Linux-libre 4.5.1-gnupck-4.5.1-gnu

1 files changed, 376 insertions, 0 deletions

diff --git a/fs/aufs/rdu.c b/fs/aufs/rdu.c
new file mode 100644
index 000000000..ec0844673
--- /dev/null
+++ b/fs/aufs/rdu.c
@@ -0,0 +1,376 @@
+/*
+ * Copyright (C) 2005-2016 Junjiro R. Okajima
+ */
+
+/*
+ * 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 bend;
+	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;
+
+	err = !access_ok(VERIFY_WRITE, 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))
+		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);
+#if 1
+	inode_lock(inode);
+#else
+	/* todo: create a new inline func inode_lock_killable() */
+	err = mutex_lock_killable(&inode->i_mutex);
+	AuTraceErr(err);
+	if (unlikely(err))
+		goto out;
+#endif
+
+	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);
+	}
+	bend = au_fbstart(file);
+	if (cookie->bindex < bend)
+		cookie->bindex = bend;
+	bend = au_fbend_dir(file);
+	/* AuDbg("b%d, b%d\n", cookie->bindex, bend); */
+	for (; !err && cookie->bindex <= bend;
+	     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_ibstart(inode)));
+	ii_read_unlock(inode);
+
+out_unlock:
+	fi_read_unlock(file);
+out_si:
+	si_read_unlock(arg.sb);
+out_mtx:
+	inode_unlock(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)
+			err = !access_ok(VERIFY_WRITE, &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