Messages in this thread Patch in this message | | | Date | Wed, 13 Jan 2010 10:30:34 GMT | From | "tip-bot for Paul E. McKenney" <> | Subject | [tip:core/rcu] vfs: Apply lockdep-based checking to rcu_dereference() uses |
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Commit-ID: 9080561f06a244fdc3c644c2524d87e819c45232 Gitweb: http://git.kernel.org/tip/9080561f06a244fdc3c644c2524d87e819c45232 Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> AuthorDate: Mon, 4 Jan 2010 18:04:09 -0800 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 13 Jan 2010 09:42:36 +0100
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: <12626570514009-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- 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 87e1290..38039af 100644 --- a/fs/file.c +++ b/fs/file.c @@ -478,7 +478,7 @@ 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; }
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