On 09/22/2014 03:20 AM, Stefan Hajnoczi wrote: > The blkdebug block driver is undocumented. Documenting it is worthwhile > since it offers powerful error injection features that are used by > qemu-iotests test cases. > > This document will make it easier for people to learn about and use > blkdebug. > > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> > --- > docs/blkdebug.txt | 142 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 142 insertions(+) > create mode 100644 docs/blkdebug.txt > > diff --git a/docs/blkdebug.txt b/docs/blkdebug.txt > new file mode 100644 > index 0000000..7e616e0 > --- /dev/null > +++ b/docs/blkdebug.txt > @@ -0,0 +1,142 @@
No worse than many other files in this directory for omitting copyright and license information (which means it inherits the default of GPLv2+ from the top-level). > + > +Rules can be placed in a .ini file: Choice of article depends on whether you pronounce it "a dot-innie" or "an eye-en-eye" file. > + > + $ cat blkdebug.conf This file suffix is not '.ini'. So the idea is more that it is a configuration file that uses '.ini' style parsing, and not that it is an actual '.ini' file. > + [inject-error] > + event = "read_aio" > + errno = "28" > + > +This rule fails all aio read requests with ENOSPC (28). Eeesh - we are really tying things to host-dependent errno values? Might be worth a paragraph explaining that ENOSPC is not always 28. Or a design improvement to the setup to allow symbolic naming of the desired actions. Or both. > + > + errno - the POSIX errno value to return when a request matches this rule > + Again, POSIX doesn't proscribe errno values, just symbolic names; and those names differ in values across different OS. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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