--- /dev/null
+/*
+ * Copyright (C) 2005-2012 Junjiro R. Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * sub-routines for dentry cache
+ */
+
+#include "aufs.h"
+
+static void au_dpage_free(struct au_dpage *dpage)
+{
+ int i;
+ struct dentry **p;
+
+ p = dpage->dentries;
+ for (i = 0; i < dpage->ndentry; i++)
+ dput(*p++);
+ free_page((unsigned long)dpage->dentries);
+}
+
+int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp)
+{
+ int err;
+ void *p;
+
+ err = -ENOMEM;
+ dpages->dpages = kmalloc(sizeof(*dpages->dpages), gfp);
+ if (unlikely(!dpages->dpages))
+ goto out;
+
+ p = (void *)__get_free_page(gfp);
+ if (unlikely(!p))
+ goto out_dpages;
+
+ dpages->dpages[0].ndentry = 0;
+ dpages->dpages[0].dentries = p;
+ dpages->ndpage = 1;
+ return 0; /* success */
+
+out_dpages:
+ kfree(dpages->dpages);
+out:
+ return err;
+}
+
+void au_dpages_free(struct au_dcsub_pages *dpages)
+{
+ int i;
+ struct au_dpage *p;
+
+ p = dpages->dpages;
+ for (i = 0; i < dpages->ndpage; i++)
+ au_dpage_free(p++);
+ kfree(dpages->dpages);
+}
+
+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(!dentry->d_count);
+ dpage->dentries[dpage->ndentry++] = dget_dlock(dentry);
+ return 0; /* success */
+
+out:
+ return err;
+}
+
+int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
+ au_dpages_test test, void *arg)
+{
+ int err;
+ struct dentry *this_parent;
+ struct list_head *next;
+ struct super_block *sb = root->d_sb;
+
+ err = 0;
+ write_seqlock(&rename_lock);
+ this_parent = root;
+ spin_lock(&this_parent->d_lock);
+repeat:
+ next = this_parent->d_subdirs.next;
+resume:
+ if (this_parent->d_sb == sb
+ && !IS_ROOT(this_parent)
+ && au_di(this_parent)
+ && this_parent->d_count
+ && (!test || test(this_parent, arg))) {
+ err = au_dpages_append(dpages, this_parent, GFP_ATOMIC);
+ if (unlikely(err))
+ goto out;
+ }
+
+ while (next != &this_parent->d_subdirs) {
+ struct list_head *tmp = next;
+ struct dentry *dentry = list_entry(tmp, struct dentry,
+ d_u.d_child);
+
+ next = tmp->next;
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ if (dentry->d_count) {
+ if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1,
+ _RET_IP_);
+ this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1,
+ _RET_IP_);
+ goto repeat;
+ }
+ if (dentry->d_sb == sb
+ && au_di(dentry)
+ && (!test || test(dentry, arg)))
+ err = au_dpages_append(dpages, dentry,
+ GFP_ATOMIC);
+ }
+ spin_unlock(&dentry->d_lock);
+ if (unlikely(err))
+ goto out;
+ }
+
+ if (this_parent != root) {
+ struct dentry *tmp;
+ struct dentry *child;
+
+ tmp = this_parent->d_parent;
+ rcu_read_lock();
+ spin_unlock(&this_parent->d_lock);
+ child = this_parent;
+ this_parent = tmp;
+ spin_lock(&this_parent->d_lock);
+ rcu_read_unlock();
+ next = child->d_u.d_child.next;
+ goto resume;
+ }
+
+out:
+ spin_unlock(&this_parent->d_lock);
+ write_sequnlock(&rename_lock);
+ return err;
+}
+
+int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
+ int do_include, au_dpages_test test, void *arg)
+{
+ int err;
+
+ err = 0;
+ write_seqlock(&rename_lock);
+ spin_lock(&dentry->d_lock);
+ if (do_include
+ && dentry->d_count
+ && (!test || test(dentry, arg)))
+ err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
+ spin_unlock(&dentry->d_lock);
+ if (unlikely(err))
+ goto out;
+
+ /*
+ * vfsmount_lock is unnecessary since this is a traverse in a single
+ * mount
+ */
+ while (!IS_ROOT(dentry)) {
+ dentry = dentry->d_parent; /* rename_lock is locked */
+ spin_lock(&dentry->d_lock);
+ if (dentry->d_count
+ && (!test || test(dentry, arg)))
+ err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
+ spin_unlock(&dentry->d_lock);
+ if (unlikely(err))
+ break;
+ }
+
+out:
+ write_sequnlock(&rename_lock);
+ return err;
+}
+
+static inline int au_dcsub_dpages_aufs(struct dentry *dentry, void *arg)
+{
+ return au_di(dentry) && dentry->d_sb == arg;
+}
+
+int au_dcsub_pages_rev_aufs(struct au_dcsub_pages *dpages,
+ struct dentry *dentry, int do_include)
+{
+ return au_dcsub_pages_rev(dpages, dentry, do_include,
+ au_dcsub_dpages_aufs, dentry->d_sb);
+}
+
+int au_test_subdir(struct dentry *d1, struct dentry *d2)
+{
+ struct path path[2] = {
+ {
+ .dentry = d1
+ },
+ {
+ .dentry = d2
+ }
+ };
+
+ return path_is_under(path + 0, path + 1);
+}
git.openpandora.org / pandora-kernel.git / blobdiff