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
sync.WaitGroup.Add(positive delta) is illegal if the WaitGroup counter is zero
and WaitGroup.Wait() may be called concurrently. This is problematic for
p9.connState.pendingWg, which counts inflight requests (so transitions from
zero are normal) and is waited-upon when receiving from the underlying Unix
domain socket returns an error, e.g. during connection shutdown. (Even if the
socket has been closed, new requests can still be concurrently received via
flipcall channels.)
PiperOrigin-RevId: 359416057
openedMu has lock ordering violations. Most locks go through OpenedFlag(),
which is usually taken after renameMu and opMu. On the other hand, Tlopen takes
openedMu before renameMu and opMu (via safelyRead).
Resolving this violation is simple: just drop openedMu. The opened and
openFlags fields are already protected by opMu in most cases, renameMu (for
write) in one case (via safelyGlobal), and only in doWalk by neither.
This is a bit ugly because opMu is supposed to be a "semantic" lock, but it
works. I'm open to other suggestions.
Note that doWalk has a race condition where a FID may open after the open check
but before actually walking. This race existed before this change as well; it
is not clear if it is problematic.
PiperOrigin-RevId: 346108483
- Remove sendDone, which currently does nothing whatsoever (errors sent to the
channel are completely unused). Instead, have request handlers log errors
they get from p9.send() inline.
- Replace recvOkay and recvDone with recvMu/recvIdle/recvShutdown. In addition
to being slightly clearer (IMO), this eliminates the p9.connState.service()
goroutine, significantly reducing the overhead involved in passing connection
receive access between goroutines (from buffered chan send/recv + unbuffered
chan send/recv to just a mutex unlock/lock).
PiperOrigin-RevId: 327476755
* 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
Also ensure that all flipcall transport errors not returned by p9 (converted to
EIO by the client, or dropped on the floor by channel server goroutines) are
logged.
PiperOrigin-RevId: 272963663
Currently, the path tracking in the gofer involves an O(n) lookup of
child fidRefs. This causes a significant overhead on unlinks in
directories with lots of child fidRefs (<4k).
In this transition, pathNode moves from sync.Map to normal synchronized
maps. There is a small chance of contention in walk, but the lock is
held for a very short time (and sync.Map also had a chance of requiring
locking).
OTOH, sync.Map makes it very difficult to add a fidRef reverse map.
PiperOrigin-RevId: 254489952
Neither fidRefs or children are (directly) synchronized by mu. Remove
the preconditions that say so.
That said, the surrounding does enforce some synchronization guarantees
(e.g., fidRef.renameChildTo does not atomically replace the child in the
maps). I've tried to note the need for callers to do this
synchronization.
I've also renamed the maps to what are (IMO) clearer names. As is, it is
not obvious that pathNode.fidRefs is a map of *child* fidRefs rather
than self fidRefs.
PiperOrigin-RevId: 254446965
Cache last used messages and reuse them for subsequent requests.
If more messages are needed, they are created outside the cache
on demand.
PiperOrigin-RevId: 245836910
Change-Id: Icf099ddff95df420db8e09f5cdd41dcdce406c61
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
This change also adds extensive testing to the p9 package via mocks. The sanity
checks and type checks are moved from the gofer into the core package, where
they can be more easily validated.
PiperOrigin-RevId: 218296768
Change-Id: I4fc3c326e7bf1e0e140a454cbacbcc6fd617ab55
Ayush Ranjan
Jamie Liu
Michael Pratt
Ian Gudger
Adin Scannell
Fabricio Voznika
Googler