This change gates all FUSE commands (by gating /dev/fuse) behind a runsc
flag. In order to use FUSE commands, use the --fuse flag with the --vfs2
flag. Check if FUSE is enabled by running dmesg in the sandbox.
Linux 4.18 and later make reads and writes coherent between pre-copy-up and
post-copy-up FDs representing the same file on an overlay filesystem. However,
memory mappings remain incoherent:
- Documentation/filesystems/overlayfs.rst, "Non-standard behavior": "If a file
residing on a lower layer is opened for read-only and then memory mapped with
MAP_SHARED, then subsequent changes to the file are not reflected in the
memory mapping."
- fs/overlay/file.c:ovl_mmap() passes through to the underlying FD without any
management of coherence in the overlay.
- Experimentally on Linux 5.2:
```
$ cat mmap_cat_page.c
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
int main(int argc, char **argv) {
if (argc < 2) {
errx(1, "syntax: %s [FILE]", argv[0]);
}
const int fd = open(argv[1], O_RDONLY);
if (fd < 0) {
err(1, "open(%s)", argv[1]);
}
const size_t page_size = sysconf(_SC_PAGE_SIZE);
void* page = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, 0);
if (page == MAP_FAILED) {
err(1, "mmap");
}
for (;;) {
write(1, page, strnlen(page, page_size));
if (getc(stdin) == EOF) {
break;
}
}
return 0;
}
$ gcc -O2 -o mmap_cat_page mmap_cat_page.c
$ mkdir lowerdir upperdir workdir overlaydir
$ echo old > lowerdir/file
$ sudo mount -t overlay -o "lowerdir=lowerdir,upperdir=upperdir,workdir=workdir" none overlaydir
$ ./mmap_cat_page overlaydir/file
old
^Z
[1]+ Stopped ./mmap_cat_page overlaydir/file
$ echo new > overlaydir/file
$ cat overlaydir/file
new
$ fg
./mmap_cat_page overlaydir/file
old
```
Therefore, while the VFS1 gofer client's behavior of reopening read FDs is only
necessary pre-4.18, replacing existing memory mappings (in both sentry and
application address spaces) with mappings of the new FD is required regardless
of kernel version, and this latter behavior is common to both VFS1 and VFS2.
Re-document accordingly, and change the runsc flag to enabled by default.
New test:
- Before this CL: https://source.cloud.google.com/results/invocations/5b222d2c-e918-4bae-afc4-407f5bac509b
- After this CL: https://source.cloud.google.com/results/invocations/f28c747e-d89c-4d8c-a461-602b33e71aab
PiperOrigin-RevId: 311361267
Previously we unconditionally failed to cleanup the networking files
(hostname, resolve.conf, hosts), and failed to cleanup the netns, etc on
partial setup failure.
We can drop the iptables commands from cleanup, as the routes
automatically go away when the device is deleted. Those commands were
failing previously.
Forward signals to the container, allowing it to exit normally when a
signal is received, and then for runsc to run the cleanup. This doesn't
cover cleanup when runsc is signalled before the container start, it
covers the most common case.
Fixes#2539Fixes#2540
Included:
- loader_test.go RunTest and TestStartSignal VFS2
- container_test.go TestAppExitStatus on VFS2
- experimental flag added to runsc to turn on VFS2
Note: shared mounts are not yet supported.
PiperOrigin-RevId: 307070753
GO's runtime calls the write system call twice to print "panic:"
and "the reason of this panic", so here is a race window when
other threads can print something to the log and we will see
something like this:
panic: log messages from another thread
The reason of the panic.
This confuses the syzkaller blacklist and dedup detection.
It also makes the logs generally difficult to read. e.g.,
data races often have one side of the race, followed by
a large "diagnosis" dump, finally followed by the other
side of the race.
PiperOrigin-RevId: 297887895
In general, we've learned that logging must be avoided at all
costs in the hot path. It's unlikely that the optimizations
here were significant in any case, since buffer would certainly
escape.
This also adds a test to ensure that the caller identification
works as expected, and so that logging can be benchmarked.
Original:
BenchmarkGoogleLogging-6 1222255 949 ns/op
With this change:
BenchmarkGoogleLogging-6 517323 2346 ns/op
Fixes#184
PiperOrigin-RevId: 291815420
When application is not cgroups-aware, it can spawn excessive threads
which often defaults to CPU number.
Introduce a opt-in flag that will set CPU number accordingly to CPU
quota (if available).
Fixes#1391
The first use of time.Local (usually via time.Time.Date, et. al) performs
initialization of the local timezone, which involves open several tzdata files
from the host.
Since filter installation disallows open, we should explicitly force this
initialization rather than implicitly depending on the first logging (or other
time) call occurring before filter installation.
PiperOrigin-RevId: 282053121
Adds a systemd-cgroup flag option that prints an error letting the user know
that systemd cgroups are not supported and points them to the relevant issue.
Issue #193
PiperOrigin-RevId: 277837162
Right now, we send each tcp packet separately, we call one system
call per-packet. This patch allows to generate multiple tcp packets
and send them by sendmmsg.
The arguable part of this CL is a way how to handle multiple headers.
This CL adds the next field to the Prepandable buffer.
Nginx test results:
Server Software: nginx/1.15.9
Server Hostname: 10.138.0.2
Server Port: 8080
Document Path: /10m.txt
Document Length: 10485760 bytes
w/o gso:
Concurrency Level: 5
Time taken for tests: 5.491 seconds
Complete requests: 100
Failed requests: 0
Total transferred: 1048600200 bytes
HTML transferred: 1048576000 bytes
Requests per second: 18.21 [#/sec] (mean)
Time per request: 274.525 [ms] (mean)
Time per request: 54.905 [ms] (mean, across all concurrent requests)
Transfer rate: 186508.03 [Kbytes/sec] received
sw-gso:
Concurrency Level: 5
Time taken for tests: 3.852 seconds
Complete requests: 100
Failed requests: 0
Total transferred: 1048600200 bytes
HTML transferred: 1048576000 bytes
Requests per second: 25.96 [#/sec] (mean)
Time per request: 192.576 [ms] (mean)
Time per request: 38.515 [ms] (mean, across all concurrent requests)
Transfer rate: 265874.92 [Kbytes/sec] received
w/o gso:
$ ./tcp_benchmark --client --duration 15 --ideal
[SUM] 0.0-15.1 sec 2.20 GBytes 1.25 Gbits/sec
software gso:
$ tcp_benchmark --client --duration 15 --ideal --gso $((1<<16)) --swgso
[SUM] 0.0-15.1 sec 3.99 GBytes 2.26 Gbits/sec
PiperOrigin-RevId: 276112677
Linux kernel before 4.19 doesn't implement a feature that updates
open FD after a file is open for write (and is copied to the upper
layer). Already open FD will continue to read the old file content
until they are reopened. This is especially problematic for gVisor
because it caches open files.
Flag was added to force readonly files to be reopenned when the
same file is open for write. This is only needed if using kernels
prior to 4.19.
Closes#1006
It's difficult to really test this because we never run on tests
on older kernels. I'm adding a test in GKE which uses kernels
with the overlayfs problem for 1.14 and lower.
PiperOrigin-RevId: 275115289
The simple test script has gotten out of control. Shard this script into
different pieces and attempt to impose order on overall test structure. This
change helps lay some of the foundations for future improvements.
* The runsc/test directories are moved into just test/.
* The runsc/test/testutil package is split into logical pieces.
* The scripts/ directory contains new top-level targets.
* Each test is now responsible for building targets it requires.
* The install functionality is moved into `runsc` itself for simplicity.
* The existing kokoro run_tests.sh file now just calls all (can be split).
After this change is merged, I will create multiple distinct workflows for
Kokoro, one for each of the scripts currently targeted by `run_tests.sh` today,
which should dramatically reduce the time-to-run for the Kokoro tests, and
provides a better foundation for further improvements to the infrastructure.
PiperOrigin-RevId: 267081397
'--rootless' flag lets a non-root user execute 'runsc do'.
The drawback is that the sandbox and gofer processes will
run as root inside a user namespace that is mapped to the
caller's user, intead of nobody. And network is defaulted
to '--network=host' inside the root network namespace. On
the bright side, it's very convenient for testing:
runsc --rootless do ls
runsc --rootless do curl www.google.com
PiperOrigin-RevId: 252840970
Adds simple introspection for syscall compatibility information to Linux/AMD64.
Syscalls registered in the syscall table now have associated metadata like
name, support level, notes, and URLs to relevant issues.
Syscall information can be exported as a table, JSON, or CSV using the new
'runsc help syscalls' command. Users can use this info to debug and get info
on the compatibility of the version of runsc they are running or to generate
documentation.
PiperOrigin-RevId: 252558304
Containerd uses the last error message sent to the log to
print as failure cause for create/exec. This required a
few changes in the logging logic for runsc:
- cmd.Errorf/Fatalf: now writes a message with 'error'
level to containerd log, in addition to stderr and
debug logs, like before.
- log.Infof/Warningf/Fatalf: are not sent to containerd
log anymore. They are mostly used for debugging and not
useful to containerd. In most cases, --debug-log is
enabled and this avoids the logs messages from being
duplicated.
- stderr is not used as default log destination anymore.
Some commands assume stdio is for the container/process
running inside the sandbox and it's better to never use
it for logging. By default, logs are supressed now.
PiperOrigin-RevId: 251881815
This allows an fdbased endpoint to have multiple underlying fd's from which
packets can be read and dispatched/written to.
This should allow for higher throughput as well as better scalability of the
network stack as number of connections increases.
Updates #231
PiperOrigin-RevId: 251852825
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
It provides an easy way to run commands to quickly test gVisor.
By default it maps the host root as the container root with a
writable overlay on top (so the host root is not modified).
Example:
sudo runsc do ls -lh --color
sudo runsc do ~/src/test/my-test.sh
PiperOrigin-RevId: 243178711
Change-Id: I05f3d6ce253fe4b5f1362f4a07b5387f6ddb5dd9
Ridwan Sharif
gVisor bot
Jamie Liu
Bhasker Hariharan
Michael Pratt
Fabricio Voznika
Zach Koopmans
Adin Scannell
Andrei Vagin
Aleksandr Razumov
Aleksandr Razumov
Ian Lewis
Robert Tonic
Bin Lu
praveensastry
Kevin Krakauer