scsi: qla2xxx: Use mutex protection during qla2x00_sysfs_read_fw_dump()

Add mutex protection to prevent driver from freeing the FW dump buffer
while the extraction is in progress.

[mkp: commit desc]
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_attr.c

@@ -29,24 +29,27 @@ qla2x00_sysfs_read_fw_dump(struct file *filp, struct kobject *kobj,
 	if (!(ha->fw_dump_reading || ha->mctp_dump_reading))
 		return 0;
 
+	mutex_lock(&ha->optrom_mutex);
 	if (IS_P3P_TYPE(ha)) {
 		if (off < ha->md_template_size) {
 			rval = memory_read_from_buffer(buf, count,
 			    &off, ha->md_tmplt_hdr, ha->md_template_size);
-			return rval;
+		} else {
+			off -= ha->md_template_size;
+			rval = memory_read_from_buffer(buf, count,
+			    &off, ha->md_dump, ha->md_dump_size);
 		}
-		off -= ha->md_template_size;
-		rval = memory_read_from_buffer(buf, count,
-		    &off, ha->md_dump, ha->md_dump_size);
-		return rval;
-	} else if (ha->mctp_dumped && ha->mctp_dump_reading)
-		return memory_read_from_buffer(buf, count, &off, ha->mctp_dump,
+	} else if (ha->mctp_dumped && ha->mctp_dump_reading) {
+		rval = memory_read_from_buffer(buf, count, &off, ha->mctp_dump,
 		    MCTP_DUMP_SIZE);
-	else if (ha->fw_dump_reading)
-		return memory_read_from_buffer(buf, count, &off, ha->fw_dump,
+	} else if (ha->fw_dump_reading) {
+		rval = memory_read_from_buffer(buf, count, &off, ha->fw_dump,
 					ha->fw_dump_len);
-	else
-		return 0;
+	} else {
+		rval = 0;
+	}
+	mutex_unlock(&ha->optrom_mutex);
+	return rval;
 }
 
 static ssize_t

drivers/scsi/qla2xxx/qla_init.c

@@ -3234,6 +3234,7 @@ qla2x00_alloc_fw_dump(scsi_qla_host_t *vha)
 			    "Unable to allocate (%d KB) for firmware dump.\n",
 			    dump_size / 1024);
 		} else {
+			mutex_lock(&ha->optrom_mutex);
 			if (ha->fw_dumped) {
 				memcpy(fw_dump, ha->fw_dump, ha->fw_dump_len);
 				vfree(ha->fw_dump);
@@ -3253,8 +3254,10 @@ qla2x00_alloc_fw_dump(scsi_qla_host_t *vha)
 				    "Allocated (%d KB) for firmware dump.\n",
 				    dump_size / 1024);
 
-				if (IS_QLA27XX(ha) || IS_QLA28XX(ha))
+				if (IS_QLA27XX(ha) || IS_QLA28XX(ha)) {
+					mutex_unlock(&ha->optrom_mutex);
 					return;
+				}
 
 				ha->fw_dump->signature[0] = 'Q';
 				ha->fw_dump->signature[1] = 'L';
@@ -3277,6 +3280,7 @@ qla2x00_alloc_fw_dump(scsi_qla_host_t *vha)
 					htonl(offsetof
 					    (struct qla2xxx_fw_dump, isp));
 			}
+			mutex_unlock(&ha->optrom_mutex);
 		}
 	}
 }