[PATCH 11/67] aufs superblock private data

[hooanon05@yahoo.co.jp]

From: Junjiro Okajima <hooanon05@yahoo.co.jp>

	initial commit
	aufs superblock private data

Signed-off-by: Junjiro Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/sbinfo.c |  268 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 268 insertions(+), 0 deletions(-)

diff --git a/fs/aufs/sbinfo.c b/fs/aufs/sbinfo.c
new file mode 100644
index 0000000..a412811
--- /dev/null
+++ b/fs/aufs/sbinfo.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright (C) 2005-2008 Junjiro 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
+ */
+
+/*
+ * superblock private data
+ *
+ * $Id: sbinfo.c,v 1.4 2008/05/12 00:28:22 sfjro Exp $
+ */
+
+#include <linux/mnt_namespace.h>
+#include <linux/smp_lock.h>
+#include "aufs.h"
+
+/*
+ * they are necessary regardless sysfs is disabled.
+ */
+void au_si_free(struct kobject *kobj)
+{
+	struct au_sbinfo *sbinfo;
+	struct super_block *sb;
+
+	LKTRTrace("kobj %p\n", kobj);
+	sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
+	LKTRTrace("sbinfo %p\n", sbinfo);
+	AuDebugOn(!list_empty(&sbinfo->si_plink));
+
+	sb = sbinfo->si_sb;
+	if (unlikely(!au_ftest_si(sbinfo, FAILED_INIT))) {
+		au_sbilist_lock();
+		au_sbilist_del(sbinfo);
+		au_sbilist_unlock();
+	}
+
+	si_write_lock(sb);
+	au_xino_clr(sb);
+	au_br_free(sbinfo);
+	kfree(sbinfo->si_branch);
+	si_write_unlock(sb);
+
+	//AuDbg("free\n");
+ 	kfree(sbinfo);
+}
+
+int au_si_alloc(struct super_block *sb)
+{
+	int err;
+	struct au_sbinfo *sbinfo;
+
+	AuTraceEnter();
+
+	err = -ENOMEM;
+	sbinfo = kmalloc(sizeof(*sbinfo), GFP_KERNEL);
+	//if (LktrCond) {kfree(sbinfo); sbinfo = NULL;}
+	if (unlikely(!sbinfo))
+		goto out;
+	sbinfo->si_branch = kzalloc(sizeof(*sbinfo->si_branch), GFP_KERNEL);
+	//if (LktrCond) {kfree(sbinfo->si_branch); sbinfo->si_branch = NULL;}
+	if (unlikely(!sbinfo->si_branch))
+		goto out_sbinfo;
+
+	memset(&sbinfo->si_kobj, 0, sizeof(sbinfo->si_kobj));
+	err = sysaufs_si_init(sbinfo);
+	if (unlikely(err))
+		goto out_br;
+
+	au_rw_init_wlock(&sbinfo->si_rwsem);
+	sbinfo->si_generation = 0;
+	//sbinfo->si_generation = INT_MAX - 2;
+	sbinfo->au_si_status = 0;
+	sbinfo->si_bend = -1;
+	sbinfo->si_last_br_id = 0;
+
+	sbinfo->si_wbr_copyup = AuWbrCopyup_Def;
+	sbinfo->si_wbr_create = AuWbrCreate_Def;
+	sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + AuWbrCopyup_Def;
+	sbinfo->si_wbr_create_ops = au_wbr_create_ops + AuWbrCreate_Def;
+
+	sbinfo->si_mntflags = AuOpt_Def;
+
+	sbinfo->si_xread = NULL;
+	sbinfo->si_xwrite = NULL;
+	sbinfo->si_xib = NULL;
+	mutex_init(&sbinfo->si_xib_mtx);
+	sbinfo->si_xib_buf = NULL;
+	/* leave si_xib_last_pindex and si_xib_next_bit */
+
+	au_nwt_init(&sbinfo->si_nowait);
+
+	sbinfo->si_rdcache = AUFS_RDCACHE_DEF * HZ;
+	sbinfo->si_dirwh = AUFS_DIRWH_DEF;
+
+	spin_lock_init(&sbinfo->si_plink_lock);
+	INIT_LIST_HEAD(&sbinfo->si_plink);
+
+	au_robr_lvma_init(sbinfo);
+
+	/* leave other members for sysaufs and si_mnt. */
+	sbinfo->si_sb = sb;
+
+	sb->s_fs_info = sbinfo;
+	//sysaufs_si_get(sb);
+
+	au_debug_sbinfo_init(sbinfo);
+	return 0; /* success */
+
+ out_br:
+	kfree(sbinfo->si_branch);
+ out_sbinfo:
+	kfree(sbinfo);
+ out:
+	AuTraceErr(err);
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct au_branch *au_sbr(struct super_block *sb, aufs_bindex_t bindex)
+{
+	struct au_branch *br;
+
+	SiMustAnyLock(sb);
+	AuDebugOn(bindex < 0 || au_sbend(sb) < bindex);
+	br = au_sbi(sb)->si_branch[0 + bindex];
+	AuDebugOn(!br);
+	return br;
+}
+
+au_gen_t au_sigen_inc(struct super_block *sb)
+{
+	au_gen_t gen;
+
+	SiMustWriteLock(sb);
+	gen = ++au_sbi(sb)->si_generation;
+	au_update_digen(sb->s_root);
+	au_update_iigen(sb->s_root->d_inode);
+	sb->s_root->d_inode->i_version++;
+	return gen;
+}
+
+int au_find_bindex(struct super_block *sb, struct au_branch *br)
+{
+	aufs_bindex_t bindex, bend;
+
+	bend = au_sbend(sb);
+	for (bindex = 0; bindex <= bend; bindex++)
+		if (au_sbr(sb, bindex) == br)
+			return bindex;
+	return -1;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* dentry and super_block lock. call at entry point */
+void aufs_read_lock(struct dentry *dentry, int flags)
+{
+	si_read_lock(dentry->d_sb, flags);
+	if (au_ftest_lock(flags, DW))
+		di_write_lock_child(dentry);
+	else
+		di_read_lock_child(dentry, flags);
+}
+
+void aufs_read_unlock(struct dentry *dentry, int flags)
+{
+	if (au_ftest_lock(flags, DW))
+		di_write_unlock(dentry);
+	else
+		di_read_unlock(dentry, flags);
+	si_read_unlock(dentry->d_sb);
+}
+
+void aufs_write_lock(struct dentry *dentry)
+{
+	si_write_lock(dentry->d_sb);
+	di_write_lock_child(dentry);
+}
+
+void aufs_write_unlock(struct dentry *dentry)
+{
+	di_write_unlock(dentry);
+	si_write_unlock(dentry->d_sb);
+}
+
+void aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags)
+{
+	AuDebugOn(d1 == d2 || d1->d_sb != d2->d_sb);
+	si_read_lock(d1->d_sb, flags);
+	di_write_lock2_child(d1, d2, au_ftest_lock(flags, DIR));
+}
+
+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2)
+{
+	AuDebugOn(d1 == d2 || d1->d_sb != d2->d_sb);
+	di_write_unlock2(d1, d2);
+	si_read_unlock(d1->d_sb);
+}
+
+/* ---------------------------------------------------------------------- */
+
+aufs_bindex_t au_new_br_id(struct super_block *sb)
+{
+	aufs_bindex_t br_id;
+	struct au_sbinfo *sbinfo;
+
+	AuTraceEnter();
+	SiMustWriteLock(sb);
+
+	sbinfo = au_sbi(sb);
+	while (1) {
+		br_id = ++sbinfo->si_last_br_id;
+		if (br_id && au_br_index(sb, br_id) < 0)
+			return br_id;
+	}
+}
+
+//todo: dirty
+/*
+ * when you mntput() for the return value of this function,
+ * you have to store it to your local var.
+ * ie. never mntput si_mntcache directly.
+ */
+struct vfsmount *au_mntcache_get(struct super_block *sb)
+{
+	struct au_sbinfo *sbinfo;
+	struct mnt_namespace *ns;
+	struct vfsmount *pos, *mnt;
+
+	AuTraceEnter();
+
+	sbinfo = au_sbi(sb);
+
+	spin_lock(&sbinfo->si_mntcache_lock);
+	if (sbinfo->si_mntcache)
+		goto out;
+
+	/* vfsmount_lock is not exported */
+	//root_mnt = current->fs->root.mnt;
+	/* no get/put */
+	AuDebugOn(!current->nsproxy);
+	ns = current->nsproxy->mnt_ns;
+	AuDebugOn(!ns);
+	list_for_each_entry(pos, &ns->list, mnt_list)
+		if (pos->mnt_sb == sb) {
+			sbinfo->si_mntcache = pos;
+			break;
+		}
+	AuDebugOn(!sbinfo->si_mntcache);
+
+ out:
+	mnt = mntget(sbinfo->si_mntcache);
+	spin_unlock(&sbinfo->si_mntcache_lock);
+	return mnt;
+}
-- 
1.4.4.4