Merge tag 'driver-core-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

Pull driver core updates from Greg KH:
 "Here are the driver core / kernfs changes for 6.16-rc1.

  Not a huge number of changes this development cycle, here's the
  summary of what is included in here:

   - kernfs locking tweaks, pushing some global locks down into a per-fs
     image lock

   - rust driver core and pci device bindings added for new features.

   - sysfs const work for bin_attributes.

     The final churn of switching away from and removing the
     transitional struct members, "read_new", "write_new" and
     "bin_attrs_new" will come after the merge window to avoid
     unnecesary merge conflicts.

   - auxbus device creation helpers added

   - fauxbus fix for creating sysfs files after the probe completed
     properly

   - other tiny updates for driver core things.

  All of these have been in linux-next for over a week with no reported
  issues"

* tag 'driver-core-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  kernfs: Relax constraint in draining guard
  Documentation: embargoed-hardware-issues.rst: Remove myself
  drivers: hv: fix up const issue with vmbus_chan_bin_attrs
  firmware_loader: use SHA-256 library API instead of crypto_shash API
  docs: debugfs: do not recommend debugfs_remove_recursive
  PM: wakeup: Do not expose 4 device wakeup source APIs
  kernfs: switch global kernfs_rename_lock to per-fs lock
  kernfs: switch global kernfs_idr_lock to per-fs lock
  driver core: auxiliary bus: Fix IS_ERR() vs NULL mixup in __devm_auxiliary_device_create()
  sysfs: constify attribute_group::bin_attrs
  sysfs: constify bin_attribute argument of bin_attribute::read/write()
  software node: Correct a OOB check in software_node_get_reference_args()
  devres: simplify devm_kstrdup() using devm_kmemdup()
  platform: replace magic number with macro PLATFORM_DEVID_NONE
  component: do not try to unbind unbound components
  driver core: auxiliary bus: add device creation helpers
  driver core: faux: Add sysfs groups after probing

1 files changed, 12 insertions, 4 deletions

diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 40a2a9cd819d..6061b6f70d2a 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -19,8 +19,6 @@
 #include <linux/kernfs.h>
 #include <linux/fs_context.h>
 
-extern rwlock_t kernfs_rename_lock;
-
 struct kernfs_iattrs {
 	kuid_t			ia_uid;
 	kgid_t			ia_gid;
@@ -40,6 +38,7 @@ struct kernfs_root {
 
 	/* private fields, do not use outside kernfs proper */
 	struct idr		ino_idr;
+	spinlock_t		kernfs_idr_lock;	/* root->ino_idr */
 	u32			last_id_lowbits;
 	u32			id_highbits;
 	struct kernfs_syscall_ops *syscall_ops;
@@ -52,6 +51,9 @@ struct kernfs_root {
 	struct rw_semaphore	kernfs_iattr_rwsem;
 	struct rw_semaphore	kernfs_supers_rwsem;
 
+	/* kn->parent and kn->name */
+	rwlock_t		kernfs_rename_lock;
+
 	struct rcu_head		rcu;
 };
 
@@ -107,6 +109,11 @@ static inline bool kernfs_root_is_locked(const struct kernfs_node *kn)
 	return lockdep_is_held(&kernfs_root(kn)->kernfs_rwsem);
 }
 
+static inline bool kernfs_rename_is_locked(const struct kernfs_node *kn)
+{
+	return lockdep_is_held(&kernfs_root(kn)->kernfs_rename_lock);
+}
+
 static inline const char *kernfs_rcu_name(const struct kernfs_node *kn)
 {
 	return rcu_dereference_check(kn->name, kernfs_root_is_locked(kn));
@@ -117,14 +124,15 @@ static inline struct kernfs_node *kernfs_parent(const struct kernfs_node *kn)
 	/*
 	 * The kernfs_node::__parent remains valid within a RCU section. The kn
 	 * can be reparented (and renamed) which changes the entry. This can be
-	 * avoided by locking kernfs_root::kernfs_rwsem or kernfs_rename_lock.
+	 * avoided by locking kernfs_root::kernfs_rwsem or
+	 * kernfs_root::kernfs_rename_lock.
 	 * Both locks can be used to obtain a reference on __parent. Once the
 	 * reference count reaches 0 then the node is about to be freed
 	 * and can not be renamed (or become a different parent) anymore.
 	 */
 	return rcu_dereference_check(kn->__parent,
 				     kernfs_root_is_locked(kn) ||
-				     lockdep_is_held(&kernfs_rename_lock) ||
+				     kernfs_rename_is_locked(kn) ||
 				     !atomic_read(&kn->count));
 }