Software GSO implementation currently has a complicated code path with
implicit assumptions that all packets to WritePackets carry same Data
and it does this to avoid allocations on the path etc. But this makes it
hard to reuse the WritePackets API.
This change breaks all such assumptions by introducing a new Vectorised
View API ReadToVV which can be used to cleanly split a VV into multiple
independent VVs. Further this change also makes packet buffers linkable
to form an intrusive list. This allows us to get rid of the array of
packet buffers that are passed in the WritePackets API call and replace
it with a list of packet buffers.
While this code does introduce some more allocations in the benchmarks
it doesn't cause any degradation.
Updates #231
PiperOrigin-RevId: 304731742
This change involves several steps:
- Refactor the VFS1 unix socket implementation to share methods between VFS1
and VFS2 where possible. Re-implement the rest.
- Override the default PRead, Read, PWrite, Write, Ioctl, Release methods in
FileDescriptionDefaultImpl.
- Add functions to create and initialize a new Dentry/Inode and FileDescription
for a Unix socket file.
Updates #1476
PiperOrigin-RevId: 304689796
NAME_MAX should be enforced per filesystem implementation
because other file systems may not have the same restriction.
Gofer filesystem now keeps a reference to the kernel clock to
avoid lookup in the Context on file access to update atime.
Update access, modification, and status change times in tmpfs.
Updates #1197, #1198.
PiperOrigin-RevId: 304527148
This is mostly required for PipeTest_OffsetCalls.
The options are DenyPRead/PWrite rather than AllowPRead/PWrite since, in Linux
terms, fs/open.c:do_dentry_open sets FMODE_PREAD|FMODE_PWRITE unconditionally
(although it allows filesystem implementations of open to unset these flags),
so they're set for most FDs; it's usually FDs created outside of open(2) that
don't get them, e.g.:
- Syscall-created pipes (fs/pipe.c:create_pipe_files =>
fs/file_table.c:alloc_file_pseudo)
- Epoll instances (fs/eventpoll.c:do_epoll_create =>
fs/anon_inodes.c:anon_inode_getfile => alloc_file_pseudo)
- Sockets (net/socket.c:sock_alloc_file => alloc_file_pseudo)
This CL adds the flags to epoll instances; a subsequent CL reworks the VFS2
implementation of pipe FDs to be filesystem-independent and adds the flags
there, and sockets aren't implemented yet.
Updates #1035
PiperOrigin-RevId: 304506434
Refactor the existing socket interface to share methods between VFS1 and VFS2.
The method signatures do not contain anything filesystem-related, so they don't
need to be re-defined for VFS2.
Updates #1476, #1478, #1484, #1485.
PiperOrigin-RevId: 304184545
A socket mount where anonymous sockets will reside is added to the
VirtualFilesystem. Socketfs is built on top of kernfs.
Updates #1476, #1478, #1484, #1485.
PiperOrigin-RevId: 304095251
When copyUp fails, we attempt to clean up the upper filesystem by removing any
files that have already been copied-up. If the cleanup fails, we panic because
the "overlay filesystem is in an inconsistent state".
This CL adds the original copy-up error to the panic information, to hopefully
make it easier to track down how the overlay filesystem got into the
inconsistent state.
PiperOrigin-RevId: 304053370
In the case of other signals (preemption), inject a normal bounce and
defer the signal until the vCPU has been returned from guest mode.
PiperOrigin-RevId: 303799678
Both have analogues in Linux:
* struct file_system_type has a char *name field.
* struct super_block keeps a pointer to the file_system_type.
These fields are necessary to support the `filesystem type` field in
/proc/[pid]/mountinfo.
PiperOrigin-RevId: 303434063
BoundEndpointAt() is needed to support Unix sockets bound at a
file path, corresponding to BoundEndpoint() in VFS1.
Updates #1476.
PiperOrigin-RevId: 303258251
Using the host-defined file owner matches VFS1. It is more correct to use the
host-defined mode, since the cached value may become out of date. However,
kernfs.Inode.Mode() does not return an error--other filesystems on kernfs are
in-memory so retrieving mode should not fail. Therefore, if the host syscall
fails, we rely on a cached value instead.
Updates #1672.
PiperOrigin-RevId: 303220864
This feature will match UID and GID of the packet creator, for locally
generated packets. This match is only valid in the OUTPUT and POSTROUTING
chains. Forwarded packets do not have any socket associated with them.
Packets from kernel threads do have a socket, but usually no owner.
Pushing it down requires all implementation to check for
exec individualy which is not maintanable. Making it part
of GenericCheckPermissions add extra cost to everyone that
calls it. So it's better to keep is in
VirtualFilesystem.OpenAt.
Updates #1193
PiperOrigin-RevId: 302982993
This is a precursor to be being able to build an intrusive list
of PacketBuffers for use in queuing disciplines being implemented.
Updates #2214
PiperOrigin-RevId: 302677662
utimensat is used by hostfs for setting timestamps on imported fds. Previously,
this would crash the sandbox since utimensat was not allowed.
Correct the VFS2 version of hostfs to match the call in VFS1.
PiperOrigin-RevId: 301970121
workMu is removed and e.mu is now a mutex that supports TryLock. The packet
processing path tries to lock the mutex and if its locked it will just queue the
packet and move on. The endpoint.UnlockUser() will process any backlog of
packets before unlocking the socket.
This simplifies the locking inside tcp endpoints a lot. Further the
endpoint.LockUser() implements spinning as long as the lock is not held by
another syscall goroutine. This ensures low latency as not spinning leads to the
task thread being put to sleep if the lock is held by the packet dispatch
path. This is suboptimal as the lower layer rarely holds the lock for long so
implementing spinning here helps.
If the lock is held by another task goroutine then we just proceed to call
LockUser() and the task could be put to sleep.
The protocol goroutines themselves just call e.mu.Lock() and block if the
lock is currently not available.
Updates #231, #357
PiperOrigin-RevId: 301808349
Refactor fs/host.TTYFileOperations so that the relevant functionality can be
shared with VFS2 (fsimpl/host.ttyFD).
Incorporate host.defaultFileFD into the default host.fileDescription. This way,
there is no need for a separate default_file.go. As in vfs1, the TTY file
implementation can be built on top of this default and override operations as
necessary (PRead/Read/PWrite/Write, Release, Ioctl).
Note that these changes still need to be plumbed into runsc, which refers to
imported TTYs in control/proc.go:ExecAsync.
Updates #1672.
PiperOrigin-RevId: 301718157
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
Dean Deng
Bhasker Hariharan
Adin Scannell
Fabricio Voznika
Jamie Liu
Nicolas Lacasse
Michael Pratt
Rahat Mahmood
gVisor bot
Nayana Bidari
Ian Lewis
Zach Koopmans
Andrei Vagin