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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-02-22 17:04:52 -0800
committerIngo Molnar <mingo@elte.hu>2010-02-25 10:34:48 +0100
commit7dc52157982ab771f40e3c0b7dc55b954c3c2d19 (patch)
treea41e39174d9535f0c678eb36249ceee4a1775d6b /include/linux/fdtable.h
parent497f0ab39cd25bed317b29482c147c967f7ecd1f (diff)
vfs: Apply lockdep-based checking to rcu_dereference() uses
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> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: Alexander Viro <viro@zeniv.linux.org.uk> LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/fdtable.h')
-rw-r--r--include/linux/fdtable.h8
1 files changed, 6 insertions, 2 deletions
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index a2ec74bc4812..144412ffaced 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -57,7 +57,11 @@ 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) || \
+ atomic_read(&files->count) == 1))
struct file_operations;
struct vfsmount;
@@ -78,7 +82,7 @@ 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) || atomic_read(&files->count) == 1);
return file;
}