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2020-04-21Remove filesystem structure from vfs.Dentry.Jamie Liu
This change: - Drastically simplifies the synchronization model: filesystem structure is both implementation-defined and implementation-synchronized. - Allows implementations of vfs.DentryImpl to use implementation-specific dentry types, reducing casts during path traversal. - Doesn't require dentries representing non-directory files to waste space on a map of children. - Allows dentry revalidation and mount lookup to be correctly ordered (fixed FIXME in fsimpl/gofer/filesystem.go). - Removes the need to have two separate maps in gofer.dentry (dentry.vfsd.children and dentry.negativeChildren) for positive and negative lookups respectively. //pkg/sentry/fsimpl/tmpfs/benchmark_test.go: name old time/op new time/op delta VFS2TmpfsStat/1-112 172ns ± 4% 165ns ± 3% -4.08% (p=0.002 n=9+9) VFS2TmpfsStat/2-112 199ns ± 3% 195ns ±10% ~ (p=0.132 n=8+9) VFS2TmpfsStat/3-112 230ns ± 2% 216ns ± 2% -6.15% (p=0.000 n=8+8) VFS2TmpfsStat/8-112 390ns ± 2% 358ns ± 4% -8.33% (p=0.000 n=9+8) VFS2TmpfsStat/64-112 2.20µs ± 3% 2.01µs ± 3% -8.48% (p=0.000 n=10+8) VFS2TmpfsStat/100-112 3.42µs ± 9% 3.08µs ± 2% -9.82% (p=0.000 n=9+8) VFS2TmpfsMountStat/1-112 278ns ± 1% 286ns ±15% ~ (p=0.712 n=8+10) VFS2TmpfsMountStat/2-112 311ns ± 4% 298ns ± 2% -4.27% (p=0.000 n=9+8) VFS2TmpfsMountStat/3-112 339ns ± 3% 330ns ± 9% ~ (p=0.070 n=8+9) VFS2TmpfsMountStat/8-112 503ns ± 3% 466ns ± 3% -7.38% (p=0.000 n=8+8) VFS2TmpfsMountStat/64-112 2.53µs ±16% 2.17µs ± 7% -14.19% (p=0.000 n=10+9) VFS2TmpfsMountStat/100-112 3.60µs ± 4% 3.30µs ± 8% -8.33% (p=0.001 n=8+9) Updates #1035 PiperOrigin-RevId: 307655892
2020-04-16Implement pipe(2) and pipe2(2) for VFS2.Jamie Liu
Updates #1035 PiperOrigin-RevId: 306968644
2020-04-14Pass O_LARGEFILE in syscalls/linux/vfs2.openat.Jamie Liu
Needed for PipeTest_Flags: files opened by open() and openat() get O_LARGEFILE (on architectures with 64-bit off_t), but not FDs created by other syscalls such as pipe(). Updates #1035 PiperOrigin-RevId: 306504788
2020-04-10Port extended attributes to VFS2.Dean Deng
As in VFS1, we only support the user.* namespace. Plumbing is added to tmpfs and goferfs. Note that because of the slightly different order of checks between VFS2 and Linux, one of the xattr tests needs to be relaxed slightly. Fixes #2363. PiperOrigin-RevId: 305985121
2020-04-08Clean up TODOsFabricio Voznika
PiperOrigin-RevId: 305592245
2020-04-06Port timerfd to VFS2.Nicolas Lacasse
PiperOrigin-RevId: 305067208
2020-04-04Record VFS2 sockets in global socket map.Dean Deng
Updates #1476, #1478, #1484, #1485. PiperOrigin-RevId: 304845354
2020-04-03Add FileDescriptionImpl for Unix sockets.Dean Deng
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
2020-04-02Fix typo in TODO comments.Dean Deng
PiperOrigin-RevId: 304508083
2020-04-02Add equivalents to FMODE_PREAD/PWRITE to VFS2.Jamie Liu
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
2020-03-31Fix /proc/self/mounts and /proc/self/mountinfo in VFS2.Nicolas Lacasse
Some extra fields were added to the Mount type to expose necessary data to the proc filesystem. PiperOrigin-RevId: 304053361
2020-03-27Add vfs.PathnameReachable().Jamie Liu
/proc/[pid]/mount* omit mounts whose mount point is outside the chroot, which is checked (indirectly) via __d_path(). PiperOrigin-RevId: 303434226
2020-03-27Add FilesystemType.Name method, and FilesystemType field to Filesystem struct.Nicolas Lacasse
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
2020-03-26Add BoundEndpointAt filesystem operation.Dean Deng
BoundEndpointAt() is needed to support Unix sockets bound at a file path, corresponding to BoundEndpoint() in VFS1. Updates #1476. PiperOrigin-RevId: 303258251
2020-03-26Add unique ID to Mount type.Nicolas Lacasse
Analagous to Linux's mount.mnt_id. This ID is displayed in /proc/[pid]/mountinfo. PiperOrigin-RevId: 303185564
2020-03-26Combine file mode and isDir argumentsFabricio Voznika
Updates #1035 PiperOrigin-RevId: 303021328
2020-03-25Remove TODO to push down exec permission checkFabricio Voznika
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
2020-03-25Misc fixes to make stat_test pass (almost)Fabricio Voznika
The only test failing now requires socket which is not available in VFS2 yet. Updates #1198 PiperOrigin-RevId: 302976572
2020-03-16Enforce file size rlimits in VFS2Fabricio Voznika
Updates #1035 PiperOrigin-RevId: 301255357
2020-03-16Add calls to vfs.CheckSetStat to fsimplsFabricio Voznika
Only gofer filesystem was calling vfs.CheckSetStat for vfs.FilesystemImpl.SetStatAt and vfs.FileDescriptionImpl.SetStat. Updates #1193, #1672, #1197 PiperOrigin-RevId: 301226522
2020-03-13Implement access/faccessat for VFS2.Dean Deng
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 #1965 Fixes #2101 PiperOrigin-RevId: 300796067
2020-03-13Add support for mount flagsFabricio Voznika
Plumbs MS_NOEXEC and MS_RDONLY. Others are TODO. Updates #1623 #1193 PiperOrigin-RevId: 300764669
2020-03-06Add plumbing for importing fds in VFS2, along with non-socket, non-TTY impl.Dean Deng
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
2020-02-25Add VFS.NewDisconnectedMount().Jamie Liu
Analogous to Linux's kern_mount(). PiperOrigin-RevId: 297259580
2020-02-25Port most syscalls to VFS2.Jamie Liu
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
2020-02-14Remove linux.EpollEvent.Fd.gVisor bot
glibc defines struct epoll_event in such a way that epoll_event.data.fd exists. However, the kernel's definition of struct epoll_event makes epoll_event.data an opaque uint64, so naming half of it "fd" just introduces confusion. Remove the Fd field, and make Data a [2]int32 to compensate. Also add required padding to linux.EpollEvent on ARM64. PiperOrigin-RevId: 295250424
2020-02-14Allow vfs.IterDirentsCallback.Handle() to return an error.gVisor bot
This is easier than storing errors from e.g. CopyOut in the callback. PiperOrigin-RevId: 295230021
2020-02-14Inline vfs.VirtualFilesystem in Kernel structgVisor bot
This saves one pointer dereference per VFS access. Updates #1623 PiperOrigin-RevId: 295216176
2020-02-14Plumb VFS2 inside the SentrygVisor bot
- 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
2020-02-13Add FileExec flag to OpenOptionsgVisor bot
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
2020-02-04Remove argument from vfs.MountNamespace.DecRef()Fabricio Voznika
Updates #1035 PiperOrigin-RevId: 293194631
2020-01-31Implement file locks for regular tmpfs files in VFSv2.Dean Deng
Add a file lock implementation that can be embedded into various filesystem implementations. Updates #1480 PiperOrigin-RevId: 292614758
2020-01-29Add plumbing for file locks in VFS2.Dean Deng
Updates #1480 PiperOrigin-RevId: 292180192
2020-01-28Add support for WritableSource in DynamicBytesFileDescriptionImplFabricio Voznika
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
2020-01-28Add VFS2 support for epoll.Jamie Liu
PiperOrigin-RevId: 291997879
2020-01-28Implement an anon_inode equivalent for VFS2.Jamie Liu
PiperOrigin-RevId: 291986033
2020-01-27Update package locations.Adin Scannell
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
2020-01-27Standardize on tools directory.Adin Scannell
PiperOrigin-RevId: 291745021
2020-01-24Add anonymous device number allocation to VFS2.Jamie Liu
Note that in VFS2, filesystem device numbers are per-vfs.FilesystemImpl rather than global, avoiding the need for a "registry" type to handle save/restore. (This is more consistent with Linux anyway: compare e.g. mm/shmem.c:shmem_mount() => fs/super.c:mount_nodev() => (indirectly) set_anon_super().) PiperOrigin-RevId: 291425193
2020-01-22Move VFS2 handling of FD readability/writability to vfs.FileDescription.Jamie Liu
PiperOrigin-RevId: 291006713
2020-01-16Add more files to /proc/[pid]/*Fabricio Voznika
Files not implemented require VFSv2 plumbing into the kernel. Also, cgroup is not implemented yet. Updates #1195 PiperOrigin-RevId: 290129176
2020-01-09New sync package.Ian Gudger
* 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
2019-12-30Add VFS2 support for device special files.Jamie Liu
- 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
2019-12-27Add VFS2 support for /proc/filesystems.Jamie Liu
Updates #1195 PiperOrigin-RevId: 287269106
2019-12-26Initial procfs implementation in VFSv2Fabricio Voznika
Updates #1195 PiperOrigin-RevId: 287227722
2019-12-23Clean up vfs.FilesystemImpl methods that operate on parent directories.Jamie Liu
- 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
2019-12-20Add vfs.ResolvingPath.HandleJump().Jamie Liu
PiperOrigin-RevId: 286666533
2019-12-20Add vfs.Dentry.Children().Jamie Liu
PiperOrigin-RevId: 286660774
2019-12-20Move VFS2 file description status flags to vfs.FileDescription.Jamie Liu
PiperOrigin-RevId: 286616668
2019-12-18Add VFS2 plumbing for extended attributes.Jamie Liu
PiperOrigin-RevId: 286281274