similar to: [nbdkit PATCH] truncate: Detect large image overflow with round-up

The truncate filter tried to be careful to lock access to setting or reading the real_size variable learned from calling next_ops->get_size, in anticipation of not behaving incorrectly if the NBD protocol makes dynamic resize supported, and where the global variable could serve as a cache rather than having to always call next_ops->get_size to recompute things. However, nbdkit-plugin.pod

Since we're using ({ .. }) gcc/clang extension, let's rewrite the rounding.h change too. Rich.

While working on adding assertions to pthread_mutex_lock calls, I noticed that the truncate filter's use of mutex didn't really protect us, and isn't really necessary. Cleaning that up also spotted a couple of other potential cleanups. Eric Blake (4): filters: Drop useless .open callbacks truncate: Fix corruption when plugin changes per-connection size truncate: Test for safe

On 9/17/18 3:38 PM, Richard W.M. Jones wrote: > These are used at various places in the code already. This > refactoring simply moves them to a common header file and should have > no other effect. > --- > common/include/rounding.h | 59 +++++++++++++++++++++++++++++++++++++ > filters/cache/Makefile.am | 3 +- > filters/cache/cache.c | 2 +- >

On 08/01/2018 06:10 AM, Richard W.M. Jones wrote: > This can truncate, extend, or round up/down to a multiple. > --- > common-rules.mk | 3 +- > configure.ac | 1 + > filters/offset/nbdkit-offset-filter.pod | 7 +- > filters/partition/nbdkit-partition-filter.pod | 1 + >

These are used at various places in the code already. This refactoring simply moves them to a common header file and should have no other effect. --- common/include/rounding.h | 59 +++++++++++++++++++++++++++++++++++++ filters/cache/Makefile.am | 3 +- filters/cache/cache.c | 2 +- filters/cow/Makefile.am | 3 +- filters/cow/cow.c | 2 +- filters/truncate/truncate.c

This refactoring also fixes a bug spotted by Eric Blake: nbdkit --filter truncate pattern size=5G round-up=512 results in a 1G virtual disk. --- common/include/rounding.h | 58 ++++++++++++++++++++++++++++++++++ filters/cache/Makefile.am | 3 +- filters/cache/cache.c | 2 +- filters/cow/Makefile.am | 3 +- filters/cow/cow.c | 2 +- filters/truncate/truncate.c | 5

This can truncate, extend, or round up/down to a multiple. --- common-rules.mk | 3 +- configure.ac | 1 + filters/offset/nbdkit-offset-filter.pod | 7 +- filters/partition/nbdkit-partition-filter.pod | 1 + filters/truncate/Makefile.am | 60 ++++ filters/truncate/nbdkit-truncate-filter.pod | 87

This can truncate, extend, or round up/down to a multiple. --- common-rules.mk | 3 +- configure.ac | 1 + filters/offset/nbdkit-offset-filter.pod | 7 +- filters/partition/nbdkit-partition-filter.pod | 1 + filters/truncate/Makefile.am | 61 ++++ filters/truncate/nbdkit-truncate-filter.pod | 88

I have dropped the map filter from this series for now while I try to get it working. However I think the truncate filter is in a good shape. This incorporates all feedback from Eric's review. Also there are three small fixes to the filter code, all revealed when I was testing using multiple filters which we'd not done much of before. Rich.

The partitioning plugin patch is the same (except for rebasing). However I have changed the first two patches based on feedback received. In particular this fixes a very serious bug found by Eric Blake in the current truncate filter. Rich.

With these patches, a majority of tests pass. The notable things which are still broken: - Because FreeBSD links /home -> /usr/home, $(pwd) gives a different result from realpath(2). Therefore some tests which implicitly rely on (eg) a plugin which calls nbdkit_realpath internally and then checking that path against $(pwd) fail. - Shebangs (#!) don't seem to work the same way

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.

From: Joerg Roedel <jroedel at suse.de> When booted through startup_64 the kernel keeps running on the EFI page-table until the KASLR code sets up its own page-table. Without KASLR the pre-decompression boot code never switches off the EFI page-table. Change that by unconditionally switching to a kernel controlled page-table after relocation. This makes sure we can make changes to the

While shuffling quite a few things around, this gets us closer to native, which clearly had a reason to do the DMI scan early. Signed-off-by: Jan Beulich <jbeulich@novell.com> Index: head-2007-02-08/arch/i386/mm/ioremap-xen.c =================================================================== --- head-2007-02-08.orig/arch/i386/mm/ioremap-xen.c 2007-02-08 17:07:13.000000000 +0100 +++

It is easy to demonstrate that our blocksize filter has a bug: if the minblock= setting is a higher granularity than the underlying plugin actually supports, and the client is trying to collect block status for the entire disk, a mid-block transition in the plugin can result in the filter rounding a request so small that it no longer makes progress, causing the client to see: nbd.Error:

This patch series proposes two new filters. * truncate: This can truncate, extend, round up or round down the size of a plugin/device. A typical usage is to fix the qemu problem that it can only handle devices which are a multiple of 512-bytes: nbdkit --filter=truncate random size=500 round-up=512 This will serve a virtual device with size 512 bytes. Reading from the last 12 bytes will

On Thu, 23 May 2019 08:10:44 -0700 Linus Torvalds <torvalds at linux-foundation.org> wrote: > On Thu, May 23, 2019 at 7:00 AM Steven Rostedt <rostedt at goodmis.org> wrote: > > > > +# define roundup_64(x, y) ( \ > > +{ \ > > + typeof(y) __y = y;

No need for filters to specify their model in two different ways; the callback alone is sufficient. Since all filters are in-tree, we can deal with the API/ABI change made here. Signed-off-by: Eric Blake <eblake@redhat.com> --- docs/nbdkit-filter.pod | 48 +++++++++++++++------------------ include/nbdkit-filter.h | 6 ++--- filters/cow/cow.c | 2 --

Add a helper function get_real_size() to make it easier to add sanity checking that mutex calls don't fail. Signed-off-by: Eric Blake <eblake@redhat.com> --- I'm a bit unsure why truncate.c needs a lock anyway. I guess it's because we are storing 'size' and 'real_size' as globals rather than per-connection values in the handle, and we're worrying about