Only gofer filesystem was calling vfs.CheckSetStat for
vfs.FilesystemImpl.SetStatAt and vfs.FileDescriptionImpl.SetStat.
Updates #1193, #1672, #1197
PiperOrigin-RevId: 301226522
- When setting up the virtual filesystem, mount a host.filesystem to contain
all files that need to be imported.
- Make read/preadv syscalls to the host in cases where preadv2 may not be
supported yet (likewise for writing).
- Make save/restore functions in kernel/kernel.go return early if vfs2 is
enabled.
PiperOrigin-RevId: 300922353
- Make oomScoreAdj a ThreadGroup field (Linux: signal_struct::oom_score_adj).
- Avoid deadlock caused by Task.OOMScoreAdj()/SetOOMScoreAdj() locking Task.mu
and TaskSet.mu in the wrong order (via Task.ExitState()).
PiperOrigin-RevId: 300814698
Note that the raw faccessat system call does not actually take a flags argument;
according to faccessat(2), the glibc wrapper implements the flags by using
fstatat(2). Remove the flag argument that we try to extract from vfs1, which
would just be a garbage value.
Updates #1965Fixes#2101
PiperOrigin-RevId: 300796067
In VFS2, imported file descriptors are stored in a kernfs-based filesystem.
Upon calling ImportFD, the host fd can be accessed in two ways:
1. a FileDescription that can be added to the FDTable, and
2. a Dentry in the host.filesystem mount, which we will want to access through
magic symlinks in /proc/[pid]/fd/.
An implementation of the kernfs.Inode interface stores a unique host fd. This
inode can be inserted into file descriptions as well as dentries.
This change also plumbs in three FileDescriptionImpls corresponding to fds for
sockets, TTYs, and other files (only the latter is implemented here).
These implementations will mostly make corresponding syscalls to the host.
Where possible, the logic is ported over from pkg/sentry/fs/host.
Updates #1672
PiperOrigin-RevId: 299417263
Adds an oom_score_adj and oom_score proc file stub. oom_score_adj accepts
writes of values -1000 to 1000 and persists the value with the task. New tasks
inherit the parent's oom_score_adj.
oom_score is a read-only stub that always returns the value '0'.
Issue #202
PiperOrigin-RevId: 299245355
gofer.dentryReadWriter.WriteFromBlocks was not updating
gofer.dentry.size after a write operation that skips the
cache.
Updates #1198
PiperOrigin-RevId: 298708646
pipe and pipe2 aren't ported, pending a slight rework of pipe FDs for VFS2.
mount and umount2 aren't ported out of temporary laziness. access and faccessat
need additional FSImpl methods to implement properly, but are stubbed to
prevent googletest from CHECK-failing. Other syscalls require additional
plumbing.
Updates #1623
PiperOrigin-RevId: 297188448
TCP/IP will work with netstack networking. hostinet doesn't work, and sockets
will have the same behavior as it is now.
Before the userspace is able to create device, the default loopback device can
be used to test.
/proc/net and /sys/net will still be connected to the root network stack; this
is the same behavior now.
Issue #1833
PiperOrigin-RevId: 296309389
tmpfs.fileDescription now implements ConfigureMMap. And tmpfs.regularFile
implement memmap.Mappable. The methods are mostly unchanged from VFS1 tmpfs.
PiperOrigin-RevId: 296234557
- Added fsbridge package with interface that can be used to open
and read from VFS1 and VFS2 files.
- Converted ELF loader to use fsbridge
- Added VFS2 types to FSContext
- Added vfs.MountNamespace to ThreadGroup
Updates #1623
PiperOrigin-RevId: 295183950
This allow callers to say whether the file is being
opened to be executed, so that the proper checks can
be done from FilesystemImpl.OpenAt()
Updates #1623
PiperOrigin-RevId: 295042595
Fixes#1812. (The more direct cause of the deadlock is panic unsafety because
the historically high cost of defer means that we avoid it in hot paths,
including much of MM; defer is much cheaper as of Go 1.14, but still a
measurable overhead.)
PiperOrigin-RevId: 294560316
Updates #1198
Opening host pipes (by spinning in fdpipe) and host sockets is not yet
complete, and will be done in a future CL.
Major differences from VFS1 gofer client (sentry/fs/gofer), with varying levels
of backportability:
- "Cache policies" are replaced by InteropMode, which control the behavior of
timestamps in addition to caching. Under InteropModeExclusive (analogous to
cacheAll) and InteropModeWritethrough (analogous to cacheAllWritethrough),
client timestamps are *not* written back to the server (it is not possible in
9P or Linux for clients to set ctime, so writing back client-authoritative
timestamps results in incoherence between atime/mtime and ctime). Under
InteropModeShared (analogous to cacheRemoteRevalidating), client timestamps
are not used at all (remote filesystem clocks are authoritative). cacheNone
is translated to InteropModeShared + new option
filesystemOptions.specialRegularFiles.
- Under InteropModeShared, "unstable attribute" reloading for permission
checks, lookup, and revalidation are fused, which is feasible in VFS2 since
gofer.filesystem controls path resolution. This results in a ~33% reduction
in RPCs for filesystem operations compared to cacheRemoteRevalidating. For
example, consider stat("/foo/bar/baz") where "/foo/bar/baz" fails
revalidation, resulting in the instantiation of a new dentry:
VFS1 RPCs:
getattr("/") // fs.MountNamespace.FindLink() => fs.Inode.CheckPermission() => gofer.inodeOperations.check() => gofer.inodeOperations.UnstableAttr()
walkgetattr("/", "foo") = fid1 // fs.Dirent.walk() => gofer.session.Revalidate() => gofer.cachePolicy.Revalidate()
clunk(fid1)
getattr("/foo") // CheckPermission
walkgetattr("/foo", "bar") = fid2 // Revalidate
clunk(fid2)
getattr("/foo/bar") // CheckPermission
walkgetattr("/foo/bar", "baz") = fid3 // Revalidate
clunk(fid3)
walkgetattr("/foo/bar", "baz") = fid4 // fs.Dirent.walk() => gofer.inodeOperations.Lookup
getattr("/foo/bar/baz") // linux.stat() => gofer.inodeOperations.UnstableAttr()
VFS2 RPCs:
getattr("/") // gofer.filesystem.walkExistingLocked()
walkgetattr("/", "foo") = fid1 // gofer.filesystem.stepExistingLocked()
clunk(fid1)
// No getattr: walkgetattr already updated metadata for permission check
walkgetattr("/foo", "bar") = fid2
clunk(fid2)
walkgetattr("/foo/bar", "baz") = fid3
// No clunk: fid3 used for new gofer.dentry
// No getattr: walkgetattr already updated metadata for stat()
- gofer.filesystem.unlinkAt() does not require instantiation of a dentry that
represents the file to be deleted. Updates #898.
- gofer.regularFileFD.OnClose() skips Tflushf for regular files under
InteropModeExclusive, as it's nonsensical to request a remote file flush
without flushing locally-buffered writes to that remote file first.
- Symlink targets are cached when InteropModeShared is not in effect.
- p9.QID.Path (which is already required to be unique for each file within a
server, and is accordingly already synthesized from device/inode numbers in
all known gofers) is used as-is for inode numbers, rather than being mapped
along with attr.RDev in the client to yet another synthetic inode number.
- Relevant parts of fsutil.CachingInodeOperations are inlined directly into
gofer package code. This avoids having to duplicate part of its functionality
in fsutil.HostMappable.
PiperOrigin-RevId: 293190213
WritableSource is a convenience interface used for files that can
be written to, e.g. /proc/net/ipv4/tpc_sack. It reads max of 4KB
and only from offset 0 which should cover most cases. It can be
extended as neeed.
Updates #1195
PiperOrigin-RevId: 292056924
Because the abi will depend on the core types for marshalling (usermem,
context, safemem, safecopy), these need to be flattened from the sentry
directory. These packages contain no sentry-specific details.
PiperOrigin-RevId: 291811289
* Rename syncutil to sync.
* Add aliases to sync types.
* Replace existing usage of standard library sync package.
This will make it easier to swap out synchronization primitives. For example,
this will allow us to use primitives from github.com/sasha-s/go-deadlock to
check for lock ordering violations.
Updates #1472
PiperOrigin-RevId: 289033387
- Renamed memfs to tmpfs.
- Copied fileRangeSet bits from fs/fsutil/ to fsimpl/tmpfs/
- Changed tmpfs to be backed by filemem instead of byte slice.
- regularFileReadWriter uses a sync.Pool, similar to gofer client.
PiperOrigin-RevId: 288356380
- Add FileDescriptionOptions.UseDentryMetadata, which reduces the amount of
boilerplate needed for device FDs and the like between filesystems.
- Switch back to having FileDescription.Init() take references on the Mount and
Dentry; otherwise managing refcounts around failed calls to
OpenDeviceSpecialFile() / Device.Open() is tricky.
PiperOrigin-RevId: 287575574
- Make FilesystemImpl methods that operate on parent directories require
!rp.Done() (i.e. there is at least one path component to resolve) as
precondition and postcondition (in cases where they do not finish path
resolution due to mount boundary / absolute symlink), and require that they
do not need to follow the last path component (the file being created /
deleted) as a symlink. Check for these in VFS.
- Add FilesystemImpl.GetParentDentryAt(), which is required to obtain the old
parent directory for VFS.RenameAt(). (Passing the Dentry to be renamed
instead has the wrong semantics if the file named by the old path is a mount
point since the Dentry will be on the wrong Mount.)
- Update memfs to implement these methods correctly (?), including RenameAt.
- Change fspath.Parse() to allow empty paths (to simplify implementation of
AT_EMPTY_PATH).
- Change vfs.PathOperation to take a fspath.Path instead of a raw pathname;
non-test callers will need to fspath.Parse() pathnames themselves anyway in
order to detect absolute paths and select PathOperation.Start accordingly.
PiperOrigin-RevId: 286934941
Fabricio Voznika
Dean Deng
Jamie Liu
Ting-Yu Wang
Ian Lewis
gVisor bot
Adin Scannell
Rahat Mahmood
Nicolas Lacasse
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