The only remaining user of ovl_cleanup() is ovl_cleanup_locked(), so we
no longer need both.

This patch renames ovl_cleanup() to ovl_cleanup_locked() and makes it
static.
ovl_cleanup_unlocked() is renamed to ovl_cleanup().

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/20250716004725.1206467-22-neil@brown.name
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Rather than locking the directory(s) before calling
ovl_cleanup_and_whiteout(), change it (and ovl_whiteout()) to do the
locking, so the locking can be fine grained as will be needed for
proposed locking changes.

Sometimes this is called to whiteout something in the index dir, in
which case only that dir must be locked.  In one case it is called on
something in an upperdir, so two directories must be locked.  We use
ovl_lock_rename_workdir() for this and remove the restriction that
upperdir cannot be indexdir - because now sometimes it is.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/20250716004725.1206467-18-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>

Rather than calling ovl_workdir_cleanup() with the dir already locked,
change it to take the dir lock only when needed.

Also change ovl_workdir_cleanup() to take a dentry for the parent rather
than an inode.

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/20250716004725.1206467-16-neil@brown.name
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Only take the dir lock when needed, rather than for the whole loop.

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/20250716004725.1206467-15-neil@brown.name
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Instead of taking the directory lock for the whole cleanup, only take it
when needed.

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/20250716004725.1206467-14-neil@brown.name
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Rather than lock the directory for the whole operation, use
ovl_lookup_upper_unlocked() and ovl_cleanup_unlocked() to take the lock
only when needed.

This makes way for future changes where locks are taken on individual
dentries rather than the whole directory.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/20250716004725.1206467-11-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>

all users of 'struct renamedata' have the dentry for the old and new
directories, and often have no use for the inode except to store it in
the renamedata.

This patch changes struct renamedata to hold the dentry, rather than
the inode, for the old and new directories, and changes callers to
match.  The names are also changed from a _dir suffix to _parent.  This
is consistent with other usage in namei.c and elsewhere.

This results in the removal of several local variables and several
dereferences of ->d_inode at the cost of adding ->d_inode dereferences
to vfs_rename().

Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/174977089072.608730.4244531834577097454@noble.neil.brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>

Pull overlayfs update from Miklos Szeredi:

 - Fix a regression in getting the path of an open file (e.g. in
   /proc/PID/maps) for a nested overlayfs setup (André Almeida)

 - Support data-only layers and verity in a user namespace (unprivileged
   composefs use case)

 - Fix a gcc warning (Kees)

 - Cleanups

* tag 'ovl-update-v2-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
  ovl: Annotate struct ovl_entry with __counted_by()
  ovl: Replace offsetof() with struct_size() in ovl_stack_free()
  ovl: Replace offsetof() with struct_size() in ovl_cache_entry_new()
  ovl: Check for NULL d_inode() in ovl_dentry_upper()
  ovl: Use str_on_off() helper in ovl_show_options()
  ovl: don't require "metacopy=on" for "verity"
  ovl: relax redirect/metacopy requirements for lower -> data redirect
  ovl: make redirect/metacopy rejection consistent
  ovl: Fix nested backing file paths

Pull misc vfs updates from Christian Brauner:
 "This contains the usual selections of misc updates for this cycle.

  Features:

   - Use folios for symlinks in the page cache

     FUSE already uses folios for its symlinks. Mirror that conversion
     in the generic code and the NFS code. That lets us get rid of a few
     folio->page->folio conversions in this path, and some of the few
     remaining users of read_cache_page() / read_mapping_page()

   - Try and make a few filesystem operations killable on the VFS
     inode->i_mutex level

   - Add sysctl vfs_cache_pressure_denom for bulk file operations

     Some workloads need to preserve more dentries than we currently
     allow through out sysctl interface

     A HDFS servers with 12 HDDs per server, on a HDFS datanode startup
     involves scanning all files and caching their metadata (including
     dentries and inodes) in memory. Each HDD contains approximately 2
     million files, resulting in a total of ~20 million cached dentries
     after initialization

     To minimize dentry reclamation, they set vfs_cache_pressure to 1.
     Despite this configuration, memory pressure conditions can still
     trigger reclamation of up to 50% of cached dentries, reducing the
     cache from 20 million to approximately 10 million entries. During
     the subsequent cache rebuild period, any HDFS datanode restart
     operation incurs substantial latency penalties until full cache
     recovery completes

     To maintain service stability, more dentries need to be preserved
     during memory reclamation. The current minimum reclaim ratio (1/100
     of total dentries) remains too aggressive for such workload. This
     patch introduces vfs_cache_pressure_denom for more granular cache
     pressure control

     The configuration [vfs_cache_pressure=1,
     vfs_cache_pressure_denom=10000] effectively maintains the full 20
     million dentry cache under memory pressure, preventing datanode
     restart performance degradation

   - Avoid some jumps in inode_permission() using likely()/unlikely()

   - Avid a memory access which is most likely a cache miss when
     descending into devcgroup_inode_permission()

   - Add fastpath predicts for stat() and fdput()

   - Anonymous inodes currently don't come with a proper mode causing
     issues in the kernel when we want to add useful VFS debug assert.
     Fix that by giving them a proper mode and masking it off when we
     report it to userspace which relies on them not having any mode

   - Anonymous inodes currently allow to change inode attributes because
     the VFS falls back to simple_setattr() if i_op->setattr isn't
     implemented. This means the ownership and mode for every single
     user of anon_inode_inode can be changed. Block that as it's either
     useless or actively harmful. If specific ownership is needed the
     respective subsystem should allocate anonymous inodes from their
     own private superblock

   - Raise SB_I_NODEV and SB_I_NOEXEC on the anonymous inode superblock

   - Add proper tests for anonymous inode behavior

   - Make it easy to detect proper anonymous inodes and to ensure that
     we can detect them in codepaths such as readahead()

  Cleanups:

   - Port pidfs to the new anon_inode_{g,s}etattr() helpers

   - Try to remove the uselib() system call

   - Add unlikely branch hint return path for poll

   - Add unlikely branch hint on return path for core_sys_select

   - Don't allow signals to interrupt getdents copying for fuse

   - Provide a size hint to dir_context for during readdir()

   - Use writeback_iter directly in mpage_writepages

   - Update compression and mtime descriptions in initramfs
     documentation

   - Update main netfs API document

   - Remove useless plus one in super_cache_scan()

   - Remove unnecessary NULL-check guards during setns()

   - Add separate separate {get,put}_cgroup_ns no-op cases

  Fixes:

   - Fix typo in root= kernel parameter description

   - Use KERN_INFO for infof()|info_plog()|infofc()

   - Correct comments of fs_validate_description()

   - Mark an unlikely if condition with unlikely() in
     vfs_parse_monolithic_sep()

   - Delete macro fsparam_u32hex()

   - Remove unused and problematic validate_constant_table()

   - Fix potential unsigned integer underflow in fs_name()

   - Make file-nr output the total allocated file handles"

* tag 'vfs-6.16-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (43 commits)
  fs: Pass a folio to page_put_link()
  nfs: Use a folio in nfs_get_link()
  fs: Convert __page_get_link() to use a folio
  fs/read_write: make default_llseek() killable
  fs/open: make do_truncate() killable
  fs/open: make chmod_common() and chown_common() killable
  include/linux/fs.h: add inode_lock_killable()
  readdir: supply dir_context.count as readdir buffer size hint
  vfs: Add sysctl vfs_cache_pressure_denom for bulk file operations
  fuse: don't allow signals to interrupt getdents copying
  Documentation: fix typo in root= kernel parameter description
  include/cgroup: separate {get,put}_cgroup_ns no-op case
  kernel/nsproxy: remove unnecessary guards
  fs: use writeback_iter directly in mpage_writepages
  fs: remove useless plus one in super_cache_scan()
  fs: add S_ANON_INODE
  fs: remove uselib() system call
  device_cgroup: avoid access to ->i_rdev in the common case in devcgroup_inode_permission()
  fs/fs_parse: Remove unused and problematic validate_constant_table()
  fs: touch up predicts in inode_permission()
  ...

This is a preparation for large readdir buffers in fuse.

Simply setting the fuse buffer size to the userspace buffer size should
work, the record sizes are similar (fuse's is slightly larger than libc's,
so no overflow should ever happen).

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Jaco Kroon <jaco@uls.co.za>
Link: https://lore.kernel.org/20250513151012.1476536-1-mszeredi@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>