It has been pointed out that some controllers can not accept multiple
lines of output at once. In particular, io.max can only set one device
at a time.
Practically, the only multi-line resource values we can get come from
unified.* -- let's write those line by line.
Add a test case.
Reported-by: Tao Shen <shentaoskyking@gmail.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
A few cases relied on the fact that systemd is used, and thus
/sys/fs/cgroup/user.slice is available.
Guess what, in case of "make unittest" it might not be.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Only some libcontainer packages can be built on non-linux platforms
(not that it make sense, but at least go build succeeds). Let's call
these "good" packages.
For all other packages (i.e. ones that fail to build with GOOS other
than linux), it does not make sense to have linux build tag (as they
are broken already, and thus are not and can not be used on anything
other than Linux).
Remove linux build tag for all non-"good" packages.
This was mostly done by the following script, with just a few manual
fixes on top.
function list_good_pkgs() {
for pkg in $(find . -type d -print); do
GOOS=freebsd go build $pkg 2>/dev/null \
&& GOOS=solaris go build $pkg 2>/dev/null \
&& echo $pkg
done | sed -e 's|^./||' | tr '\n' '|' | sed -e 's/|$//'
}
function remove_tag() {
sed -i -e '\|^// +build linux$|d' $1
go fmt $1
}
SKIP="^("$(list_good_pkgs)")"
for f in $(git ls-files . | grep .go$); do
if echo $f | grep -qE "$SKIP"; then
echo skip $f
continue
fi
echo proc $f
remove_tag $f
done
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Fix reading cgroup files from the top cgroup directory, i.e.
/sys/fs/cgroup.
The code was working for for any subdirectory of /sys/fs/cgroup, but
for dir="/sys/fs/cgroup" a fallback (open and fstatfs) was used, because
of the way the function worked with the dir argument.
Fix those cases, and add unit tests to make sure they work. While at it,
make the rules for dir and name components more relaxed, and add test
cases for this, too.
While at it, improve OpenFile documentation, and remove a duplicated
doc comment for openFile.
Without these fixes, the unit test fails the following cases:
file_test.go:67: case {path:/sys/fs/cgroup name:cgroup.controllers}: fallback
file_test.go:67: case {path:/sys/fs/cgroup/ name:cgroup.controllers}: openat2 /sys/fs/cgroup//cgroup.controllers: invalid cross-device link
file_test.go:67: case {path:/sys/fs/cgroup/ name:/cgroup.controllers}: openat2 /sys/fs/cgroup///cgroup.controllers: invalid cross-device link
file_test.go:67: case {path:/ name:/sys/fs/cgroup/cgroup.controllers}: fallback
file_test.go:67: case {path:/ name:sys/fs/cgroup/cgroup.controllers}: fallback
file_test.go:67: case {path:/sys/fs/cgroup/cgroup.controllers name:}: openat2 /sys/fs/cgroup/cgroup.controllers/: not a directory
Here "fallback" means openat2-based implementation fails, and the fallback code
is used (and works).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This is a better place as cgroups itself is using these.
Should help with moving more stuff common in between fs and fs2 to
fscommon.
Looks big, but this is just moving the code around:
fscommon/{fscommon,open}.go -> cgroups/file.go
fscommon/fscommon_test.go -> cgroups/file_test.go
and fixes for TestMode moved to a different package.
There's no functional change.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
