aufs5.7-20200622.patch

+	h_parent = br->br_wbr->wbr_plink;
+	tgtname.len = plink_name(a, sizeof(a), inode, bindex);
+
+	if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID)) {
+		struct au_do_plink_lkup_args args = {
+			.errp		= &h_dentry,
+			.tgtname	= &tgtname,
+			.h_parent	= h_parent,
+			.br		= br
+		};
+
+		wkq_err = au_wkq_wait(au_call_do_plink_lkup, &args);
+		if (unlikely(wkq_err))
+			h_dentry = ERR_PTR(wkq_err);
+	} else
+		h_dentry = au_do_plink_lkup(&tgtname, h_parent, br);
+
+	return h_dentry;
+}
+
+/* create a pseudo-link */
+static int do_whplink(struct qstr *tgt, struct dentry *h_parent,
+		      struct dentry *h_dentry, struct au_branch *br)
+{
+	int err;
+	struct path h_path = {
+		.mnt = au_br_mnt(br)
+	};
+	struct inode *h_dir, *delegated;
+
+	h_dir = d_inode(h_parent);
+	inode_lock_nested(h_dir, AuLsc_I_CHILD2);
+again:
+	h_path.dentry = vfsub_lkup_one(tgt, h_parent);
+	err = PTR_ERR(h_path.dentry);
+	if (IS_ERR(h_path.dentry))
+		goto out;
+
+	err = 0;
+	/* wh.plink dir is not monitored */
+	/* todo: is it really safe? */
+	if (d_is_positive(h_path.dentry)
+	    && d_inode(h_path.dentry) != d_inode(h_dentry)) {
+		delegated = NULL;
+		err = vfsub_unlink(h_dir, &h_path, &delegated, /*force*/0);
+		if (unlikely(err == -EWOULDBLOCK)) {
+			pr_warn("cannot retry for NFSv4 delegation"
+				" for an internal unlink\n");
+			iput(delegated);
+		}
+		dput(h_path.dentry);
+		h_path.dentry = NULL;
+		if (!err)
+			goto again;
+	}
+	if (!err && d_is_negative(h_path.dentry)) {
+		delegated = NULL;
+		err = vfsub_link(h_dentry, h_dir, &h_path, &delegated);
+		if (unlikely(err == -EWOULDBLOCK)) {
+			pr_warn("cannot retry for NFSv4 delegation"
+				" for an internal link\n");
+			iput(delegated);
+		}
+	}
+	dput(h_path.dentry);
+
+out:
+	inode_unlock(h_dir);
+	return err;
+}
+
+struct do_whplink_args {
+	int *errp;
+	struct qstr *tgt;
+	struct dentry *h_parent;
+	struct dentry *h_dentry;
+	struct au_branch *br;
+};
+
+static void call_do_whplink(void *args)
+{
+	struct do_whplink_args *a = args;
+	*a->errp = do_whplink(a->tgt, a->h_parent, a->h_dentry, a->br);
+}
+
+static int whplink(struct dentry *h_dentry, struct inode *inode,
+		   aufs_bindex_t bindex, struct au_branch *br)
+{
+	int err, wkq_err;
+	struct au_wbr *wbr;
+	struct dentry *h_parent;
+	char a[PLINK_NAME_LEN];
+	struct qstr tgtname = QSTR_INIT(a, 0);
+
+	wbr = au_sbr(inode->i_sb, bindex)->br_wbr;
+	h_parent = wbr->wbr_plink;
+	tgtname.len = plink_name(a, sizeof(a), inode, bindex);
+
+	/* always superio. */
+	if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID)) {
+		struct do_whplink_args args = {
+			.errp		= &err,
+			.tgt		= &tgtname,
+			.h_parent	= h_parent,
+			.h_dentry	= h_dentry,
+			.br		= br
+		};
+		wkq_err = au_wkq_wait(call_do_whplink, &args);
+		if (unlikely(wkq_err))
+			err = wkq_err;
+	} else
+		err = do_whplink(&tgtname, h_parent, h_dentry, br);
+
+	return err;
+}
+
+/*
+ * create a new pseudo-link for @h_dentry on @bindex.
+ * the linked inode is held in aufs @inode.
+ */
+void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
+		     struct dentry *h_dentry)
+{
+	struct super_block *sb;
+	struct au_sbinfo *sbinfo;
+	struct hlist_bl_head *hbl;
+	struct hlist_bl_node *pos;
+	struct au_icntnr *icntnr;
+	int found, err, cnt, i;
+
+	sb = inode->i_sb;
+	sbinfo = au_sbi(sb);
+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
+	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
+
+	found = au_plink_test(inode);
+	if (found)
+		return;
+
+	i = au_plink_hash(inode->i_ino);
+	hbl = sbinfo->si_plink + i;
+	au_igrab(inode);
+
+	hlist_bl_lock(hbl);
+	hlist_bl_for_each_entry(icntnr, pos, hbl, plink) {
+		if (&icntnr->vfs_inode == inode) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found) {
+		icntnr = container_of(inode, struct au_icntnr, vfs_inode);
+		hlist_bl_add_head(&icntnr->plink, hbl);
+	}
+	hlist_bl_unlock(hbl);
+	if (!found) {
+		cnt = au_hbl_count(hbl);
+#define msg "unexpectedly unbalanced or too many pseudo-links"
+		if (cnt > AUFS_PLINK_WARN)
+			AuWarn1(msg ", %d\n", cnt);
+#undef msg
+		err = whplink(h_dentry, inode, bindex, au_sbr(sb, bindex));
+		if (unlikely(err)) {
+			pr_warn("err %d, damaged pseudo link.\n", err);
+			au_hbl_del(&icntnr->plink, hbl);
+			iput(&icntnr->vfs_inode);
+		}
+	} else
+		iput(&icntnr->vfs_inode);
+}
+
+/* free all plinks */
+void au_plink_put(struct super_block *sb, int verbose)
+{
+	int i, warned;
+	struct au_sbinfo *sbinfo;
+	struct hlist_bl_head *hbl;
+	struct hlist_bl_node *pos, *tmp;
+	struct au_icntnr *icntnr;
+
+	SiMustWriteLock(sb);
+
+	sbinfo = au_sbi(sb);
+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
+	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
+
+	/* no spin_lock since sbinfo is write-locked */
+	warned = 0;
+	for (i = 0; i < AuPlink_NHASH; i++) {
+		hbl = sbinfo->si_plink + i;
+		if (!warned && verbose && !hlist_bl_empty(hbl)) {
+			pr_warn("pseudo-link is not flushed");
+			warned = 1;
+		}
+		hlist_bl_for_each_entry_safe(icntnr, pos, tmp, hbl, plink)
+			iput(&icntnr->vfs_inode);
+		INIT_HLIST_BL_HEAD(hbl);
+	}
+}
+
+void au_plink_clean(struct super_block *sb, int verbose)
+{
+	struct dentry *root;
+
+	root = sb->s_root;
+	aufs_write_lock(root);
+	if (au_opt_test(au_mntflags(sb), PLINK))
+		au_plink_put(sb, verbose);
+	aufs_write_unlock(root);
+}
+
+static int au_plink_do_half_refresh(struct inode *inode, aufs_bindex_t br_id)
+{
+	int do_put;
+	aufs_bindex_t btop, bbot, bindex;
+
+	do_put = 0;
+	btop = au_ibtop(inode);
+	bbot = au_ibbot(inode);
+	if (btop >= 0) {
+		for (bindex = btop; bindex <= bbot; bindex++) {
+			if (!au_h_iptr(inode, bindex)
+			    || au_ii_br_id(inode, bindex) != br_id)
+				continue;
+			au_set_h_iptr(inode, bindex, NULL, 0);
+			do_put = 1;
+			break;
+		}
+		if (do_put)
+			for (bindex = btop; bindex <= bbot; bindex++)
+				if (au_h_iptr(inode, bindex)) {
+					do_put = 0;
+					break;
+				}
+	} else
+		do_put = 1;
+
+	return do_put;
+}
+
+/* free the plinks on a branch specified by @br_id */
+void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id)
+{
+	struct au_sbinfo *sbinfo;
+	struct hlist_bl_head *hbl;
+	struct hlist_bl_node *pos, *tmp;
+	struct au_icntnr *icntnr;
+	struct inode *inode;
+	int i, do_put;
+
+	SiMustWriteLock(sb);
+
+	sbinfo = au_sbi(sb);
+	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
+	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
+
+	/* no bit_lock since sbinfo is write-locked */
+	for (i = 0; i < AuPlink_NHASH; i++) {
+		hbl = sbinfo->si_plink + i;
+		hlist_bl_for_each_entry_safe(icntnr, pos, tmp, hbl, plink) {
+			inode = au_igrab(&icntnr->vfs_inode);
+			ii_write_lock_child(inode);
+			do_put = au_plink_do_half_refresh(inode, br_id);
+			if (do_put) {
+				hlist_bl_del(&icntnr->plink);
+				iput(inode);
+			}
+			ii_write_unlock(inode);
+			iput(inode);
+		}
+	}
+}
diff -Naur null/fs/aufs/poll.c linux-5.7/fs/aufs/poll.c
--- /dev/null
+++ linux-5.7/fs/aufs/poll.c	2020-08-22 11:57:41.471782894 +0200
@@ -0,0 +1,51 @@
+// 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/>.
+ */
+
+/*
+ * poll operation
+ * There is only one filesystem which implements ->poll operation, currently.
+ */
+
+#include "aufs.h"
+
+__poll_t aufs_poll(struct file *file, struct poll_table_struct *pt)
+{
+	__poll_t mask;
+	struct file *h_file;
+	struct super_block *sb;
+
+	/* We should pretend an error happened. */
+	mask = EPOLLERR /* | EPOLLIN | EPOLLOUT */;
+	sb = file->f_path.dentry->d_sb;
+	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
+
+	h_file = au_read_pre(file, /*keep_fi*/0, /*lsc*/0);
+	if (IS_ERR(h_file)) {
+		AuDbg("h_file %ld\n", PTR_ERR(h_file));
+		goto out;
+	}
+
+	mask = vfs_poll(h_file, pt);
+	fput(h_file); /* instead of au_read_post() */
+
+out:
+	si_read_unlock(sb);
+	if (mask & EPOLLERR)
+		AuDbg("mask 0x%x\n", mask);
+	return mask;
+}
diff -Naur null/fs/aufs/posix_acl.c linux-5.7/fs/aufs/posix_acl.c
--- /dev/null
+++ linux-5.7/fs/aufs/posix_acl.c	2020-08-22 11:57:41.471782894 +0200
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014-2020 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/>.
+ */
+
+/*
+ * posix acl operations
+ */
+
+#include <linux/fs.h>
+#include "aufs.h"
+
+struct posix_acl *aufs_get_acl(struct inode *inode, int type)
+{
+	struct posix_acl *acl;
+	int err;
+	aufs_bindex_t bindex;
+	struct inode *h_inode;
+	struct super_block *sb;
+
+	acl = NULL;
+	sb = inode->i_sb;
+	si_read_lock(sb, AuLock_FLUSH);
+	ii_read_lock_child(inode);
+	if (!(sb->s_flags & SB_POSIXACL))
+		goto out;
+
+	bindex = au_ibtop(inode);
+	h_inode = au_h_iptr(inode, bindex);
+	if (unlikely(!h_inode
+		     || ((h_inode->i_mode & S_IFMT)
+			 != (inode->i_mode & S_IFMT)))) {
+		err = au_busy_or_stale();
+		acl = ERR_PTR(err);
+		goto out;
+	}
+
+	/* always topmost only */
+	acl = get_acl(h_inode, type);
+	if (IS_ERR(acl))
+		forget_cached_acl(inode, type);
+	else
+		set_cached_acl(inode, type, acl);
+
+out:
+	ii_read_unlock(inode);
+	si_read_unlock(sb);
+
+	AuTraceErrPtr(acl);
+	return acl;
+}
+
+int aufs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	int err;
+	ssize_t ssz;
+	struct dentry *dentry;
+	struct au_sxattr arg = {
+		.type = AU_ACL_SET,
+		.u.acl_set = {
+			.acl	= acl,
+			.type	= type
+		},
+	};
+
+	IMustLock(inode);
+
+	if (inode->i_ino == AUFS_ROOT_INO)
+		dentry = dget(inode->i_sb->s_root);
+	else {
+		dentry = d_find_alias(inode);
+		if (!dentry)
+			dentry = d_find_any_alias(inode);
+		if (!dentry) {
+			pr_warn("cannot handle this inode, "
+				"please report to aufs-users ML\n");
+			err = -ENOENT;
+			goto out;
+		}
+	}
+
+	ssz = au_sxattr(dentry, inode, &arg);
+	/* forget even it if succeeds since the branch might set differently */
+	forget_cached_acl(inode, type);
+	dput(dentry);
+	err = ssz;
+	if (ssz >= 0)
+		err = 0;
+
+out:
+	return err;
+}
diff -Naur null/fs/aufs/procfs.c linux-5.7/fs/aufs/procfs.c
--- /dev/null
+++ linux-5.7/fs/aufs/procfs.c	2020-08-22 11:57:41.471782894 +0200
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2010-2020 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/>.
+ */
+
+/*
+ * procfs interfaces
+ */
+
+#include <linux/proc_fs.h>
+#include "aufs.h"
+
+static int au_procfs_plm_release(struct inode *inode, struct file *file)
+{
+	struct au_sbinfo *sbinfo;
+
+	sbinfo = file->private_data;
+	if (sbinfo) {
+		au_plink_maint_leave(sbinfo);
+		kobject_put(&sbinfo->si_kobj);
+	}
+
+	return 0;
+}
+
+static void au_procfs_plm_write_clean(struct file *file)
+{
+	struct au_sbinfo *sbinfo;
+
+	sbinfo = file->private_data;
+	if (sbinfo)
+		au_plink_clean(sbinfo->si_sb, /*verbose*/0);
+}
+
+static int au_procfs_plm_write_si(struct file *file, unsigned long id)
+{
+	int err;
+	struct super_block *sb;
+	struct au_sbinfo *sbinfo;
+	struct hlist_bl_node *pos;
+
+	err = -EBUSY;
+	if (unlikely(file->private_data))
+		goto out;
+
+	sb = NULL;
+	/* don't use au_sbilist_lock() here */
+	hlist_bl_lock(&au_sbilist);
+	hlist_bl_for_each_entry(sbinfo, pos, &au_sbilist, si_list)
+		if (id == sysaufs_si_id(sbinfo)) {
+			if (kobject_get_unless_zero(&sbinfo->si_kobj))
+				sb = sbinfo->si_sb;
+			break;
+		}
+	hlist_bl_unlock(&au_sbilist);
+
+	err = -EINVAL;
+	if (unlikely(!sb))
+		goto out;
+
+	err = au_plink_maint_enter(sb);
+	if (!err)
+		/* keep kobject_get() */
+		file->private_data = sbinfo;
+	else
+		kobject_put(&sbinfo->si_kobj);
+out:
+	return err;
+}
+
+/*
+ * Accept a valid "si=xxxx" only.
+ * Once it is accepted successfully, accept "clean" too.
+ */
+static ssize_t au_procfs_plm_write(struct file *file, const char __user *ubuf,
+				   size_t count, loff_t *ppos)
+{
+	ssize_t err;
+	unsigned long id;
+	/* last newline is allowed */
+	char buf[3 + sizeof(unsigned long) * 2 + 1];
+
+	err = -EACCES;
+	if (unlikely(!capable(CAP_SYS_ADMIN)))
+		goto out;
+
+	err = -EINVAL;
+	if (unlikely(count > sizeof(buf)))
+		goto out;
+
+	err = copy_from_user(buf, ubuf, count);
+	if (unlikely(err)) {
+		err = -EFAULT;
+		goto out;
+	}
+	buf[count] = 0;
+
+	err = -EINVAL;
+	if (!strcmp("clean", buf)) {
+		au_procfs_plm_write_clean(file);
+		goto out_success;
+	} else if (unlikely(strncmp("si=", buf, 3)))
+		goto out;
+
+	err = kstrtoul(buf + 3, 16, &id);
+	if (unlikely(err))
+		goto out;
+
+	err = au_procfs_plm_write_si(file, id);
+	if (unlikely(err))
+		goto out;
+
+out_success:
+	err = count; /* success */
+out:
+	return err;
+}
+
+static const struct proc_ops au_procfs_plm_op = {
+	.proc_write	= au_procfs_plm_write,
+	.proc_release	= au_procfs_plm_release
+};
+
+/* ---------------------------------------------------------------------- */
+
+static struct proc_dir_entry *au_procfs_dir;
+
+void au_procfs_fin(void)
+{
+	remove_proc_entry(AUFS_PLINK_MAINT_NAME, au_procfs_dir);
+	remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL);
+}
+
+int __init au_procfs_init(void)
+{
+	int err;
+	struct proc_dir_entry *entry;
+
+	err = -ENOMEM;
+	au_procfs_dir = proc_mkdir(AUFS_PLINK_MAINT_DIR, NULL);
+	if (unlikely(!au_procfs_dir))
+		goto out;
+
+	entry = proc_create(AUFS_PLINK_MAINT_NAME, S_IFREG | 0200,
+			    au_procfs_dir, &au_procfs_plm_op);
+	if (unlikely(!entry))
+		goto out_dir;
+
+	err = 0;
+	goto out; /* success */
+
+
+out_dir:
+	remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL);
+out:
+	return err;
+}
diff -Naur null/fs/aufs/rdu.c linux-5.7/fs/aufs/rdu.c
--- /dev/null
+++ linux-5.7/fs/aufs/rdu.c	2020-08-22 11:57:41.471782894 +0200
@@ -0,0 +1,384 @@
+// 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/>.
+ */
+
+/*
+ * readdir in userspace.
+ */
+
+#include <linux/compat.h>
+#include <linux/fs_stack.h>
+#include <linux/security.h>
+#include "aufs.h"
+
+/* bits for struct aufs_rdu.flags */
+#define	AuRdu_CALLED	1
+#define	AuRdu_CONT	(1 << 1)
+#define	AuRdu_FULL	(1 << 2)
+#define au_ftest_rdu(flags, name)	((flags) & AuRdu_##name)
+#define au_fset_rdu(flags, name) \
+	do { (flags) |= AuRdu_##name; } while (0)
+#define au_fclr_rdu(flags, name) \
+	do { (flags) &= ~AuRdu_##name; } while (0)
+
+struct au_rdu_arg {
+	struct dir_context		ctx;
+	struct aufs_rdu			*rdu;
+	union au_rdu_ent_ul		ent;
+	unsigned long			end;
+
+	struct super_block		*sb;
+	int				err;
+};
+
+static int au_rdu_fill(struct dir_context *ctx, const char *name, int nlen,
+		       loff_t offset, u64 h_ino, unsigned int d_type)
+{
+	int err, len;
+	struct au_rdu_arg *arg = container_of(ctx, struct au_rdu_arg, ctx);
+	struct aufs_rdu *rdu = arg->rdu;
+	struct au_rdu_ent ent;
+
+	err = 0;
+	arg->err = 0;
+	au_fset_rdu(rdu->cookie.flags, CALLED);
+	len = au_rdu_len(nlen);
+	if (arg->ent.ul + len  < arg->end) {
+		ent.ino = h_ino;
+		ent.bindex = rdu->cookie.bindex;
+		ent.type = d_type;
+		ent.nlen = nlen;
+		if (unlikely(nlen > AUFS_MAX_NAMELEN))
+			ent.type = DT_UNKNOWN;
+
+		/* unnecessary to support mmap_sem since this is a dir */
+		err = -EFAULT;
+		if (copy_to_user(arg->ent.e, &ent, sizeof(ent)))
+			goto out;
+		if (copy_to_user(arg->ent.e->name, name, nlen))
+			goto out;
+		/* the terminating NULL */
+		if (__put_user(0, arg->ent.e->name + nlen))
+			goto out;
+		err = 0;
+		/* AuDbg("%p, %.*s\n", arg->ent.p, nlen, name); */
+		arg->ent.ul += len;
+		rdu->rent++;
+	} else {
+		err = -EFAULT;
+		au_fset_rdu(rdu->cookie.flags, FULL);
+		rdu->full = 1;
+		rdu->tail = arg->ent;
+	}
+
+out:
+	/* AuTraceErr(err); */
+	return err;
+}
+
+static int au_rdu_do(struct file *h_file, struct au_rdu_arg *arg)
+{
+	int err;
+	loff_t offset;
+	struct au_rdu_cookie *cookie = &arg->rdu->cookie;
+
+	/* we don't have to care (FMODE_32BITHASH | FMODE_64BITHASH) for ext4 */
+	offset = vfsub_llseek(h_file, cookie->h_pos, SEEK_SET);
+	err = offset;
+	if (unlikely(offset != cookie->h_pos))
+		goto out;
+
+	err = 0;
+	do {
+		arg->err = 0;
+		au_fclr_rdu(cookie->flags, CALLED);
+		/* smp_mb(); */
+		err = vfsub_iterate_dir(h_file, &arg->ctx);
+		if (err >= 0)
+			err = arg->err;
+	} while (!err
+		 && au_ftest_rdu(cookie->flags, CALLED)
+		 && !au_ftest_rdu(cookie->flags, FULL));
+	cookie->h_pos = h_file->f_pos;
+
+out:
+	AuTraceErr(err);
+	return err;
+}
+
+static int au_rdu(struct file *file, struct aufs_rdu *rdu)
+{
+	int err;
+	aufs_bindex_t bbot;
+	struct au_rdu_arg arg = {
+		.ctx = {
+			.actor = au_rdu_fill
+		}
+	};
+	struct dentry *dentry;
+	struct inode *inode;
+	struct file *h_file;
+	struct au_rdu_cookie *cookie = &rdu->cookie;
+
+	/* VERIFY_WRITE */
+	err = !access_ok(rdu->ent.e, rdu->sz);
+	if (unlikely(err)) {
+		err = -EFAULT;
+		AuTraceErr(err);
+		goto out;
+	}
+	rdu->rent = 0;
+	rdu->tail = rdu->ent;
+	rdu->full = 0;
+	arg.rdu = rdu;
+	arg.ent = rdu->ent;
+	arg.end = arg.ent.ul;
+	arg.end += rdu->sz;
+
+	err = -ENOTDIR;
+	if (unlikely(!file->f_op->iterate && !file->f_op->iterate_shared))
+		goto out;
+
+	err = security_file_permission(file, MAY_READ);
+	AuTraceErr(err);
+	if (unlikely(err))
+		goto out;
+
+	dentry = file->f_path.dentry;
+	inode = d_inode(dentry);
+	inode_lock_shared(inode);
+
+	arg.sb = inode->i_sb;
+	err = si_read_lock(arg.sb, AuLock_FLUSH | AuLock_NOPLM);
+	if (unlikely(err))
+		goto out_mtx;
+	err = au_alive_dir(dentry);
+	if (unlikely(err))
+		goto out_si;
+	/* todo: reval? */
+	fi_read_lock(file);
+
+	err = -EAGAIN;
+	if (unlikely(au_ftest_rdu(cookie->flags, CONT)
+		     && cookie->generation != au_figen(file)))
+		goto out_unlock;
+
+	err = 0;
+	if (!rdu->blk) {
+		rdu->blk = au_sbi(arg.sb)->si_rdblk;
+		if (!rdu->blk)
+			rdu->blk = au_dir_size(file, /*dentry*/NULL);
+	}
+	bbot = au_fbtop(file);
+	if (cookie->bindex < bbot)
+		cookie->bindex = bbot;
+	bbot = au_fbbot_dir(file);
+	/* AuDbg("b%d, b%d\n", cookie->bindex, bbot); */
+	for (; !err && cookie->bindex <= bbot;
+	     cookie->bindex++, cookie->h_pos = 0) {
+		h_file = au_hf_dir(file, cookie->bindex);
+		if (!h_file)
+			continue;
+
+		au_fclr_rdu(cookie->flags, FULL);
+		err = au_rdu_do(h_file, &arg);
+		AuTraceErr(err);
+		if (unlikely(au_ftest_rdu(cookie->flags, FULL) || err))
+			break;
+	}
+	AuDbg("rent %llu\n", rdu->rent);
+
+	if (!err && !au_ftest_rdu(cookie->flags, CONT)) {
+		rdu->shwh = !!au_opt_test(au_sbi(arg.sb)->si_mntflags, SHWH);
+		au_fset_rdu(cookie->flags, CONT);
+		cookie->generation = au_figen(file);
+	}
+
+	ii_read_lock_child(inode);
+	fsstack_copy_attr_atime(inode, au_h_iptr(inode, au_ibtop(inode)));
+	ii_read_unlock(inode);
+
+out_unlock:
+	fi_read_unlock(file);
+out_si:
+	si_read_unlock(arg.sb);
+out_mtx:
+	inode_unlock_shared(inode);
+out:
+	AuTraceErr(err);
+	return err;
+}
+
+static int au_rdu_ino(struct file *file, struct aufs_rdu *rdu)
+{
+	int err;
+	ino_t ino;
+	unsigned long long nent;
+	union au_rdu_ent_ul *u;
+	struct au_rdu_ent ent;
+	struct super_block *sb;
+
+	err = 0;
+	nent = rdu->nent;
+	u = &rdu->ent;
+	sb = file->f_path.dentry->d_sb;
+	si_read_lock(sb, AuLock_FLUSH);
+	while (nent-- > 0) {
+		/* unnecessary to support mmap_sem since this is a dir */
+		err = copy_from_user(&ent, u->e, sizeof(ent));
+		if (!err)
+			/* VERIFY_WRITE */
+			err = !access_ok(&u->e->ino, sizeof(ino));
+		if (unlikely(err)) {
+			err = -EFAULT;
+			AuTraceErr(err);
+			break;
+		}
+
+		/* AuDbg("b%d, i%llu\n", ent.bindex, ent.ino); */
+		if (!ent.wh)
+			err = au_ino(sb, ent.bindex, ent.ino, ent.type, &ino);
+		else
+			err = au_wh_ino(sb, ent.bindex, ent.ino, ent.type,
+					&ino);
+		if (unlikely(err)) {
+			AuTraceErr(err);
+			break;
+		}
+
+		err = __put_user(ino, &u->e->ino);
+		if (unlikely(err)) {
+			err = -EFAULT;
+			AuTraceErr(err);
+			break;
+		}
+		u->ul += au_rdu_len(ent.nlen);
+	}
+	si_read_unlock(sb);
+
+	return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int au_rdu_verify(struct aufs_rdu *rdu)
+{
+	AuDbg("rdu{%llu, %p, %u | %u | %llu, %u, %u | "
+	      "%llu, b%d, 0x%x, g%u}\n",
+	      rdu->sz, rdu->ent.e, rdu->verify[AufsCtlRduV_SZ],
+	      rdu->blk,
+	      rdu->rent, rdu->shwh, rdu->full,
+	      rdu->cookie.h_pos, rdu->cookie.bindex, rdu->cookie.flags,
+	      rdu->cookie.generation);
+
+	if (rdu->verify[AufsCtlRduV_SZ] == sizeof(*rdu))
+		return 0;
+
+	AuDbg("%u:%u\n",
+	      rdu->verify[AufsCtlRduV_SZ], (unsigned int)sizeof(*rdu));
+	return -EINVAL;
+}
+
+long au_rdu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	long err, e;
+	struct aufs_rdu rdu;
+	void __user *p = (void __user *)arg;
+
+	err = copy_from_user(&rdu, p, sizeof(rdu));
+	if (unlikely(err)) {
+		err = -EFAULT;
+		AuTraceErr(err);
+		goto out;
+	}
+	err = au_rdu_verify(&rdu);
+	if (unlikely(err))
+		goto out;
+
+	switch (cmd) {
+	case AUFS_CTL_RDU:
+		err = au_rdu(file, &rdu);
+		if (unlikely(err))
+			break;
+
+		e = copy_to_user(p, &rdu, sizeof(rdu));
+		if (unlikely(e)) {
+			err = -EFAULT;
+			AuTraceErr(err);
+		}
+		break;
+	case AUFS_CTL_RDU_INO:
+		err = au_rdu_ino(file, &rdu);
+		break;
+
+	default:
+		/* err = -ENOTTY; */
+		err = -EINVAL;
+	}
+
+out:
+	AuTraceErr(err);
+	return err;
+}
+
+#ifdef CONFIG_COMPAT
+long au_rdu_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	long err, e;
+	struct aufs_rdu rdu;
+	void __user *p = compat_ptr(arg);
+
+	/* todo: get_user()? */
+	err = copy_from_user(&rdu, p, sizeof(rdu));
+	if (unlikely(err)) {
+		err = -EFAULT;
+		AuTraceErr(err);
+		goto out;
+	}
+	rdu.ent.e = compat_ptr(rdu.ent.ul);
+	err = au_rdu_verify(&rdu);
+	if (unlikely(err))
+		goto out;
+
+	switch (cmd) {
+	case AUFS_CTL_RDU:
+		err = au_rdu(file, &rdu);
+		if (unlikely(err))
+			break;
+
+		rdu.ent.ul = ptr_to_compat(rdu.ent.e);
+		rdu.tail.ul = ptr_to_compat(rdu.tail.e);
+		e = copy_to_user(p, &rdu, sizeof(rdu));
+		if (unlikely(e)) {
+			err = -EFAULT;
+			AuTraceErr(err);
+		}
+		break;
+	case AUFS_CTL_RDU_INO:
+		err = au_rdu_ino(file, &rdu);
+		break;
+
+	default:
+		/* err = -ENOTTY; */
+		err = -EINVAL;
+	}
+
+out:
+	AuTraceErr(err);
+	return err;
+}
+#endif
diff -Naur null/fs/aufs/rwsem.h linux-5.7/fs/aufs/rwsem.h
--- /dev/null