Merge tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core and sysfs patch set for 3.14-rc1.

  There's a lot of work here moving sysfs logic out into a "kernfs" to
  allow other subsystems to also have a virtual filesystem with the same
  attributes of sysfs (handle device disconnect, dynamic creation /
  removal as needed / unneeded, etc)

  This is primarily being done for the cgroups filesystem, but the goal
  is to also move debugfs to it when it is ready, solving all of the
  known issues in that filesystem as well.  The code isn't completed
  yet, but all should be stable now (there is a big section that was
  reverted due to problems found when testing)

  There's also some other smaller fixes, and a driver core addition that
  allows for a "collection" of objects, that the DRM people will be
  using soon (it's in this tree to make merges after -rc1 easier)

  All of this has been in linux-next with no reported issues"

* tag 'driver-core-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (113 commits)
  kernfs: associate a new kernfs_node with its parent on creation
  kernfs: add struct dentry declaration in kernfs.h
  kernfs: fix get_active failure handling in kernfs_seq_*()
  Revert "kernfs: fix get_active failure handling in kernfs_seq_*()"
  Revert "kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq"
  Revert "kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()"
  Revert "kernfs: remove KERNFS_REMOVED"
  Revert "kernfs: restructure removal path to fix possible premature return"
  Revert "kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove()"
  Revert "kernfs: remove kernfs_addrm_cxt"
  Revert "kernfs: make kernfs_get_active() block if the node is deactivated but not removed"
  Revert "kernfs: implement kernfs_{de|re}activate[_self]()"
  Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers"
  Revert "pci: use device_remove_file_self() instead of device_schedule_callback()"
  Revert "scsi: use device_remove_file_self() instead of device_schedule_callback()"
  Revert "s390: use device_remove_file_self() instead of device_schedule_callback()"
  Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
  Revert "kernfs: remove unnecessary NULL check in __kernfs_remove()"
  kernfs: remove unnecessary NULL check in __kernfs_remove()
  drivers/base: provide an infrastructure for componentised subsystems
  ...

1 files changed, 376 insertions, 0 deletions

diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
new file mode 100644
index 000000000000..5be9f0228a3b
--- /dev/null
+++ b/include/linux/kernfs.h
@@ -0,0 +1,376 @@
+/*
+ * kernfs.h - pseudo filesystem decoupled from vfs locking
+ *
+ * This file is released under the GPLv2.
+ */
+
+#ifndef __LINUX_KERNFS_H
+#define __LINUX_KERNFS_H
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+#include <linux/lockdep.h>
+#include <linux/rbtree.h>
+#include <linux/atomic.h>
+#include <linux/completion.h>
+
+struct file;
+struct dentry;
+struct iattr;
+struct seq_file;
+struct vm_area_struct;
+struct super_block;
+struct file_system_type;
+
+struct kernfs_open_node;
+struct kernfs_iattrs;
+
+enum kernfs_node_type {
+        KERNFS_DIR              = 0x0001,
+        KERNFS_FILE             = 0x0002,
+        KERNFS_LINK             = 0x0004,
+};
+
+#define KERNFS_TYPE_MASK        0x000f
+#define KERNFS_ACTIVE_REF       KERNFS_FILE
+#define KERNFS_FLAG_MASK        ~KERNFS_TYPE_MASK
+
+enum kernfs_node_flag {
+        KERNFS_REMOVED          = 0x0010,
+        KERNFS_NS               = 0x0020,
+        KERNFS_HAS_SEQ_SHOW     = 0x0040,
+        KERNFS_HAS_MMAP         = 0x0080,
+        KERNFS_LOCKDEP          = 0x0100,
+        KERNFS_STATIC_NAME      = 0x0200,
+};
+
+/* type-specific structures for kernfs_node union members */
+struct kernfs_elem_dir {
+        unsigned long           subdirs;
+        /* children rbtree starts here and goes through kn->rb */
+        struct rb_root          children;
+
+        /*
+         * The kernfs hierarchy this directory belongs to.  This fits
+         * better directly in kernfs_node but is here to save space.
+         */
+        struct kernfs_root      *root;
+};
+
+struct kernfs_elem_symlink {
+        struct kernfs_node      *target_kn;
+};
+
+struct kernfs_elem_attr {
+        const struct kernfs_ops *ops;
+        struct kernfs_open_node *open;
+        loff_t                  size;
+};
+
+/*
+ * kernfs_node - the building block of kernfs hierarchy.  Each and every
+ * kernfs node is represented by single kernfs_node.  Most fields are
+ * private to kernfs and shouldn't be accessed directly by kernfs users.
+ *
+ * As long as s_count reference is held, the kernfs_node itself is
+ * accessible.  Dereferencing elem or any other outer entity requires
+ * active reference.
+ */
+struct kernfs_node {
+        atomic_t                count;
+        atomic_t                active;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        struct lockdep_map      dep_map;
+#endif
+        /* the following two fields are published */
+        struct kernfs_node      *parent;
+        const char              *name;
+
+        struct rb_node          rb;
+
+        union {
+                struct completion       *completion;
+                struct kernfs_node      *removed_list;
+        } u;
+
+        const void              *ns;    /* namespace tag */
+        unsigned int            hash;   /* ns + name hash */
+        union {
+                struct kernfs_elem_dir          dir;
+                struct kernfs_elem_symlink      symlink;
+                struct kernfs_elem_attr         attr;
+        };
+
+        void                    *priv;
+
+        unsigned short          flags;
+        umode_t                 mode;
+        unsigned int            ino;
+        struct kernfs_iattrs    *iattr;
+};
+
+/*
+ * kernfs_dir_ops may be specified on kernfs_create_root() to support
+ * directory manipulation syscalls.  These optional callbacks are invoked
+ * on the matching syscalls and can perform any kernfs operations which
+ * don't necessarily have to be the exact operation requested.
+ */
+struct kernfs_dir_ops {
+        int (*mkdir)(struct kernfs_node *parent, const char *name,
+                     umode_t mode);
+        int (*rmdir)(struct kernfs_node *kn);
+        int (*rename)(struct kernfs_node *kn, struct kernfs_node *new_parent,
+                      const char *new_name);
+};
+
+struct kernfs_root {
+        /* published fields */
+        struct kernfs_node      *kn;
+
+        /* private fields, do not use outside kernfs proper */
+        struct ida              ino_ida;
+        struct kernfs_dir_ops   *dir_ops;
+};
+
+struct kernfs_open_file {
+        /* published fields */
+        struct kernfs_node      *kn;
+        struct file             *file;
+
+        /* private fields, do not use outside kernfs proper */
+        struct mutex            mutex;
+        int                     event;
+        struct list_head        list;
+
+        bool                    mmapped;
+        const struct vm_operations_struct *vm_ops;
+};
+
+struct kernfs_ops {
+        /*
+         * Read is handled by either seq_file or raw_read().
+         *
+         * If seq_show() is present, seq_file path is active.  Other seq
+         * operations are optional and if not implemented, the behavior is
+         * equivalent to single_open().  @sf->private points to the
+         * associated kernfs_open_file.
+         *
+         * read() is bounced through kernel buffer and a read larger than
+         * PAGE_SIZE results in partial operation of PAGE_SIZE.
+         */
+        int (*seq_show)(struct seq_file *sf, void *v);
+
+        void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
+        void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
+        void (*seq_stop)(struct seq_file *sf, void *v);
+
+        ssize_t (*read)(struct kernfs_open_file *of, char *buf, size_t bytes,
+                        loff_t off);
+
+        /*
+         * write() is bounced through kernel buffer and a write larger than
+         * PAGE_SIZE results in partial operation of PAGE_SIZE.
+         */
+        ssize_t (*write)(struct kernfs_open_file *of, char *buf, size_t bytes,
+                         loff_t off);
+
+        int (*mmap)(struct kernfs_open_file *of, struct vm_area_struct *vma);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        struct lock_class_key   lockdep_key;
+#endif
+};
+
+#ifdef CONFIG_SYSFS
+
+static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
+{
+        return kn->flags & KERNFS_TYPE_MASK;
+}
+
+/**
+ * kernfs_enable_ns - enable namespace under a directory
+ * @kn: directory of interest, should be empty
+ *
+ * This is to be called right after @kn is created to enable namespace
+ * under it.  All children of @kn must have non-NULL namespace tags and
+ * only the ones which match the super_block's tag will be visible.
+ */
+static inline void kernfs_enable_ns(struct kernfs_node *kn)
+{
+        WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
+        WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
+        kn->flags |= KERNFS_NS;
+}
+
+/**
+ * kernfs_ns_enabled - test whether namespace is enabled
+ * @kn: the node to test
+ *
+ * Test whether namespace filtering is enabled for the children of @ns.
+ */
+static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
+{
+        return kn->flags & KERNFS_NS;
+}
+
+struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent,
+                                           const char *name, const void *ns);
+void kernfs_get(struct kernfs_node *kn);
+void kernfs_put(struct kernfs_node *kn);
+
+struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops,
+                                       void *priv);
+void kernfs_destroy_root(struct kernfs_root *root);
+
+struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent,
+                                         const char *name, umode_t mode,
+                                         void *priv, const void *ns);
+struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent,
+                                         const char *name,
+                                         umode_t mode, loff_t size,
+                                         const struct kernfs_ops *ops,
+                                         void *priv, const void *ns,
+                                         bool name_is_static,
+                                         struct lock_class_key *key);
+struct kernfs_node *kernfs_create_link(struct kernfs_node *parent,
+                                       const char *name,
+                                       struct kernfs_node *target);
+void kernfs_remove(struct kernfs_node *kn);
+int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name,
+                             const void *ns);
+int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
+                     const char *new_name, const void *new_ns);
+int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
+void kernfs_notify(struct kernfs_node *kn);
+
+const void *kernfs_super_ns(struct super_block *sb);
+struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
+                               struct kernfs_root *root, const void *ns);
+void kernfs_kill_sb(struct super_block *sb);
+
+void kernfs_init(void);
+
+#else   /* CONFIG_SYSFS */
+
+static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
+{ return 0; }   /* whatever */
+
+static inline void kernfs_enable_ns(struct kernfs_node *kn) { }
+
+static inline bool kernfs_ns_enabled(struct kernfs_node *kn)
+{ return false; }
+
+static inline struct kernfs_node *
+kernfs_find_and_get_ns(struct kernfs_node *parent, const char *name,
+                       const void *ns)
+{ return NULL; }
+
+static inline void kernfs_get(struct kernfs_node *kn) { }
+static inline void kernfs_put(struct kernfs_node *kn) { }
+
+static inline struct kernfs_root *
+kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_destroy_root(struct kernfs_root *root) { }
+
+static inline struct kernfs_node *
+kernfs_create_dir_ns(struct kernfs_node *parent, const char *name,
+                     umode_t mode, void *priv, const void *ns)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline struct kernfs_node *
+__kernfs_create_file(struct kernfs_node *parent, const char *name,
+                     umode_t mode, loff_t size, const struct kernfs_ops *ops,
+                     void *priv, const void *ns, bool name_is_static,
+                     struct lock_class_key *key)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline struct kernfs_node *
+kernfs_create_link(struct kernfs_node *parent, const char *name,
+                   struct kernfs_node *target)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_remove(struct kernfs_node *kn) { }
+
+static inline int kernfs_remove_by_name_ns(struct kernfs_node *kn,
+                                           const char *name, const void *ns)
+{ return -ENOSYS; }
+
+static inline int kernfs_rename_ns(struct kernfs_node *kn,
+                                   struct kernfs_node *new_parent,
+                                   const char *new_name, const void *new_ns)
+{ return -ENOSYS; }
+
+static inline int kernfs_setattr(struct kernfs_node *kn,
+                                 const struct iattr *iattr)
+{ return -ENOSYS; }
+
+static inline void kernfs_notify(struct kernfs_node *kn) { }
+
+static inline const void *kernfs_super_ns(struct super_block *sb)
+{ return NULL; }
+
+static inline struct dentry *
+kernfs_mount_ns(struct file_system_type *fs_type, int flags,
+                struct kernfs_root *root, const void *ns)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_kill_sb(struct super_block *sb) { }
+
+static inline void kernfs_init(void) { }
+
+#endif  /* CONFIG_SYSFS */
+
+static inline struct kernfs_node *
+kernfs_find_and_get(struct kernfs_node *kn, const char *name)
+{
+        return kernfs_find_and_get_ns(kn, name, NULL);
+}
+
+static inline struct kernfs_node *
+kernfs_create_dir(struct kernfs_node *parent, const char *name, umode_t mode,
+                  void *priv)
+{
+        return kernfs_create_dir_ns(parent, name, mode, priv, NULL);
+}
+
+static inline struct kernfs_node *
+kernfs_create_file_ns(struct kernfs_node *parent, const char *name,
+                      umode_t mode, loff_t size, const struct kernfs_ops *ops,
+                      void *priv, const void *ns)
+{
+        struct lock_class_key *key = NULL;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+        key = (struct lock_class_key *)&ops->lockdep_key;
+#endif
+        return __kernfs_create_file(parent, name, mode, size, ops, priv, ns,
+                                    false, key);
+}
+
+static inline struct kernfs_node *
+kernfs_create_file(struct kernfs_node *parent, const char *name, umode_t mode,
+                   loff_t size, const struct kernfs_ops *ops, void *priv)
+{
+        return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);
+}
+
+static inline int kernfs_remove_by_name(struct kernfs_node *parent,
+                                        const char *name)
+{
+        return kernfs_remove_by_name_ns(parent, name, NULL);
+}
+
+static inline struct dentry *
+kernfs_mount(struct file_system_type *fs_type, int flags,
+             struct kernfs_root *root)
+{
+        return kernfs_mount_ns(fs_type, flags, root, NULL);
+}
+
+#endif  /* __LINUX_KERNFS_H */