Re: [Libguestfs] [PATCH VERSION 4] Generic partition creation interface.

On Thu, Nov 05, 2009 at 01:15:03PM +0000, Richard W.M. Jones wrote: > After a bit of discussion with Jim Meyering I've decided to withdraw > this and rewrite it based on libparted. Using the parted command line > tool is just too unpredictable. After going down this rathole I decided maybe that wasn't such a good plan after all. The following patch goes back to using the command line interface, but we have made guestfs_part_disk work for both MBR and GPT formats (thanks to Jim). Most of the rest of the patch is concerned with updating documentation and examples to emphasize using guestfs_part* instead of guestfs_sfdisk* calls. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://et.redhat.com/~rjones/virt-df/ >From 74914b6fd255d849c8d5caf482e9c727f0a13afd Mon Sep 17 00:00:00 2001 From: Richard Jones <rjones(a)redhat.com&gt; Date: Wed, 4 Nov 2009 23:15:26 +0000 Subject: [PATCH] Generic partition creation interface. The current sfdisk interface works, but is somewhat limited since it can only deal with MBR-style partitions. For disks larger than 2TB, MBR partitions are unsuitable and we need to provide access to other partition table types (eg. GPT).

+int +do_part_add (const char *device, const char *prlogex, + int64_t startsect, int64_t endsect) +{ + char *err; + int r; + char startstr[32]; + char endstr[32]; + + /* Check and translate prlogex. */ + if (strcmp (prlogex, "primary") == 0 || + strcmp (prlogex, "logical") == 0 || + strcmp (prlogex, "extended") == 0) + ; + else if (strcmp (prlogex, "p") == 0) + prlogex = "primary"; + else if (strcmp (prlogex, "l") == 0) + prlogex = "logical"; + else if (strcmp (prlogex, "e") == 0) + prlogex = "extended"; + else { + reply_with_error ("part-add: unknown partition type: %s: this should be \"primary\", \"logical\" or \"extended\"", prlogex); + return -1;

+int +do_part_disk (const char *device, const char *parttype) +{ + char *err; + int r; + const char *startstr; + const char *endstr; + + parttype = check_parttype (parttype); + if (!parttype) { + reply_with_error ("part-disk: unknown partition type: common choices are \"gpt\" and \"msdos\""); + return -1; + } + + /* Voooooodooooooooo (thanks Jim Meyering for working this out). */ + if (strcmp (parttype, "msdos") == 0) { + startstr = "1s"; + endstr = "-1s"; + } else if (strcmp (parttype, "gpt") == 0) { + startstr = "34s"; + endstr = "-34s"; + } else { + /* untested */ + startstr = "1s"; + endstr = "-1s"; + } + + r = command (NULL, &err, + "/sbin/parted", "-s", "--", device, + "mklabel", parttype, + /* This slightly wrong - in the GPT case it will give + * the partition the name "primary". We have to give + * it some name, so this is as good as any. + */ + "mkpart", "primary", startstr, endstr,