Pull vfs mount updates from Al Viro:
 "Several piles this cycle, this mount-related one being the largest and
  trickiest:

   - saner handling of guards in fs/namespace.c, getting rid of
     needlessly strong locking in some of the users

   - lock_mount() calling conventions change - have it set the
     environment for attaching to given location, storing the results in
     caller-supplied object, without altering the passed struct path.

     Make unlock_mount() called as __cleanup for those objects. It's not
     exactly guard(), but similar to it

   - MNT_WRITE_HOLD done right.

     mnt_hold_writers() does *not* mess with ->mnt_flags anymore, so
     insertion of a new mount into ->s_mounts of underlying superblock
     does not, in itself, expose ->mnt_flags of that mount to concurrent
     modifications

   - getting rid of pathological cases when umount() spends quadratic
     time removing the victims from propagation graph - part of that had
     been dealt with last cycle, this should finish it

   - a bunch of stuff constified

   - assorted cleanups

* tag 'pull-mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
  constify {__,}mnt_is_readonly()
  WRITE_HOLD machinery: no need for to bump mount_lock seqcount
  struct mount: relocate MNT_WRITE_HOLD bit
  preparations to taking MNT_WRITE_HOLD out of ->mnt_flags
  setup_mnt(): primitive for connecting a mount to filesystem
  simplify the callers of mnt_unhold_writers()
  copy_mnt_ns(): use guards
  copy_mnt_ns(): use the regular mechanism for freeing empty mnt_ns on failure
  open_detached_copy(): separate creation of namespace into helper
  open_detached_copy(): don't bother with mount_lock_hash()
  path_has_submounts(): use guard(mount_locked_reader)
  fs/namespace.c: sanitize descriptions for {__,}lookup_mnt()
  ecryptfs: get rid of pointless mount references in ecryptfs dentries
  umount_tree(): take all victims out of propagation graph at once
  do_mount(): use __free(path_put)
  do_move_mount_old(): use __free(path_put)
  constify can_move_mount_beneath() arguments
  path_umount(): constify struct path argument
  may_copy_tree(), __do_loopback(): constify struct path argument
  path_mount(): constify struct path argument
  ...

... and use that to constify the pointers in callers

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

strcpy() is deprecated; use strscpy() instead.

Link: https://github.com/KSPP/linux/issues/88
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Paul Moore <paul@paul-moore.com>

collect_mounts() has several problems - one can't iterate over the results
directly, so it has to be done with callback passed to iterate_mounts();
it has an oopsable race with d_invalidate(); it creates temporary clones
of mounts invisibly for sync umount (IOW, you can have non-lazy umount
succeed leaving filesystem not mounted anywhere and yet still busy).

A saner approach is to give caller an array of struct path that would pin
every mount in a subtree, without cloning any mounts.

        * collect_mounts()/drop_collected_mounts()/iterate_mounts() is gone
        * collect_paths(where, preallocated, size) gives either ERR_PTR(-E...) or
a pointer to array of struct path, one for each chunk of tree visible under
'where' (i.e. the first element is a copy of where, followed by (mount,root)
for everything mounted under it - the same set collect_mounts() would give).
Unlike collect_mounts(), the mounts are *not* cloned - we just get pinning
references to the roots of subtrees in the caller's namespace.
        Array is terminated by {NULL, NULL} struct path.  If it fits into
preallocated array (on-stack, normally), that's where it goes; otherwise
it's allocated by kmalloc_array().  Passing 0 as size means that 'preallocated'
is ignored (and expected to be NULL).
        * drop_collected_paths(paths, preallocated) is given the array returned
by an earlier call of collect_paths() and the preallocated array passed to that
call.  All mount/dentry references are dropped and array is kfree'd if it's not
equal to 'preallocated'.
        * instead of iterate_mounts(), users should just iterate over array
of struct path - nothing exotic is needed for that.  Existing users (all in
audit_tree.c) are converted.

[folded a fix for braino reported by Venkat Rao Bagalkote <venkat88@linux.ibm.com>]

Fixes: 80b5dce8c59b0 ("vfs: Add a function to lazily unmount all mounts from any dentry")
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

In preparation to passing an object pointer to fsnotify_find_mark(), add
a wrapper fsnotify_find_inode_mark() and use it where possible.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20240317184154.1200192-4-amir73il@gmail.com>

Pull non-MM updates from Andrew Morton:
 "As usual, lots of singleton and doubleton patches all over the tree
  and there's little I can say which isn't in the individual changelogs.

  The lengthier patch series are

   - 'kdump: use generic functions to simplify crashkernel reservation
     in arch', from Baoquan He. This is mainly cleanups and
     consolidation of the 'crashkernel=' kernel parameter handling

   - After much discussion, David Laight's 'minmax: Relax type checks in
     min() and max()' is here. Hopefully reduces some typecasting and
     the use of min_t() and max_t()

   - A group of patches from Oleg Nesterov which clean up and slightly
     fix our handling of reads from /proc/PID/task/... and which remove
     task_struct.thread_group"

* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
  scripts/gdb/vmalloc: disable on no-MMU
  scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
  .mailmap: add address mapping for Tomeu Vizoso
  mailmap: update email address for Claudiu Beznea
  tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
  .mailmap: map Benjamin Poirier's address
  scripts/gdb: add lx_current support for riscv
  ocfs2: fix a spelling typo in comment
  proc: test ProtectionKey in proc-empty-vm test
  proc: fix proc-empty-vm test with vsyscall
  fs/proc/base.c: remove unneeded semicolon
  do_io_accounting: use sig->stats_lock
  do_io_accounting: use __for_each_thread()
  ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
  ocfs2: fix a typo in a comment
  scripts/show_delta: add __main__ judgement before main code
  treewide: mark stuff as __ro_after_init
  fs: ocfs2: check status values
  proc: test /proc/${pid}/statm
  compiler.h: move __is_constexpr() to compiler.h
  ...

__read_mostly predates __ro_after_init. Many variables which are marked
__read_mostly should have been __ro_after_init from day 1.

Also, mark some stuff as "const" and "__init" while I'm at it.

[akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning]
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct audit_chunk.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: audit@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>

audit inode marks pin the inode so there is no need to set the
FSNOTIFY_GROUP_NOFS flag.

Link: https://lore.kernel.org/r/20220422120327.3459282-9-amir73il@gmail.com
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220321112310.vpr7oxro2xkz5llh@quack3.lan/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

Add flags argument to fsnotify_alloc_group(), define and use the flag
FSNOTIFY_GROUP_USER in inotify and fanotify instead of the helper
fsnotify_alloc_user_group() to indicate user allocation.

Although the flag FSNOTIFY_GROUP_USER is currently not used after group
allocation, we store the flags argument in the group struct for future
use of other group flags.

Link: https://lore.kernel.org/r/20220422120327.3459282-5-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>