Commit 3d1900a4 authored Sep 26, 2019 by Maxim Levitsky Committed by Daniel P. Berrangé May 07, 2020

block: luks: better error message when creating too large files

Currently if you attampt to create too large file with luks you
get the following error message:

Formatting 'test.luks', fmt=luks size=17592186044416 key-secret=sec0
qemu-img: test.luks: Could not resize file: File too large

While for raw format the error message is
qemu-img: test.img: The image size is too large for file format 'raw'

The reason for this is that qemu-img checks for errono of the failure,
and presents the later error when it is -EFBIG

However crypto generic code 'swallows' the errno and replaces it
with -EIO.

As an attempt to make it better, we can make luks driver,
detect -EFBIG and in this case present a better error message,
which is what this patch does

The new error message is:

qemu-img: error creating test.luks: The requested file size is too large

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1534898


Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

parent ccebb5f3

block/crypto.c

+21 −4

Original line number	Diff line number	Diff line
		@@ -104,18 +104,35 @@ static ssize_t block_crypto_init_func(QCryptoBlock *block,
		Error **errp)
		{
		struct BlockCryptoCreateData *data = opaque;
		Error *local_error = NULL;
		int ret;

		if (data->size > INT64_MAX \|\| headerlen > INT64_MAX - data->size) {
		error_setg(errp, "The requested file size is too large");
		return -EFBIG;
		ret = -EFBIG;
		goto error;
		}

		/* User provided size should reflect amount of space made
		* available to the guest, so we must take account of that
		* which will be used by the crypto header
		*/
		return blk_truncate(data->blk, data->size + headerlen, false,
		data->prealloc, 0, errp);
		ret = blk_truncate(data->blk, data->size + headerlen, false,
		data->prealloc, 0, &local_error);

		if (ret >= 0) {
		return ret;
		}

		error:
		if (ret == -EFBIG) {
		/* Replace the error message with a better one */
		error_free(local_error);
		error_setg(errp, "The requested file size is too large");
		} else {
		error_propagate(errp, local_error);
		}

		return ret;
		}