Commit 53dbb0b4 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: split out ovl_get_lowerstack() from ovl_fill_super() 



Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 87ad447a

fs/overlayfs/super.c

+72 −50
Original line number Diff line number Diff line
@@ -895,6 +895,75 @@ static int ovl_get_workpath(struct ovl_fs *ufs, struct path *upperpath, 
	return err;

}



static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs,

			      struct path **stackp, unsigned int *stacklenp)

{

	int err;

	char *lowertmp, *lower;

	struct path *stack;

	unsigned int stacklen, numlower, i;

	bool remote = false;



	err = -ENOMEM;

	lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL);

	if (!lowertmp)

		goto out;



	err = -EINVAL;

	stacklen = ovl_split_lowerdirs(lowertmp);

	if (stacklen > OVL_MAX_STACK) {

		pr_err("overlayfs: too many lower directories, limit is %d\n",

		       OVL_MAX_STACK);

		goto out;

	} else if (!ufs->config.upperdir && stacklen == 1) {

		pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");

		goto out;

	}



	err = -ENOMEM;

	stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL);

	if (!stack)

		goto out;



	err = -EINVAL;

	lower = lowertmp;

	for (numlower = 0; numlower < stacklen; numlower++) {

		err = ovl_lower_dir(lower, &stack[numlower], ufs,

				    &sb->s_stack_depth, &remote);

		if (err)

			goto out_free_stack;



		lower = strchr(lower, '\0') + 1;

	}



	err = -EINVAL;

	sb->s_stack_depth++;

	if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {

		pr_err("overlayfs: maximum fs stacking depth exceeded\n");

		goto out_free_stack;

	}



	*stackp = stack;

	*stacklenp = numlower;



	if (remote)

		sb->s_d_op = &ovl_reval_dentry_operations;

	else

		sb->s_d_op = &ovl_dentry_operations;



	err = 0;



out:

	kfree(lowertmp);

	return err;



out_free_stack:

	for (i = 0; i < numlower; i++)

		path_put(&stack[i]);

	kfree(stack);

	goto out;

}



static int ovl_fill_super(struct super_block *sb, void *data, int silent)

{

	struct path upperpath = { };
@@ -903,12 +972,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	struct ovl_entry *oe;

	struct ovl_fs *ufs;

	struct path *stack = NULL;

	char *lowertmp;

	char *lower;

	unsigned int numlower;

	unsigned int stacklen = 0;

	unsigned int numlower = 0;

	unsigned int i;

	bool remote = false;

	struct cred *cred;

	int err;
@@ -948,44 +1013,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 


		sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth;

	}

	err = -ENOMEM;

	lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL);

	if (!lowertmp)

		goto out_unlock_workdentry;



	err = -EINVAL;

	stacklen = ovl_split_lowerdirs(lowertmp);

	if (stacklen > OVL_MAX_STACK) {

		pr_err("overlayfs: too many lower directories, limit is %d\n",

		       OVL_MAX_STACK);

		goto out_free_lowertmp;

	} else if (!ufs->config.upperdir && stacklen == 1) {

		pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");

		goto out_free_lowertmp;

	}



	err = -ENOMEM;

	stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL);

	if (!stack)

		goto out_free_lowertmp;



	err = -EINVAL;

	lower = lowertmp;

	for (numlower = 0; numlower < stacklen; numlower++) {

		err = ovl_lower_dir(lower, &stack[numlower], ufs,

				    &sb->s_stack_depth, &remote);

	err = ovl_get_lowerstack(sb, ufs, &stack, &numlower);

	if (err)

			goto out_put_lowerpath;



		lower = strchr(lower, '\0') + 1;

	}



	err = -EINVAL;

	sb->s_stack_depth++;

	if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {

		pr_err("overlayfs: maximum fs stacking depth exceeded\n");

		goto out_put_lowerpath;

	}

		goto out_unlock_workdentry;



	if (ufs->config.upperdir) {

		ufs->upper_mnt = clone_private_mount(&upperpath);
@@ -1145,11 +1175,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	if (!ufs->indexdir)

		ufs->config.index = false;



	if (remote)

		sb->s_d_op = &ovl_reval_dentry_operations;

	else

		sb->s_d_op = &ovl_dentry_operations;



	err = -ENOMEM;

	ufs->creator_cred = cred = prepare_creds();

	if (!cred)
@@ -1173,7 +1198,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
		mntput(stack[i].mnt);

	kfree(stack);

	mntput(workpath.mnt);

	kfree(lowertmp);



	if (upperpath.dentry) {

		oe->has_upper = true;
@@ -1212,8 +1236,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
	for (i = 0; i < numlower; i++)

		path_put(&stack[i]);

	kfree(stack);

out_free_lowertmp:

	kfree(lowertmp);

out_unlock_workdentry:

	if (ufs->workdir_locked)

		ovl_inuse_unlock(workpath.dentry);