/*
- * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2 of the GNU General Public License as
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
*
- * Further, this software is distributed without any warranty that it is
- * free of the rightful claim of any third person regarding infringement
- * or the like. Any license provided herein, whether implied or
- * otherwise, applies only to this software file. Patent licenses, if
- * any, provided herein do not apply to combinations of this program with
- * other software, or any other product whatsoever.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write the Free Software Foundation, Inc., 59
- * Temple Place - Suite 330, Boston MA 02111-1307, USA.
- *
- * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
- * Mountain View, CA 94043, or:
- *
- * http://www.sgi.com
- *
- * For further information regarding this notice, see:
- *
- * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_SUPPORT_MRLOCK_H__
#define __XFS_SUPPORT_MRLOCK_H__
#include <linux/rwsem.h>
-enum { MR_NONE, MR_ACCESS, MR_UPDATE };
-
typedef struct {
struct rw_semaphore mr_lock;
+#ifdef DEBUG
int mr_writer;
+#endif
} mrlock_t;
+#ifdef DEBUG
+#define mrinit(mrp, name) \
+ do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0)
+#else
#define mrinit(mrp, name) \
- ( (mrp)->mr_writer = 0, init_rwsem(&(mrp)->mr_lock) )
+ do { init_rwsem(&(mrp)->mr_lock); } while (0)
+#endif
+
#define mrlock_init(mrp, t,n,s) mrinit(mrp, n)
#define mrfree(mrp) do { } while (0)
-#define mraccess(mrp) mraccessf(mrp, 0)
-#define mrupdate(mrp) mrupdatef(mrp, 0)
-static inline void mraccessf(mrlock_t *mrp, int flags)
+static inline void mraccess_nested(mrlock_t *mrp, int subclass)
{
- down_read(&mrp->mr_lock);
+ down_read_nested(&mrp->mr_lock, subclass);
}
-static inline void mrupdatef(mrlock_t *mrp, int flags)
+static inline void mrupdate_nested(mrlock_t *mrp, int subclass)
{
- down_write(&mrp->mr_lock);
+ down_write_nested(&mrp->mr_lock, subclass);
+#ifdef DEBUG
mrp->mr_writer = 1;
+#endif
}
static inline int mrtryaccess(mrlock_t *mrp)
{
if (!down_write_trylock(&mrp->mr_lock))
return 0;
+#ifdef DEBUG
mrp->mr_writer = 1;
+#endif
return 1;
}
-static inline void mrunlock(mrlock_t *mrp)
+static inline void mrunlock_excl(mrlock_t *mrp)
{
- if (mrp->mr_writer) {
- mrp->mr_writer = 0;
- up_write(&mrp->mr_lock);
- } else {
- up_read(&mrp->mr_lock);
- }
+#ifdef DEBUG
+ mrp->mr_writer = 0;
+#endif
+ up_write(&mrp->mr_lock);
}
-static inline void mrdemote(mrlock_t *mrp)
+static inline void mrunlock_shared(mrlock_t *mrp)
{
- mrp->mr_writer = 0;
- downgrade_write(&mrp->mr_lock);
+ up_read(&mrp->mr_lock);
}
-#ifdef DEBUG
-/*
- * Debug-only routine, without some platform-specific asm code, we can
- * now only answer requests regarding whether we hold the lock for write
- * (reader state is outside our visibility, we only track writer state).
- * Note: means !ismrlocked would give false positivies, so don't do that.
- */
-static inline int ismrlocked(mrlock_t *mrp, int type)
+static inline void mrdemote(mrlock_t *mrp)
{
- if (mrp && type == MR_UPDATE)
- return mrp->mr_writer;
- return 1;
-}
+#ifdef DEBUG
+ mrp->mr_writer = 0;
#endif
+ downgrade_write(&mrp->mr_lock);
+}
#endif /* __XFS_SUPPORT_MRLOCK_H__ */
projects / linux-2.6 / blobdiff