1 files changed, 273 insertions, 0 deletions
diff --git a/fs/aufs/module.c b/fs/aufs/module.c
new file mode 100644
index 000000000000..7245197a6cbf
--- /dev/null
+++ b/fs/aufs/module.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005-2020 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * module global variables and operations
+ */
+
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include "aufs.h"
+
+/* shrinkable realloc */
+void *au_krealloc(void *p, unsigned int new_sz, gfp_t gfp, int may_shrink)
+{
+	size_t sz;
+	int diff;
+
+	sz = 0;
+	diff = -1;
+	if (p) {
+#if 0 /* unused */
+		if (!new_sz) {
+			au_kfree_rcu(p);
+			p = NULL;
+			goto out;
+		}
+#else
+		AuDebugOn(!new_sz);
+#endif
+		sz = ksize(p);
+		diff = au_kmidx_sub(sz, new_sz);
+	}
+	if (sz && !diff)
+		goto out;
+
+	if (sz < new_sz)
+		/* expand or SLOB */
+		p = krealloc(p, new_sz, gfp);
+	else if (new_sz < sz && may_shrink) {
+		/* shrink */
+		void *q;
+
+		q = kmalloc(new_sz, gfp);
+		if (q) {
+			if (p) {
+				memcpy(q, p, new_sz);
+				au_kfree_try_rcu(p);
+			}
+			p = q;
+		} else
+			p = NULL;
+	}
+
+out:
+	return p;
+}
+
+void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp,
+		   int may_shrink)
+{
+	p = au_krealloc(p, new_sz, gfp, may_shrink);
+	if (p && new_sz > nused)
+		memset(p + nused, 0, new_sz - nused);
+	return p;
+}
+
+/* ---------------------------------------------------------------------- */
+/*
+ * aufs caches
+ */
+struct kmem_cache *au_cache[AuCache_Last];
+
+static void au_cache_fin(void)
+{
+	int i;
+
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+
+	/* excluding AuCache_HNOTIFY */
+	BUILD_BUG_ON(AuCache_HNOTIFY + 1 != AuCache_Last);
+	for (i = 0; i < AuCache_HNOTIFY; i++) {
+		kmem_cache_destroy(au_cache[i]);
+		au_cache[i] = NULL;
+	}
+}
+
+static int __init au_cache_init(void)
+{
+	au_cache[AuCache_DINFO] = AuCacheCtor(au_dinfo, au_di_init_once);
+	if (au_cache[AuCache_DINFO])
+		/* SLAB_DESTROY_BY_RCU */
+		au_cache[AuCache_ICNTNR] = AuCacheCtor(au_icntnr,
+						       au_icntnr_init_once);
+	if (au_cache[AuCache_ICNTNR])
+		au_cache[AuCache_FINFO] = AuCacheCtor(au_finfo,
+						      au_fi_init_once);
+	if (au_cache[AuCache_FINFO])
+		au_cache[AuCache_VDIR] = AuCache(au_vdir);
+	if (au_cache[AuCache_VDIR])
+		au_cache[AuCache_DEHSTR] = AuCache(au_vdir_dehstr);
+	if (au_cache[AuCache_DEHSTR])
+		return 0;
+
+	au_cache_fin();
+	return -ENOMEM;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int au_dir_roflags;
+
+#ifdef CONFIG_AUFS_SBILIST
+/*
+ * iterate_supers_type() doesn't protect us from
+ * remounting (branch management)
+ */
+struct hlist_bl_head au_sbilist;
+#endif
+
+/*
+ * functions for module interface.
+ */
+MODULE_LICENSE("GPL");
+/* MODULE_LICENSE("GPL v2"); */
+MODULE_AUTHOR("Junjiro R. Okajima <aufs-users@lists.sourceforge.net>");
+MODULE_DESCRIPTION(AUFS_NAME
+	" -- Advanced multi layered unification filesystem");
+MODULE_VERSION(AUFS_VERSION);
+MODULE_ALIAS_FS(AUFS_NAME);
+
+/* this module parameter has no meaning when SYSFS is disabled */
+int sysaufs_brs = 1;
+MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN");
+module_param_named(brs, sysaufs_brs, int, 0444);
+
+/* this module parameter has no meaning when USER_NS is disabled */
+bool au_userns;
+MODULE_PARM_DESC(allow_userns, "allow unprivileged to mount under userns");
+module_param_named(allow_userns, au_userns, bool, 0444);
+
+/* ---------------------------------------------------------------------- */
+
+static char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */
+
+int au_seq_path(struct seq_file *seq, struct path *path)
+{
+	int err;
+
+	err = seq_path(seq, path, au_esc_chars);
+	if (err >= 0)
+		err = 0;
+	else
+		err = -ENOMEM;
+
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int __init aufs_init(void)
+{
+	int err, i;
+	char *p;
+
+	p = au_esc_chars;
+	for (i = 1; i <= ' '; i++)
+		*p++ = i;
+	*p++ = '\\';
+	*p++ = '\x7f';
+	*p = 0;
+
+	au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE);
+
+	memcpy(aufs_iop_nogetattr, aufs_iop, sizeof(aufs_iop));
+	for (i = 0; i < AuIop_Last; i++)
+		aufs_iop_nogetattr[i].getattr = NULL;
+
+	memset(au_cache, 0, sizeof(au_cache));	/* including hnotify */
+
+	au_sbilist_init();
+	sysaufs_brs_init();
+	au_debug_init();
+	au_dy_init();
+	err = sysaufs_init();
+	if (unlikely(err))
+		goto out;
+	err = dbgaufs_init();
+	if (unlikely(err))
+		goto out_sysaufs;
+	err = au_procfs_init();
+	if (unlikely(err))
+		goto out_dbgaufs;
+	err = au_wkq_init();
+	if (unlikely(err))
+		goto out_procfs;
+	err = au_loopback_init();
+	if (unlikely(err))
+		goto out_wkq;
+	err = au_hnotify_init();
+	if (unlikely(err))
+		goto out_loopback;
+	err = au_sysrq_init();
+	if (unlikely(err))
+		goto out_hin;
+	err = au_cache_init();
+	if (unlikely(err))
+		goto out_sysrq;
+
+	aufs_fs_type.fs_flags |= au_userns ? FS_USERNS_MOUNT : 0;
+	err = register_filesystem(&aufs_fs_type);
+	if (unlikely(err))
+		goto out_cache;
+
+	/* since we define pr_fmt, call printk directly */
+	printk(KERN_INFO AUFS_NAME " " AUFS_VERSION "\n");
+	goto out; /* success */
+
+out_cache:
+	au_cache_fin();
+out_sysrq:
+	au_sysrq_fin();
+out_hin:
+	au_hnotify_fin();
+out_loopback:
+	au_loopback_fin();
+out_wkq:
+	au_wkq_fin();
+out_procfs:
+	au_procfs_fin();
+out_dbgaufs:
+	dbgaufs_fin();
+out_sysaufs:
+	sysaufs_fin();
+	au_dy_fin();
+out:
+	return err;
+}
+
+static void __exit aufs_exit(void)
+{
+	unregister_filesystem(&aufs_fs_type);
+	au_cache_fin();
+	au_sysrq_fin();
+	au_hnotify_fin();
+	au_loopback_fin();
+	au_wkq_fin();
+	au_procfs_fin();
+	dbgaufs_fin();
+	sysaufs_fin();
+	au_dy_fin();
+}
+
+module_init(aufs_init);
+module_exit(aufs_exit);