1 files changed, 268 insertions, 0 deletions
diff --git a/fs/aufs/dentry.h b/fs/aufs/dentry.h
new file mode 100644
index 000000000000..3b443fc7eef0
--- /dev/null
+++ b/fs/aufs/dentry.h
@@ -0,0 +1,268 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2005-2019 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/>.
+ */
+
+/*
+ * lookup and dentry operations
+ */
+
+#ifndef __AUFS_DENTRY_H__
+#define __AUFS_DENTRY_H__
+
+#ifdef __KERNEL__
+
+#include <linux/dcache.h>
+#include "dirren.h"
+#include "rwsem.h"
+
+struct au_hdentry {
+	struct dentry		*hd_dentry;
+	aufs_bindex_t		hd_id;
+};
+
+struct au_dinfo {
+	atomic_t		di_generation;
+
+	struct au_rwsem		di_rwsem;
+	aufs_bindex_t		di_btop, di_bbot, di_bwh, di_bdiropq;
+	unsigned char		di_tmpfile; /* to allow the different name */
+	struct au_hdentry	*di_hdentry;
+	struct rcu_head		rcu;
+} ____cacheline_aligned_in_smp;
+
+/* ---------------------------------------------------------------------- */
+
+/* flags for au_lkup_dentry() */
+#define AuLkup_ALLOW_NEG	1
+#define AuLkup_IGNORE_PERM	(1 << 1)
+#define AuLkup_DIRREN		(1 << 2)
+#define au_ftest_lkup(flags, name)	((flags) & AuLkup_##name)
+#define au_fset_lkup(flags, name) \
+	do { (flags) |= AuLkup_##name; } while (0)
+#define au_fclr_lkup(flags, name) \
+	do { (flags) &= ~AuLkup_##name; } while (0)
+
+#ifndef CONFIG_AUFS_DIRREN
+#undef AuLkup_DIRREN
+#define AuLkup_DIRREN 0
+#endif
+
+struct au_do_lookup_args {
+	unsigned int		flags;
+	mode_t			type;
+	struct qstr		whname, *name;
+	struct au_dr_lookup	dirren;
+};
+
+/* ---------------------------------------------------------------------- */
+
+/* dentry.c */
+extern const struct dentry_operations aufs_dop, aufs_dop_noreval;
+struct au_branch;
+struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent);
+int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir,
+		struct dentry *h_parent, struct au_branch *br);
+
+int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t btop,
+		   unsigned int flags);
+int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex, int wh);
+int au_refresh_dentry(struct dentry *dentry, struct dentry *parent);
+int au_reval_dpath(struct dentry *dentry, unsigned int sigen);
+void au_refresh_dop(struct dentry *dentry, int force_reval);
+
+/* dinfo.c */
+void au_di_init_once(void *_di);
+struct au_dinfo *au_di_alloc(struct super_block *sb, unsigned int lsc);
+void au_di_free(struct au_dinfo *dinfo);
+void au_di_swap(struct au_dinfo *a, struct au_dinfo *b);
+void au_di_cp(struct au_dinfo *dst, struct au_dinfo *src);
+int au_di_init(struct dentry *dentry);
+void au_di_fin(struct dentry *dentry);
+int au_di_realloc(struct au_dinfo *dinfo, int nbr, int may_shrink);
+
+void di_read_lock(struct dentry *d, int flags, unsigned int lsc);
+void di_read_unlock(struct dentry *d, int flags);
+void di_downgrade_lock(struct dentry *d, int flags);
+void di_write_lock(struct dentry *d, unsigned int lsc);
+void di_write_unlock(struct dentry *d);
+void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir);
+void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir);
+void di_write_unlock2(struct dentry *d1, struct dentry *d2);
+
+struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex);
+struct dentry *au_h_d_alias(struct dentry *dentry, aufs_bindex_t bindex);
+aufs_bindex_t au_dbtail(struct dentry *dentry);
+aufs_bindex_t au_dbtaildir(struct dentry *dentry);
+
+void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
+		   struct dentry *h_dentry);
+int au_digen_test(struct dentry *dentry, unsigned int sigen);
+int au_dbrange_test(struct dentry *dentry);
+void au_update_digen(struct dentry *dentry);
+void au_update_dbrange(struct dentry *dentry, int do_put_zero);
+void au_update_dbtop(struct dentry *dentry);
+void au_update_dbbot(struct dentry *dentry);
+int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry);
+
+/* ---------------------------------------------------------------------- */
+
+static inline struct au_dinfo *au_di(struct dentry *dentry)
+{
+	return dentry->d_fsdata;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* lock subclass for dinfo */
+enum {
+	AuLsc_DI_CHILD,		/* child first */
+	AuLsc_DI_CHILD2,	/* rename(2), link(2), and cpup at hnotify */
+	AuLsc_DI_CHILD3,	/* copyup dirs */
+	AuLsc_DI_PARENT,
+	AuLsc_DI_PARENT2,
+	AuLsc_DI_PARENT3,
+	AuLsc_DI_TMP		/* temp for replacing dinfo */
+};
+
+/*
+ * di_read_lock_child, di_write_lock_child,
+ * di_read_lock_child2, di_write_lock_child2,
+ * di_read_lock_child3, di_write_lock_child3,
+ * di_read_lock_parent, di_write_lock_parent,
+ * di_read_lock_parent2, di_write_lock_parent2,
+ * di_read_lock_parent3, di_write_lock_parent3,
+ */
+#define AuReadLockFunc(name, lsc) \
+static inline void di_read_lock_##name(struct dentry *d, int flags) \
+{ di_read_lock(d, flags, AuLsc_DI_##lsc); }
+
+#define AuWriteLockFunc(name, lsc) \
+static inline void di_write_lock_##name(struct dentry *d) \
+{ di_write_lock(d, AuLsc_DI_##lsc); }
+
+#define AuRWLockFuncs(name, lsc) \
+	AuReadLockFunc(name, lsc) \
+	AuWriteLockFunc(name, lsc)
+
+AuRWLockFuncs(child, CHILD);
+AuRWLockFuncs(child2, CHILD2);
+AuRWLockFuncs(child3, CHILD3);
+AuRWLockFuncs(parent, PARENT);
+AuRWLockFuncs(parent2, PARENT2);
+AuRWLockFuncs(parent3, PARENT3);
+
+#undef AuReadLockFunc
+#undef AuWriteLockFunc
+#undef AuRWLockFuncs
+
+#define DiMustNoWaiters(d)	AuRwMustNoWaiters(&au_di(d)->di_rwsem)
+#define DiMustAnyLock(d)	AuRwMustAnyLock(&au_di(d)->di_rwsem)
+#define DiMustWriteLock(d)	AuRwMustWriteLock(&au_di(d)->di_rwsem)
+
+/* ---------------------------------------------------------------------- */
+
+/* todo: memory barrier? */
+static inline unsigned int au_digen(struct dentry *d)
+{
+	return atomic_read(&au_di(d)->di_generation);
+}
+
+static inline void au_h_dentry_init(struct au_hdentry *hdentry)
+{
+	hdentry->hd_dentry = NULL;
+}
+
+static inline struct au_hdentry *au_hdentry(struct au_dinfo *di,
+					    aufs_bindex_t bindex)
+{
+	return di->di_hdentry + bindex;
+}
+
+static inline void au_hdput(struct au_hdentry *hd)
+{
+	if (hd)
+		dput(hd->hd_dentry);
+}
+
+static inline aufs_bindex_t au_dbtop(struct dentry *dentry)
+{
+	DiMustAnyLock(dentry);
+	return au_di(dentry)->di_btop;
+}
+
+static inline aufs_bindex_t au_dbbot(struct dentry *dentry)
+{
+	DiMustAnyLock(dentry);
+	return au_di(dentry)->di_bbot;
+}
+
+static inline aufs_bindex_t au_dbwh(struct dentry *dentry)
+{
+	DiMustAnyLock(dentry);
+	return au_di(dentry)->di_bwh;
+}
+
+static inline aufs_bindex_t au_dbdiropq(struct dentry *dentry)
+{
+	DiMustAnyLock(dentry);
+	return au_di(dentry)->di_bdiropq;
+}
+
+/* todo: hard/soft set? */
+static inline void au_set_dbtop(struct dentry *dentry, aufs_bindex_t bindex)
+{
+	DiMustWriteLock(dentry);
+	au_di(dentry)->di_btop = bindex;
+}
+
+static inline void au_set_dbbot(struct dentry *dentry, aufs_bindex_t bindex)
+{
+	DiMustWriteLock(dentry);
+	au_di(dentry)->di_bbot = bindex;
+}
+
+static inline void au_set_dbwh(struct dentry *dentry, aufs_bindex_t bindex)
+{
+	DiMustWriteLock(dentry);
+	/* dbwh can be outside of btop - bbot range */
+	au_di(dentry)->di_bwh = bindex;
+}
+
+static inline void au_set_dbdiropq(struct dentry *dentry, aufs_bindex_t bindex)
+{
+	DiMustWriteLock(dentry);
+	au_di(dentry)->di_bdiropq = bindex;
+}
+
+/* ---------------------------------------------------------------------- */
+
+#ifdef CONFIG_AUFS_HNOTIFY
+static inline void au_digen_dec(struct dentry *d)
+{
+	atomic_dec(&au_di(d)->di_generation);
+}
+
+static inline void au_hn_di_reinit(struct dentry *dentry)
+{
+	dentry->d_fsdata = NULL;
+}
+#else
+AuStubVoid(au_hn_di_reinit, struct dentry *dentry __maybe_unused)
+#endif /* CONFIG_AUFS_HNOTIFY */
+
+#endif /* __KERNEL__ */
+#endif /* __AUFS_DENTRY_H__ */