/*
* returns: -ERRNO if error (returned to user)
* 0: tell VFS to invalidate dentry
* 1: dentry is valid
*/
static int esdfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct path lower_path;
struct path lower_parent_path;
struct dentry *parent_dentry = NULL;
struct dentry *lower_dentry = NULL;
struct dentry *lower_parent_dentry = NULL;
int err = 1;
if (nd && (nd->flags & LOOKUP_RCU))
return -ECHILD;
/* short-circuit if it's root */
spin_lock(&dentry->d_lock);
if (IS_ROOT(dentry)) {
spin_unlock(&dentry->d_lock);
return 1;
}
spin_unlock(&dentry->d_lock);
esdfs_get_lower_path(dentry, &lower_path);
lower_dentry = lower_path.dentry;
esdfs_get_lower_parent(dentry, lower_dentry, &lower_parent_dentry);
parent_dentry = dget_parent(dentry);
esdfs_get_lower_path(parent_dentry, &lower_parent_path);
if (lower_parent_path.dentry != lower_parent_dentry)
goto drop;
/* can't do strcmp if lower is hashed */
spin_lock(&lower_dentry->d_lock);
if (d_unhashed(lower_dentry)) {
spin_unlock(&lower_dentry->d_lock);
goto drop;
}
spin_lock(&dentry->d_lock);
if (lower_dentry->d_name.len != dentry->d_name.len ||
strncasecmp(lower_dentry->d_name.name,
dentry->d_name.name,
dentry->d_name.len) != 0) {
err = 0;
__d_drop(dentry); /* already holding spin lock */
}
spin_unlock(&dentry->d_lock);
spin_unlock(&lower_dentry->d_lock);
esdfs_revalidate_perms(dentry);
goto out;
drop:
d_drop(dentry);
err = 0;
out:
esdfs_put_lower_path(parent_dentry, &lower_parent_path);
dput(parent_dentry);
esdfs_put_lower_parent(dentry, &lower_parent_dentry);
esdfs_put_lower_path(dentry, &lower_path);
return err;
}
/*
* The locking rules in esdfs_rename are complex. We could use a simpler
* superblock-level name-space lock for renames and copy-ups.
*/
static int esdfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int err = 0;
struct dentry *lower_old_dentry = NULL;
struct dentry *lower_new_dentry = NULL;
struct dentry *lower_old_dir_dentry = NULL;
struct dentry *lower_new_dir_dentry = NULL;
struct dentry *trap = NULL;
struct path lower_old_path, lower_new_path;
int mask;
const struct cred *creds =
esdfs_override_creds(ESDFS_SB(old_dir->i_sb), &mask);
if (!creds)
return -ENOMEM;
/* Never rename to or from a pseudo hard link target. */
if (ESDFS_DENTRY_HAS_STUB(old_dentry))
esdfs_get_lower_stub_path(old_dentry, &lower_old_path);
else
esdfs_get_lower_path(old_dentry, &lower_old_path);
if (ESDFS_DENTRY_HAS_STUB(new_dentry))
esdfs_get_lower_stub_path(new_dentry, &lower_new_path);
else
esdfs_get_lower_path(new_dentry, &lower_new_path);
lower_old_dentry = lower_old_path.dentry;
lower_new_dentry = lower_new_path.dentry;
esdfs_get_lower_parent(old_dentry, lower_old_dentry,
&lower_old_dir_dentry);
esdfs_get_lower_parent(new_dentry, lower_new_dentry,
&lower_new_dir_dentry);
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancestor of target */
if (trap == lower_old_dentry) {
err = -EINVAL;
goto out;
}
/* target should not be ancestor of source */
if (trap == lower_new_dentry) {
err = -ENOTEMPTY;
goto out;
}
err = mnt_want_write(lower_old_path.mnt);
if (err)
goto out;
err = mnt_want_write(lower_new_path.mnt);
if (err)
goto out_drop_old_write;
err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry);
if (err)
goto out_err;
esdfs_copy_attr(new_dir, lower_new_dir_dentry->d_inode);
fsstack_copy_inode_size(new_dir, lower_new_dir_dentry->d_inode);
if (new_dir != old_dir) {
esdfs_copy_attr(old_dir,
lower_old_dir_dentry->d_inode);
fsstack_copy_inode_size(old_dir,
lower_old_dir_dentry->d_inode);
}
/* Drop any old links */
if (ESDFS_DENTRY_HAS_STUB(old_dentry))
d_drop(old_dentry);
if (ESDFS_DENTRY_HAS_STUB(new_dentry))
d_drop(new_dentry);
out_err:
mnt_drop_write(lower_new_path.mnt);
out_drop_old_write:
mnt_drop_write(lower_old_path.mnt);
out:
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
esdfs_put_lower_parent(old_dentry, &lower_old_dir_dentry);
esdfs_put_lower_parent(new_dentry, &lower_new_dir_dentry);
esdfs_put_lower_path(old_dentry, &lower_old_path);
esdfs_put_lower_path(new_dentry, &lower_new_path);
esdfs_revert_creds(creds, &mask);
return err;
}