->result = DID_BAD_TARGET << 16;
goto out;
}
- if (scmnd->host_scribble == (void *) -1L)
- goto out;
-
- req_index = (long) scmnd->host_scribble;
- printk(KERN_ERR "Abort for req_index %d\n", req_index);
-
- req = &target->req_ring[req_index];
init_completion(&req->done);
iu = __srp_get_tx_iu(target);
@@ -1177,10 +1158,10 @@ static int srp_send_tsk_mgmt(struct scsi
memset(tsk_mgmt, 0, sizeof *tsk_mgmt);
tsk_mgmt->opcode = SRP_TSK_MGMT;
- tsk_mgmt->lun = cpu_to_be64((u64) scmnd->device->lun << 48);
- tsk_mgmt->tag = req_index | SRP_TAG_TSK_MGMT;
+ tsk_mgmt->lun = cpu_to_be64((u64) req->scmnd->device->lun << 48);
+ tsk_mgmt->tag = req->index | SRP_TAG_TSK_MGMT;
tsk_mgmt->tsk_mgmt_func = func;
- tsk_mgmt->task_tag = req_index;
+ tsk_mgmt->task_tag = req->index;
if (__srp_post_send(target, iu, sizeof *tsk_mgmt))
goto out;
@@ -1188,37 +1169,85 @@ static int srp_send_tsk_mgmt(struct scsi
req->tsk_mgmt = iu;
spin_unlock_irq(target->scsi_host->host_lock);
+
if (!wait_for_completion_timeout(&req->done,
msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS)))
- return FAILED;
- spin_lock_irq(target->scsi_host->host_lock);
+ return -1;
- if (req->cmd_done) {
- srp_remove_req(target, req, req_index);
- scmnd->scsi_done(scmnd);
- } else if (!req->tsk_status) {
- srp_remove_req(target, req, req_index);
- scmnd->result = DID_ABORT << 16;
- ret = SUCCESS;
- }
+ return 0;
out:
spin_unlock_irq(target->scsi_host->host_lock);
- return ret;
+ return -1;
+}
+
+static int srp_find_req(struct srp_target_port *target,
+ struct scsi_cmnd *scmnd,
+ struct srp_request **req)
+{
+ if (scmnd->host_scribble == (void *) -1L)
+ return -1;
+
+ *req = &target->req_ring[(long) scmnd->host_scribble];
+
+ return 0;
}
static int srp_abort(struct scsi_cmnd *scmnd)
{
+ struct srp_target_port *target = host_to_target(scmnd->device->host);
+ struct srp_request *req;
+ int ret = SUCCESS;
+
printk(KERN_ERR "SRP abort called\n");
- return srp_send_tsk_mgmt(scmnd, SRP_TSK_ABORT_TASK);
+ if (srp_find_req(target, scmnd, &req))
+ return FAILED;
+ if (srp_send_tsk_mgmt(target, req, SRP_TSK_ABORT_TASK))
+ return FAILED;
+
+ spin_lock_irq(target->scsi_host->host_lock);
+
+ if (req->cmd_done) {
+ srp_remove_req(target, req);
+ scmnd->scsi_done(scmnd);
+ } else if (!req->tsk_status) {
+ srp_remove_req(target, req);
+ scmnd->result = DID_ABORT << 16;
+ } else
+ ret = FAILED;
+
+ spin_unlock_irq(target->scsi_host->host_lock);
+
+ return ret;
}
static int srp_reset_device(struct scsi_cmnd *scmnd)
{
+ struct srp_target_port *target = host_to_target(scmnd->device->host);
+ struct srp_request *req, *tmp;
+
printk(KERN_ERR "SRP reset_device called\n");
- return srp_send_tsk_mgmt(scmnd, SRP_TSK_LUN_RESET);
+ if (srp_find_req(target, scmnd, &req))
+ return FAILED;
+ if (srp_send_tsk_mgmt(target, req, SRP_TSK_LUN_RESET))
+ return FAILED;
+ if (req->tsk_status)
+ return FAILED;
+
+ spin_lock_irq(target->scsi_host->host_lock);
+
+ list_for_each_entry_safe(req, tmp, &target->req_queue, list)
+ if (req->scmnd->device == scmnd->device) {
+ req->scmnd->result = DID_RESET << 16;
+ scmnd->scsi_done(scmnd);
+ srp_remove_req(target, req);
+ }
+
+ spin_unlock_irq(target->scsi_host->host_lock);
+
+ return SUCCESS;
}
static int srp_reset_host(struct scsi_cmnd *scmnd)
@@ -1518,10 +1547,12 @@ static ssize_t srp_create_target(struct
INIT_WORK(&target->work, srp_reconnect_work, target);
- for (i = 0; i < SRP_SQ_SIZE - 1; ++i)
- target->req_ring[i].next = i + 1;
- target->req_ring[SRP_SQ_SIZE - 1].next = -1;
+ INIT_LIST_HEAD(&target->free_reqs);
INIT_LIST_HEAD(&target->req_queue);
+ for (i = 0; i < SRP_SQ_SIZE; ++i) {
+ target->req_ring[i].index = i;
+ list_add_tail(&target->req_ring[i].list, &target->free_reqs);
+ }
ret = srp_parse_options(buf, target);
if (ret)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index bd7f7c3..c5cd43a 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -101,7 +101,7 @@ struct srp_request {
*/
struct scatterlist fake_sg;
struct completion done;
- short next;
+ short index;
u8 cmd_done;
u8 tsk_status;
};
@@ -133,7 +133,7 @@ struct srp_target_port {
unsigned tx_tail;
struct srp_iu *tx_ring[SRP_SQ_SIZE + 1];
- int req_head;
+ struct list_head free_reqs;
struct list_head req_queue;
struct srp_request req_ring[SRP_SQ_SIZE];
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