/*
   * JFFS2 -- Journalling Flash File System, Version 2.
   *

   * Copyright © 2001-2007 Red Hat, Inc.

   *
   * Created by David Woodhouse <dwmw2@infradead.org>
   *
   * For licensing information, see the file 'LICENCE' in this directory.
   *

   */
  
  #ifndef __JFFS2_NODELIST_H__
  #define __JFFS2_NODELIST_H__

  #include <linux/fs.h>
  #include <linux/types.h>
  #include <linux/jffs2.h>

  #include "jffs2_fs_sb.h"
  #include "jffs2_fs_i.h"

  #include "xattr.h"
  #include "acl.h"

  #include "summary.h"

  
  #ifdef __ECOS
  #include "os-ecos.h"
  #else

  #include "os-linux.h"
  #endif

  #define JFFS2_NATIVE_ENDIAN
  
  /* Note we handle mode bits conversion from JFFS2 (i.e. Linux) to/from
     whatever OS we're actually running on here too. */
  
  #if defined(JFFS2_NATIVE_ENDIAN)
  #define cpu_to_je16(x) ((jint16_t){x})
  #define cpu_to_je32(x) ((jint32_t){x})
  #define cpu_to_jemode(x) ((jmode_t){os_to_jffs2_mode(x)})

  #define constant_cpu_to_je16(x) ((jint16_t){x})
  #define constant_cpu_to_je32(x) ((jint32_t){x})

  #define je16_to_cpu(x) ((x).v16)
  #define je32_to_cpu(x) ((x).v32)
  #define jemode_to_cpu(x) (jffs2_to_os_mode((x).m))
  #elif defined(JFFS2_BIG_ENDIAN)
  #define cpu_to_je16(x) ((jint16_t){cpu_to_be16(x)})
  #define cpu_to_je32(x) ((jint32_t){cpu_to_be32(x)})
  #define cpu_to_jemode(x) ((jmode_t){cpu_to_be32(os_to_jffs2_mode(x))})

  #define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_be16(x)})
  #define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_be32(x)})

  #define je16_to_cpu(x) (be16_to_cpu(x.v16))
  #define je32_to_cpu(x) (be32_to_cpu(x.v32))
  #define jemode_to_cpu(x) (be32_to_cpu(jffs2_to_os_mode((x).m)))
  #elif defined(JFFS2_LITTLE_ENDIAN)
  #define cpu_to_je16(x) ((jint16_t){cpu_to_le16(x)})
  #define cpu_to_je32(x) ((jint32_t){cpu_to_le32(x)})
  #define cpu_to_jemode(x) ((jmode_t){cpu_to_le32(os_to_jffs2_mode(x))})

  #define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_le16(x)})
  #define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_le32(x)})

  #define je16_to_cpu(x) (le16_to_cpu(x.v16))
  #define je32_to_cpu(x) (le32_to_cpu(x.v32))
  #define jemode_to_cpu(x) (le32_to_cpu(jffs2_to_os_mode((x).m)))

  #else

  #error wibble
  #endif

  /* The minimal node header size */
  #define JFFS2_MIN_NODE_HEADER sizeof(struct jffs2_raw_dirent)

  /*
    This is all we need to keep in-core for each raw node during normal
    operation. As and when we do read_inode on a particular inode, we can

    scan the nodes which are listed for it and build up a proper map of

    which nodes are currently valid. JFFSv1 always used to keep that whole
    map in core for each inode.
  */
  struct jffs2_raw_node_ref
  {
  	struct jffs2_raw_node_ref *next_in_ino; /* Points to the next raw_node_ref

  		for this object. If this _is_ the last, it points to the inode_cache,
  		xattr_ref or xattr_datum instead. The common part of those structures
  		has NULL in the first word. See jffs2_raw_ref_to_ic() below */

  	uint32_t flash_offset;

  #undef TEST_TOTLEN

  #ifdef TEST_TOTLEN

  	uint32_t __totlen; /* This may die; use ref_totlen(c, jeb, ) below */

  #endif

  };

  #define REF_LINK_NODE ((int32_t)-1)
  #define REF_EMPTY_NODE ((int32_t)-2)
  
  /* Use blocks of about 256 bytes */
  #define REFS_PER_BLOCK ((255/sizeof(struct jffs2_raw_node_ref))-1)
  
  static inline struct jffs2_raw_node_ref *ref_next(struct jffs2_raw_node_ref *ref)
  {
  	ref++;
  
  	/* Link to another block of refs */
  	if (ref->flash_offset == REF_LINK_NODE) {
  		ref = ref->next_in_ino;
  		if (!ref)
  			return ref;
  	}
  
  	/* End of chain */
  	if (ref->flash_offset == REF_EMPTY_NODE)
  		return NULL;
  
  	return ref;
  }

  static inline struct jffs2_inode_cache *jffs2_raw_ref_to_ic(struct jffs2_raw_node_ref *raw)
  {

  	while(raw->next_in_ino)

  		raw = raw->next_in_ino;

  
  	/* NB. This can be a jffs2_xattr_datum or jffs2_xattr_ref and
  	   not actually a jffs2_inode_cache. Check ->class */
  	return ((struct jffs2_inode_cache *)raw);
  }

  	/* flash_offset & 3 always has to be zero, because nodes are

  	   always aligned at 4 bytes. So we have a couple of extra bits

  	   to play with, which indicate the node's status; see below: */

  #define REF_UNCHECKED	0	/* We haven't yet checked the CRC or built its inode */
  #define REF_OBSOLETE	1	/* Obsolete, can be completely ignored */
  #define REF_PRISTINE	2	/* Completely clean. GC without looking */
  #define REF_NORMAL	3	/* Possibly overlapped. Read the page and write again on GC */
  #define ref_flags(ref)		((ref)->flash_offset & 3)
  #define ref_offset(ref)		((ref)->flash_offset & ~3)
  #define ref_obsolete(ref)	(((ref)->flash_offset & 3) == REF_OBSOLETE)
  #define mark_ref_normal(ref)    do { (ref)->flash_offset = ref_offset(ref) | REF_NORMAL; } while(0)

  /* Dirent nodes should be REF_PRISTINE only if they are not a deletion
     dirent. Deletion dirents should be REF_NORMAL so that GC gets to
     throw them away when appropriate */
  #define dirent_node_state(rd)	( (je32_to_cpu((rd)->ino)?REF_PRISTINE:REF_NORMAL) )

  /* NB: REF_PRISTINE for an inode-less node (ref->next_in_ino == NULL) indicates
     it is an unknown node of type JFFS2_NODETYPE_RWCOMPAT_COPY, so it'll get
     copied. If you need to do anything different to GC inode-less nodes, then
     you need to modify gc.c accordingly. */

  
  /* For each inode in the filesystem, we need to keep a record of
     nlink, because it would be a PITA to scan the whole directory tree
     at read_inode() time to calculate it, and to keep sufficient information

     in the raw_node_ref (basically both parent and child inode number for

     dirent nodes) would take more space than this does. We also keep
     a pointer to the first physical node which is part of this inode, too.
  */
  struct jffs2_inode_cache {

  	/* First part of structure is shared with other objects which
  	   can terminate the raw node refs' next_in_ino list -- which
  	   currently struct jffs2_xattr_datum and struct jffs2_xattr_ref. */

  	struct jffs2_full_dirent *scan_dents; /* Used during scan to hold
  		temporary lists of dirents, and later must be set to
  		NULL to mark the end of the raw_node_ref->next_in_ino
  		chain. */

  	struct jffs2_raw_node_ref *nodes;

  	uint8_t class;	/* It's used for identification */
  
  	/* end of shared structure */
  
  	uint8_t flags;
  	uint16_t state;

  	uint32_t ino;

  	struct jffs2_inode_cache *next;

  #ifdef CONFIG_JFFS2_FS_XATTR

  	struct jffs2_xattr_ref *xref;

  #endif

  	uint32_t pino_nlink;	/* Directories store parent inode
  				   here; other inodes store nlink.
  				   Zero always means that it's
  				   completely unlinked. */

  };
  
  /* Inode states for 'state' above. We need the 'GC' state to prevent
     someone from doing a read_inode() while we're moving a 'REF_PRISTINE'
     node without going through all the iget() nonsense */
  #define INO_STATE_UNCHECKED	0	/* CRC checks not yet done */
  #define INO_STATE_CHECKING	1	/* CRC checks in progress */
  #define INO_STATE_PRESENT	2	/* In core */
  #define INO_STATE_CHECKEDABSENT	3	/* Checked, cleared again */
  #define INO_STATE_GC		4	/* GCing a 'pristine' node */
  #define INO_STATE_READING	5	/* In read_inode() */

  #define INO_STATE_CLEARING	6	/* In clear_inode() */

  #define INO_FLAGS_XATTR_CHECKED	0x01	/* has no duplicate xattr_ref */
  
  #define RAWNODE_CLASS_INODE_CACHE	0
  #define RAWNODE_CLASS_XATTR_DATUM	1
  #define RAWNODE_CLASS_XATTR_REF		2

  #define INOCACHE_HASHSIZE_MIN 128
  #define INOCACHE_HASHSIZE_MAX 1024

  #define write_ofs(c) ((c)->nextblock->offset + (c)->sector_size - (c)->nextblock->free_size)

  /*

    Larger representation of a raw node, kept in-core only when the

    struct inode for this particular ino is instantiated.
  */
  
  struct jffs2_full_dnode
  {
  	struct jffs2_raw_node_ref *raw;
  	uint32_t ofs; /* The offset to which the data of this node belongs */
  	uint32_t size;
  	uint32_t frags; /* Number of fragments which currently refer

  			to this node. When this reaches zero,

  			the node is obsolete.  */
  };

  /*

     Even larger representation of a raw node, kept in-core only while
     we're actually building up the original map of which nodes go where,
     in read_inode()
  */
  struct jffs2_tmp_dnode_info
  {

  	struct rb_node rb;

  	struct jffs2_full_dnode *fn;
  	uint32_t version;

  	uint32_t data_crc;
  	uint32_t partial_crc;

  	uint16_t csize;
  	uint16_t overlapped;
  };
  
  /* Temporary data structure used during readinode. */
  struct jffs2_readinode_info
  {
  	struct rb_root tn_root;
  	struct jffs2_tmp_dnode_info *mdata_tn;
  	uint32_t highest_version;
  	uint32_t latest_mctime;
  	uint32_t mctime_ver;
  	struct jffs2_full_dirent *fds;
  	struct jffs2_raw_node_ref *latest_ref;

  };

  
  struct jffs2_full_dirent
  {
  	struct jffs2_raw_node_ref *raw;
  	struct jffs2_full_dirent *next;
  	uint32_t version;
  	uint32_t ino; /* == zero for unlink */
  	unsigned int nhash;
  	unsigned char type;
  	unsigned char name[0];
  };
  
  /*

    Fragments - used to build a map of which raw node to obtain

    data from for each part of the ino
  */
  struct jffs2_node_frag
  {
  	struct rb_node rb;
  	struct jffs2_full_dnode *node; /* NULL for holes */
  	uint32_t size;
  	uint32_t ofs; /* The offset to which this fragment belongs */
  };
  
  struct jffs2_eraseblock
  {
  	struct list_head list;
  	int bad_count;
  	uint32_t offset;		/* of this block in the MTD */
  
  	uint32_t unchecked_size;
  	uint32_t used_size;
  	uint32_t dirty_size;
  	uint32_t wasted_size;
  	uint32_t free_size;	/* Note that sector_size - free_size
  				   is the address of the first free space */

  	uint32_t allocated_refs;

  	struct jffs2_raw_node_ref *first_node;
  	struct jffs2_raw_node_ref *last_node;
  
  	struct jffs2_raw_node_ref *gc_node;	/* Next node to be garbage collected */
  };

  static inline int jffs2_blocks_use_vmalloc(struct jffs2_sb_info *c)
  {
  	return ((c->flash_size / c->sector_size) * sizeof (struct jffs2_eraseblock)) > (128 * 1024);
  }

  #define ref_totlen(a, b, c) __jffs2_ref_totlen((a), (b), (c))

  #define ALLOC_NORMAL	0	/* Normal allocation */
  #define ALLOC_DELETION	1	/* Deletion node. Best to allow it */
  #define ALLOC_GC	2	/* Space requested for GC. Give it or die */
  #define ALLOC_NORETRY	3	/* For jffs2_write_dnode: On failure, return -EAGAIN instead of retrying */
  
  /* How much dirty space before it goes on the very_dirty_list */
  #define VERYDIRTY(c, size) ((size) >= ((c)->sector_size / 2))
  
  /* check if dirty space is more than 255 Byte */

  #define ISDIRTY(size) ((size) >  sizeof (struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN)

  
  #define PAD(x) (((x)+3)&~3)

  static inline int jffs2_encode_dev(union jffs2_device_node *jdev, dev_t rdev)
  {
  	if (old_valid_dev(rdev)) {

  		jdev->old_id = cpu_to_je16(old_encode_dev(rdev));
  		return sizeof(jdev->old_id);

  	} else {

  		jdev->new_id = cpu_to_je32(new_encode_dev(rdev));
  		return sizeof(jdev->new_id);

  	}
  }

  static inline struct jffs2_node_frag *frag_first(struct rb_root *root)
  {

  	struct rb_node *node = rb_first(root);

  
  	if (!node)
  		return NULL;

  	return rb_entry(node, struct jffs2_node_frag, rb);
  }

  
  static inline struct jffs2_node_frag *frag_last(struct rb_root *root)
  {

  	struct rb_node *node = rb_last(root);

  
  	if (!node)
  		return NULL;

  	return rb_entry(node, struct jffs2_node_frag, rb);
  }

  #define frag_next(frag) rb_entry(rb_next(&(frag)->rb), struct jffs2_node_frag, rb)
  #define frag_prev(frag) rb_entry(rb_prev(&(frag)->rb), struct jffs2_node_frag, rb)
  #define frag_parent(frag) rb_entry(rb_parent(&(frag)->rb), struct jffs2_node_frag, rb)
  #define frag_left(frag) rb_entry((frag)->rb.rb_left, struct jffs2_node_frag, rb)
  #define frag_right(frag) rb_entry((frag)->rb.rb_right, struct jffs2_node_frag, rb)
  #define frag_erase(frag, list) rb_erase(&frag->rb, list);

  #define tn_next(tn) rb_entry(rb_next(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
  #define tn_prev(tn) rb_entry(rb_prev(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
  #define tn_parent(tn) rb_entry(rb_parent(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
  #define tn_left(tn) rb_entry((tn)->rb.rb_left, struct jffs2_tmp_dnode_info, rb)
  #define tn_right(tn) rb_entry((tn)->rb.rb_right, struct jffs2_tmp_dnode_info, rb)
  #define tn_erase(tn, list) rb_erase(&tn->rb, list);
  #define tn_last(list) rb_entry(rb_last(list), struct jffs2_tmp_dnode_info, rb)
  #define tn_first(list) rb_entry(rb_first(list), struct jffs2_tmp_dnode_info, rb)

  /* nodelist.c */

  void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);

  void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state);
  struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
  void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new);
  void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old);
  void jffs2_free_ino_caches(struct jffs2_sb_info *c);
  void jffs2_free_raw_node_refs(struct jffs2_sb_info *c);
  struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset);
  void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c_delete);

  int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn);

  uint32_t jffs2_truncate_fragtree (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size);

  struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
  					       struct jffs2_eraseblock *jeb,
  					       uint32_t ofs, uint32_t len,
  					       struct jffs2_inode_cache *ic);

  extern uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c,
  				   struct jffs2_eraseblock *jeb,
  				   struct jffs2_raw_node_ref *ref);

  
  /* nodemgmt.c */
  int jffs2_thread_should_wake(struct jffs2_sb_info *c);

  int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,

  			uint32_t *len, int prio, uint32_t sumsize);

  int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,

  			uint32_t *len, uint32_t sumsize);

  struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c, 
  						       uint32_t ofs, uint32_t len,
  						       struct jffs2_inode_cache *ic);

  void jffs2_complete_reservation(struct jffs2_sb_info *c);
  void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *raw);

  
  /* write.c */
  int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint32_t mode, struct jffs2_raw_inode *ri);

  struct jffs2_full_dnode *jffs2_write_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
  					   struct jffs2_raw_inode *ri, const unsigned char *data,
  					   uint32_t datalen, int alloc_mode);
  struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
  					     struct jffs2_raw_dirent *rd, const unsigned char *name,
  					     uint32_t namelen, int alloc_mode);

  int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,

  			    struct jffs2_raw_inode *ri, unsigned char *buf,

  			    uint32_t offset, uint32_t writelen, uint32_t *retlen);

  int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f,

  		    struct jffs2_raw_inode *ri, const struct qstr *qstr);

  int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, const char *name,
  		    int namelen, struct jffs2_inode_info *dead_f, uint32_t time);
  int jffs2_do_link(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino,
  		   uint8_t type, const char *name, int namelen, uint32_t time);

  
  
  /* readinode.c */

  int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,

  			uint32_t ino, struct jffs2_raw_inode *latest_node);
  int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
  void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
  
  /* malloc.c */
  int jffs2_create_slab_caches(void);
  void jffs2_destroy_slab_caches(void);
  
  struct jffs2_full_dirent *jffs2_alloc_full_dirent(int namesize);
  void jffs2_free_full_dirent(struct jffs2_full_dirent *);
  struct jffs2_full_dnode *jffs2_alloc_full_dnode(void);
  void jffs2_free_full_dnode(struct jffs2_full_dnode *);
  struct jffs2_raw_dirent *jffs2_alloc_raw_dirent(void);
  void jffs2_free_raw_dirent(struct jffs2_raw_dirent *);
  struct jffs2_raw_inode *jffs2_alloc_raw_inode(void);
  void jffs2_free_raw_inode(struct jffs2_raw_inode *);
  struct jffs2_tmp_dnode_info *jffs2_alloc_tmp_dnode_info(void);
  void jffs2_free_tmp_dnode_info(struct jffs2_tmp_dnode_info *);

  int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,

  				 struct jffs2_eraseblock *jeb, int nr);

  void jffs2_free_refblock(struct jffs2_raw_node_ref *);

  struct jffs2_node_frag *jffs2_alloc_node_frag(void);
  void jffs2_free_node_frag(struct jffs2_node_frag *);
  struct jffs2_inode_cache *jffs2_alloc_inode_cache(void);
  void jffs2_free_inode_cache(struct jffs2_inode_cache *);

  #ifdef CONFIG_JFFS2_FS_XATTR
  struct jffs2_xattr_datum *jffs2_alloc_xattr_datum(void);
  void jffs2_free_xattr_datum(struct jffs2_xattr_datum *);
  struct jffs2_xattr_ref *jffs2_alloc_xattr_ref(void);
  void jffs2_free_xattr_ref(struct jffs2_xattr_ref *);
  #endif

  
  /* gc.c */
  int jffs2_garbage_collect_pass(struct jffs2_sb_info *c);
  
  /* read.c */
  int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
  		     struct jffs2_full_dnode *fd, unsigned char *buf,
  		     int ofs, int len);
  int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
  			   unsigned char *buf, uint32_t offset, uint32_t len);
  char *jffs2_getlink(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
  
  /* scan.c */
  int jffs2_scan_medium(struct jffs2_sb_info *c);
  void jffs2_rotate_lists(struct jffs2_sb_info *c);

  struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
  int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);

  int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t size);

  
  /* build.c */
  int jffs2_do_mount_fs(struct jffs2_sb_info *c);
  
  /* erase.c */

  int jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count);

  void jffs2_free_jeb_node_refs(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);

  #ifdef CONFIG_JFFS2_FS_WRITEBUFFER

  /* wbuf.c */
  int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino);
  int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c);
  int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
  int jffs2_write_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
  #endif

  #include "debug.h"

  #endif /* __JFFS2_NODELIST_H__ */