Commit Graph

35 Commits

Author SHA1 Message Date
Dean Deng 09ddb5a426 Port extended attributes to VFS2.
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
2020-04-10 19:02:55 -07:00
Fabricio Voznika 6dd5a1f3fe Clean up TODOs
PiperOrigin-RevId: 305592245
2020-04-08 17:58:13 -07:00
Jamie Liu dd98fdd5be Correctly implement magic symlinks in VFS2 procfs.
Updates #1195

PiperOrigin-RevId: 305143567
2020-04-06 16:32:37 -07:00
Fabricio Voznika dd3bc49997 Add NAME_MAX checks and update file times
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
2020-04-02 19:39:03 -07:00
Nicolas Lacasse 10f2c8db91 Add FilesystemType.Name method, and FilesystemType field to Filesystem struct.
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
2020-03-27 16:56:16 -07:00
Dean Deng 76a7ace751 Add BoundEndpointAt filesystem operation.
BoundEndpointAt() is needed to support Unix sockets bound at a
file path, corresponding to BoundEndpoint() in VFS1.

Updates #1476.

PiperOrigin-RevId: 303258251
2020-03-26 21:52:24 -07:00
Fabricio Voznika de694e5484 Combine file mode and isDir arguments
Updates #1035

PiperOrigin-RevId: 303021328
2020-03-26 08:48:04 -07:00
Fabricio Voznika 2a6c4369be Enforce file size rlimits in VFS2
Updates #1035

PiperOrigin-RevId: 301255357
2020-03-16 16:00:49 -07:00
Fabricio Voznika 0f60799a4f Add calls to vfs.CheckSetStat to fsimpls
Only gofer filesystem was calling vfs.CheckSetStat for
vfs.FilesystemImpl.SetStatAt and vfs.FileDescriptionImpl.SetStat.

Updates #1193, #1672, #1197

PiperOrigin-RevId: 301226522
2020-03-16 13:29:12 -07:00
Fabricio Voznika 9712775028 Disallow kernfs.Inode.SetStat for readonly inodes
Updates #1195, #1193

PiperOrigin-RevId: 300950993
2020-03-14 13:48:06 -07:00
Fabricio Voznika 45a8ae240d Add remaining procfs files
Closes #1195

PiperOrigin-RevId: 300867055
2020-03-13 18:57:07 -07:00
Dean Deng 2e38408f20 Implement access/faccessat for VFS2.
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
2020-03-13 11:41:08 -07:00
Dean Deng 960f6a975b Add plumbing for importing fds in VFS2, along with non-socket, non-TTY impl.
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
2020-03-06 12:59:49 -08:00
gVisor bot 3557b26651 Allow vfs.IterDirentsCallback.Handle() to return an error.
This is easier than storing errors from e.g. CopyOut in the callback.

PiperOrigin-RevId: 295230021
2020-02-14 14:40:35 -08:00
gVisor bot e4c7f3e6f6 Inline vfs.VirtualFilesystem in Kernel struct
This saves one pointer dereference per VFS access.

Updates #1623

PiperOrigin-RevId: 295216176
2020-02-14 13:40:39 -08:00
gVisor bot 4075de11be Plumb VFS2 inside the Sentry
- 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
2020-02-14 11:12:47 -08:00
gVisor bot a6024f7f5f Add FileExec flag to OpenOptions
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
2020-02-13 17:57:36 -08:00
Fabricio Voznika bfa0bba72a Redirect FIXME to gvisor.dev
PiperOrigin-RevId: 294272755
2020-02-10 12:04:38 -08:00
Fabricio Voznika 396c574db2 Add support for WritableSource in DynamicBytesFileDescriptionImpl
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
2020-01-28 18:31:28 -08:00
Adin Scannell 0e2f1b7abd Update package locations.
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
2020-01-27 15:31:32 -08:00
Adin Scannell d29e59af9f Standardize on tools directory.
PiperOrigin-RevId: 291745021
2020-01-27 12:21:00 -08:00
Rahat Mahmood 896bd654b6 De-duplicate common test functionality for VFS2 filesystems.
PiperOrigin-RevId: 291041576
2020-01-22 15:16:21 -08:00
Jamie Liu 5ab1213a6c Move VFS2 handling of FD readability/writability to vfs.FileDescription.
PiperOrigin-RevId: 291006713
2020-01-22 12:29:36 -08:00
Rahat Mahmood ad1968ed56 Implement sysfs.
PiperOrigin-RevId: 290822487
2020-01-21 15:13:26 -08:00
Fabricio Voznika 3dd3275da7 Add more files to /proc/[pid]/*
Files not implemented require VFSv2 plumbing into the kernel.
Also, cgroup is not implemented yet.

Updates #1195

PiperOrigin-RevId: 290129176
2020-01-16 14:10:05 -08:00
Fabricio Voznika 7b7c31820b Add remaining /proc/* and /proc/sys/* files
Except for one under /proc/sys/net/ipv4/tcp_sack.
/proc/pid/* is still incomplete.

Updates #1195

PiperOrigin-RevId: 290120438
2020-01-16 12:30:21 -08:00
Ian Gudger 27500d529f New sync package.
* 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
2020-01-09 22:02:24 -08:00
Jamie Liu 1f384ac42b Add VFS2 support for device special files.
- 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
2019-12-30 11:36:41 -08:00
Jamie Liu 796f53c0be Add VFS2 support for /proc/filesystems.
Updates #1195

PiperOrigin-RevId: 287269106
2019-12-27 00:13:54 -08:00
Fabricio Voznika 3c125eb219 Initial procfs implementation in VFSv2
Updates #1195

PiperOrigin-RevId: 287227722
2019-12-26 14:45:35 -08:00
Fabricio Voznika 574e988f2b Fix deadlock in kernfs.Filesystem.revalidateChildLocked
It was calling Dentry.InsertChild with the dentry's mutex
already locked.

Updates #1035

PiperOrigin-RevId: 286962742
2019-12-23 17:32:46 -08:00
Jamie Liu f45df7505b Clean up vfs.FilesystemImpl methods that operate on parent directories.
- 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
2019-12-23 13:18:39 -08:00
Jamie Liu 3eb489ed6c Move VFS2 file description status flags to vfs.FileDescription.
PiperOrigin-RevId: 286616668
2019-12-20 11:53:48 -08:00
Jamie Liu 744401297a Add VFS2 plumbing for extended attributes.
PiperOrigin-RevId: 286281274
2019-12-18 15:48:45 -08:00
Rahat Mahmood 007707a072 Implement kernfs.
PiperOrigin-RevId: 285231002
2019-12-12 11:20:47 -08:00