scsi: be2iscsi: Fix for crash in beiscsi_eh_device_reset

System crashes when sg_reset is executed in a loop.
CPU: 13 PID: 7073 Comm: sg_reset Tainted: G            E   4.8.0-rc1+ #4
RIP: 0010:[<ffffffffa0825370>]  [<ffffffffa0825370>]
beiscsi_eh_device_reset+0x160/0x520 [be2iscsi]
Call Trace:
[<ffffffff814c7c77>] ? scsi_host_alloc_command+0x47/0xc0
[<ffffffff814caafa>] scsi_try_bus_device_reset+0x2a/0x50
[<ffffffff814cb46e>] scsi_ioctl_reset+0x13e/0x260
[<ffffffff814ca477>] scsi_ioctl+0x137/0x3d0
[<ffffffffa05e4ba2>] sg_ioctl+0x572/0xc20 [sg]
[<ffffffff8123f627>] do_vfs_ioctl+0xa7/0x5d0

The accesses to beiscsi_io_task is being protected in device reset handler
with frwd_lock but the freeing of task can happen under back_lock.

Hold the reference of iscsi_task till invalidation completes.
This prevents use of ICD when invalidation of that ICD is being processed.
Use frwd_lock for iscsi_tasks looping and back_lock to access
beiscsi_io_task structures.

Rewrite mgmt_invalidation_icds to handle allocation and freeing of IOCTL
buffer in one place.

Signed-off-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 61 insertions, 46 deletions

diff --git a/drivers/scsi/be2iscsi/be_mgmt.c b/drivers/scsi/be2iscsi/be_mgmt.c
index 5f02e8db7df0..110c0d076d9a 100644
--- a/drivers/scsi/be2iscsi/be_mgmt.c
+++ b/drivers/scsi/be2iscsi/be_mgmt.c
@@ -128,52 +128,6 @@ unsigned int mgmt_vendor_specific_fw_cmd(struct be_ctrl_info *ctrl,
 	return tag;
 }
 
-unsigned int  mgmt_invalidate_icds(struct beiscsi_hba *phba,
-				struct invldt_cmd_tbl *inv_tbl,
-				unsigned int num_invalidate, unsigned int cid,
-				struct be_dma_mem *nonemb_cmd)
-
-{
-	struct be_ctrl_info *ctrl = &phba->ctrl;
-	struct be_mcc_wrb *wrb;
-	struct be_sge *sge;
-	struct invldt_cmds_params_in *req;
-	unsigned int i, tag;
-
-	if (num_invalidate > BE_INVLDT_CMD_TBL_SZ)
-		return 0;
-
-	mutex_lock(&ctrl->mbox_lock);
-	wrb = alloc_mcc_wrb(phba, &tag);
-	if (!wrb) {
-		mutex_unlock(&ctrl->mbox_lock);
-		return 0;
-	}
-
-	req = nonemb_cmd->va;
-	memset(req, 0, sizeof(*req));
-	sge = nonembedded_sgl(wrb);
-
-	be_wrb_hdr_prepare(wrb, sizeof(*req), false, 1);
-	be_cmd_hdr_prepare(&req->hdr, CMD_SUBSYSTEM_ISCSI,
-			OPCODE_COMMON_ISCSI_ERROR_RECOVERY_INVALIDATE_COMMANDS,
-			sizeof(*req));
-	req->ref_handle = 0;
-	req->cleanup_type = CMD_ISCSI_COMMAND_INVALIDATE;
-	for (i = 0; i < num_invalidate; i++) {
-		req->table[i].icd = inv_tbl[i].icd;
-		req->table[i].cid = inv_tbl[i].cid;
-		req->icd_count++;
-	}
-	sge->pa_hi = cpu_to_le32(upper_32_bits(nonemb_cmd->dma));
-	sge->pa_lo = cpu_to_le32(nonemb_cmd->dma & 0xFFFFFFFF);
-	sge->len = cpu_to_le32(nonemb_cmd->size);
-
-	be_mcc_notify(phba, tag);
-	mutex_unlock(&ctrl->mbox_lock);
-	return tag;
-}
-
 unsigned int mgmt_invalidate_connection(struct beiscsi_hba *phba,
 					 struct beiscsi_endpoint *beiscsi_ep,
 					 unsigned short cid,
@@ -1496,3 +1450,64 @@ void beiscsi_offload_cxn_v2(struct beiscsi_offload_params *params,
 		     (params->dw[offsetof(struct amap_beiscsi_offload_params,
 		      exp_statsn) / 32] + 1));
 }
+
+int beiscsi_mgmt_invalidate_icds(struct beiscsi_hba *phba,
+				 struct invldt_cmd_tbl *inv_tbl,
+				 unsigned int nents)
+{
+	struct be_ctrl_info *ctrl = &phba->ctrl;
+	struct invldt_cmds_params_in *req;
+	struct be_dma_mem nonemb_cmd;
+	struct be_mcc_wrb *wrb;
+	unsigned int i, tag;
+	struct be_sge *sge;
+	int rc;
+
+	if (!nents || nents > BE_INVLDT_CMD_TBL_SZ)
+		return -EINVAL;
+
+	nonemb_cmd.size = sizeof(union be_invldt_cmds_params);
+	nonemb_cmd.va = pci_zalloc_consistent(phba->ctrl.pdev,
+					      nonemb_cmd.size,
+					      &nonemb_cmd.dma);
+	if (!nonemb_cmd.va) {
+		beiscsi_log(phba, KERN_ERR, BEISCSI_LOG_EH,
+			    "BM_%d : invldt_cmds_params alloc failed\n");
+		return -ENOMEM;
+	}
+
+	mutex_lock(&ctrl->mbox_lock);
+	wrb = alloc_mcc_wrb(phba, &tag);
+	if (!wrb) {
+		mutex_unlock(&ctrl->mbox_lock);
+		pci_free_consistent(phba->ctrl.pdev, nonemb_cmd.size,
+				    nonemb_cmd.va, nonemb_cmd.dma);
+		return -ENOMEM;
+	}
+
+	req = nonemb_cmd.va;
+	be_wrb_hdr_prepare(wrb, nonemb_cmd.size, false, 1);
+	be_cmd_hdr_prepare(&req->hdr, CMD_SUBSYSTEM_ISCSI,
+			OPCODE_COMMON_ISCSI_ERROR_RECOVERY_INVALIDATE_COMMANDS,
+			sizeof(*req));
+	req->ref_handle = 0;
+	req->cleanup_type = CMD_ISCSI_COMMAND_INVALIDATE;
+	for (i = 0; i < nents; i++) {
+		req->table[i].icd = inv_tbl[i].icd;
+		req->table[i].cid = inv_tbl[i].cid;
+		req->icd_count++;
+	}
+	sge = nonembedded_sgl(wrb);
+	sge->pa_hi = cpu_to_le32(upper_32_bits(nonemb_cmd.dma));
+	sge->pa_lo = cpu_to_le32(lower_32_bits(nonemb_cmd.dma));
+	sge->len = cpu_to_le32(nonemb_cmd.size);
+
+	be_mcc_notify(phba, tag);
+	mutex_unlock(&ctrl->mbox_lock);
+
+	rc = beiscsi_mccq_compl_wait(phba, tag, NULL, &nonemb_cmd);
+	if (rc != -EBUSY)
+		pci_free_consistent(phba->ctrl.pdev, nonemb_cmd.size,
+				    nonemb_cmd.va, nonemb_cmd.dma);
+	return rc;
+}