/*
   * (C) 2001 Clemson University and The University of Chicago
   *
   * See COPYING in top-level directory.
   */
  
  /*

   *  The ORANGEFS Linux kernel support allows ORANGEFS volumes to be mounted and

   *  accessed through the Linux VFS (i.e. using standard I/O system calls).
   *  This support is only needed on clients that wish to mount the file system.
   *
   */
  
  /*

   *  Declarations and macros for the ORANGEFS Linux kernel support.

   */

  #ifndef __ORANGEFSKERNEL_H
  #define __ORANGEFSKERNEL_H

  
  #include <linux/kernel.h>
  #include <linux/moduleparam.h>
  #include <linux/statfs.h>
  #include <linux/backing-dev.h>
  #include <linux/device.h>
  #include <linux/mpage.h>
  #include <linux/namei.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/fs.h>
  #include <linux/vmalloc.h>
  
  #include <linux/aio.h>
  #include <linux/posix_acl.h>
  #include <linux/posix_acl_xattr.h>
  #include <linux/compat.h>
  #include <linux/mount.h>
  #include <linux/uaccess.h>
  #include <linux/atomic.h>
  #include <linux/uio.h>
  #include <linux/sched.h>
  #include <linux/mm.h>
  #include <linux/wait.h>
  #include <linux/dcache.h>
  #include <linux/pagemap.h>
  #include <linux/poll.h>
  #include <linux/rwsem.h>
  #include <linux/xattr.h>
  #include <linux/exportfs.h>
  
  #include <asm/unaligned.h>

  #include "orangefs-dev-proto.h"

  #ifdef ORANGEFS_KERNEL_DEBUG
  #define ORANGEFS_DEFAULT_OP_TIMEOUT_SECS       10

  #else

  #define ORANGEFS_DEFAULT_OP_TIMEOUT_SECS       20

  #endif

  #define ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS   30

  #define ORANGEFS_DEFAULT_SLOT_TIMEOUT_SECS     900	/* 15 minutes */

  #define ORANGEFS_REQDEVICE_NAME          "pvfs2-req"

  #define ORANGEFS_DEVREQ_MAGIC             0x20030529
  #define ORANGEFS_LINK_MAX                 0x000000FF
  #define ORANGEFS_PURGE_RETRY_COUNT     0x00000005

  #define ORANGEFS_MAX_NUM_OPTIONS          0x00000004
  #define ORANGEFS_MAX_MOUNT_OPT_LEN        0x00000080
  #define ORANGEFS_MAX_FSKEY_LEN            64

  #define MAX_DEV_REQ_UPSIZE (2 * sizeof(__s32) +   \

  sizeof(__u64) + sizeof(struct orangefs_upcall_s))

  #define MAX_DEV_REQ_DOWNSIZE (2 * sizeof(__s32) + \

  sizeof(__u64) + sizeof(struct orangefs_downcall_s))

  /*

   * valid orangefs kernel operation states

   *
   * unknown  - op was just initialized
   * waiting  - op is on request_list (upward bound)
   * inprogr  - op is in progress (waiting for downcall)
   * serviced - op has matching downcall; ok
   * purged   - op has to start a timer since client-core
   *            exited uncleanly before servicing op

   * given up - submitter has given up waiting for it

   */

  enum orangefs_vfs_op_states {

  	OP_VFS_STATE_UNKNOWN = 0,
  	OP_VFS_STATE_WAITING = 1,
  	OP_VFS_STATE_INPROGR = 2,
  	OP_VFS_STATE_SERVICED = 4,
  	OP_VFS_STATE_PURGED = 8,

  	OP_VFS_STATE_GIVEN_UP = 16,

  };

  /*

   * An array of client_debug_mask will be built to hold debug keyword/mask
   * values fetched from userspace.
   */
  struct client_debug_mask {
  	char *keyword;
  	__u64 mask1;
  	__u64 mask2;
  };
  
  /*

   * orangefs kernel memory related flags

   */

  #if ((defined ORANGEFS_KERNEL_DEBUG) && (defined CONFIG_DEBUG_SLAB))
  #define ORANGEFS_CACHE_CREATE_FLAGS SLAB_RED_ZONE

  #else

  #define ORANGEFS_CACHE_CREATE_FLAGS 0
  #endif /* ((defined ORANGEFS_KERNEL_DEBUG) && (defined CONFIG_DEBUG_SLAB)) */

  /* orangefs xattr and acl related defines */
  #define ORANGEFS_XATTR_INDEX_POSIX_ACL_ACCESS  1
  #define ORANGEFS_XATTR_INDEX_POSIX_ACL_DEFAULT 2
  #define ORANGEFS_XATTR_INDEX_TRUSTED           3
  #define ORANGEFS_XATTR_INDEX_DEFAULT           4

  #define ORANGEFS_XATTR_NAME_ACL_ACCESS XATTR_NAME_POSIX_ACL_ACCESS
  #define ORANGEFS_XATTR_NAME_ACL_DEFAULT XATTR_NAME_POSIX_ACL_DEFAULT

  #define ORANGEFS_XATTR_NAME_TRUSTED_PREFIX "trusted."
  #define ORANGEFS_XATTR_NAME_DEFAULT_PREFIX ""

  /* these functions are defined in orangefs-utils.c */

  int orangefs_prepare_cdm_array(char *debug_array_string);
  int orangefs_prepare_debugfs_help_string(int);

  /* defined in orangefs-debugfs.c */
  int orangefs_client_debug_init(void);

  
  void debug_string_to_mask(char *, void *, int);
  void do_c_mask(int, char *, struct client_debug_mask **);
  void do_k_mask(int, char *, __u64 **);
  
  void debug_mask_to_string(void *, int);
  void do_k_string(void *, int);
  void do_c_string(void *, int);
  int check_amalgam_keyword(void *, int);
  int keyword_is_amalgam(char *);

  /*these variables are defined in orangefs-mod.c */
  extern char kernel_debug_string[ORANGEFS_MAX_DEBUG_STRING_LEN];
  extern char client_debug_string[ORANGEFS_MAX_DEBUG_STRING_LEN];
  extern char client_debug_array_string[ORANGEFS_MAX_DEBUG_STRING_LEN];

  extern unsigned int kernel_mask_set_mod_init;

  extern int orangefs_init_acl(struct inode *inode, struct inode *dir);
  extern const struct xattr_handler *orangefs_xattr_handlers[];

  extern struct posix_acl *orangefs_get_acl(struct inode *inode, int type);
  extern int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type);

  /*
   * Redefine xtvec structure so that we could move helper functions out of
   * the define
   */
  struct xtvec {
  	__kernel_off_t xtv_off;		/* must be off_t */
  	__kernel_size_t xtv_len;	/* must be size_t */
  };
  
  /*

   * orangefs data structures

   */

  struct orangefs_kernel_op_s {
  	enum orangefs_vfs_op_states op_state;

  	__u64 tag;
  
  	/*

  	 * Set uses_shared_memory to non zero if this operation uses
  	 * shared memory. If true, then a retry on the op must also
  	 * get a new shared memory buffer and re-populate it.
  	 * Cancels don't care - it only matters for service_operation()
  	 * retry logics and cancels don't go through it anymore. It
  	 * safely stays non-zero when we use it as slot_to_free.

  	 */

  	union {
  		int uses_shared_memory;
  		int slot_to_free;
  	};

  	struct orangefs_upcall_s upcall;
  	struct orangefs_downcall_s downcall;

  	struct completion waitq;

  	spinlock_t lock;

  	int attempts;
  
  	struct list_head list;
  };

  #define set_op_state_waiting(op)     ((op)->op_state = OP_VFS_STATE_WAITING)
  #define set_op_state_inprogress(op)  ((op)->op_state = OP_VFS_STATE_INPROGR)

  #define set_op_state_given_up(op)  ((op)->op_state = OP_VFS_STATE_GIVEN_UP)

  static inline void set_op_state_serviced(struct orangefs_kernel_op_s *op)
  {
  	op->op_state = OP_VFS_STATE_SERVICED;

  	complete(&op->waitq);

  }

  
  #define op_state_waiting(op)     ((op)->op_state & OP_VFS_STATE_WAITING)
  #define op_state_in_progress(op) ((op)->op_state & OP_VFS_STATE_INPROGR)
  #define op_state_serviced(op)    ((op)->op_state & OP_VFS_STATE_SERVICED)
  #define op_state_purged(op)      ((op)->op_state & OP_VFS_STATE_PURGED)

  #define op_state_given_up(op)    ((op)->op_state & OP_VFS_STATE_GIVEN_UP)

  #define op_is_cancel(op)         ((op)->upcall.type == ORANGEFS_VFS_OP_CANCEL)

  void op_release(struct orangefs_kernel_op_s *op);

  extern void orangefs_bufmap_put(int);
  static inline void put_cancel(struct orangefs_kernel_op_s *op)
  {
  	orangefs_bufmap_put(op->slot_to_free);
  	op_release(op);
  }
  
  static inline void set_op_state_purged(struct orangefs_kernel_op_s *op)
  {
  	spin_lock(&op->lock);
  	if (unlikely(op_is_cancel(op))) {

  		list_del_init(&op->list);

  		spin_unlock(&op->lock);
  		put_cancel(op);
  	} else {
  		op->op_state |= OP_VFS_STATE_PURGED;

  		complete(&op->waitq);

  		spin_unlock(&op->lock);
  	}
  }

  /* per inode private orangefs info */
  struct orangefs_inode_s {
  	struct orangefs_object_kref refn;
  	char link_target[ORANGEFS_NAME_MAX];

  	__s64 blksize;
  	/*
  	 * Reading/Writing Extended attributes need to acquire the appropriate

  	 * reader/writer semaphore on the orangefs_inode_s structure.

  	 */
  	struct rw_semaphore xattr_sem;
  
  	struct inode vfs_inode;
  	sector_t last_failed_block_index_read;
  
  	/*
  	 * State of in-memory attributes not yet flushed to disk associated
  	 * with this object
  	 */
  	unsigned long pinode_flags;

  };
  
  #define P_ATIME_FLAG 0
  #define P_MTIME_FLAG 1
  #define P_CTIME_FLAG 2
  #define P_MODE_FLAG  3
  
  #define ClearAtimeFlag(pinode) clear_bit(P_ATIME_FLAG, &(pinode)->pinode_flags)
  #define SetAtimeFlag(pinode)   set_bit(P_ATIME_FLAG, &(pinode)->pinode_flags)
  #define AtimeFlag(pinode)      test_bit(P_ATIME_FLAG, &(pinode)->pinode_flags)
  
  #define ClearMtimeFlag(pinode) clear_bit(P_MTIME_FLAG, &(pinode)->pinode_flags)
  #define SetMtimeFlag(pinode)   set_bit(P_MTIME_FLAG, &(pinode)->pinode_flags)
  #define MtimeFlag(pinode)      test_bit(P_MTIME_FLAG, &(pinode)->pinode_flags)
  
  #define ClearCtimeFlag(pinode) clear_bit(P_CTIME_FLAG, &(pinode)->pinode_flags)
  #define SetCtimeFlag(pinode)   set_bit(P_CTIME_FLAG, &(pinode)->pinode_flags)
  #define CtimeFlag(pinode)      test_bit(P_CTIME_FLAG, &(pinode)->pinode_flags)
  
  #define ClearModeFlag(pinode) clear_bit(P_MODE_FLAG, &(pinode)->pinode_flags)
  #define SetModeFlag(pinode)   set_bit(P_MODE_FLAG, &(pinode)->pinode_flags)
  #define ModeFlag(pinode)      test_bit(P_MODE_FLAG, &(pinode)->pinode_flags)

  /* per superblock private orangefs info */
  struct orangefs_sb_info_s {
  	struct orangefs_khandle root_khandle;

  	__s32 fs_id;
  	int id;
  	int flags;

  #define ORANGEFS_OPT_INTR	0x01
  #define ORANGEFS_OPT_LOCAL_LOCK	0x02
  	char devname[ORANGEFS_MAX_SERVER_ADDR_LEN];

  	struct super_block *sb;
  	int mount_pending;
  	struct list_head list;
  };
  
  /*

   * structure that holds the state of any async I/O operation issued
   * through the VFS. Needed especially to handle cancellation requests
   * or even completion notification so that the VFS client-side daemon
   * can free up its vfs_request slots.
   */

  struct orangefs_kiocb_s {

  	/* the pointer to the task that initiated the AIO */
  	struct task_struct *tsk;
  
  	/* pointer to the kiocb that kicked this operation */
  	struct kiocb *kiocb;
  
  	/* buffer index that was used for the I/O */

  	struct orangefs_bufmap *bufmap;

  	int buffer_index;

  	/* orangefs kernel operation type */
  	struct orangefs_kernel_op_s *op;

  
  	/* The user space buffers from/to which I/O is being staged */
  	struct iovec *iov;
  
  	/* number of elements in the iovector */
  	unsigned long nr_segs;
  
  	/* set to indicate the type of the operation */
  	int rw;
  
  	/* file offset */
  	loff_t offset;
  
  	/* and the count in bytes */
  	size_t bytes_to_be_copied;
  
  	ssize_t bytes_copied;
  	int needs_cleanup;
  };

  struct orangefs_stats {

  	unsigned long cache_hits;
  	unsigned long cache_misses;
  	unsigned long reads;
  	unsigned long writes;
  };

  extern struct orangefs_stats g_orangefs_stats;

  
  /*

   * NOTE: See Documentation/filesystems/porting for information
   * on implementing FOO_I and properly accessing fs private data
   */

  static inline struct orangefs_inode_s *ORANGEFS_I(struct inode *inode)

  {

  	return container_of(inode, struct orangefs_inode_s, vfs_inode);

  }

  static inline struct orangefs_sb_info_s *ORANGEFS_SB(struct super_block *sb)

  {

  	return (struct orangefs_sb_info_s *) sb->s_fs_info;

  }
  
  /* ino_t descends from "unsigned long", 8 bytes, 64 bits. */

  static inline ino_t orangefs_khandle_to_ino(struct orangefs_khandle *khandle)

  {
  	union {
  		unsigned char u[8];
  		__u64 ino;
  	} ihandle;
  
  	ihandle.u[0] = khandle->u[0] ^ khandle->u[4];
  	ihandle.u[1] = khandle->u[1] ^ khandle->u[5];
  	ihandle.u[2] = khandle->u[2] ^ khandle->u[6];
  	ihandle.u[3] = khandle->u[3] ^ khandle->u[7];
  	ihandle.u[4] = khandle->u[12] ^ khandle->u[8];
  	ihandle.u[5] = khandle->u[13] ^ khandle->u[9];
  	ihandle.u[6] = khandle->u[14] ^ khandle->u[10];
  	ihandle.u[7] = khandle->u[15] ^ khandle->u[11];
  
  	return ihandle.ino;
  }

  static inline struct orangefs_khandle *get_khandle_from_ino(struct inode *inode)

  {

  	return &(ORANGEFS_I(inode)->refn.khandle);

  }
  
  static inline __s32 get_fsid_from_ino(struct inode *inode)
  {

  	return ORANGEFS_I(inode)->refn.fs_id;

  }
  
  static inline ino_t get_ino_from_khandle(struct inode *inode)
  {

  	struct orangefs_khandle *khandle;

  	ino_t ino;
  
  	khandle = get_khandle_from_ino(inode);

  	ino = orangefs_khandle_to_ino(khandle);

  	return ino;
  }
  
  static inline ino_t get_parent_ino_from_dentry(struct dentry *dentry)
  {
  	return get_ino_from_khandle(dentry->d_parent->d_inode);
  }
  
  static inline int is_root_handle(struct inode *inode)
  {
  	gossip_debug(GOSSIP_DCACHE_DEBUG,
  		     "%s: root handle: %pU, this handle: %pU:
  ",
  		     __func__,

  		     &ORANGEFS_SB(inode->i_sb)->root_khandle,

  		     get_khandle_from_ino(inode));

  	if (ORANGEFS_khandle_cmp(&(ORANGEFS_SB(inode->i_sb)->root_khandle),

  			     get_khandle_from_ino(inode)))
  		return 0;
  	else
  		return 1;
  }

  static inline int match_handle(struct orangefs_khandle resp_handle,

  			       struct inode *inode)
  {
  	gossip_debug(GOSSIP_DCACHE_DEBUG,
  		     "%s: one handle: %pU, another handle:%pU:
  ",
  		     __func__,
  		     &resp_handle,
  		     get_khandle_from_ino(inode));

  	if (ORANGEFS_khandle_cmp(&resp_handle, get_khandle_from_ino(inode)))

  		return 0;
  	else
  		return 1;
  }
  
  /*

   * defined in orangefs-cache.c

   */
  int op_cache_initialize(void);
  int op_cache_finalize(void);

  struct orangefs_kernel_op_s *op_alloc(__s32 type);

  void orangefs_new_tag(struct orangefs_kernel_op_s *op);

  char *get_opname_string(struct orangefs_kernel_op_s *new_op);

  int orangefs_inode_cache_initialize(void);
  int orangefs_inode_cache_finalize(void);

  /*

   * defined in orangefs-mod.c

   */
  void purge_inprogress_ops(void);
  
  /*
   * defined in waitqueue.c
   */

  void purge_waiting_ops(void);
  
  /*
   * defined in super.c
   */

  struct dentry *orangefs_mount(struct file_system_type *fst,

  			   int flags,
  			   const char *devname,
  			   void *data);

  void orangefs_kill_sb(struct super_block *sb);

  int orangefs_remount(struct orangefs_sb_info_s *);

  
  int fsid_key_table_initialize(void);
  void fsid_key_table_finalize(void);
  
  /*
   * defined in inode.c
   */

  __u32 convert_to_orangefs_mask(unsigned long lite_mask);
  struct inode *orangefs_new_inode(struct super_block *sb,

  			      struct inode *dir,
  			      int mode,
  			      dev_t dev,

  			      struct orangefs_object_kref *ref);

  int orangefs_setattr(struct dentry *dentry, struct iattr *iattr);

  int orangefs_getattr(struct vfsmount *mnt,

  		  struct dentry *dentry,
  		  struct kstat *kstat);

  int orangefs_permission(struct inode *inode, int mask);

  /*
   * defined in xattr.c
   */

  int orangefs_setxattr(struct dentry *dentry,

  		   const char *name,
  		   const void *value,
  		   size_t size,
  		   int flags);

  ssize_t orangefs_getxattr(struct dentry *dentry,

  		       const char *name,
  		       void *buffer,
  		       size_t size);

  ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size);

  
  /*
   * defined in namei.c
   */

  struct inode *orangefs_iget(struct super_block *sb,
  			 struct orangefs_object_kref *ref);

  ssize_t orangefs_inode_read(struct inode *inode,
  			    struct iov_iter *iter,
  			    loff_t *offset,
  			    loff_t readahead_size);

  
  /*

   * defined in devorangefs-req.c

   */

  int orangefs_dev_init(void);
  void orangefs_dev_cleanup(void);

  int is_daemon_in_service(void);

  bool __is_daemon_in_service(void);

  
  /*

   * defined in orangefs-utils.c

   */

  __s32 fsid_of_op(struct orangefs_kernel_op_s *op);

  int orangefs_flush_inode(struct inode *inode);

  ssize_t orangefs_inode_getxattr(struct inode *inode,

  			     const char *prefix,
  			     const char *name,
  			     void *buffer,
  			     size_t size);

  int orangefs_inode_setxattr(struct inode *inode,

  			 const char *prefix,
  			 const char *name,
  			 const void *value,
  			 size_t size,
  			 int flags);

  int orangefs_inode_getattr(struct inode *inode, int new, int size);

  int orangefs_inode_check_changed(struct inode *inode);

  int orangefs_inode_setattr(struct inode *inode, struct iattr *iattr);

  void orangefs_make_bad_inode(struct inode *inode);

  int orangefs_unmount_sb(struct super_block *sb);

  bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op);

  int orangefs_normalize_to_errno(__s32 error_code);

  
  extern struct mutex devreq_mutex;
  extern struct mutex request_mutex;
  extern int debug;
  extern int op_timeout_secs;
  extern int slot_timeout_secs;

  extern struct list_head orangefs_superblocks;
  extern spinlock_t orangefs_superblocks_lock;
  extern struct list_head orangefs_request_list;
  extern spinlock_t orangefs_request_list_lock;
  extern wait_queue_head_t orangefs_request_list_waitq;

  extern struct list_head *htable_ops_in_progress;
  extern spinlock_t htable_ops_in_progress_lock;
  extern int hash_table_size;

  extern const struct address_space_operations orangefs_address_operations;
  extern struct backing_dev_info orangefs_backing_dev_info;
  extern struct inode_operations orangefs_file_inode_operations;
  extern const struct file_operations orangefs_file_operations;
  extern struct inode_operations orangefs_symlink_inode_operations;
  extern struct inode_operations orangefs_dir_inode_operations;
  extern const struct file_operations orangefs_dir_operations;
  extern const struct dentry_operations orangefs_dentry_operations;
  extern const struct file_operations orangefs_devreq_file_operations;

  extern wait_queue_head_t orangefs_bufmap_init_waitq;

  
  /*
   * misc convenience macros
   */

  #define ORANGEFS_OP_INTERRUPTIBLE 1   /* service_operation() is interruptible */
  #define ORANGEFS_OP_PRIORITY      2   /* service_operation() is high priority */
  #define ORANGEFS_OP_CANCELLATION  4   /* this is a cancellation */

  #define ORANGEFS_OP_NO_MUTEX      8   /* don't acquire request_mutex */

  #define ORANGEFS_OP_ASYNC         16  /* Queue it, but don't wait */

  int service_operation(struct orangefs_kernel_op_s *op,

  		      const char *op_name,
  		      int flags);

  #define get_interruptible_flag(inode) \

  	((ORANGEFS_SB(inode->i_sb)->flags & ORANGEFS_OPT_INTR) ? \
  		ORANGEFS_OP_INTERRUPTIBLE : 0)

  #define fill_default_sys_attrs(sys_attr, type, mode)			\
  do {									\
  	sys_attr.owner = from_kuid(current_user_ns(), current_fsuid()); \
  	sys_attr.group = from_kgid(current_user_ns(), current_fsgid()); \

  	sys_attr.perms = ORANGEFS_util_translate_mode(mode);		\

  	sys_attr.mtime = 0;						\
  	sys_attr.atime = 0;						\
  	sys_attr.ctime = 0;						\

  	sys_attr.mask = ORANGEFS_ATTR_SYS_ALL_SETABLE;			\

  } while (0)

  static inline void orangefs_i_size_write(struct inode *inode, loff_t i_size)

  {
  #if BITS_PER_LONG == 32 && defined(CONFIG_SMP)

  	mutex_lock(&inode->i_mutex);

  #endif
  	i_size_write(inode, i_size);
  #if BITS_PER_LONG == 32 && defined(CONFIG_SMP)

  	mutex_unlock(&inode->i_mutex);

  #endif
  }

  #endif /* __ORANGEFSKERNEL_H */