/*
   * Copyright (C) 2005, 2006
   * Avishay Traeger (avishay@gmail.com)
   * Copyright (C) 2008, 2009
   * Boaz Harrosh <bharrosh@panasas.com>
   *
   * Copyrights for code taken from ext2:
   *     Copyright (C) 1992, 1993, 1994, 1995
   *     Remy Card (card@masi.ibp.fr)
   *     Laboratoire MASI - Institut Blaise Pascal
   *     Universite Pierre et Marie Curie (Paris VI)
   *     from
   *     linux/fs/minix/inode.c
   *     Copyright (C) 1991, 1992  Linus Torvalds
   *
   * This file is part of exofs.
   *
   * exofs is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation.  Since it is based on ext2, and the only
   * valid version of GPL for the Linux kernel is version 2, the only valid
   * version of GPL for exofs is version 2.
   *
   * exofs is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with exofs; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  #ifndef __EXOFS_H__
  #define __EXOFS_H__
  
  #include <linux/fs.h>
  #include <linux/time.h>
  #include <linux/backing-dev.h>
  #include <scsi/osd_ore.h>
  
  #include "common.h"
  
  #define EXOFS_ERR(fmt, a...) printk(KERN_ERR "exofs: " fmt, ##a)
  
  #ifdef CONFIG_EXOFS_DEBUG
  #define EXOFS_DBGMSG(fmt, a...) \
  	printk(KERN_NOTICE "exofs @%s:%d: " fmt, __func__, __LINE__, ##a)
  #else
  #define EXOFS_DBGMSG(fmt, a...) \
  	do { if (0) printk(fmt, ##a); } while (0)
  #endif
  
  /* u64 has problems with printk this will cast it to unsigned long long */
  #define _LLU(x) (unsigned long long)(x)
  
  struct exofs_dev {
  	struct ore_dev ored;
  	unsigned did;
  	unsigned urilen;
  	uint8_t *uri;
  	struct kobject ed_kobj;
  };
  /*
   * our extension to the in-memory superblock
   */
  struct exofs_sb_info {
  	struct backing_dev_info bdi;		/* register our bdi with VFS  */
  	struct exofs_sb_stats s_ess;		/* Written often, pre-allocate*/
  	int		s_timeout;		/* timeout for OSD operations */
  	uint64_t	s_nextid;		/* highest object ID used     */
  	uint32_t	s_numfiles;		/* number of files on fs      */
  	spinlock_t	s_next_gen_lock;	/* spinlock for gen # update  */
  	u32		s_next_generation;	/* next gen # to use          */
  	atomic_t	s_curr_pending;		/* number of pending commands */
  
  	struct ore_layout	layout;		/* Default files layout       */
  	struct ore_comp one_comp;		/* id & cred of partition id=0*/
  	struct ore_components oc;		/* comps for the partition    */
  	struct kobject	s_kobj;			/* holds per-sbi kobject      */
  };
  
  /*
   * our extension to the in-memory inode
   */
  struct exofs_i_info {
  	struct inode   vfs_inode;          /* normal in-memory inode          */
  	wait_queue_head_t i_wq;            /* wait queue for inode            */
  	unsigned long  i_flags;            /* various atomic flags            */
  	uint32_t       i_data[EXOFS_IDATA];/*short symlink names and device #s*/
  	uint32_t       i_dir_start_lookup; /* which page to start lookup      */
  	uint64_t       i_commit_size;      /* the object's written length     */
  	struct ore_comp one_comp;	   /* same component for all devices  */
  	struct ore_components oc;	   /* inode view of the device table  */
  };
  
  static inline osd_id exofs_oi_objno(struct exofs_i_info *oi)
  {
  	return oi->vfs_inode.i_ino + EXOFS_OBJ_OFF;
  }
  
  /*
   * our inode flags
   */
  #define OBJ_2BCREATED	0	/* object will be created soon*/
  #define OBJ_CREATED	1	/* object has been created on the osd*/
  
  static inline int obj_2bcreated(struct exofs_i_info *oi)
  {
  	return test_bit(OBJ_2BCREATED, &oi->i_flags);
  }
  
  static inline void set_obj_2bcreated(struct exofs_i_info *oi)
  {
  	set_bit(OBJ_2BCREATED, &oi->i_flags);
  }
  
  static inline int obj_created(struct exofs_i_info *oi)
  {
  	return test_bit(OBJ_CREATED, &oi->i_flags);
  }
  
  static inline void set_obj_created(struct exofs_i_info *oi)
  {
  	set_bit(OBJ_CREATED, &oi->i_flags);
  }
  
  int __exofs_wait_obj_created(struct exofs_i_info *oi);
  static inline int wait_obj_created(struct exofs_i_info *oi)
  {
  	if (likely(obj_created(oi)))
  		return 0;
  
  	return __exofs_wait_obj_created(oi);
  }
  
  /*
   * get to our inode from the vfs inode
   */
  static inline struct exofs_i_info *exofs_i(struct inode *inode)
  {
  	return container_of(inode, struct exofs_i_info, vfs_inode);
  }
  
  /*
   * Maximum count of links to a file
   */
  #define EXOFS_LINK_MAX           32000
  
  /*************************
   * function declarations *
   *************************/
  
  /* inode.c               */
  unsigned exofs_max_io_pages(struct ore_layout *layout,
  			    unsigned expected_pages);
  int exofs_setattr(struct dentry *, struct iattr *);
  int exofs_write_begin(struct file *file, struct address_space *mapping,
  		loff_t pos, unsigned len, unsigned flags,
  		struct page **pagep, void **fsdata);
  extern struct inode *exofs_iget(struct super_block *, unsigned long);
  struct inode *exofs_new_inode(struct inode *, umode_t);
  extern int exofs_write_inode(struct inode *, struct writeback_control *wbc);
  extern void exofs_evict_inode(struct inode *);
  
  /* dir.c:                */
  int exofs_add_link(struct dentry *, struct inode *);
  ino_t exofs_inode_by_name(struct inode *, struct dentry *);
  int exofs_delete_entry(struct exofs_dir_entry *, struct page *);
  int exofs_make_empty(struct inode *, struct inode *);
  struct exofs_dir_entry *exofs_find_entry(struct inode *, struct dentry *,
  					 struct page **);
  int exofs_empty_dir(struct inode *);
  struct exofs_dir_entry *exofs_dotdot(struct inode *, struct page **);
  ino_t exofs_parent_ino(struct dentry *child);
  int exofs_set_link(struct inode *, struct exofs_dir_entry *, struct page *,
  		    struct inode *);
  
  /* super.c               */
  void exofs_make_credential(u8 cred_a[OSD_CAP_LEN],
  			   const struct osd_obj_id *obj);
  int exofs_sbi_write_stats(struct exofs_sb_info *sbi);
  
  /* sys.c                 */
  int exofs_sysfs_init(void);
  void exofs_sysfs_uninit(void);
  int exofs_sysfs_sb_add(struct exofs_sb_info *sbi,
  		       struct exofs_dt_device_info *dt_dev);
  void exofs_sysfs_sb_del(struct exofs_sb_info *sbi);
  int exofs_sysfs_odev_add(struct exofs_dev *edev,
  			 struct exofs_sb_info *sbi);
  void exofs_sysfs_dbg_print(void);
  
  /*********************
   * operation vectors *
   *********************/
  /* dir.c:            */
  extern const struct file_operations exofs_dir_operations;
  
  /* file.c            */
  extern const struct inode_operations exofs_file_inode_operations;
  extern const struct file_operations exofs_file_operations;
  
  /* inode.c           */
  extern const struct address_space_operations exofs_aops;
  
  /* namei.c           */
  extern const struct inode_operations exofs_dir_inode_operations;
  extern const struct inode_operations exofs_special_inode_operations;
  
  /* symlink.c         */
  extern const struct inode_operations exofs_symlink_inode_operations;
  extern const struct inode_operations exofs_fast_symlink_inode_operations;
  
  /* exofs_init_comps will initialize an ore_components device array
   * pointing to a single ore_comp struct, and a round-robin view
   * of the device table.
   * The first device of each inode is the [inode->ino % num_devices]
   * and the rest of the devices sequentially following where the
   * first device is after the last device.
   * It is assumed that the global device array at @sbi is twice
   * bigger and that the device table repeats twice.
   * See: exofs_read_lookup_dev_table()
   */
  static inline void exofs_init_comps(struct ore_components *oc,
  				    struct ore_comp *one_comp,
  				    struct exofs_sb_info *sbi, osd_id oid)
  {
  	unsigned dev_mod = (unsigned)oid, first_dev;
  
  	one_comp->obj.partition = sbi->one_comp.obj.partition;
  	one_comp->obj.id = oid;
  	exofs_make_credential(one_comp->cred, &one_comp->obj);
  
  	oc->first_dev = 0;
  	oc->numdevs = sbi->layout.group_width * sbi->layout.mirrors_p1 *
  							sbi->layout.group_count;
  	oc->single_comp = EC_SINGLE_COMP;
  	oc->comps = one_comp;
  
  	/* Round robin device view of the table */
  	first_dev = (dev_mod * sbi->layout.mirrors_p1) % sbi->oc.numdevs;
  	oc->ods = &sbi->oc.ods[first_dev];
  }
  
  #endif