Changes in Makefile

0fc8f6200d2313278fbf4539bbab74677c685531 - Merge drm/drm-fixes into drm-misc-fixes

Mon, 27 Apr 2026 10:26:49 +0200

Merge drm/drm-fixes into drm-misc-fixesGetting fixes and updates from v7.1-rc1.Signed-off-by: Thomas Zimmermann List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

f4b369c6fe0ceaba2da2daff8c9eb415f85926dd - Merge branch 'next' into for-linus

Mon, 20 Apr 2026 03:28:57 +0200

Merge branch 'next' into for-linusPrepare input updates for 7.1 merge window. List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

0421ccdfad0d92713a812a5aeb7d07b0ea7213c8 - Merge tag 'v7.0-rc3' into next

Thu, 12 Mar 2026 18:44:42 +0100

Merge tag 'v7.0-rc3' into nextSync up with the mainline to brig up the latest changes, specificallychanges to ALPS driver. List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

7c8a4671dc3247a26a702e5f5996e9f453d7070d - Merge tag 'vfs-7.1-rc1.mount.v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Wed, 15 Apr 2026 04:59:25 +0200

Merge tag 'vfs-7.1-rc1.mount.v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfsPull vfs mount updates from Christian Brauner: - Add FSMOUNT_NAMESPACE flag to fsmount() that creates a new mount namespace with the newly created filesystem attached to a copy of the real rootfs. This returns a namespace file descriptor instead of an O_PATH mount fd, similar to how OPEN_TREE_NAMESPACE works for open_tree(). This allows creating a new filesystem and immediately placing it in a new mount namespace in a single operation, which is useful for container runtimes and other namespace-based isolation mechanisms. This accompanies OPEN_TREE_NAMESPACE and avoids a needless detour via OPEN_TREE_NAMESPACE to get the same effect. Will be especially useful when you mount an actual filesystem to be used as the container rootfs. - Currently, creating a new mount namespace always copies the entire mount tree from the caller's namespace. For containers and sandboxes that intend to build their mount table from scratch this is wasteful: they inherit a potentially large mount tree only to immediately tear it down. This series adds support for creating a mount namespace that contains only a clone of the root mount, with none of the child mounts. Two new flags are introduced: - CLONE_EMPTY_MNTNS (0x400000000) for clone3(), using the 64-bit flag space - UNSHARE_EMPTY_MNTNS (0x00100000) for unshare() Both flags imply CLONE_NEWNS. The resulting namespace contains a single nullfs root mount with an immutable empty directory. The intended workflow is to then mount a real filesystem (e.g., tmpfs) over the root and build the mount table from there. - Allow MOVE_MOUNT_BENEATH to target the caller's rootfs, allowing to switch out the rootfs without pivot_root(2). The traditional approach to switching the rootfs involves pivot_root(2) or a chroot_fs_refs()-based mechanism that atomically updates fs->root for all tasks sharing the same fs_struct. This has consequences for fork(), unshare(CLONE_FS), and setns(). This series instead decomposes root-switching into individually atomic, locally-scoped steps: fd_tree = open_tree(-EBADF, "/newroot", OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC); fchdir(fd_tree); move_mount(fd_tree, "", AT_FDCWD, "/", MOVE_MOUNT_BENEATH | MOVE_MOUNT_F_EMPTY_PATH); chroot("."); umount2(".", MNT_DETACH); Since each step only modifies the caller's own state, the fork/unshare/setns races are eliminated by design. A key step to making this possible is to remove the locked mount restriction. Originally MOVE_MOUNT_BENEATH doesn't support mounting beneath a mount that is locked. The locked mount protects the underlying mount from being revealed. This is a core mechanism of unshare(CLONE_NEWUSER | CLONE_NEWNS). The mounts in the new mount namespace become locked. That effectively makes the new mount table useless as the caller cannot ever get rid of any of the mounts no matter how useless they are. We can lift this restriction though. We simply transfer the locked property from the top mount to the mount beneath. This works because what we care about is to protect the underlying mount aka the parent. The mount mounted between the parent and the top mount takes over the job of protecting the parent mount from the top mount mount. This leaves us free to remove the locked property from the top mount which can consequently be unmounted: unshare(CLONE_NEWUSER | CLONE_NEWNS) and we inherit a clone of procfs on /proc then currently we cannot unmount it as: umount -l /proc will fail with EINVAL because the procfs mount is locked. After this series we can now do: mount --beneath -t tmpfs tmpfs /proc umount -l /proc after which a tmpfs mount has been placed beneath the procfs mount. The tmpfs mount has become locked and the procfs mount has become unlocked. This means you can safely modify an inherited mount table after unprivileged namespace creation. Afterwards we simply make it possible to move a mount beneath the rootfs allowing to upgrade the rootfs. Removing the locked restriction makes this very useful for containers created with unshare(CLONE_NEWUSER | CLONE_NEWNS) to reshuffle an inherited mount table safely and MOVE_MOUNT_BENEATH makes it possible to switch out the rootfs instead of using the costly pivot_root(2).* tag 'vfs-7.1-rc1.mount.v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests/namespaces: remove unused utils.h include from listns_efault_test selftests/fsmount_ns: add missing TARGETS and fix cap test selftests/empty_mntns: fix wrong CLONE_EMPTY_MNTNS hex value in comment selftests/empty_mntns: fix statmount_alloc() signature mismatch selftests/statmount: remove duplicate wait_for_pid() mount: always duplicate mount selftests/filesystems: add MOVE_MOUNT_BENEATH rootfs tests move_mount: allow MOVE_MOUNT_BENEATH on the rootfs move_mount: transfer MNT_LOCKED selftests/filesystems: add clone3 tests for empty mount namespaces selftests/filesystems: add tests for empty mount namespaces namespace: allow creating empty mount namespaces selftests: add FSMOUNT_NAMESPACE tests selftests/statmount: add statmount_alloc() helper tools: update mount.h header mount: add FSMOUNT_NAMESPACE mount: simplify __do_loopback() mount: start iterating from start of rbtree List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

42d3b66d4cdbacfc9d120d2301b8de89cc29a914 - Merge drm/drm-next into drm-xe-next

Thu, 12 Mar 2026 15:17:56 +0100

Merge drm/drm-next into drm-xe-nextBackmerging to bring in 7.00-rc3. Important ahead GPU SVM merging THPsupport.Signed-off-by: Matthew Brost List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

0209e31659d6908c6d0788c8a495b43d0a1f6f6c - Merge patch series "fsmount: add FSMOUNT_NAMESPACE"

Fri, 23 Jan 2026 16:58:20 +0100

Merge patch series "fsmount: add FSMOUNT_NAMESPACE"Christian Brauner says:Add FSMOUNT_NAMESPACE flag to fsmount() that creates a new mountnamespace with the newly created filesystem attached to a copy of thereal rootfs. This returns a namespace file descriptor instead of anO_PATH mount fd, similar to how OPEN_TREE_NAMESPACE works foropen_tree().This allows creating a new filesystem and immediately placing it in anew mount namespace in a single operation, which is useful for containerruntimes and other namespace-based isolation mechanisms.This accompanies OPEN_TREE_NAMESPACE and avoids a needless detour viaOPEN_TREE_NAMESPACE to get the same effect. Will be especially usefulwhen you mount an actual filesystem to be used as the container rootfs.* patches from https://patch.msgid.link/20260122-work-fsmount-namespace-v1-0-5ef0a886e646@kernel.org: selftests/open_tree_ns: fix compilation selftests: add FSMOUNT_NAMESPACE tests selftests/statmount: add statmount_alloc() helper tools: update mount.h header mount: add FSMOUNT_NAMESPACE mount: simplify __do_loopback() mount: start iterating from start of rbtreeLink: https://patch.msgid.link/20260122-work-fsmount-namespace-v1-0-5ef0a886e646@kernel.orgSigned-off-by: Christian Brauner List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

3ac7ea91f3d0442caf6b079e1ddc80e06b079ff9 - selftests: add FSMOUNT_NAMESPACE tests

Thu, 22 Jan 2026 11:48:51 +0100

selftests: add FSMOUNT_NAMESPACE testsAdd selftests for FSMOUNT_NAMESPACE which creates a new mount namespacewith the newly created filesystem mounted onto a copy of the realrootfs.Link: https://patch.msgid.link/20260122-work-fsmount-namespace-v1-6-5ef0a886e646@kernel.orgSigned-off-by: Christian Brauner List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

f09812b85fa6f41058bcc46e70ac406bf9b0493a - Merge drm/drm-next into drm-intel-next

Wed, 25 Feb 2026 12:23:04 +0100

Merge drm/drm-next into drm-intel-nextSync with v7.0-rc1 which contains a few treewide changes affecting i915.Signed-off-by: Jani Nikula List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

8b85987d3cf50178f67618122d9f3bb202f62f42 - Merge drm/drm-next into drm-misc-next

Mon, 23 Feb 2026 11:48:20 +0100

Merge drm/drm-next into drm-misc-nextLet's merge 7.0-rc1 to start the new drm-misc-next windowSigned-off-by: Maxime Ripard List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

c17ee635fd3a482b2ad2bf5e269755c2eae5f25e - Merge drm/drm-fixes into drm-misc-fixes

Mon, 23 Feb 2026 10:09:45 +0100

Merge drm/drm-fixes into drm-misc-fixes7.0-rc1 was just released, let's merge it to kick the new release cycle.Signed-off-by: Maxime Ripard List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

157d3d6efd5a58466d90be3a134f9667486fe6f9 - Merge tag 'vfs-7.0-rc1.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Mon, 09 Feb 2026 23:43:47 +0100

Merge tag 'vfs-7.0-rc1.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfsPull vfs mount updates from Christian Brauner: - statmount: accept fd as a parameter Extend struct mnt_id_req with a file descriptor field and a new STATMOUNT_BY_FD flag. When set, statmount() returns mount information for the mount the fd resides on — including detached mounts (unmounted via umount2(MNT_DETACH)). For detached mounts the STATMOUNT_MNT_POINT and STATMOUNT_MNT_NS_ID mask bits are cleared since neither is meaningful. The capability check is skipped for STATMOUNT_BY_FD since holding an fd already implies prior access to the mount and equivalent information is available through fstatfs() and /proc/pid/mountinfo without privilege. Includes comprehensive selftests covering both attached and detached mount cases. - fs: Remove internal old mount API code (1 patch) Now that every in-tree filesystem has been converted to the new mount API, remove all the legacy shim code in fs_context.c that handled unconverted filesystems. This deletes ~280 lines including legacy_init_fs_context(), the legacy_fs_context struct, and associated wrappers. The mount(2) syscall path for userspace remains untouched. Documentation references to the legacy callbacks are cleaned up. - mount: add OPEN_TREE_NAMESPACE to open_tree() Container runtimes currently use CLONE_NEWNS to copy the caller's entire mount namespace — only to then pivot_root() and recursively unmount everything they just copied. With large mount tables and thousands of parallel container launches this creates significant contention on the namespace semaphore. OPEN_TREE_NAMESPACE copies only the specified mount tree (like OPEN_TREE_CLONE) but returns a mount namespace fd instead of a detached mount fd. The new namespace contains the copied tree mounted on top of a clone of the real rootfs. This functions as a combined unshare(CLONE_NEWNS) + pivot_root() in a single syscall. Works with user namespaces: an unshare(CLONE_NEWUSER) followed by OPEN_TREE_NAMESPACE creates a mount namespace owned by the new user namespace. Mount namespace file mounts are excluded from the copy to prevent cycles. Includes ~1000 lines of selftests"* tag 'vfs-7.0-rc1.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: selftests/open_tree: add OPEN_TREE_NAMESPACE tests mount: add OPEN_TREE_NAMESPACE fs: Remove internal old mount API code selftests: statmount: tests for STATMOUNT_BY_FD statmount: accept fd as a parameter statmount: permission check should return EPERM List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

1bce1a664ac25d37a327c433a01bc347f0a81bd6 - Merge patch series "mount: add OPEN_TREE_NAMESPACE"

Mon, 12 Jan 2026 13:51:32 +0100

Merge patch series "mount: add OPEN_TREE_NAMESPACE"Christian Brauner says:When creating containers the setup usually involves using CLONE_NEWNSvia clone3() or unshare(). This copies the caller's complete mountnamespace. The runtime will also assemble a new rootfs and then usepivot_root() to switch the old mount tree with the new rootfs. Afterwardit will recursively umount the old mount tree thereby getting rid of allmounts.On a basic system here where the mount table isn't particularly largethis still copies about 30 mounts. Copying all of these mounts only toget rid of them later is pretty wasteful.This is exacerbated if intermediary mount namespaces are used that onlyexist for a very short amount of time and are immediately destroyedagain causing a ton of mounts to be copied and destroyed needlessly.With a large mount table and a system where thousands or ten-thousandsof namespaces are spawned in parallel this quickly becomes a bottleneckincreasing contention on the semaphore.Extend open_tree() with a new OPEN_TREE_NAMESPACE flag. Similar toOPEN_TREE_CLONE only the indicated mount tree is copied. Instead ofreturning a file descriptor referring to that mount treeOPEN_TREE_NAMESPACE will cause open_tree() to return a file descriptorto a new mount namespace. In that new mount namespace the copied mounttree has been mounted on top of a copy of the real rootfs.The caller can setns() into that mount namespace and perform anyadditionally setup such as move_mount()ing detached mounts in there.This allows OPEN_TREE_NAMESPACE to function as a combinedunshare(CLONE_NEWNS) and pivot_root().A caller may for example choose to create an extremely minimal rootfs:fd_mntns = open_tree(-EBADF, "/var/lib/containers/wootwoot", OPEN_TREE_NAMESPACE);This will create a mount namespace where "wootwoot" has become therootfs mounted on top of the real rootfs. The caller can now setns()into this new mount namespace and assemble additional mounts.This also works with user namespaces:unshare(CLONE_NEWUSER);fd_mntns = open_tree(-EBADF, "/var/lib/containers/wootwoot", OPEN_TREE_NAMESPACE);which creates a new mount namespace owned by the earlier created usernamespace with "wootwoot" as the rootfs mounted on top of the realrootfs.This will scale a lot better when creating tons of mount namespaces andwill allow to get rid of a lot of unnecessary mount and umount cycles.It also allows to create mount namespaces without needing to spawnthrowaway helper processes.* patches from https://patch.msgid.link/20251229-work-empty-namespace-v1-0-bfb24c7b061f@kernel.org: selftests/open_tree: add OPEN_TREE_NAMESPACE tests mount: add OPEN_TREE_NAMESPACELink: https://patch.msgid.link/20251229-work-empty-namespace-v1-0-bfb24c7b061f@kernel.orgSigned-off-by: Christian Brauner List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile

b8f7622aa6e32d6fd750697b99d8ce19ad8e66d0 - selftests/open_tree: add OPEN_TREE_NAMESPACE tests

Mon, 29 Dec 2025 14:03:25 +0100

selftests/open_tree: add OPEN_TREE_NAMESPACE testsAdd tests for OPEN_TREE_NAMESPACE.Link: https://patch.msgid.link/20251229-work-empty-namespace-v1-2-bfb24c7b061f@kernel.orgTested-by: Jeff Layton Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner List of files: /linux/tools/testing/selftests/filesystems/open_tree_ns/Makefile