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2021-04-21Stub the custom "job" controller required by some workloads.Rahat Mahmood
PiperOrigin-RevId: 369724358
2021-04-21Automated rollback of changelist 369325957Michael Pratt
PiperOrigin-RevId: 369686285
2021-04-20[perf] Remove non-empty directory dentries from gofer LRU cache.Ayush Ranjan
The gofer client's LRU cache has a default limit of 1000 dentries. Any attempt to cache more dentries than that will make the LRU cache evict and destroy the least recently used dentry. However, the eviction is expensive because it requires holding fs.renameMu for writing - which in turn creates a lot of contention. All filesystem operations that involve path traversal require fs.renameMu for reading atleast. Therefore, it is in our best interest to keep the cache small and clean. When a dentry is inserted in the dentry tree, it grabs a ref on its parent for its entire lifetime. Hence the parent is longer evictable (because refs > 0). This change additionally calls checkCachingLocked on directories that have been added to so that they can be removed from the LRU cache if needed. This change implies that the LRU cache will only contain the leaves from the filesystem tree which significantly reduces the LRU cache size and consequently reduces the number of expensive LRU cache evictions. > Why are opened dentries not removed from LRU cache? When a file description is open(2)-ed, the file description holds a ref on its dentry for its entire lifetime. However, calling checkCachingLocked() on opened dentries actually ends up hurting performance. Applications usually open file descriptors for a short duration. So upon close(2), the dentry is reinserted into the cache anyway. So the precautionary work done in removing the opened dentry from the cache went for waste as it did not really reduce an eviction. Local benchmarking has shown that this change improves performance by 3-4%. Across 6 runs, without this change it took 296.127 seconds to build runsc while with this change it took only 285.136 seconds. PiperOrigin-RevId: 369510494
2021-04-20Speed up O_APPEND with remote revalidatingFabricio Voznika
Remote revalidating requires to update file size on every write on a file opened with O_APPEND. If host FD exists, it can be used to update the size and skip round trip to the gofer. With this change, O_APPEND writes with remote revalidating is almost as fast as exclusive mode: BM_Append VFS1 60.7us VFS2 56.8us VFS2 exclusive 14.2us This change 15.8us Updates #1792 PiperOrigin-RevId: 369486801
2021-04-20Move SO_RCVBUF to socketops.Nayana Bidari
Fixes #2926, #674 PiperOrigin-RevId: 369457123
2021-04-19Change verity action to be a fs memberChong Cai
Currently the verity action is a global variable, which causes the same action for all verity mounts, and is overwritten for each new verity mount. Changed it to a member of verity fs. PiperOrigin-RevId: 369348522
2021-04-19Add MultiGetAttr message to 9PFabricio Voznika
While using remote-validation, the vast majority of time spent during FS operations is re-walking the path to check for modifications and then closing the file given that in most cases it has not been modified externally. This change introduces a new 9P message called MultiGetAttr which bulks query attributes of several files in one shot. The returned attributes are then used to update cached dentries before they are walked. File attributes are updated for files that still exist. Dentries that have been deleted are removed from the cache. And negative cache entries are removed if a new file/directory was created externally. Similarly, synthetic dentries are replaced if a file/directory is created externally. The bulk update needs to be carefull not to follow symlinks, cross mount points, because the gofer doesn't know how to resolve symlinks and where mounts points are located. It also doesn't walk to the parent ("..") to avoid deadlocks. Here are the results: Workload VFS1 VFS2 Change bazel action 115s 70s 28.8s Stat/100 11,043us 7,623us 974us Updates #1638 PiperOrigin-RevId: 369325957
2021-04-16[perf] Reduce contention due to renameMu in gofer client.Ayush Ranjan
Runsc build benchmark's mutex profile shows that we are wasting roughly 25-30 seconds waiting for filesystem.renameMu to get unlocked. Earlier checkCachingLocked required the renameMu to be locked for writing. This is a filesystem wide lock which puts all other filesystem operations on hold and hence is really expensive. Something to note is that all path resolution operations hold renameMu for reading. With this change, we allow to check for caching without even holding renameMu. This change introduces more fine grained locks (fs.cacheMu and dentry.cachingMu) which protect the cache (removing the requirement to hold renameMu for writing to modify the cache) and synchronize concurrent dentry caching attempts on a per dentry basis. We still require to hold renameMu for writing while destroying dentries and evicting from the cache but this still significantly reduces the write locking critical section. Local benchmarking showed that this improved runsc build benchmark time by 4-5%. Across 6 runs, without this change it took 310.9025 seconds to build runsc while with this change it took 296.127 seconds. Runsc build benchmark's mutex profile: https://gvisor.dev/profile/gvisor-buildkite/78a3f968-36ca-4944-93f7-77a8792d56b4/28a1d260-790b-4a9e-94da-a4daede08ee3/tmp/profile/ptrace/BenchmarkBuildRunsc/page_cache.clean/filesystem.bindfs/benchmarks/runsc/mutex.pprof/flamegraph PiperOrigin-RevId: 368958136
2021-04-16Allow runsc to generate coverage reports.Dean Deng
Add a coverage-report flag that will cause the sandbox to generate a coverage report (with suffix .cov) in the debug log directory upon exiting. For the report to be generated, runsc must have been built with the following Bazel flags: `--collect_code_coverage --instrumentation_filter=...`. With coverage reports, we should be able to aggregate results across all tests to surface code coverage statistics for the project as a whole. The report is simply a text file with each line representing a covered block as `file:start_line.start_col,end_line.end_col`. Note that this is similar to the format of coverage reports generated with `go test -coverprofile`, although we omit the count and number of statements, which are not useful for us. Some simple ways of getting coverage reports: bazel test <some_test> --collect_code_coverage \ --instrumentation_filter=//pkg/... bazel build //runsc --collect_code_coverage \ --instrumentation_filter=//pkg/... runsc -coverage-report=dir/ <other_flags> do ... PiperOrigin-RevId: 368952911
2021-04-15Add S/R logic for host.ConnectedEndpointFabricio Voznika
Otherwise ConnectedEndpoint.sndbuf will be restored as 0 and writes to the socket will fail with EAGAIN. PiperOrigin-RevId: 368746660
2021-04-15Generate notification when closing host fd.Dean Deng
Thanks ianlewis@ for discovering the bug/fix! PiperOrigin-RevId: 368740744
2021-04-12Add DecRef for verity FDs that were missingChong Cai
Some FileDescriptions in verity fs were opened but DecRef() were missing after used. This could result in a ref leak. PiperOrigin-RevId: 368096759
2021-04-09Return integrity failure only if enabledChong Cai
If the parent is not enabled in verity stepLocked(), failure to find the child dentry could just mean an incorrect path. PiperOrigin-RevId: 367733412
2021-04-08Set root dentry and hash for verity before verifyChong Cai
Set root dentry and root hash in verity fs before we verify the root directory if a root hash is provided. These are used during verification. PiperOrigin-RevId: 367547346
2021-04-08Set parent after child is verifiedChong Cai
We should only set parent after child is verified. Also, if the parent is set before verified, destroyLocked() will try to grab parent.dirMu, which may cause deadlock. PiperOrigin-RevId: 367543655
2021-04-05Update gofer dentry permissions only when needed.Ayush Ranjan
Without this change, we ask the gofer server to update the permissions whenever the UID, GID or size is updated via SetStat. Consequently, we don not generate inotify events when the permissions actually change due to SGID bit getting cleared. With this change, we will update the permissions only when needed and generate inotify events. PiperOrigin-RevId: 366946842
2021-04-05Report task CPU usage through the cpuacct cgroup controller.Rahat Mahmood
PiperOrigin-RevId: 366923274
2021-04-05Allow default control values to be set for cgroupfs.Rahat Mahmood
PiperOrigin-RevId: 366891806
2021-04-05Allow user mount for verity fsChong Cai
Allow user mounting a verity fs on an existing mount by specifying mount flags root_hash and lower_path. PiperOrigin-RevId: 366843846
2021-04-02Implement cgroupfs.Rahat Mahmood
A skeleton implementation of cgroupfs. It supports trivial cpu and memory controllers with no support for hierarchies. PiperOrigin-RevId: 366561126
2021-04-02Internal change.gVisor bot
PiperOrigin-RevId: 366462448
2021-03-29[syserror] Split usermem packageZach Koopmans
Split usermem package to help remove syserror dependency in go_marshal. New hostarch package contains code not dependent on syserror. PiperOrigin-RevId: 365651233
2021-03-24Add POLLRDNORM/POLLWRNORM support.Bhasker Hariharan
On Linux these are meant to be equivalent to POLLIN/POLLOUT. Rather than hack these on in sys_poll etc it felt cleaner to just cleanup the call sites to notify for both events. This is what linux does as well. Fixes #5544 PiperOrigin-RevId: 364859977
2021-03-23setgid directory support in goferfsKevin Krakauer
Also adds support for clearing the setuid bit when appropriate (writing, truncating, changing size, changing UID, or changing GID). VFS2 only. PiperOrigin-RevId: 364661835
2021-03-16setgid directory support in overlayfsKevin Krakauer
PiperOrigin-RevId: 363276495
2021-03-15[op] Make gofer client handle return partial write length when err is nil.Ayush Ranjan
If there was a partial write (when not using the host FD) which did not generate an error, we were incorrectly returning the number of bytes attempted to write instead of the number of bytes actually written. PiperOrigin-RevId: 363058989
2021-03-11fusefs: Implement default_permissions and allow_other mount options.Rahat Mahmood
By default, fusefs defers node permission checks to the server. The default_permissions mount option enables the usual unix permission checks based on the node owner and mode bits. Previously fusefs was incorrectly checking permissions unconditionally. Additionally, fusefs should restrict filesystem access to processes started by the mount owner to prevent the fuse daemon from gaining priviledge over other processes. The allow_other mount option overrides this behaviour. Previously fusefs was incorrectly skipping this check. Updates #3229 PiperOrigin-RevId: 362419092
2021-03-11Clear Merkle tree files in RuntimeEnable modeChong Cai
The Merkle tree files need to be cleared before enabling to avoid redundant content. PiperOrigin-RevId: 362409591
2021-03-11Report filesystem-specific mount options.Rahat Mahmood
PiperOrigin-RevId: 362406813
2021-03-08Implement /proc/sys/net/ipv4/ip_local_port_rangeKevin Krakauer
Speeds up the socket stress tests by a couple orders of magnitude. PiperOrigin-RevId: 361721050
2021-03-05Implement IterDirent in verity fsChong Cai
PiperOrigin-RevId: 361196154
2021-03-03Add checklocks analyzer.Bhasker Hariharan
This validates that struct fields if annotated with "// checklocks:mu" where "mu" is a mutex field in the same struct then access to the field is only done with "mu" locked. All types that are guarded by a mutex must be annotated with // +checklocks:<mutex field name> For more details please refer to README.md. PiperOrigin-RevId: 360729328
2021-03-03[op] Replace syscall package usage with golang.org/x/sys/unix in pkg/.Ayush Ranjan
The syscall package has been deprecated in favor of golang.org/x/sys. Note that syscall is still used in the following places: - pkg/sentry/socket/hostinet/stack.go: some netlink related functionalities are not yet available in golang.org/x/sys. - syscall.Stat_t is still used in some places because os.FileInfo.Sys() still returns it and not unix.Stat_t. Updates #214 PiperOrigin-RevId: 360701387
2021-02-24Kernfs should not try to rename a file to itself.Nicolas Lacasse
One precondition of VFS.PrepareRenameAt is that the `from` and `to` dentries are not the same. Kernfs was not checking this, which could lead to a deadlock. PiperOrigin-RevId: 359385974
2021-02-24Use mapped device number + topmost inode number for all files in VFS2 overlay.Jamie Liu
Before this CL, VFS2's overlayfs uses a single private device number and an autoincrementing generated inode number for directories; this is consistent with Linux's overlayfs in the non-samefs non-xino case. However, this breaks some applications more consistently than on Linux due to more aggressive caching of Linux overlayfs dentries. Switch from using mapped device numbers + the topmost layer's inode number for just non-copied-up non-directory files, to doing so for all files. This still allows directory dev/ino numbers to change across copy-up, but otherwise keeps them consistent. Fixes #5545: ``` $ docker run --runtime=runsc-vfs2-overlay --rm ubuntu:focal bash -c "mkdir -p 1/2/3/4/5/6/7/8 && rm -rf 1 && echo done" done ``` PiperOrigin-RevId: 359350716
2021-02-24Add YAMA security module restrictions on ptrace(2).Dean Deng
Restrict ptrace(2) according to the default configurations of the YAMA security module (mode 1), which is a common default among various Linux distributions. The new access checks only permit the tracer to proceed if one of the following conditions is met: a) The tracer is already attached to the tracee. b) The target is a descendant of the tracer. c) The target has explicitly given permission to the tracer through the PR_SET_PTRACER prctl. d) The tracer has CAP_SYS_PTRACE. See security/yama/yama_lsm.c for more details. Note that these checks are added to CanTrace, which is checked for PTRACE_ATTACH as well as some other operations, e.g., checking a process' memory layout through /proc/[pid]/mem. Since this patch adds restrictions to ptrace, it may break compatibility for applications run by non-root users that, for instance, rely on being able to trace processes that are not descended from the tracer (e.g., `gdb -p`). YAMA restrictions can be turned off by setting /proc/sys/kernel/yama/ptrace_scope to 0, or exceptions can be made on a per-process basis with the PR_SET_PTRACER prctl. Reported-by: syzbot+622822d8bca08c99e8c8@syzkaller.appspotmail.com PiperOrigin-RevId: 359237723
2021-02-11Unconditionally check for directory-ness in overlay.filesystem.UnlinkAt().Jamie Liu
PiperOrigin-RevId: 357106080
2021-02-11Internal change.gVisor bot
PiperOrigin-RevId: 357090170
2021-02-11Assign controlling terminal when tty is opened and support NOCTTYKevin Krakauer
PiperOrigin-RevId: 357015186
2021-02-10Support setgid directories in tmpfs and kernfsKevin Krakauer
PiperOrigin-RevId: 356868412
2021-02-09Add support for setting SO_SNDBUF for unix domain sockets.Bhasker Hariharan
The limits for snd/rcv buffers for unix domain socket is controlled by the following sysctls on linux - net.core.rmem_default - net.core.rmem_max - net.core.wmem_default - net.core.wmem_max Today in gVisor we do not expose these sysctls but we do support setting the equivalent in netstack via stack.Options() method. But AF_UNIX sockets in gVisor can be used without netstack, with hostinet or even without any networking stack at all. Which means ideally these sysctls need to live as globals in gVisor. But rather than make this a big change for now we hardcode the limits in the AF_UNIX implementation itself (which in itself is better than where we were before) where it SO_SNDBUF was hardcoded to 16KiB. Further we bump the initial limit to a default value of 208 KiB to match linux from the paltry 16 KiB we use today. Updates #5132 PiperOrigin-RevId: 356665498
2021-02-09pipe: writeLocked has to return ErrWouldBlock if the pipe is fullAndrei Vagin
PiperOrigin-RevId: 356450303
2021-02-05[vfs] Handle `.` and `..` as last path component names in kernfs Rename.Ayush Ranjan
According to vfs.FilesystemImpl.RenameAt documentation: - If the last path component in rp is "." or "..", and opts.Flags contains RENAME_NOREPLACE, RenameAt returns EEXIST. - If the last path component in rp is "." or "..", and opts.Flags does not contain RENAME_NOREPLACE, RenameAt returns EBUSY. Reported-by: syzbot+6189786e64fe13fe43f8@syzkaller.appspotmail.com PiperOrigin-RevId: 355959266
2021-02-04Call kernfs.syntheticDir.InitRefs() on creation.Nicolas Lacasse
PiperOrigin-RevId: 355675900
2021-02-03[vfs] Make sticky bit check consistent with Linux.Ayush Ranjan
Our implementation of vfs.CheckDeleteSticky was not consistent with Linux, specifically not consistent with fs/linux.h:check_sticky(). One of the biggest differences was that the vfs implementation did not allow the owner of the sticky directory to delete files inside it that belonged to other users. This change makes our implementation consistent with Linux. Also adds an integration test to check for this. This bug is also present in VFS1. Updates #3027 PiperOrigin-RevId: 355557425
2021-01-29Fix deadlock in specialFileFD.pwriteFabricio Voznika
When file is regular and metadata cache is authoritative, metadata lock is taken. The code deadlocks trying to acquire the metadata lock again to update time stampts. PiperOrigin-RevId: 354584594
2021-01-28Change tcpip.Error to an interfaceTamir Duberstein
This makes it possible to add data to types that implement tcpip.Error. ErrBadLinkEndpoint is removed as it is unused. PiperOrigin-RevId: 354437314
2021-01-28[vfs] Fix rename implementation in OrderedChildren.Ayush Ranjan
Fixes #3027 as there is just 1 writable user using OrderedChildren's rename, unlink and rmdir (kernfs.syntheticDirectory) but it doesn't support the sticky bit yet. Fuse which is the other writable user implements its own Inode operations. PiperOrigin-RevId: 354386522
2021-01-26Initialize timestamps for gofer synthetic children.Dean Deng
Contrary to the comment on the socket test, the failure was due to an issue with goferfs rather than kernfs. PiperOrigin-RevId: 353918021
2021-01-22Implement F_GETLK fcntl.Dean Deng
Fixes #5113. PiperOrigin-RevId: 353313374
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