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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
	josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com,
	tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org,
	Valdis.Kletnieks@vt.edu, dhowells@redhat.com,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH tip/core/rcu 6/8] vfs: apply lockdep-based checking to rcu_dereference() uses
Date: Mon,  4 Jan 2010 18:04:09 -0800	[thread overview]
Message-ID: <12626570514009-git-send-email-> (raw)
In-Reply-To: <20100105020345.GA32114@linux.vnet.ibm.com>

From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and
fcheck_files().

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 fs/file.c               |    2 +-
 include/linux/fdtable.h |    7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/file.c b/fs/file.c
index f313314..c506bc6 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -477,7 +477,7 @@ repeat:
 	error = fd;
 #if 1
 	/* Sanity check */
-	if (rcu_dereference(fdt->fd[fd]) != NULL) {
+	if (rcu_dereference_raw(fdt->fd[fd]) != NULL) {
 		printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd);
 		rcu_assign_pointer(fdt->fd[fd], NULL);
 	}
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index a2ec74b..e498a0c 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -57,7 +57,10 @@ struct files_struct {
 	struct file * fd_array[NR_OPEN_DEFAULT];
 };
 
-#define files_fdtable(files) (rcu_dereference((files)->fdt))
+#define files_fdtable(files) \
+	(rcu_dereference_check((files)->fdt, \
+			       rcu_read_lock_held() || \
+			       lockdep_is_held(&(files)->file_lock)))
 
 struct file_operations;
 struct vfsmount;
@@ -78,7 +81,7 @@ static inline struct file * fcheck_files(struct files_struct *files, unsigned in
 	struct fdtable *fdt = files_fdtable(files);
 
 	if (fd < fdt->max_fds)
-		file = rcu_dereference(fdt->fd[fd]);
+		file = rcu_dereference_check(fdt->fd[fd], rcu_read_lock_held() || lockdep_is_held(&files->file_lock));
 	return file;
 }
 
-- 
1.5.2.5


  parent reply	other threads:[~2010-01-05  2:04 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-05  2:03 [PATCH tip/core/rcu 0/8] rcu: add lockdep-based diagnostics to rcu_dereference() Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 1/8] rcu: introduce lockdep-based checking to RCU read-side primitives Paul E. McKenney
2010-01-13 10:28   ` [tip:core/rcu] rcu: Introduce " tip-bot for Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 2/8] rcu: add lockdep-enabled variants of rcu_dereference() Paul E. McKenney
2010-01-13 10:28   ` [tip:core/rcu] rcu: Add " tip-bot for Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 3/8] rcu: disable lockdep checking in RCU list-traversal primitives Paul E. McKenney
2010-01-13 10:29   ` [tip:core/rcu] rcu: Disable " tip-bot for Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 4/8] net: add checking to rcu_dereference() primitives Paul E. McKenney
2010-01-13 10:30   ` [tip:core/rcu] net: Add " tip-bot for Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 5/8] sched: use lockdep-based checking on rcu_dereference() Paul E. McKenney
2010-01-13 10:29   ` [tip:core/rcu] sched: Use " tip-bot for Paul E. McKenney
2010-01-05  2:04 ` Paul E. McKenney [this message]
2010-01-13 10:30   ` [tip:core/rcu] vfs: Apply lockdep-based checking to rcu_dereference() uses tip-bot for Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 7/8] radix-tree: disable RCU lockdep checking in radix tree Paul E. McKenney
2010-01-13 10:29   ` [tip:core/rcu] radix-tree: Disable " tip-bot for Paul E. McKenney
2010-01-05  2:04 ` [PATCH tip/core/rcu 8/8] idr: apply lockdep-based diagnostics to rcu_dereference() uses Paul E. McKenney
2010-01-13 10:29   ` [tip:core/rcu] idr: Apply " tip-bot for Paul E. McKenney
2010-01-13  9:22 ` [PATCH tip/core/rcu 0/8] rcu: add lockdep-based diagnostics to rcu_dereference() Ingo Molnar
2010-01-13 16:17   ` Paul E. McKenney
2010-01-13 16:37     ` Ingo Molnar

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