Merge tag 'vfs-6.14-rc1.mount.v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs mount updates from Christian Brauner:

- Add a mountinfo program to demonstrate statmount()/listm

Merge tag 'vfs-6.14-rc1.mount.v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs mount updates from Christian Brauner:

- Add a mountinfo program to demonstrate statmount()/listmount()

Add a new "mountinfo" sample userland program that demonstrates how
to use statmount() and listmount() to get at the same info that
/proc/pid/mountinfo provides

- Remove pointless nospec.h include

- Prepend statmount.mnt_opts string with security_sb_mnt_opts()

Currently these mount options aren't accessible via statmount()

- Add new mount namespaces to mount namespace rbtree outside of the
namespace semaphore

- Lockless mount namespace lookup

Currently we take the read lock when looking for a mount namespace to
list mounts in. We can make this lockless. The simple search case can
just use a sequence counter to detect concurrent changes to the
rbtree

For walking the list of mount namespaces sequentially via nsfs we
keep a separate rcu list as rb_prev() and rb_next() aren't usable
safely with rcu. Currently there is no primitive for retrieving the
previous list member. To do this we need a new deletion primitive
that doesn't poison the prev pointer and a corresponding retrieval
helper

Since creating mount namespaces is a relatively rare event compared
with querying mounts in a foreign mount namespace this is worth it.
Once libmount and systemd pick up this mechanism to list mounts in
foreign mount namespaces this will be used very frequently

- Add extended selftests for lockless mount namespace iteration

- Add a sample program to list all mounts on the system, i.e., in
all mount namespaces

- Improve mount namespace iteration performance

Make finding the last or first mount to start iterating the mount
namespace from an O(1) operation and add selftests for iterating the
mount table starting from the first and last mount

- Use an xarray for the old mount id

While the ida does use the xarray internally we can use it explicitly
which allows us to increment the unique mount id under the xa lock.
This allows us to remove the atomic as we're now allocating both ids
in one go

- Use a shared header for vfs sample programs

- Fix build warnings for new sample program to list all mounts

* tag 'vfs-6.14-rc1.mount.v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
samples/vfs: fix build warnings
samples/vfs: use shared header
samples/vfs/mountinfo: Use __u64 instead of uint64_t
fs: remove useless lockdep assertion
fs: use xarray for old mount id
selftests: add listmount() iteration tests
fs: cache first and last mount
samples: add test-list-all-mounts
selftests: remove unneeded include
selftests: add tests for mntns iteration
seltests: move nsfs into filesystems subfolder
fs: simplify rwlock to spinlock
fs: lockless mntns lookup for nsfs
rculist: add list_bidir_{del,prev}_rcu()
fs: lockless mntns rbtree lookup
fs: add mount namespace to rbtree late
fs: prepend statmount.mnt_opts string with security_sb_mnt_opts()
mount: remove inlude/nospec.h include
samples: add a mountinfo program to demonstrate statmount()/listmount()

show more ...

Merge patch series "fs: tweak mntns iteration"

Christian Brauner <brauner@kernel.org> says:

Make finding the last or first mount to start iterating the mount
namespace from an O(1) operation and ad

Merge patch series "fs: tweak mntns iteration"

Christian Brauner <brauner@kernel.org> says:

Make finding the last or first mount to start iterating the mount
namespace from an O(1) operation and add selftests for iterating the
mount table starting from the first and last mount.

* patches from https://lore.kernel.org/r/20241215-vfs-6-14-mount-work-v1-0-fd55922c4af8@kernel.org:
selftests: add listmount() iteration tests
fs: cache first and last mount
fs: kill MNT_ONRB

Link: https://lore.kernel.org/r/20241215-vfs-6-14-mount-work-v1-0-fd55922c4af8@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

selftests: add listmount() iteration tests

Add a forward and backward iteration test for listmount().

Link: https://lore.kernel.org/r/20241215-vfs-6-14-mount-work-v1-3-fd55922c4af8@kernel.org
Signe

selftests: add listmount() iteration tests

Add a forward and backward iteration test for listmount().

Link: https://lore.kernel.org/r/20241215-vfs-6-14-mount-work-v1-3-fd55922c4af8@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

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Merge branch 'next' into for-linus

Prepare input updates for 6.12 merge window.

Merge branch 'ib/6.11-rc6-matrix-keypad-spitz' into next

Bring in changes removing support for platform data from matrix-keypad
driver.

Merge tag 'v6.11-rc1' into clk-meson-next

Linux 6.11-rc1

Merge tag 'v6.11-rc3' into trace/ring-buffer/core

The "reserve_mem" kernel command line parameter has been pulled into
v6.11. Merge the latest -rc3 to allow the persistent ring buffer memory to
be a

Merge tag 'v6.11-rc3' into trace/ring-buffer/core

The "reserve_mem" kernel command line parameter has been pulled into
v6.11. Merge the latest -rc3 to allow the persistent ring buffer memory to
be able to be mapped at the address specified by the "reserve_mem" command
line parameter.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

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Merge tag 'v6.11-rc1' into for-6.12

Linux 6.11-rc1

Merge drm/drm-next into drm-xe-next

Get drm-xe-next on v6.11-rc2 and synchronized with drm-intel-next for
the display side. This resolves the current conflict for the
enable_display module parameter

Merge drm/drm-next into drm-xe-next

Get drm-xe-next on v6.11-rc2 and synchronized with drm-intel-next for
the display side. This resolves the current conflict for the
enable_display module parameter and allows further pending refactors.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

show more ...

Merge drm/drm-next into drm-misc-next

Get drm-misc-next to the state of v6.11-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

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

Sync with v6.11-rc1 in general, and specifically get the new
BACKLIGHT_POWER_ constants for power states.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge branch 'linus' into x86/mm

Bring x86 and selftests up to date

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

Let's start the new drm-misc-fixes cycle by bringing in 6.11-rc1.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge branch 'next' into for-linus

Prepare input updates for 6.11 merge window.

Merge tag 'v6.9' into next

Sync up with the mainline to bring in the new cleanup API.

Merge drm/drm-next into drm-intel-gt-next

Some display refactoring patches are needed in order to allow conflict-
less merging.

Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>

Merge tag 'vfs-6.11.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs mount query updates from Christian Brauner:
"This contains work to extend the abilities of listmount() a

Merge tag 'vfs-6.11.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs mount query updates from Christian Brauner:
"This contains work to extend the abilities of listmount() and
statmount() and various fixes and cleanups.

Features:

- Allow iterating through mounts via listmount() from newest to
oldest. This makes it possible for mount(8) to keep iterating the
mount table in reverse order so it gets newest mounts first.

- Relax permissions on listmount() and statmount().

It's not necessary to have capabilities in the initial namespace:
it is sufficient to have capabilities in the owning namespace of
the mount namespace we're located in to list unreachable mounts in
that namespace.

- Extend both listmount() and statmount() to list and stat mounts in
foreign mount namespaces.

Currently the only way to iterate over mount entries in mount
namespaces that aren't in the caller's mount namespace is by
crawling through /proc in order to find /proc/<pid>/mountinfo for
the relevant mount namespace.

This is both very clumsy and hugely inefficient. So extend struct
mnt_id_req with a new member that allows to specify the mount
namespace id of the mount namespace we want to look at.

Luckily internally we already have most of the infrastructure for
this so we just need to expose it to userspace. Give userspace a
way to retrieve the id of a mount namespace via statmount() and
through a new nsfs ioctl() on mount namespace file descriptor.

This comes with appropriate selftests.

- Expose mount options through statmount().

Currently if userspace wants to get mount options for a mount and
with statmount(), they still have to open /proc/<pid>/mountinfo to
parse mount options. Simply the information through statmount()
directly.

Afterwards it's possible to only rely on statmount() and
listmount() to retrieve all and more information than
/proc/<pid>/mountinfo provides.

This comes with appropriate selftests.

Fixes:

- Avoid copying to userspace under the namespace semaphore in
listmount.

Cleanups:

- Simplify the error handling in listmount by relying on our newly
added cleanup infrastructure.

- Refuse invalid mount ids early for both listmount and statmount"

* tag 'vfs-6.11.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: reject invalid last mount id early
fs: refuse mnt id requests with invalid ids early
fs: find rootfs mount of the mount namespace
fs: only copy to userspace on success in listmount()
sefltests: extend the statmount test for mount options
fs: use guard for namespace_sem in statmount()
fs: export mount options via statmount()
fs: rename show_mnt_opts -> show_vfsmnt_opts
selftests: add a test for the foreign mnt ns extensions
fs: add an ioctl to get the mnt ns id from nsfs
fs: Allow statmount() in foreign mount namespace
fs: Allow listmount() in foreign mount namespace
fs: export the mount ns id via statmount
fs: keep an index of current mount namespaces
fs: relax permissions for statmount()
listmount: allow listing in reverse order
fs: relax permissions for listmount()
fs: simplify error handling
fs: don't copy to userspace under namespace semaphore
path: add cleanup helper

show more ...

Merge patch series "Support foreign mount namespace with statmount/listmount"

Josef Bacik <josef@toxicpanda.com> says:

Currently the only way to iterate over mount entries in mount namespaces that

Merge patch series "Support foreign mount namespace with statmount/listmount"

Josef Bacik <josef@toxicpanda.com> says:

Currently the only way to iterate over mount entries in mount namespaces that
aren't your own is to trawl through /proc in order to find /proc/$PID/mountinfo
for the mount namespace that you want. This is hugely inefficient, so extend
both statmount() and listmount() to allow specifying a mount namespace id in
order to get to mounts in other mount namespaces.

There are a few components to this

1. Having a global index of the mount namespace based on the ->seq value in the
mount namespace. This gives us a unique identifier that isn't re-used.
2. Support looking up mount namespaces based on that unique identifier, and
validating the user has permission to access the given mount namespace.
3. Provide a new ioctl() on nsfs in order to extract the unique identifier we
can use for statmount() and listmount().

The code is relatively straightforward, and there is a selftest provided to
validate everything works properly.

This is based on vfs.all as of last week, so must be applied onto a tree that
has Christians error handling rework in this area. If you wish you can pull the
tree directly here

https://github.com/josefbacik/linux/tree/listmount.combined

Christian and I collaborated on this series, which is why there's patches from
both of us in this series.

Christian Brauner (4):
fs: relax permissions for listmount()
fs: relax permissions for statmount()
fs: Allow listmount() in foreign mount namespace
fs: Allow statmount() in foreign mount namespace

Josef Bacik (4):
fs: keep an index of current mount namespaces
fs: export the mount ns id via statmount
fs: add an ioctl to get the mnt ns id from nsfs
selftests: add a test for the foreign mnt ns extensions

fs/mount.h | 2 +
fs/namespace.c | 240 ++++++++++--
fs/nsfs.c | 14 +
include/uapi/linux/mount.h | 6 +-
include/uapi/linux/nsfs.h | 2 +
.../selftests/filesystems/statmount/Makefile | 2 +-
.../filesystems/statmount/statmount.h | 46 +++
.../filesystems/statmount/statmount_test.c | 53 +--
.../filesystems/statmount/statmount_test_ns.c | 360 ++++++++++++++++++
9 files changed, 659 insertions(+), 66 deletions(-)
create mode 100644 tools/testing/selftests/filesystems/statmount/statmount.h
create mode 100644 tools/testing/selftests/filesystems/statmount/statmount_test_ns.c

Link: https://lore.kernel.org/r/cover.1719243756.git.josef@toxicpanda.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

selftests: add a test for the foreign mnt ns extensions

This tests both statmount and listmount to make sure they work with the
extensions that allow us to specify a mount ns to enter in order to fi

selftests: add a test for the foreign mnt ns extensions

This tests both statmount and listmount to make sure they work with the
extensions that allow us to specify a mount ns to enter in order to find
the mount entries.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/2d1a35bc9ab94b4656c056c420f25e429e7eb0b1.1719243756.git.josef@toxicpanda.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

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

Sync to get the drm_printer changes to drm-intel-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge tag 'drm-misc-next-2024-02-08' into msm-next

Merge the drm-misc tree to uprev MSM CI.

Signed-off-by: Rob Clark <robdclark@chromium.org>

Merge drm/drm-next into drm-misc-next

Kickstart 6.9 development cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-xe-next

Sync to v6.8-rc1.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@k

Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

Conflicts:
arch/x86/include/asm/percpu.h
arch/x86/include/asm/text-patching.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>

show more ...

Merge branch 'linus' into x86/mm, to refresh the branch and pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>