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path: root/runsc/boot/vfs.go
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2020-06-23Port /dev/tty device to VFS2.Nicolas Lacasse
Support is limited to the functionality that exists in VFS1. Updates #2923 #1035 PiperOrigin-RevId: 317981417
2020-06-11Add //pkg/sentry/fsimpl/overlay.Jamie Liu
Major differences from existing overlay filesystems: - Linux allows lower layers in an overlay to require revalidation, but not the upper layer. VFS1 allows the upper layer in an overlay to require revalidation, but not the lower layer. VFS2 does not allow any layers to require revalidation. (Now that vfs.MkdirOptions.ForSyntheticMountpoint exists, no uses of overlay in VFS1 are believed to require upper layer revalidation; in particular, the requirement that the upper layer support the creation of "trusted." extended attributes for whiteouts effectively required the upper filesystem to be tmpfs in most cases.) - Like VFS1, but unlike Linux, VFS2 overlay does not attempt to make mutations of the upper layer atomic using a working directory and features like RENAME_WHITEOUT. (This may change in the future, since not having a working directory makes error recovery for some operations, e.g. rmdir, particularly painful.) - Like Linux, but unlike VFS1, VFS2 represents whiteouts using character devices with rdev == 0; the equivalent of the whiteout attribute on directories is xattr trusted.overlay.opaque = "y"; and there is no equivalent to the whiteout attribute on non-directories since non-directories are never merged with lower layers. - Device and inode numbers work as follows: - In Linux, modulo the xino feature and a special case for when all layers are the same filesystem: - Directories use the overlay filesystem's device number and an ephemeral inode number assigned by the overlay. - Non-directories that have been copied up use the device and inode number assigned by the upper filesystem. - Non-directories that have not been copied up use a per-(overlay, layer)-pair device number and the inode number assigned by the lower filesystem. - In VFS1, device and inode numbers always come from the lower layer unless "whited out"; this has the adverse effect of requiring interaction with the lower filesystem even for non-directory files that exist on the upper layer. - In VFS2, device and inode numbers are assigned as in Linux, except that xino and the samefs special case are not supported. - Like Linux, but unlike VFS1, VFS2 does not attempt to maintain memory mapping coherence across copy-up. (This may have to change in the future, as users may be dependent on this property.) - Like Linux, but unlike VFS1, VFS2 uses the overlayfs mounter's credentials when interacting with the overlay's layers, rather than the caller's. - Like Linux, but unlike VFS1, VFS2 permits multiple lower layers in an overlay. - Like Linux, but unlike VFS1, VFS2's overlay filesystem is application-mountable. Updates #1199 PiperOrigin-RevId: 316019067
2020-06-08Combine executable lookup codeFabricio Voznika
Run vs. exec, VFS1 vs. VFS2 were executable lookup were slightly different from each other. Combine them all into the same logic. PiperOrigin-RevId: 315426443
2020-06-05Implement mount(2) and umount2(2) for VFS2.Rahat Mahmood
This is mostly syscall plumbing, VFS2 already implements the internals of mounts. In addition to the syscall defintions, the following mount-related mechanisms are updated: - Implement MS_NOATIME for VFS2, but only for tmpfs and goferfs. The other VFS2 filesystems don't implement node-level timestamps yet. - Implement the 'mode', 'uid' and 'gid' mount options for VFS2's tmpfs. - Plumb mount namespace ownership, which is necessary for checking appropriate capabilities during mount(2). Updates #1035 PiperOrigin-RevId: 315035352
2020-06-01More runsc changes for VFS2Fabricio Voznika
- Add /tmp handling - Apply mount options - Enable more container_test tests - Forward signals to child process when test respaws process to run as root inside namespace. Updates #1487 PiperOrigin-RevId: 314263281
2020-05-29Refactor the ResolveExecutablePath logic.Nicolas Lacasse
PiperOrigin-RevId: 313871804
2020-05-28Automated rollback of changelist 309082540Fabricio Voznika
PiperOrigin-RevId: 313636920
2020-05-13Fix runsc association of gofers and FDs on VFS2.Jamie Liu
Updates #1487 PiperOrigin-RevId: 311443628
2020-05-13Use VFS2 mount namesFabricio Voznika
Updates #1487 PiperOrigin-RevId: 311356385
2020-05-12Adjust a few log messagesFabricio Voznika
PiperOrigin-RevId: 311234146
2020-05-07Update privateunixsocket TODOs.Dean Deng
Synthetic sockets do not have the race condition issue in VFS2, and we will get rid of privateunixsocket as well. Fixes #1200. PiperOrigin-RevId: 310386474
2020-05-04Mount VSFS2 filesystem using root credentialsFabricio Voznika
PiperOrigin-RevId: 309787938
2020-05-04Add TTY support on VFS2 to runscFabricio Voznika
Updates #1623, #1487 PiperOrigin-RevId: 309777922
2020-04-24VFS2: Get HelloWorld image tests to pass with VFS2Zach Koopmans
This change includes: - Modifications to loader_test.go to get TestCreateMountNamespace to pass with VFS2. - Changes necessary to get TestHelloWorld in image tests to pass with VFS2. This means runsc can run the hello-world container with docker on VSF2. Note: Containers that use sockets will not run with these changes. See "//test/image/...". Any tests here with sockets currently fail (which is all of them but HelloWorld). PiperOrigin-RevId: 308363072
2020-04-23Add vfs.MkdirOptions.ForSyntheticMountpoint.Jamie Liu
PiperOrigin-RevId: 308143529
2020-04-17Get /bin/true to run on VFS2Zach Koopmans
Included: - loader_test.go RunTest and TestStartSignal VFS2 - container_test.go TestAppExitStatus on VFS2 - experimental flag added to runsc to turn on VFS2 Note: shared mounts are not yet supported. PiperOrigin-RevId: 307070753