similar to: [PATCH nbdkit v3 0/3] Add partitioning plugin.

nbdkit partitioning boot.img swap.img root.img ... creates a virtual disk by adding a partition table. In ancient times Xen used to do this. Rich.

This is a revised version of the two series previously posted here: https://www.redhat.com/archives/libguestfs/2019-January/msg00137.html https://www.redhat.com/archives/libguestfs/2019-January/msg00139.html There have been many smaller changes but the highlights are: - Using SECTOR_SIZE instead of hard-coding 512 everywhere. - Additional safety checks that the EBR chain doesn't jump

An evolution of the patch I posted yesterday to qemu-devel (https://www.mail-archive.com/qemu-devel@nongnu.org/msg588920.html) which (a) works and (b) has a test. Rich.

This was a rather longer trip around the houses than I anticipated! The basic purpose of the patch series is to set $nbdkit_stdio_safe to "0" or "1" in sh and eval plugin scripts. To do that, I ended up adding a nicer way to manipulate environ lists, and to do that, I ended up adding a whole generic vector implementation which is applicable in a lot of different places.

I think this addresses everything in Eric's v2 review. Note that the first patch is best viewed using ‘-w’ to ignore whitespaces changes. Rich.

v1 was here: https://www.redhat.com/archives/libguestfs/2019-January/thread.html#00198 For v2 I changed most existing prerequisite tests to use the new mechanism. I only changed simple tests. There are a few more complex tests that don't fit the “requires model” and those are not changed. I normalized qemu-io/qemu-img testing to always use the --version flag, where previously we used a mix

Another interesting thing you can do with this plugin: https://rwmj.wordpress.com/2019/02/19/nbdkit-linuxdisk-plugin/ v2: - Fix inconsistent tab/space. - All 3 plugins now contain a block of text pointing to the other 2 plugins. - TMDIR -> TMPDIR - Unlink the temporary file and other cleanups along error paths. - fclose -> pclose, and check the return value for errors. -

Turns out Japanese trains are good for coding! In supermin we have a bunch of code to create the libguestfs appliance. It creates it directly using libext2fs (part of e2fsprogs). We can use the same technique to create ext2 virtual disks in nbdkit, which is what this new plugin does. Why a new plugin instead of modifying the floppy plugin? See the 4/4 commit message for an explanation. The

Create a partitioned virtual drive from a list of one or more files each containing single partitions. The plugin concatenates the files together and generates a virtual partition table so that NBD clients see a single partitioned disk. For example: nbdkit partitioning boot.img swap.img root.img creates a virtual disk with 3 partitions. --- configure.ac |

Add nbdkit-floppy-plugin, “inspired” by qemu's VVFAT driver, but without the ability to handle writes. The implementation is pretty complete, supporting FAT32, LFNs, volume labels, timestamps, etc, and it passes both ‘make check’ and ‘make check-valgrind’. Usage is simple; to serve the current directory: $ nbdkit floppy . Then using guestfish (or any NBD client): $ guestfish --ro

This implements support for MBR logical partitions in nbdkit-partition-filter, complementing existing support in the partitioning plugin. Rich.

For v3 I reimplemented this using mke2fs -d. This obviously makes the implementation a whole lot simpler, but cannot support multiple directory merging. Patches 1-3 are the same as before. I've also reproduced the notes from v2 below. v2: - Fix inconsistent tab/space. - All 3 plugins now contain a block of text pointing to the other 2 plugins. - TMDIR -> TMPDIR - Unlink the

On 08/02/2018 02:05 PM, Nir Soffer wrote: > fallocate(FALLOC_FL_ZERO_RANGE) is supportd for block devices with > modern kernel, but when it is not, we fall back to manual zeroing. > > Check if the underlying file is a block device when opening the file, > and fall back to ioctl(BLKZEROOUT) for aligned zero requests for a > block device. > > +++ b/plugins/file/file.c >

--- common/include/isaligned.h | 11 +++++------ plugins/file/file.c | 4 ++-- plugins/vddk/vddk.c | 8 ++++---- 3 files changed, 11 insertions(+), 12 deletions(-) diff --git a/common/include/isaligned.h b/common/include/isaligned.h index e693820..81ce8a7 100644 --- a/common/include/isaligned.h +++ b/common/include/isaligned.h @@ -36,16 +36,15 @@ #include <assert.h>

This is the second version to support efficient zero for block devices on older kernels (e.g. RHEL 7.5), and file systems that do not support yet FALLOC_FS_ZERO_RANGE (e.g. NFS 4.2). Changes since v1: - Split to smaller patches - Skip linux only includes on other systems - Skip code using BLKZEROOUT if the macro is not defined - Try BLKZEROOUT only if the offset and count are aligned to device

This version addresses some of the comments on v2. Changes since v2: - file_zero: Add missing space in function call - is_aligned: Assert that align is indeed a power of 2 - Spelling in commit message Not changed: - Eric commented that spacing was off: https://www.redhat.com/archives/libguestfs/2018-August/msg00113.html but I could not find anything wrong. - Eric asked if ioctl.h will cause

This is the third version to support efficient zero for block devices on older kernels (e.g. RHEL 7.5), and file systems that do not support yet FALLOC_FS_ZERO_RANGE (e.g. NFS 4.2). Changes since v2: - Revert file_can_trim change, since it is too late to change the value after negotiation. Changing the capability dinamically may be useful internally, but it should be done via other means. -

There's a lot of code in nbdkit-file-plugin which it would be nice to reuse elsewhere. One possible approach (as outlined here) is simply to move the file callbacks (like file.pread, file.pwrite, file.zero etc) to a new mini-library. They can then be consumed by other plugins fairly easily by doing: static void * foo_open (int readonly) { struct fileops *fops; int fd, flags; /*

--- .../nbdkit-partitioning-plugin.pod | 29 ++-- plugins/partitioning/virtual-disk.h | 12 +- plugins/partitioning/partition-mbr.c | 132 +++++++++++++++--- plugins/partitioning/partitioning.c | 28 ++-- plugins/partitioning/virtual-disk.c | 42 +++++- tests/Makefile.am | 4 +- tests/test-partitioning5.sh

This version addresses comments on v3. Changes since v3: - Finally got spacing right (Eric) - Reorder includes (Richard) - Return 0 or -1 instead of r (Richard) - Add common/include/isaligned.h to Makefile.am (Richard) v3 was here: https://www.redhat.com/archives/libguestfs/2018-August/msg00177.html Nir Soffer (4): file: Avoid unsupported fallocate() calls file: Support zero without