[PATCH 02/12] libblock: Use self-contained mutex for disk lock
Sebastian Huber
sebastian.huber at embedded-brains.de
Thu Dec 21 14:09:50 UTC 2017
Update #2843.
---
cpukit/libblock/src/diskdevs.c | 101 ++++++++++++-----------------------------
cpukit/sapi/include/confdefs.h | 9 +---
2 files changed, 32 insertions(+), 78 deletions(-)
diff --git a/cpukit/libblock/src/diskdevs.c b/cpukit/libblock/src/diskdevs.c
index cb1f15707f..836cc4973e 100644
--- a/cpukit/libblock/src/diskdevs.c
+++ b/cpukit/libblock/src/diskdevs.c
@@ -10,7 +10,7 @@
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv at oktet.ru>
*
- * Copyright (c) 2009-2012 embedded brains GmbH.
+ * Copyright (c) 2009, 2017 embedded brains GmbH.
*/
#if HAVE_CONFIG_H
@@ -26,6 +26,7 @@
#include <rtems/diskdevs.h>
#include <rtems/blkdev.h>
#include <rtems/bdbuf.h>
+#include <rtems/thread.h>
#define DISKTAB_INITIAL_SIZE 8
@@ -42,7 +43,7 @@ static rtems_disk_device_table *disktab;
static rtems_device_major_number disktab_size;
/* Mutual exclusion semaphore for disk devices table */
-static rtems_id diskdevs_mutex;
+static rtems_mutex diskdevs_mutex = RTEMS_MUTEX_INITIALIZER("diskdevs");
/* diskdevs data structures protection flag.
* Normally, only table lookup operations performed. It is quite fast, so
@@ -59,33 +60,20 @@ static volatile bool diskdevs_protected;
RTEMS_INTERRUPT_LOCK_DEFINE(static, diskdevs_lock, "diskdevs")
-static rtems_status_code
+static rtems_status_code disk_delete_locked(dev_t dev);
+
+static void
disk_lock(void)
{
- rtems_status_code sc = RTEMS_SUCCESSFUL;
-
- sc = rtems_semaphore_obtain(diskdevs_mutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
- if (sc == RTEMS_SUCCESSFUL) {
- diskdevs_protected = true;
-
- return RTEMS_SUCCESSFUL;
- } else {
- return RTEMS_NOT_CONFIGURED;
- }
+ rtems_mutex_lock(&diskdevs_mutex);
+ diskdevs_protected = true;
}
static void
disk_unlock(void)
{
- rtems_status_code sc = RTEMS_SUCCESSFUL;
-
diskdevs_protected = false;
-
- sc = rtems_semaphore_release(diskdevs_mutex);
- if (sc != RTEMS_SUCCESSFUL) {
- /* FIXME: Error number */
- rtems_fatal_error_occurred(0xdeadbeef);
- }
+ rtems_mutex_unlock(&diskdevs_mutex);
}
static rtems_disk_device *
@@ -247,10 +235,7 @@ rtems_status_code rtems_disk_create_phys(
return RTEMS_INVALID_ADDRESS;
}
- sc = disk_lock();
- if (sc != RTEMS_SUCCESSFUL) {
- return sc;
- }
+ disk_lock();
sc = create_disk(dev, name, &dd, &alloc_name);
if (sc != RTEMS_SUCCESSFUL) {
@@ -272,7 +257,7 @@ rtems_status_code rtems_disk_create_phys(
if (sc != RTEMS_SUCCESSFUL) {
dd->ioctl = null_handler;
- rtems_disk_delete(dev);
+ disk_delete_locked(dev);
disk_unlock();
return sc;
@@ -302,10 +287,7 @@ rtems_status_code rtems_disk_create_log(
rtems_disk_device *dd = NULL;
char *alloc_name = NULL;
- sc = disk_lock();
- if (sc != RTEMS_SUCCESSFUL) {
- return sc;
- }
+ disk_lock();
phys_dd = get_disk_entry(phys, true);
if (phys_dd == NULL) {
@@ -335,7 +317,7 @@ rtems_status_code rtems_disk_create_log(
if (sc != RTEMS_SUCCESSFUL) {
dd->ioctl = null_handler;
- rtems_disk_delete(dev);
+ disk_delete_locked(dev);
disk_unlock();
return sc;
@@ -404,36 +386,37 @@ rtems_disk_cleanup(rtems_disk_device *disk_to_remove)
}
}
-rtems_status_code
-rtems_disk_delete(dev_t dev)
+static rtems_status_code
+disk_delete_locked(dev_t dev)
{
- rtems_status_code sc = RTEMS_SUCCESSFUL;
rtems_disk_device *dd = NULL;
- sc = disk_lock();
- if (sc != RTEMS_SUCCESSFUL) {
- return sc;
- }
-
dd = get_disk_entry(dev, true);
if (dd == NULL) {
- disk_unlock();
-
return RTEMS_INVALID_ID;
}
dd->deleted = true;
rtems_disk_cleanup(dd);
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code
+rtems_disk_delete(dev_t dev)
+{
+ rtems_status_code sc;
+
+ disk_lock();
+ sc = disk_delete_locked(dev);
disk_unlock();
- return RTEMS_SUCCESSFUL;
+ return sc;
}
rtems_disk_device *
rtems_disk_obtain(dev_t dev)
{
- rtems_status_code sc = RTEMS_SUCCESSFUL;
rtems_disk_device *dd = NULL;
rtems_interrupt_lock_context lock_context;
@@ -445,11 +428,9 @@ rtems_disk_obtain(dev_t dev)
} else {
rtems_interrupt_lock_release(&diskdevs_lock, &lock_context);
- sc = disk_lock();
- if (sc == RTEMS_SUCCESSFUL) {
- dd = get_disk_entry(dev, false);
- disk_unlock();
- }
+ disk_lock();
+ dd = get_disk_entry(dev, false);
+ disk_unlock();
}
return dd;
@@ -478,7 +459,6 @@ rtems_disk_release(rtems_disk_device *dd)
rtems_disk_device *
rtems_disk_next(dev_t dev)
{
- rtems_status_code sc = RTEMS_SUCCESSFUL;
rtems_disk_device_table *dtab = NULL;
rtems_device_major_number major = 0;
rtems_device_minor_number minor = 0;
@@ -499,10 +479,7 @@ rtems_disk_next(dev_t dev)
}
}
- sc = disk_lock();
- if (sc != RTEMS_SUCCESSFUL) {
- return NULL;
- }
+ disk_lock();
if (major >= disktab_size) {
disk_unlock();
@@ -547,23 +524,8 @@ rtems_disk_io_initialize(void)
return RTEMS_NO_MEMORY;
}
- diskdevs_protected = false;
- sc = rtems_semaphore_create(
- rtems_build_name('D', 'D', 'E', 'V'),
- 1,
- RTEMS_BINARY_SEMAPHORE | RTEMS_PRIORITY | RTEMS_INHERIT_PRIORITY,
- 0,
- &diskdevs_mutex
- );
- if (sc != RTEMS_SUCCESSFUL) {
- free(disktab);
-
- return RTEMS_NO_MEMORY;
- }
-
sc = rtems_bdbuf_init();
if (sc != RTEMS_SUCCESSFUL) {
- rtems_semaphore_delete(diskdevs_mutex);
free(disktab);
return RTEMS_UNSATISFIED;
@@ -594,9 +556,6 @@ rtems_disk_io_done(void)
}
free(disktab);
- rtems_semaphore_delete(diskdevs_mutex);
-
- diskdevs_mutex = RTEMS_ID_NONE;
disktab = NULL;
disktab_size = 0;
diff --git a/cpukit/sapi/include/confdefs.h b/cpukit/sapi/include/confdefs.h
index 1c993dd099..06e9f74732 100755
--- a/cpukit/sapi/include/confdefs.h
+++ b/cpukit/sapi/include/confdefs.h
@@ -1832,22 +1832,17 @@ extern rtems_initialization_tasks_table Initialization_tasks[];
0 : CONFIGURE_BDBUF_TASK_STACK_SIZE - CONFIGURE_MINIMUM_TASK_STACK_SIZE))
#ifdef RTEMS_BDBUF_USE_PTHREAD
- /*
- * Semaphores:
- * o disk lock
- */
- #define _CONFIGURE_LIBBLOCK_SEMAPHORES 1
+ #define _CONFIGURE_LIBBLOCK_SEMAPHORES 0
#else
/*
* Semaphores:
- * o disk lock
* o bdbuf lock
* o bdbuf sync lock
* o bdbuf access condition
* o bdbuf transfer condition
* o bdbuf buffer condition
*/
- #define _CONFIGURE_LIBBLOCK_SEMAPHORES 6
+ #define _CONFIGURE_LIBBLOCK_SEMAPHORES 5
#endif
#if defined(CONFIGURE_HAS_OWN_BDBUF_TABLE) || \
--
2.12.3
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