The identifier 'stdin' is reserved in C. It can be #defined to any
statement that evaluates to a FILE*. We do not want that for our field,
so change to a more descriptive name.
The RADOS Block Device (rbd) can be used as any other block device with
further layers on top of it, hence allow the common persistent storage
rules to apply, including watching for changes.
We typically want to deal in usec_t, hence let's change the prototype
accordingly, and do proper range checks. Also, make sure are not
confused by negative times.
Do something similar for mktime_or_timegm().
This is a more comprehensive alternative to #34065
Replaces: #34065
An error message is already printed directly after, so the user already
knows that the validation failed. This also isn't done for the other
validation functions.
When sd-firstboot is ran during first boot of a new system this missing
newline leads to a bootup message being appended on the same line as the
message instructing to press a key.
Given that debug_invocation is a Unit thing, make
service_set_debug_invocation() generic. Plus, don't
say "Service failed", as it would be spurious when
Restart=always.
When dealing with copying COW images, we have to make a tradeoff:
- Either we don't touch the NOCOW bit on the copied file COW and get
an instant copy because we're able to reflink, but we might get
reduced performance if the source file was COW as COW files and lots
of random writes don't play well together.
- Or we force NOCOW for the copied file, which means we have to do a
full copy as reflinking from COW files to NOCOW files or vice versa
is not supported.
In exec-invoke.c, we've opted for the first option. In nspawn.c and
discover-image.c, we've opted for the second option.
In nspawn, this applies to the --ephemeral option to make ephemeral
copies. In discover-image.c, this applies to cloning images into
/var/lib/machines. Both these features might be used to run many
machines of the same original image. We really don't want to force
a full copy onto users in these scenarios when they're expecting
reflink behavior, leading to them running out of disk space. Instead,
degraded performance in their machines is a much less severe issue,
which they will discover on their own if it affects them, at which
point they can make their original image NOCOW at which point they'll
get both the reflinks and better performance.
Given the above reasoning, let's switch nspawn.c and discover-image.c
to use COPY_NOCOW_AFTER as well instead of enabling NOCOW upfront and
forcing a copy if the original source image is COW.
Unless otherwise requested, if we're going to copy a nocow file, make the
target file nocow as well.
Aside from keeping the performance characteristics of the cow or nocow file
intact, reflinking also only works from cow to cow or nocow to nocow files.
Reflinking from cow to nocow or nocow to cow files does not work and can
easily lead to unexpected copies for users, so by keeping the nocow bit
intact across copies by default we also make sure reflinks always work.
Yu Watanabe
Bastien Nocera
A. Wilcox
Peter Rajnoha
Daan De Meyer
Lennart Poettering
Michael Ferrari
Ivan Shapovalov
Mike Yuan