[ofa-general] [PATCH v3] RDMA/nes: Account for freed pbl after hw operation

[Chien Tung]

From: Don Wood <donald.e.wood at intel.com>

Fix occurrences where the software pbl counts were changed
before the hardware was updated.  This bug allowed another thread
to overallocate the hardware resources.

Add proper pbl accounting in case nes_reg_mr failed.

Signed-off-by: Don Wood <donald.e.wood at intel.com>
---
V3 change:

In nes_dealloc_fmr(), check return code from nes_dealloc_mw before
pbl accounting.


diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c
index 4cfb4d9..b42b17a 100644
--- a/drivers/infiniband/hw/nes/nes_verbs.c
+++ b/drivers/infiniband/hw/nes/nes_verbs.c
@@ -551,6 +551,7 @@ static int nes_dealloc_fmr(struct ib_fmr *ibfmr)
 	struct nes_device *nesdev = nesvnic->nesdev;
 	struct nes_adapter *nesadapter = nesdev->nesadapter;
 	int i = 0;
+	int rc;
 
 	/* free the resources */
 	if (nesfmr->leaf_pbl_cnt == 0) {
@@ -572,7 +573,9 @@ static int nes_dealloc_fmr(struct ib_fmr *ibfmr)
 	nesmr->ibmw.rkey = ibfmr->rkey;
 	nesmr->ibmw.uobject = NULL;
 
-	if (nesfmr->nesmr.pbls_used != 0) {
+	rc = nes_dealloc_mw(&nesmr->ibmw);
+
+	if ((rc == 0) && (nesfmr->nesmr.pbls_used != 0)) {
 		spin_lock_irqsave(&nesadapter->pbl_lock, flags);
 		if (nesfmr->nesmr.pbl_4k) {
 			nesadapter->free_4kpbl += nesfmr->nesmr.pbls_used;
@@ -584,7 +587,7 @@ static int nes_dealloc_fmr(struct ib_fmr *ibfmr)
 		spin_unlock_irqrestore(&nesadapter->pbl_lock, flags);
 	}
 
-	return nes_dealloc_mw(&nesmr->ibmw);
+	return rc;
 }
 
 
@@ -1993,7 +1996,16 @@ static int nes_reg_mr(struct nes_device *nesdev, struct nes_pd *nespd,
 			stag, ret, cqp_request->major_code, cqp_request->minor_code);
 	major_code = cqp_request->major_code;
 	nes_put_cqp_request(nesdev, cqp_request);
-
+	if ((!ret || major_code) && pbl_count != 0) {
+		spin_lock_irqsave(&nesadapter->pbl_lock, flags);
+		if (pbl_count > 1)
+			nesadapter->free_4kpbl += pbl_count+1;
+		else if (residual_page_count > 32)
+			nesadapter->free_4kpbl += pbl_count;
+		else
+			nesadapter->free_256pbl += pbl_count;
+		spin_unlock_irqrestore(&nesadapter->pbl_lock, flags);
+	}
 	if (!ret)
 		return -ETIME;
 	else if (major_code)
@@ -2607,24 +2619,6 @@ static int nes_dereg_mr(struct ib_mr *ib_mr)
 	cqp_request->waiting = 1;
 	cqp_wqe = &cqp_request->cqp_wqe;
 
-	spin_lock_irqsave(&nesadapter->pbl_lock, flags);
-	if (nesmr->pbls_used != 0) {
-		if (nesmr->pbl_4k) {
-			nesadapter->free_4kpbl += nesmr->pbls_used;
-			if (nesadapter->free_4kpbl > nesadapter->max_4kpbl) {
-				printk(KERN_ERR PFX "free 4KB PBLs(%u) has exceeded the max(%u)\n",
-						nesadapter->free_4kpbl, nesadapter->max_4kpbl);
-			}
-		} else {
-			nesadapter->free_256pbl += nesmr->pbls_used;
-			if (nesadapter->free_256pbl > nesadapter->max_256pbl) {
-				printk(KERN_ERR PFX "free 256B PBLs(%u) has exceeded the max(%u)\n",
-						nesadapter->free_256pbl, nesadapter->max_256pbl);
-			}
-		}
-	}
-
-	spin_unlock_irqrestore(&nesadapter->pbl_lock, flags);
 	nes_fill_init_cqp_wqe(cqp_wqe, nesdev);
 	set_wqe_32bit_value(cqp_wqe->wqe_words, NES_CQP_WQE_OPCODE_IDX,
 			NES_CQP_DEALLOCATE_STAG | NES_CQP_STAG_VA_TO |
@@ -2642,11 +2636,6 @@ static int nes_dereg_mr(struct ib_mr *ib_mr)
 			" CQP Major:Minor codes = 0x%04X:0x%04X\n",
 			ib_mr->rkey, ret, cqp_request->major_code, cqp_request->minor_code);
 
-	nes_free_resource(nesadapter, nesadapter->allocated_mrs,
-			(ib_mr->rkey & 0x0fffff00) >> 8);
-
-	kfree(nesmr);
-
 	major_code = cqp_request->major_code;
 	minor_code = cqp_request->minor_code;
 
@@ -2662,8 +2651,33 @@ static int nes_dereg_mr(struct ib_mr *ib_mr)
 				" to destroy STag, ib_mr=%p, rkey = 0x%08X\n",
 				major_code, minor_code, ib_mr, ib_mr->rkey);
 		return -EIO;
-	} else
-		return 0;
+	}
+
+	if (nesmr->pbls_used != 0) {
+		spin_lock_irqsave(&nesadapter->pbl_lock, flags);
+		if (nesmr->pbl_4k) {
+			nesadapter->free_4kpbl += nesmr->pbls_used;
+			if (nesadapter->free_4kpbl > nesadapter->max_4kpbl)
+				printk(KERN_ERR PFX "free 4KB PBLs(%u) has "
+					"exceeded the max(%u)\n",
+					nesadapter->free_4kpbl,
+					nesadapter->max_4kpbl);
+		} else {
+			nesadapter->free_256pbl += nesmr->pbls_used;
+			if (nesadapter->free_256pbl > nesadapter->max_256pbl)
+				printk(KERN_ERR PFX "free 256B PBLs(%u) has "
+					"exceeded the max(%u)\n",
+					nesadapter->free_256pbl,
+					nesadapter->max_256pbl);
+		}
+		spin_unlock_irqrestore(&nesadapter->pbl_lock, flags);
+	}
+	nes_free_resource(nesadapter, nesadapter->allocated_mrs,
+			(ib_mr->rkey & 0x0fffff00) >> 8);
+
+	kfree(nesmr);
+
+	return 0;
 }
 
 
-- 
1.5.3.3