cache the value of file_inode() in struct file

Note that this thing does *not* contribute to inode refcount;
it's pinned down by dentry.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/open.c b/fs/open.c
index 62f907e3bc36..806d4589559f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -689,7 +689,7 @@ static int do_dentry_open(struct file *f,
                 f->f_mode = FMODE_PATH;
 
         path_get(&f->f_path);
-        inode = file_inode(f);
+        inode = f->f_inode = f->f_path.dentry->d_inode;
         if (f->f_mode & FMODE_WRITE) {
                 error = __get_file_write_access(inode, f->f_path.mnt);
                 if (error)
@@ -752,6 +752,7 @@ cleanup_file:
         path_put(&f->f_path);
         f->f_path.mnt = NULL;
         f->f_path.dentry = NULL;
+        f->f_inode = NULL;
         return error;
 }