[PATCH 2/6] AFS: Use d_automount() rather than abusing follow_link()

David Howells
2010-07-22T17:59:06Z

Make AFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/afs/dir.c | 1 +
fs/afs/internal.h | 1 +
fs/afs/mntpt.c | 46 +++++++++++++++-------------------------------
3 files changed, 17 insertions(+), 31 deletions(-)

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index b42d5cc..5366f9b 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -65,6 +65,7 @@ static 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
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 5f679b7..2c700dc 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -583,6 +583,7 @@ extern int afs_abort_to_error(u32);
extern const struct inode_operations afs_mntpt_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);

diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index a9e2303..ea9cfee 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -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 = {
@@ -33,7 +32,6 @@ 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,
};
@@ -82,6 +80,7 @@ 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);
}

@@ -205,52 +204,37 @@ 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);
schedule_delayed_work(&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 */
- while (d_mountpoint(nd->path.dentry) &&
- follow_down(&nd->path))
- ;
- err = 0;
+ 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);
}

/*