AFS: Use d_automount() rather than abusing follow_link()
David Howells [Fri, 14 Jan 2011 19:04:05 +0000 (19:04 +0000)]
Make AFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/afs/dir.c
fs/afs/inode.c
fs/afs/internal.h
fs/afs/mntpt.c

index e6a4ab9..20c106f 100644 (file)
@@ -66,6 +66,7 @@ const struct dentry_operations afs_fs_dentry_operations = {
        .d_revalidate   = afs_d_revalidate,
        .d_delete       = afs_d_delete,
        .d_release      = afs_d_release,
+       .d_automount    = afs_d_automount,
 };
 
 #define AFS_DIR_HASHTBL_SIZE   128
index 0747339..db66c52 100644 (file)
@@ -184,7 +184,8 @@ struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
        inode->i_generation     = 0;
 
        set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
-       inode->i_flags |= S_NOATIME;
+       set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+       inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
        unlock_new_inode(inode);
        _leave(" = %p", inode);
        return inode;
index 58c633b..5a9b684 100644 (file)
@@ -592,6 +592,7 @@ extern const struct inode_operations afs_mntpt_inode_operations;
 extern const struct inode_operations afs_autocell_inode_operations;
 extern const struct file_operations afs_mntpt_file_operations;
 
+extern struct vfsmount *afs_d_automount(struct path *);
 extern int afs_mntpt_check_symlink(struct afs_vnode *, struct key *);
 extern void afs_mntpt_kill_timer(void);
 
index f3e891d..d23b2e3 100644 (file)
@@ -24,7 +24,6 @@ static struct dentry *afs_mntpt_lookup(struct inode *dir,
                                       struct dentry *dentry,
                                       struct nameidata *nd);
 static int afs_mntpt_open(struct inode *inode, struct file *file);
-static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd);
 static void afs_mntpt_expiry_timed_out(struct work_struct *work);
 
 const struct file_operations afs_mntpt_file_operations = {
@@ -34,13 +33,11 @@ const struct file_operations afs_mntpt_file_operations = {
 
 const struct inode_operations afs_mntpt_inode_operations = {
        .lookup         = afs_mntpt_lookup,
-       .follow_link    = afs_mntpt_follow_link,
        .readlink       = page_readlink,
        .getattr        = afs_getattr,
 };
 
 const struct inode_operations afs_autocell_inode_operations = {
-       .follow_link    = afs_mntpt_follow_link,
        .getattr        = afs_getattr,
 };
 
@@ -88,6 +85,7 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)
                _debug("symlink is a mountpoint");
                spin_lock(&vnode->lock);
                set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+               vnode->vfs_inode.i_flags |= S_AUTOMOUNT;
                spin_unlock(&vnode->lock);
        }
 
@@ -238,49 +236,37 @@ error_no_devname:
 }
 
 /*
- * follow a link from a mountpoint directory, thus causing it to be mounted
+ * handle an automount point
  */
-static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd)
+struct vfsmount *afs_d_automount(struct path *path)
 {
        struct vfsmount *newmnt;
        int err;
 
-       _enter("%p{%s},{%s:%p{%s},}",
-              dentry,
-              dentry->d_name.name,
-              nd->path.mnt->mnt_devname,
-              dentry,
-              nd->path.dentry->d_name.name);
-
-       dput(nd->path.dentry);
-       nd->path.dentry = dget(dentry);
+       _enter("{%s,%s}", path->mnt->mnt_devname, path->dentry->d_name.name);
 
-       newmnt = afs_mntpt_do_automount(nd->path.dentry);
-       if (IS_ERR(newmnt)) {
-               path_put(&nd->path);
-               return (void *)newmnt;
-       }
+       newmnt = afs_mntpt_do_automount(path->dentry);
+       if (IS_ERR(newmnt))
+               return newmnt;
 
        mntget(newmnt);
-       err = do_add_mount(newmnt, &nd->path, MNT_SHRINKABLE, &afs_vfsmounts);
+       err = do_add_mount(newmnt, path, MNT_SHRINKABLE, &afs_vfsmounts);
        switch (err) {
        case 0:
-               path_put(&nd->path);
-               nd->path.mnt = newmnt;
-               nd->path.dentry = dget(newmnt->mnt_root);
                queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
                                   afs_mntpt_expiry_timeout * HZ);
-               break;
+               _leave(" = %p {%s}", newmnt, newmnt->mnt_devname);
+               return newmnt;
        case -EBUSY:
                /* someone else made a mount here whilst we were busy */
-               err = follow_down(&nd->path, false);
+               mntput(newmnt);
+               _leave(" = NULL [EBUSY]");
+               return NULL;
        default:
                mntput(newmnt);
-               break;
+               _leave(" = %d", err);
+               return ERR_PTR(err);
        }
-
-       _leave(" = %d", err);
-       return ERR_PTR(err);
 }
 
 /*