vfs: take path_get_longterm() out of write_seqcount scope (82234e61) · Commits · e / devices / android_kernel_xiaomi_markw

fs/fs_struct.c

+15 −12

Original line number	Diff line number	Diff line
		@@ -26,11 +26,11 @@ void set_fs_root(struct fs_struct fs, struct path path)
		{
		struct path old_root;

		path_get_longterm(path);
		spin_lock(&fs->lock);
		write_seqcount_begin(&fs->seq);
		old_root = fs->root;
		fs->root = *path;
		path_get_longterm(path);
		write_seqcount_end(&fs->seq);
		spin_unlock(&fs->lock);
		if (old_root.dentry)
		@@ -45,11 +45,11 @@ void set_fs_pwd(struct fs_struct fs, struct path path)
		{
		struct path old_pwd;

		path_get_longterm(path);
		spin_lock(&fs->lock);
		write_seqcount_begin(&fs->seq);
		old_pwd = fs->pwd;
		fs->pwd = *path;
		path_get_longterm(path);
		write_seqcount_end(&fs->seq);
		spin_unlock(&fs->lock);

		@@ -57,6 +57,14 @@ void set_fs_pwd(struct fs_struct fs, struct path path)
		path_put_longterm(&old_pwd);
		}

		static inline int replace_path(struct path p, const struct path old, const struct path *new)
		{
		if (likely(p->dentry != old->dentry \|\| p->mnt != old->mnt))
		return 0;
		p = new;
		return 1;
		}

		void chroot_fs_refs(struct path old_root, struct path new_root)
		{
		struct task_struct g, p;
		@@ -68,21 +76,16 @@ void chroot_fs_refs(struct path old_root, struct path new_root)
		task_lock(p);
		fs = p->fs;
		if (fs) {
		int hits = 0;
		spin_lock(&fs->lock);
		write_seqcount_begin(&fs->seq);
		if (fs->root.dentry == old_root->dentry
		&& fs->root.mnt == old_root->mnt) {
		path_get_longterm(new_root);
		fs->root = *new_root;
		hits += replace_path(&fs->root, old_root, new_root);
		hits += replace_path(&fs->pwd, old_root, new_root);
		write_seqcount_end(&fs->seq);
		while (hits--) {
		count++;
		}
		if (fs->pwd.dentry == old_root->dentry
		&& fs->pwd.mnt == old_root->mnt) {
		path_get_longterm(new_root);
		fs->pwd = *new_root;
		count++;
		}
		write_seqcount_end(&fs->seq);
		spin_unlock(&fs->lock);
		}
		task_unlock(p);