vfs: split __dentry_open()

Split __dentry_open() into two functions:

  do_dentry_open() - does most of the actual work, doesn't put file on failure
  open_check_o_direct() - after a successful open, checks direct_IO method

This will allow i_op->atomic_open to do just the file initialization and leave
the direct_IO checking to the VFS.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/internal.h b/fs/internal.h
index 8040af4..18bc216 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -100,6 +100,7 @@ extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
 
 extern long do_handle_open(int mountdirfd,
                           struct file_handle __user *ufh, int open_flag);
+extern int open_check_o_direct(struct file *f);
 
 /*
  * inode.c

diff --git a/fs/open.c b/fs/open.c
index d543012..9daa1ce 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -654,10 +654,23 @@ static inline int __get_file_write_access(struct inode *inode,
        return error;
 }
 
-static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
-                                       struct file *f,
-                                       int (*open)(struct inode *, struct file *),
-                                       const struct cred *cred)
+int open_check_o_direct(struct file *f)
+{
+       /* NB: we're sure to have correct a_ops only after f_op->open */
+       if (f->f_flags & O_DIRECT) {
+               if (!f->f_mapping->a_ops ||
+                   ((!f->f_mapping->a_ops->direct_IO) &&
+                   (!f->f_mapping->a_ops->get_xip_mem))) {
+                       return -EINVAL;
+               }
+       }
+       return 0;
+}
+
+static struct file *do_dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+                                  struct file *f,
+                                  int (*open)(struct inode *, struct file *),
+                                  const struct cred *cred)
 {
        static const struct file_operations empty_fops = {};
        struct inode *inode;
@@ -713,16 +726,6 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 
        file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
 
-       /* NB: we're sure to have correct a_ops only after f_op->open */
-       if (f->f_flags & O_DIRECT) {
-               if (!f->f_mapping->a_ops ||
-                   ((!f->f_mapping->a_ops->direct_IO) &&
-                   (!f->f_mapping->a_ops->get_xip_mem))) {
-                       fput(f);
-                       f = ERR_PTR(-EINVAL);
-               }
-       }
-
        return f;
 
 cleanup_all:
@@ -750,6 +753,22 @@ cleanup_file:
        return ERR_PTR(error);
 }
 
+static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+                               struct file *f,
+                               int (*open)(struct inode *, struct file *),
+                               const struct cred *cred)
+{
+       struct file *res = do_dentry_open(dentry, mnt, f, open, cred);
+       if (!IS_ERR(res)) {
+               int error = open_check_o_direct(f);
+               if (error) {
+                       fput(res);
+                       res = ERR_PTR(error);
+               }
+       }
+       return res;
+}
+
 /**
  * lookup_instantiate_filp - instantiates the open intent filp
  * @nd: pointer to nameidata