similar to: [nbdkit PATCH 0/3] Fix data integrity in vddk plugin

I believe this roughly implements Nir's proposal here: https://www.redhat.com/archives/libguestfs/2020-August/msg00028.html Unfortunately it doesn't work for me. It actually slows things down quite a lot, for reasons I don't understand. Note the adjustment of the pool-max parameter and how it affects the total time. The results are quite reproducible. $ ./nbdkit -r -U - vddk

This has already been pushed upstream. I am simply posting these here so we have a reference in the mailing list in case we find bugs later (as I'm sure we will - it's a complex patch series). Great thanks to Eric Blake for tireless review on this one. It also seems to have identified a few minor bugs in qemu along the way. Rich.

When using VIXDISKLIB_FLAG_OPEN_SINGLE_LINK, parent images are not taken into account. However, the data we get from VixDiskLib_QueryAllocatedBlocks() has such granularity that it might return incorrect information. For example when the top image has only one block allocated, we get information about the whole chunk being allocated. This results in the consequent read to return invalid data -

Not sure what version we're up to, but this reimplements extents using the new simpler structure described in this thread: https://www.redhat.com/archives/libguestfs/2019-March/msg00077.html I also fixed most of the things that Eric pointed out in the previous review, although I need to go back over his replies and check I've got everything. This needs a bit more testing. However the

I'm not sure exactly which version we're up to, but let's say it's version 4. I'm a lot happier with this version: - all filters have been reviewed and changed where I think that's necessary - can_extents is properly defined and implemented now - NBD protocol is followed - I believe it addresses all previous review points where possible The "only" thing

I want to post this but mainly for discussion and early review. It's not safe for these patches to all go upstream yet (because not all filters have been checked/adjusted), but if any patches were to go upstream then probably 1 & 2 only are safe. File, VDDK, memory and data plugins all work, although I have only done minimal testing on them. The current tests, such as they are, all

We had a query yesterday about the VDDK plugin and making it actually obey the weird "Multithreading Considerations" rules in the VDDK documentation (https://vdc-download.vmware.com/vmwb-repository/dcr-public/8f96698a-0e7b-4d67-bb6c-d18a1d101540/ef536a47-27cd-481a-90ef-76b38e75353c/vsphere-vddk-671-programming-guide.pdf) This patch is my attempt to implement this. The idea is that the

The pool is only used for readonly connections, since writable connections usually take a lock on the server side and therefore you cannot open more than one. --- plugins/vddk/nbdkit-vddk-plugin.pod | 7 + plugins/vddk/vddk.c | 201 ++++++++++++++++++++++------ 2 files changed, 164 insertions(+), 44 deletions(-) diff --git a/plugins/vddk/nbdkit-vddk-plugin.pod

On Thu, Aug 6, 2020, 16:16 Richard W.M. Jones <rjones@redhat.com> wrote: > The pool is only used for readonly connections, since writable > connections usually take a lock on the server side and therefore you > cannot open more than one. > --- > plugins/vddk/nbdkit-vddk-plugin.pod | 7 + > plugins/vddk/vddk.c | 201 ++++++++++++++++++++++------ > 2

From: Martin Kletzander <mkletzan@redhat.com> Signed-off-by: Martin Kletzander <mkletzan@redhat.com> --- plugins/vddk/nbdkit-vddk-plugin.pod | 7 ++++++- plugins/vddk/vddk-structs.h | 1 + plugins/vddk/vddk.c | 10 ++++++++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/plugins/vddk/nbdkit-vddk-plugin.pod

This is my second attempt at this. The first version (also not working) was here: https://www.redhat.com/archives/libguestfs/2019-October/msg00062.html In part 1/2 I introduce a new .ready_to_serve plugin method which is called after forking and just before accepting any client connection. The idea would be that plugins could start background threads here. However this doesn't work well in

I suppose we may as well implement the only other flag too ... It's not clear what this does, something like O_DIRECT I imagine. Rich.

On 3/20/19 5:11 PM, Richard W.M. Jones wrote: > This uses a new API VixDiskLib_QueryAllocatedBlocks provided in > VDDK >= 6.7. > > Thanks: Martin Kletzander. > --- > plugins/vddk/vddk-structs.h | 15 +++- > plugins/vddk/vddk.c | 138 ++++++++++++++++++++++++++++++++++++ > 2 files changed, 152 insertions(+), 1 deletion(-) > > +static int >

In can_extents we test whether the VDDK function VixDiskLib_QueryAllocatedBlocks works before declaring that extents are supported. This VDDK function can fail in several ways but most notable if the server doesn't support querying extents. In this case VDDK raises an error message through the error_function callback, which we turn into a call to nbdkit_error. In most cases this will cause

This uses a new API VixDiskLib_QueryAllocatedBlocks provided in VDDK >= 6.7. Thanks: Martin Kletzander. --- plugins/vddk/vddk-structs.h | 15 +++- plugins/vddk/vddk.c | 138 ++++++++++++++++++++++++++++++++++++ 2 files changed, 152 insertions(+), 1 deletion(-) diff --git a/plugins/vddk/vddk-structs.h b/plugins/vddk/vddk-structs.h index dbed94a..df88322 100644 ---

the data in holes is actually not zeros as there might be a parent image having other data. Properly reporting (non-)zero hole extents allows clients to have information about whether the data in the image is unallocated, but the read will return zero blocks (HOLE+ZERO) or whether the data is just not in this later of the image (only HOLE). Signed-off-by: Martin Kletzander

In my logs I can see that end_form_tag is being deprecated. I wanted to make the switch now but cannot get the new end tag to work. THIS WORKS: <%= form_remote_tag :url =>{:action => "next_question", :kwiz_id => @kwiz.id, :position => @next_position} %> <% @question.choices.each do

This is exactly the same as v1: https://www.redhat.com/archives/libguestfs/2018-December/msg00004.html except that it now frees the bitmap on unload (which the old code did not - there was always a memory leak). Rich.

As I've spent really too long today investigating this, I want to document this in a public email, even though there's nothing really that interesting here. One thing you find from search for VDD 6.7 / VixDiskLib_QueryAllocatedBlocks issues with Google is that we must be one of the very few users out there. And the other thing is that it's quite broken. All testing was done using

v2: https://www.redhat.com/archives/libguestfs/2018-December/msg00039.html v2 -> v3: - Fix all the issues raised in Eric's review. - Precompute some numbers to make the calculations easier. - Calculations now use bitshifts and masks in preference to division and modulo. - Clear existing bits before setting (which fixes a bug in the cache filter). Rich.