make path_init() unconditionally paired with terminate_walk() (edc2b1da) · Commits · 戴 / test

fs/namei.c

+16 −16

Original line number	Diff line number	Diff line
		@@ -2125,12 +2125,15 @@ OK:
		}
		}

		/* must be paired with terminate_walk() */
		static const char path_init(struct nameidata nd, unsigned flags)
		{
		const char *s = nd->name->name;

		if (!*s)
		flags &= ~LOOKUP_RCU;
		if (flags & LOOKUP_RCU)
		rcu_read_lock();

		nd->last_type = LAST_ROOT; /* if there are only slashes... */
		nd->flags = flags \| LOOKUP_JUMPED \| LOOKUP_PARENT;
		@@ -2143,7 +2146,6 @@ static const char path_init(struct nameidata nd, unsigned flags)
		nd->path = nd->root;
		nd->inode = inode;
		if (flags & LOOKUP_RCU) {
		rcu_read_lock();
		nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
		nd->root_seq = nd->seq;
		nd->m_seq = read_seqbegin(&mount_lock);
		@@ -2159,21 +2161,15 @@ static const char path_init(struct nameidata nd, unsigned flags)

		nd->m_seq = read_seqbegin(&mount_lock);
		if (*s == '/') {
		if (flags & LOOKUP_RCU)
		rcu_read_lock();
		set_root(nd);
		if (likely(!nd_jump_root(nd)))
		return s;
		nd->root.mnt = NULL;
		rcu_read_unlock();
		return ERR_PTR(-ECHILD);
		} else if (nd->dfd == AT_FDCWD) {
		if (flags & LOOKUP_RCU) {
		struct fs_struct *fs = current->fs;
		unsigned seq;

		rcu_read_lock();

		do {
		seq = read_seqcount_begin(&fs->seq);
		nd->path = fs->pwd;
		@@ -2195,16 +2191,13 @@ static const char path_init(struct nameidata nd, unsigned flags)

		dentry = f.file->f_path.dentry;

		if (*s) {
		if (!d_can_lookup(dentry)) {
		if (*s && unlikely(!d_can_lookup(dentry))) {
		fdput(f);
		return ERR_PTR(-ENOTDIR);
		}
		}

		nd->path = f.file->f_path;
		if (flags & LOOKUP_RCU) {
		rcu_read_lock();
		nd->inode = nd->path.dentry->d_inode;
		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
		} else {
		@@ -2272,8 +2265,10 @@ static int path_lookupat(struct nameidata nd, unsigned flags, struct path path
		const char *s = path_init(nd, flags);
		int err;

		if (IS_ERR(s))
		if (IS_ERR(s)) {
		terminate_walk(nd);
		return PTR_ERR(s);
		}

		if (unlikely(flags & LOOKUP_DOWN)) {
		err = handle_lookup_down(nd);
		@@ -2337,8 +2332,10 @@ static int path_parentat(struct nameidata *nd, unsigned flags,
		{
		const char *s = path_init(nd, flags);
		int err;
		if (IS_ERR(s))
		if (IS_ERR(s)) {
		terminate_walk(nd);
		return PTR_ERR(s);
		}
		err = link_path_walk(s, nd);
		if (!err)
		err = complete_walk(nd);
		@@ -2666,8 +2663,10 @@ path_mountpoint(struct nameidata nd, unsigned flags, struct path path)
		{
		const char *s = path_init(nd, flags);
		int err;
		if (IS_ERR(s))
		if (IS_ERR(s)) {
		terminate_walk(nd);
		return PTR_ERR(s);
		}
		while (!(err = link_path_walk(s, nd)) &&
		(err = mountpoint_last(nd)) > 0) {
		s = trailing_symlink(nd);
		@@ -3512,6 +3511,7 @@ static struct file path_openat(struct nameidata nd,

		s = path_init(nd, flags);
		if (IS_ERR(s)) {
		terminate_walk(nd);
		fput(file);
		return ERR_CAST(s);
		}

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