[PATCH] add a file_permission helper

A few more callers of permission() just want to check for a different access
pattern on an already open file.  This patch adds a wrapper for permission()
that takes a file in preparation of per-mount read-only support and to clean
up the callers a little.  The helper is not intended for new code, everything
without the interface set in stone should use vfs_permission()

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 8ae0db6..2568eb4 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -150,7 +150,7 @@
 
 		/* if the binary is not readable than enforce mm->dumpable=0
 		   regardless of the interpreter's permissions */
-		if (permission(bprm->file->f_dentry->d_inode, MAY_READ, NULL))
+		if (file_permission(bprm->file, MAY_READ))
 			bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 
 		allow_write_access(bprm->file);