1 files changed, 356 insertions, 0 deletions
diff --git a/fs/aufs/sbinfo.c b/fs/aufs/sbinfo.c
new file mode 100644
index 000000000..4e59efc08
--- /dev/null
+++ b/fs/aufs/sbinfo.c
@@ -0,0 +1,356 @@
+/*
+ * Copyright (C) 2005-2015 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/>.
+ */
+
+/*
+ * superblock private data
+ */
+
+#include "aufs.h"
+
+/*
+ * they are necessary regardless sysfs is disabled.
+ */
+void au_si_free(struct kobject *kobj)
+{
+	int i;
+	struct au_sbinfo *sbinfo;
+	char *locked __maybe_unused; /* debug only */
+
+	sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
+	for (i = 0; i < AuPlink_NHASH; i++)
+		AuDebugOn(!hlist_empty(&sbinfo->si_plink[i].head));
+	AuDebugOn(atomic_read(&sbinfo->si_nowait.nw_len));
+
+	au_rw_write_lock(&sbinfo->si_rwsem);
+	au_br_free(sbinfo);
+	au_rw_write_unlock(&sbinfo->si_rwsem);
+
+	AuDebugOn(radix_tree_gang_lookup
+		  (&sbinfo->au_si_pid.tree, (void **)&locked,
+		   /*first_index*/PID_MAX_DEFAULT - 1,
+		   /*max_items*/sizeof(locked)/sizeof(*locked)));
+
+	kfree(sbinfo->si_branch);
+	kfree(sbinfo->au_si_pid.bitmap);
+	mutex_destroy(&sbinfo->si_xib_mtx);
+	AuRwDestroy(&sbinfo->si_rwsem);
+
+	kfree(sbinfo);
+}
+
+int au_si_alloc(struct super_block *sb)
+{
+	int err, i;
+	struct au_sbinfo *sbinfo;
+	static struct lock_class_key aufs_si;
+
+	err = -ENOMEM;
+	sbinfo = kzalloc(sizeof(*sbinfo), GFP_NOFS);
+	if (unlikely(!sbinfo))
+		goto out;
+
+	BUILD_BUG_ON(sizeof(unsigned long) !=
+		     sizeof(*sbinfo->au_si_pid.bitmap));
+	sbinfo->au_si_pid.bitmap = kcalloc(BITS_TO_LONGS(PID_MAX_DEFAULT),
+					sizeof(*sbinfo->au_si_pid.bitmap),
+					GFP_NOFS);
+	if (unlikely(!sbinfo->au_si_pid.bitmap))
+		goto out_sbinfo;
+
+	/* will be reallocated separately */
+	sbinfo->si_branch = kzalloc(sizeof(*sbinfo->si_branch), GFP_NOFS);
+	if (unlikely(!sbinfo->si_branch))
+		goto out_pidmap;
+
+	err = sysaufs_si_init(sbinfo);
+	if (unlikely(err))
+		goto out_br;
+
+	au_nwt_init(&sbinfo->si_nowait);
+	au_rw_init_wlock(&sbinfo->si_rwsem);
+	au_rw_class(&sbinfo->si_rwsem, &aufs_si);
+	spin_lock_init(&sbinfo->au_si_pid.tree_lock);
+	INIT_RADIX_TREE(&sbinfo->au_si_pid.tree, GFP_ATOMIC | __GFP_NOFAIL);
+
+	atomic_long_set(&sbinfo->si_ninodes, 0);
+	atomic_long_set(&sbinfo->si_nfiles, 0);
+
+	sbinfo->si_bend = -1;
+	sbinfo->si_last_br_id = AUFS_BRANCH_MAX / 2;
+
+	sbinfo->si_wbr_copyup = AuWbrCopyup_Def;
+	sbinfo->si_wbr_create = AuWbrCreate_Def;
+	sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + sbinfo->si_wbr_copyup;
+	sbinfo->si_wbr_create_ops = au_wbr_create_ops + sbinfo->si_wbr_create;
+
+	au_fhsm_init(sbinfo);
+
+	sbinfo->si_mntflags = au_opts_plink(AuOpt_Def);
+
+	sbinfo->si_xino_jiffy = jiffies;
+	sbinfo->si_xino_expire
+		= msecs_to_jiffies(AUFS_XINO_DEF_SEC * MSEC_PER_SEC);
+	mutex_init(&sbinfo->si_xib_mtx);
+	sbinfo->si_xino_brid = -1;
+	/* leave si_xib_last_pindex and si_xib_next_bit */
+
+	au_sphl_init(&sbinfo->si_aopen);
+
+	sbinfo->si_rdcache = msecs_to_jiffies(AUFS_RDCACHE_DEF * MSEC_PER_SEC);
+	sbinfo->si_rdblk = AUFS_RDBLK_DEF;
+	sbinfo->si_rdhash = AUFS_RDHASH_DEF;
+	sbinfo->si_dirwh = AUFS_DIRWH_DEF;
+
+	for (i = 0; i < AuPlink_NHASH; i++)
+		au_sphl_init(sbinfo->si_plink + i);
+	init_waitqueue_head(&sbinfo->si_plink_wq);
+	spin_lock_init(&sbinfo->si_plink_maint_lock);
+
+	au_sphl_init(&sbinfo->si_files);
+
+	/* leave other members for sysaufs and si_mnt. */
+	sbinfo->si_sb = sb;
+	sb->s_fs_info = sbinfo;
+	si_pid_set(sb);
+	return 0; /* success */
+
+out_br:
+	kfree(sbinfo->si_branch);
+out_pidmap:
+	kfree(sbinfo->au_si_pid.bitmap);
+out_sbinfo:
+	kfree(sbinfo);
+out:
+	return err;
+}
+
+int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr)
+{
+	int err, sz;
+	struct au_branch **brp;
+
+	AuRwMustWriteLock(&sbinfo->si_rwsem);
+
+	err = -ENOMEM;
+	sz = sizeof(*brp) * (sbinfo->si_bend + 1);
+	if (unlikely(!sz))
+		sz = sizeof(*brp);
+	brp = au_kzrealloc(sbinfo->si_branch, sz, sizeof(*brp) * nbr, GFP_NOFS);
+	if (brp) {
+		sbinfo->si_branch = brp;
+		err = 0;
+	}
+
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+unsigned int au_sigen_inc(struct super_block *sb)
+{
+	unsigned int gen;
+	struct inode *inode;
+
+	SiMustWriteLock(sb);
+
+	gen = ++au_sbi(sb)->si_generation;
+	au_update_digen(sb->s_root);
+	inode = d_inode(sb->s_root);
+	au_update_iigen(inode, /*half*/0);
+	inode->i_version++;
+	return gen;
+}
+
+aufs_bindex_t au_new_br_id(struct super_block *sb)
+{
+	aufs_bindex_t br_id;
+	int i;
+	struct au_sbinfo *sbinfo;
+
+	SiMustWriteLock(sb);
+
+	sbinfo = au_sbi(sb);
+	for (i = 0; i <= AUFS_BRANCH_MAX; i++) {
+		br_id = ++sbinfo->si_last_br_id;
+		AuDebugOn(br_id < 0);
+		if (br_id && au_br_index(sb, br_id) < 0)
+			return br_id;
+	}
+
+	return -1;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* it is ok that new 'nwt' tasks are appended while we are sleeping */
+int si_read_lock(struct super_block *sb, int flags)
+{
+	int err;
+
+	err = 0;
+	if (au_ftest_lock(flags, FLUSH))
+		au_nwt_flush(&au_sbi(sb)->si_nowait);
+
+	si_noflush_read_lock(sb);
+	err = au_plink_maint(sb, flags);
+	if (unlikely(err))
+		si_read_unlock(sb);
+
+	return err;
+}
+
+int si_write_lock(struct super_block *sb, int flags)
+{
+	int err;
+
+	if (au_ftest_lock(flags, FLUSH))
+		au_nwt_flush(&au_sbi(sb)->si_nowait);
+
+	si_noflush_write_lock(sb);
+	err = au_plink_maint(sb, flags);
+	if (unlikely(err))
+		si_write_unlock(sb);
+
+	return err;
+}
+
+/* dentry and super_block lock. call at entry point */
+int aufs_read_lock(struct dentry *dentry, int flags)
+{
+	int err;
+	struct super_block *sb;
+
+	sb = dentry->d_sb;
+	err = si_read_lock(sb, flags);
+	if (unlikely(err))
+		goto out;
+
+	if (au_ftest_lock(flags, DW))
+		di_write_lock_child(dentry);
+	else
+		di_read_lock_child(dentry, flags);
+
+	if (au_ftest_lock(flags, GEN)) {
+		err = au_digen_test(dentry, au_sigen(sb));
+		AuDebugOn(!err && au_dbrange_test(dentry));
+		if (unlikely(err))
+			aufs_read_unlock(dentry, flags);
+	}
+
+out:
+	return err;
+}
+
+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, AuLock_FLUSH | AuLock_NOPLMW);
+	di_write_lock_child(dentry);
+}
+
+void aufs_write_unlock(struct dentry *dentry)
+{
+	di_write_unlock(dentry);
+	si_write_unlock(dentry->d_sb);
+}
+
+int aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags)
+{
+	int err;
+	unsigned int sigen;
+	struct super_block *sb;
+
+	sb = d1->d_sb;
+	err = si_read_lock(sb, flags);
+	if (unlikely(err))
+		goto out;
+
+	di_write_lock2_child(d1, d2, au_ftest_lock(flags, DIR));
+
+	if (au_ftest_lock(flags, GEN)) {
+		sigen = au_sigen(sb);
+		err = au_digen_test(d1, sigen);
+		AuDebugOn(!err && au_dbrange_test(d1));
+		if (!err) {
+			err = au_digen_test(d2, sigen);
+			AuDebugOn(!err && au_dbrange_test(d2));
+		}
+		if (unlikely(err))
+			aufs_read_and_write_unlock2(d1, d2);
+	}
+
+out:
+	return err;
+}
+
+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2)
+{
+	di_write_unlock2(d1, d2);
+	si_read_unlock(d1->d_sb);
+}
+
+/* ---------------------------------------------------------------------- */
+
+int si_pid_test_slow(struct super_block *sb)
+{
+	void *p;
+
+	rcu_read_lock();
+	p = radix_tree_lookup(&au_sbi(sb)->au_si_pid.tree, current->pid);
+	rcu_read_unlock();
+
+	return (long)!!p;
+}
+
+void si_pid_set_slow(struct super_block *sb)
+{
+	int err;
+	struct au_sbinfo *sbinfo;
+
+	AuDebugOn(si_pid_test_slow(sb));
+
+	sbinfo = au_sbi(sb);
+	err = radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
+	AuDebugOn(err);
+	spin_lock(&sbinfo->au_si_pid.tree_lock);
+	err = radix_tree_insert(&sbinfo->au_si_pid.tree, current->pid,
+				/*any valid ptr*/sb);
+	spin_unlock(&sbinfo->au_si_pid.tree_lock);
+	AuDebugOn(err);
+	radix_tree_preload_end();
+}
+
+void si_pid_clr_slow(struct super_block *sb)
+{
+	void *p;
+	struct au_sbinfo *sbinfo;
+
+	AuDebugOn(!si_pid_test_slow(sb));
+
+	sbinfo = au_sbi(sb);
+	spin_lock(&sbinfo->au_si_pid.tree_lock);
+	p = radix_tree_delete(&sbinfo->au_si_pid.tree, current->pid);
+	spin_unlock(&sbinfo->au_si_pid.tree_lock);
+}