Unverified Commit d10771d5 authored by Christian Brauner's avatar Christian Brauner
Browse files

Merge patch series "ovl: simplify ovl_parse_param_lowerdir()" 

Simplify and fix overlayfs layer parsing so the maximum of 500 layers
can be used.

* patches from https://lore.kernel.org/r/20240705011510.794025-1-chengzhihao1@huawei.com:
  ovl: ovl_parse_param_lowerdir: Add missed '\n' for pr_err
  ovl: fix wrong lowerdir number check for parameter Opt_lowerdir
  ovl: pass string to ovl_parse_layer()

Link: https://lore.kernel.org/r/20240705011510.794025-1-chengzhihao1@huawei.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parents 996b37da 441e36ef

fs/overlayfs/params.c

+12 −39
Original line number Diff line number Diff line
@@ -353,6 +353,8 @@ static void ovl_add_layer(struct fs_context *fc, enum ovl_opt layer, 
	case Opt_datadir_add:

		ctx->nr_data++;

		fallthrough;

	case Opt_lowerdir:

		fallthrough;

	case Opt_lowerdir_add:

		WARN_ON(ctx->nr >= ctx->capacity);

		l = &ctx->lower[ctx->nr++];
@@ -365,10 +367,9 @@ static void ovl_add_layer(struct fs_context *fc, enum ovl_opt layer, 
	}

}



static int ovl_parse_layer(struct fs_context *fc, struct fs_parameter *param,

			   enum ovl_opt layer)

static int ovl_parse_layer(struct fs_context *fc, const char *layer_name, enum ovl_opt layer)

{

	char *name = kstrdup(param->string, GFP_KERNEL);

	char *name = kstrdup(layer_name, GFP_KERNEL);

	bool upper = (layer == Opt_upperdir || layer == Opt_workdir);

	struct path path;

	int err;
@@ -376,7 +377,7 @@ static int ovl_parse_layer(struct fs_context *fc, struct fs_parameter *param, 
	if (!name)

		return -ENOMEM;



	if (upper)

	if (upper || layer == Opt_lowerdir)

		err = ovl_mount_dir(name, &path);

	else

		err = ovl_mount_dir_noesc(name, &path);
@@ -432,7 +433,6 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) 
{

	int err;

	struct ovl_fs_context *ctx = fc->fs_private;

	struct ovl_fs_context_layer *l;

	char *dup = NULL, *iter;

	ssize_t nr_lower, nr;

	bool data_layer = false;
@@ -449,7 +449,7 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) 
		return 0;



	if (*name == ':') {

		pr_err("cannot append lower layer");

		pr_err("cannot append lower layer\n");

		return -EINVAL;

	}
@@ -472,35 +472,11 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) 
		goto out_err;

	}



	if (nr_lower > ctx->capacity) {

		err = -ENOMEM;

		l = krealloc_array(ctx->lower, nr_lower, sizeof(*ctx->lower),

				   GFP_KERNEL_ACCOUNT);

		if (!l)

			goto out_err;



		ctx->lower = l;

		ctx->capacity = nr_lower;

	}



	iter = dup;

	l = ctx->lower;

	for (nr = 0; nr < nr_lower; nr++, l++) {

		ctx->nr++;

		memset(l, 0, sizeof(*l));



		err = ovl_mount_dir(iter, &l->path);

	for (nr = 0; nr < nr_lower; nr++) {

		err = ovl_parse_layer(fc, iter, Opt_lowerdir);

		if (err)

			goto out_put;



		err = ovl_mount_dir_check(fc, &l->path, Opt_lowerdir, iter, false);

		if (err)

			goto out_put;



		err = -ENOMEM;

		l->name = kstrdup(iter, GFP_KERNEL_ACCOUNT);

		if (!l->name)

			goto out_put;

			goto out_err;



		if (data_layer)

			ctx->nr_data++;
@@ -517,8 +493,8 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) 
			 * there are no data layers.

			 */

			if (ctx->nr_data > 0) {

				pr_err("regular lower layers cannot follow data lower layers");

				goto out_put;

				pr_err("regular lower layers cannot follow data lower layers\n");

				goto out_err;

			}



			data_layer = false;
@@ -532,9 +508,6 @@ static int ovl_parse_param_lowerdir(const char *name, struct fs_context *fc) 
	kfree(dup);

	return 0;



out_put:

	ovl_reset_lowerdirs(ctx);



out_err:

	kfree(dup);
@@ -582,7 +555,7 @@ static int ovl_parse_param(struct fs_context *fc, struct fs_parameter *param) 
	case Opt_datadir_add:

	case Opt_upperdir:

	case Opt_workdir:

		err = ovl_parse_layer(fc, param, opt);

		err = ovl_parse_layer(fc, param->string, opt);

		break;

	case Opt_default_permissions:

		config->default_permissions = true;