static struct dentry *get_next_positive_subdir(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
struct list_head *next;
struct dentry *p, *q;
spin_lock(&sbi->lookup_lock);
if (prev == NULL) {
spin_lock(&root->d_lock);
prev = dget_dlock(root);
next = prev->d_subdirs.next;
p = prev;
goto start;
}
p = prev;
spin_lock(&p->d_lock);
again:
next = p->d_u.d_child.next;
start:
if (next == &root->d_subdirs) {
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return NULL;
}
q = list_entry(next, struct dentry, d_u.d_child);
spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
if (!simple_positive(q)) {
spin_unlock(&p->d_lock);
lock_set_subclass(&q->d_lock.dep_map, 0, _RET_IP_);
p = q;
goto again;
}
dget_dlock(q);
spin_unlock(&q->d_lock);
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return q;
}
static void sel_remove_entries(struct dentry *de)
{
struct list_head *node;
spin_lock(&de->d_lock);
node = de->d_subdirs.next;
while (node != &de->d_subdirs) {
struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
list_del_init(node);
if (d->d_inode) {
dget_dlock(d);
spin_unlock(&de->d_lock);
spin_unlock(&d->d_lock);
d_delete(d);
simple_unlink(de->d_inode, d);
dput(d);
spin_lock(&de->d_lock);
} else
spin_unlock(&d->d_lock);
node = de->d_subdirs.next;
}
spin_unlock(&de->d_lock);
}
static int remove_file(struct dentry *parent, char *name)
{
struct dentry *tmp;
int ret;
tmp = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(tmp)) {
ret = PTR_ERR(tmp);
goto bail;
}
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
simple_unlink(parent->d_inode, tmp);
} else
spin_unlock(&tmp->d_lock);
ret = 0;
bail:
/*
* We don't expect clients to care about the return value, but
* it's there if they need it.
*/
return ret;
}
/*
* Calculate and dget next entry in top down tree traversal.
*/
static struct dentry *get_next_positive_dentry(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
struct list_head *next;
struct dentry *p, *ret;
if (prev == NULL)
return dget(root);
spin_lock(&sbi->lookup_lock);
relock:
p = prev;
spin_lock(&p->d_lock);
again:
next = p->d_subdirs.next;
if (next == &p->d_subdirs) {
while (1) {
struct dentry *parent;
if (p == root) {
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return NULL;
}
parent = p->d_parent;
if (!spin_trylock(&parent->d_lock)) {
spin_unlock(&p->d_lock);
cpu_relax();
goto relock;
}
spin_unlock(&p->d_lock);
next = p->d_child.next;
p = parent;
if (next != &parent->d_subdirs)
break;
}
}
ret = list_entry(next, struct dentry, d_child);
spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
/* Negative dentry - try next */
if (!simple_positive(ret)) {
spin_unlock(&p->d_lock);
lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_);
p = ret;
goto again;
}
dget_dlock(ret);
spin_unlock(&ret->d_lock);
spin_unlock(&p->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return ret;
}
/*
* Calculate and dget next entry in the subdirs list under root.
*/
static struct dentry *get_next_positive_subdir(struct dentry *prev,
struct dentry *root)
{
struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
struct list_head *next;
struct dentry *q;
spin_lock(&sbi->lookup_lock);
spin_lock(&root->d_lock);
if (prev)
next = prev->d_child.next;
else {
prev = dget_dlock(root);
next = prev->d_subdirs.next;
}
cont:
if (next == &root->d_subdirs) {
spin_unlock(&root->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return NULL;
}
q = list_entry(next, struct dentry, d_child);
spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
/* Already gone or negative dentry (under construction) - try next */
if (!d_count(q) || !simple_positive(q)) {
spin_unlock(&q->d_lock);
next = q->d_child.next;
goto cont;
}
dget_dlock(q);
spin_unlock(&q->d_lock);
spin_unlock(&root->d_lock);
spin_unlock(&sbi->lookup_lock);
dput(prev);
return q;
}
static int remove_file(struct dentry *parent, char *name)
{
struct dentry *tmp;
int ret;
tmp = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(tmp)) {
ret = PTR_ERR(tmp);
goto bail;
}
#if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,36))
spin_lock(&dcache_lock);
#endif
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
#if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,36))
dget_locked(tmp);
#else
dget_dlock(tmp);
#endif
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
#if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,36))
spin_unlock(&dcache_lock);
#endif
simple_unlink(parent->d_inode, tmp);
} else {
spin_unlock(&tmp->d_lock);
#if (LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,36))
spin_unlock(&dcache_lock);
#endif
}
ret = 0;
bail:
/*
* We don't expect clients to care about the return value, but
* it's there if they need it.
*/
return ret;
}
static int au_dpages_append(struct au_dcsub_pages *dpages,
struct dentry *dentry, gfp_t gfp)
{
int err, sz;
struct au_dpage *dpage;
void *p;
dpage = dpages->dpages + dpages->ndpage - 1;
sz = PAGE_SIZE / sizeof(dentry);
if (unlikely(dpage->ndentry >= sz)) {
AuLabel(new dpage);
err = -ENOMEM;
sz = dpages->ndpage * sizeof(*dpages->dpages);
p = au_kzrealloc(dpages->dpages, sz,
sz + sizeof(*dpages->dpages), gfp);
if (unlikely(!p))
goto out;
dpages->dpages = p;
dpage = dpages->dpages + dpages->ndpage;
p = (void *)__get_free_page(gfp);
if (unlikely(!p))
goto out;
dpage->ndentry = 0;
dpage->dentries = p;
dpages->ndpage++;
}
AuDebugOn(!d_count(dentry));
dpage->dentries[dpage->ndentry++] = dget_dlock(dentry);
return 0; /* success */
out:
return err;
}
