/* this @nd *IS* still used */
static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
struct dentry *parent;
char *buf;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false)))
printk(KERN_ERR
"unionfs: put_link failed to revalidate dentry\n");
unionfs_check_dentry(dentry);
#if 0
/* XXX: can't run this check b/c this fxn can receive a poisoned 'nd' PTR */
unionfs_check_nd(nd);
#endif
buf = nd_get_link(nd);
if (!IS_ERR(buf))
kfree(buf);
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
}
static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
char *buf;
int len = PAGE_SIZE, err;
mm_segment_t old_fs;
struct dentry *parent;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
/* This is freed by the put_link method assuming a successful call. */
buf = kmalloc(len, GFP_KERNEL);
if (unlikely(!buf)) {
err = -ENOMEM;
goto out;
}
/* read the symlink, and then we will follow it */
old_fs = get_fs();
set_fs(KERNEL_DS);
err = __unionfs_readlink(dentry, buf, len);
set_fs(old_fs);
if (err < 0) {
kfree(buf);
buf = NULL;
goto out;
}
buf[err] = 0;
nd_set_link(nd, buf);
err = 0;
out:
if (err >= 0) {
unionfs_check_nd(nd);
unionfs_check_dentry(dentry);
}
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
return ERR_PTR(err);
}
/* this @nd *IS* still used */
static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd,
void *cookie)
{
struct dentry *parent;
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
parent = unionfs_lock_parent(dentry, UNIONFS_DMUTEX_PARENT);
unionfs_lock_dentry(dentry, UNIONFS_DMUTEX_CHILD);
if (unlikely(!__unionfs_d_revalidate(dentry, parent, false)))
printk(KERN_ERR
"unionfs: put_link failed to revalidate dentry\n");
unionfs_check_dentry(dentry);
unionfs_check_nd(nd);
kfree(nd_get_link(nd));
unionfs_unlock_dentry(dentry);
unionfs_unlock_parent(dentry, parent);
unionfs_read_unlock(dentry->d_sb);
}
