rbd: trigger an error on invalid max snaps value

[zxysilent]

It is necessary to determine whether cMaxSnaps is a large 0. Otherwise, the following code will panic

// GetSnapshotNames returns more than just the names of snapshots
// associated with the rbd image.
//
// Implements:
//
//	int rbd_snap_list(rbd_image_t image, rbd_snap_info_t *snaps, int *max_snaps);
func (image *Image) GetSnapshotNames() (snaps []SnapInfo, err error) {
	if err := image.validate(imageIsOpen); err != nil {
		return nil, err
	}

	var c_max_snaps C.int

	ret := C.rbd_snap_list(image.image, nil, &c_max_snaps)
 	if c_max_snaps < 1 {
		return nil, RBDError(ret)
	}
	c_snaps := make([]C.rbd_snap_info_t, c_max_snaps)
	snaps = make([]SnapInfo, c_max_snaps)

	ret = C.rbd_snap_list(image.image,
		&c_snaps[0], &c_max_snaps)
	if ret < 0 {
		return nil, RBDError(ret)
	}

	for i, s := range c_snaps {
		snaps[i] = SnapInfo{Id: uint64(s.id),
			Size: uint64(s.size),
			Name: C.GoString(s.name)}
	}

	C.rbd_snap_list_end(&c_snaps[0])
	return snaps[:len(snaps)-1], nil
}

[phlogistonjohn]

Thanks for the change, on first glance the code seems reasonable. However, the commit message needs updating. Please add your 'Signed-off-by' to the commit and update your commit message to conform to the project's typical flow of <pkg>: <short_desc>. In your case I suggest rbd: trigger an error on invalid max snaps value or something like that. Thanks!

[zxysilent]

Thank you, this is my first time submitting an MR for this project

[anoopcs9]

Thank you, this is my first time submitting an MR for this project

I did a force push to have a single commit with the change. This way the git history is much cleaner.

[phlogistonjohn]

@Mergifyio rebase

[mergify]

rebase

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