/*
   *  linux/fs/hpfs/anode.c
   *
   *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
   *
   *  handling HPFS anode tree that contains file allocation info
   */
  
  #include "hpfs_fn.h"
  
  /* Find a sector in allocation tree */
  
  secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
  		   struct bplus_header *btree, unsigned sec,
  		   struct buffer_head *bh)
  {
  	anode_secno a = -1;
  	struct anode *anode;
  	int i;
  	int c1, c2 = 0;
  	go_down:
  	if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
  	if (btree->internal) {
  		for (i = 0; i < btree->n_used_nodes; i++)

  			if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
  				a = le32_to_cpu(btree->u.internal[i].down);

  				brelse(bh);
  				if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
  				btree = &anode->btree;
  				goto go_down;
  			}
  		hpfs_error(s, "sector %08x not found in internal anode %08x", sec, a);
  		brelse(bh);
  		return -1;
  	}
  	for (i = 0; i < btree->n_used_nodes; i++)

  		if (le32_to_cpu(btree->u.external[i].file_secno) <= sec &&
  		    le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > sec) {
  			a = le32_to_cpu(btree->u.external[i].disk_secno) + sec - le32_to_cpu(btree->u.external[i].file_secno);

  			if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, a, 1, "data")) {
  				brelse(bh);
  				return -1;
  			}
  			if (inode) {
  				struct hpfs_inode_info *hpfs_inode = hpfs_i(inode);

  				hpfs_inode->i_file_sec = le32_to_cpu(btree->u.external[i].file_secno);
  				hpfs_inode->i_disk_sec = le32_to_cpu(btree->u.external[i].disk_secno);
  				hpfs_inode->i_n_secs = le32_to_cpu(btree->u.external[i].length);

  			}
  			brelse(bh);
  			return a;
  		}
  	hpfs_error(s, "sector %08x not found in external anode %08x", sec, a);
  	brelse(bh);
  	return -1;
  }
  
  /* Add a sector to tree */
  
  secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsigned fsecno)
  {
  	struct bplus_header *btree;
  	struct anode *anode = NULL, *ranode = NULL;
  	struct fnode *fnode;
  	anode_secno a, na = -1, ra, up = -1;
  	secno se;
  	struct buffer_head *bh, *bh1, *bh2;
  	int n;
  	unsigned fs;
  	int c1, c2 = 0;
  	if (fnod) {
  		if (!(fnode = hpfs_map_fnode(s, node, &bh))) return -1;
  		btree = &fnode->btree;
  	} else {
  		if (!(anode = hpfs_map_anode(s, node, &bh))) return -1;
  		btree = &anode->btree;
  	}
  	a = node;
  	go_down:
  	if ((n = btree->n_used_nodes - 1) < -!!fnod) {
  		hpfs_error(s, "anode %08x has no entries", a);
  		brelse(bh);
  		return -1;
  	}
  	if (btree->internal) {

  		a = le32_to_cpu(btree->u.internal[n].down);
  		btree->u.internal[n].file_secno = cpu_to_le32(-1);

  		mark_buffer_dirty(bh);
  		brelse(bh);
  		if (hpfs_sb(s)->sb_chk)
  			if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_add_sector_to_btree #1")) return -1;
  		if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
  		btree = &anode->btree;
  		goto go_down;
  	}
  	if (n >= 0) {

  		if (le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length) != fsecno) {

  			hpfs_error(s, "allocated size %08x, trying to add sector %08x, %cnode %08x",

  				le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length), fsecno,

  				fnod?'f':'a', node);
  			brelse(bh);
  			return -1;
  		}

  		if (hpfs_alloc_if_possible(s, se = le32_to_cpu(btree->u.external[n].disk_secno) + le32_to_cpu(btree->u.external[n].length))) {
  			btree->u.external[n].length = cpu_to_le32(le32_to_cpu(btree->u.external[n].length) + 1);

  			mark_buffer_dirty(bh);
  			brelse(bh);
  			return se;
  		}
  	} else {
  		if (fsecno) {
  			hpfs_error(s, "empty file %08x, trying to add sector %08x", node, fsecno);
  			brelse(bh);
  			return -1;
  		}
  		se = !fnod ? node : (node + 16384) & ~16383;
  	}	

  	if (!(se = hpfs_alloc_sector(s, se, 1, fsecno*ALLOC_M>ALLOC_FWD_MAX ? ALLOC_FWD_MAX : fsecno*ALLOC_M<ALLOC_FWD_MIN ? ALLOC_FWD_MIN : fsecno*ALLOC_M))) {

  		brelse(bh);
  		return -1;
  	}

  	fs = n < 0 ? 0 : le32_to_cpu(btree->u.external[n].file_secno) + le32_to_cpu(btree->u.external[n].length);

  	if (!btree->n_free_nodes) {

  		up = a != node ? le32_to_cpu(anode->up) : -1;

  		if (!(anode = hpfs_alloc_anode(s, a, &na, &bh1))) {
  			brelse(bh);
  			hpfs_free_sectors(s, se, 1);
  			return -1;
  		}
  		if (a == node && fnod) {

  			anode->up = cpu_to_le32(node);

  			anode->btree.fnode_parent = 1;
  			anode->btree.n_used_nodes = btree->n_used_nodes;
  			anode->btree.first_free = btree->first_free;
  			anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
  			memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
  			btree->internal = 1;
  			btree->n_free_nodes = 11;
  			btree->n_used_nodes = 1;

  			btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
  			btree->u.internal[0].file_secno = cpu_to_le32(-1);
  			btree->u.internal[0].down = cpu_to_le32(na);

  			mark_buffer_dirty(bh);
  		} else if (!(ranode = hpfs_alloc_anode(s, /*a*/0, &ra, &bh2))) {
  			brelse(bh);
  			brelse(bh1);
  			hpfs_free_sectors(s, se, 1);
  			hpfs_free_sectors(s, na, 1);
  			return -1;
  		}
  		brelse(bh);
  		bh = bh1;
  		btree = &anode->btree;
  	}
  	btree->n_free_nodes--; n = btree->n_used_nodes++;

  	btree->first_free = cpu_to_le16(le16_to_cpu(btree->first_free) + 12);
  	btree->u.external[n].disk_secno = cpu_to_le32(se);
  	btree->u.external[n].file_secno = cpu_to_le32(fs);
  	btree->u.external[n].length = cpu_to_le32(1);

  	mark_buffer_dirty(bh);
  	brelse(bh);
  	if ((a == node && fnod) || na == -1) return se;
  	c2 = 0;

  	while (up != (anode_secno)-1) {

  		struct anode *new_anode;
  		if (hpfs_sb(s)->sb_chk)
  			if (hpfs_stop_cycles(s, up, &c1, &c2, "hpfs_add_sector_to_btree #2")) return -1;
  		if (up != node || !fnod) {
  			if (!(anode = hpfs_map_anode(s, up, &bh))) return -1;
  			btree = &anode->btree;
  		} else {
  			if (!(fnode = hpfs_map_fnode(s, up, &bh))) return -1;
  			btree = &fnode->btree;
  		}
  		if (btree->n_free_nodes) {
  			btree->n_free_nodes--; n = btree->n_used_nodes++;

  			btree->first_free = cpu_to_le16(le16_to_cpu(btree->first_free) + 8);
  			btree->u.internal[n].file_secno = cpu_to_le32(-1);
  			btree->u.internal[n].down = cpu_to_le32(na);
  			btree->u.internal[n-1].file_secno = cpu_to_le32(fs);

  			mark_buffer_dirty(bh);
  			brelse(bh);
  			brelse(bh2);
  			hpfs_free_sectors(s, ra, 1);
  			if ((anode = hpfs_map_anode(s, na, &bh))) {

  				anode->up = cpu_to_le32(up);

  				anode->btree.fnode_parent = up == node && fnod;
  				mark_buffer_dirty(bh);
  				brelse(bh);
  			}
  			return se;
  		}

  		up = up != node ? le32_to_cpu(anode->up) : -1;
  		btree->u.internal[btree->n_used_nodes - 1].file_secno = cpu_to_le32(/*fs*/-1);

  		mark_buffer_dirty(bh);
  		brelse(bh);
  		a = na;
  		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
  			anode = new_anode;

  			/*anode->up = cpu_to_le32(up != -1 ? up : ra);*/

  			anode->btree.internal = 1;
  			anode->btree.n_used_nodes = 1;
  			anode->btree.n_free_nodes = 59;

  			anode->btree.first_free = cpu_to_le16(16);
  			anode->btree.u.internal[0].down = cpu_to_le32(a);
  			anode->btree.u.internal[0].file_secno = cpu_to_le32(-1);

  			mark_buffer_dirty(bh);
  			brelse(bh);
  			if ((anode = hpfs_map_anode(s, a, &bh))) {

  				anode->up = cpu_to_le32(na);

  				mark_buffer_dirty(bh);
  				brelse(bh);
  			}
  		} else na = a;
  	}
  	if ((anode = hpfs_map_anode(s, na, &bh))) {

  		anode->up = cpu_to_le32(node);

  		if (fnod) anode->btree.fnode_parent = 1;
  		mark_buffer_dirty(bh);
  		brelse(bh);
  	}
  	if (!fnod) {
  		if (!(anode = hpfs_map_anode(s, node, &bh))) {
  			brelse(bh2);
  			return -1;
  		}
  		btree = &anode->btree;
  	} else {
  		if (!(fnode = hpfs_map_fnode(s, node, &bh))) {
  			brelse(bh2);
  			return -1;
  		}
  		btree = &fnode->btree;
  	}

  	ranode->up = cpu_to_le32(node);
  	memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));

  	if (fnod) ranode->btree.fnode_parent = 1;
  	ranode->btree.n_free_nodes = (ranode->btree.internal ? 60 : 40) - ranode->btree.n_used_nodes;
  	if (ranode->btree.internal) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
  		struct anode *unode;

  		if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
  			unode->up = cpu_to_le32(ra);

  			unode->btree.fnode_parent = 0;
  			mark_buffer_dirty(bh1);
  			brelse(bh1);
  		}
  	}
  	btree->internal = 1;
  	btree->n_free_nodes = fnod ? 10 : 58;
  	btree->n_used_nodes = 2;

  	btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
  	btree->u.internal[0].file_secno = cpu_to_le32(fs);
  	btree->u.internal[0].down = cpu_to_le32(ra);
  	btree->u.internal[1].file_secno = cpu_to_le32(-1);
  	btree->u.internal[1].down = cpu_to_le32(na);

  	mark_buffer_dirty(bh);
  	brelse(bh);
  	mark_buffer_dirty(bh2);
  	brelse(bh2);
  	return se;
  }
  
  /*
   * Remove allocation tree. Recursion would look much nicer but
   * I want to avoid it because it can cause stack overflow.
   */
  
  void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
  {
  	struct bplus_header *btree1 = btree;
  	struct anode *anode = NULL;
  	anode_secno ano = 0, oano;
  	struct buffer_head *bh;
  	int level = 0;
  	int pos = 0;
  	int i;
  	int c1, c2 = 0;
  	int d1, d2;
  	go_down:
  	d2 = 0;
  	while (btree1->internal) {

  		ano = le32_to_cpu(btree1->u.internal[pos].down);

  		if (level) brelse(bh);
  		if (hpfs_sb(s)->sb_chk)
  			if (hpfs_stop_cycles(s, ano, &d1, &d2, "hpfs_remove_btree #1"))
  				return;
  		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
  		btree1 = &anode->btree;
  		level++;
  		pos = 0;
  	}
  	for (i = 0; i < btree1->n_used_nodes; i++)

  		hpfs_free_sectors(s, le32_to_cpu(btree1->u.external[i].disk_secno), le32_to_cpu(btree1->u.external[i].length));

  	go_up:
  	if (!level) return;
  	brelse(bh);
  	if (hpfs_sb(s)->sb_chk)
  		if (hpfs_stop_cycles(s, ano, &c1, &c2, "hpfs_remove_btree #2")) return;
  	hpfs_free_sectors(s, ano, 1);
  	oano = ano;

  	ano = le32_to_cpu(anode->up);

  	if (--level) {
  		if (!(anode = hpfs_map_anode(s, ano, &bh))) return;
  		btree1 = &anode->btree;
  	} else btree1 = btree;
  	for (i = 0; i < btree1->n_used_nodes; i++) {

  		if (le32_to_cpu(btree1->u.internal[i].down) == oano) {

  			if ((pos = i + 1) < btree1->n_used_nodes)
  				goto go_down;
  			else
  				goto go_up;
  		}
  	}
  	hpfs_error(s,
  		   "reference to anode %08x not found in anode %08x "
  		   "(probably bad up pointer)",
  		   oano, level ? ano : -1);
  	if (level)
  		brelse(bh);
  }
  
  /* Just a wrapper around hpfs_bplus_lookup .. used for reading eas */
  
  static secno anode_lookup(struct super_block *s, anode_secno a, unsigned sec)
  {
  	struct anode *anode;
  	struct buffer_head *bh;
  	if (!(anode = hpfs_map_anode(s, a, &bh))) return -1;
  	return hpfs_bplus_lookup(s, NULL, &anode->btree, sec, bh);
  }
  
  int hpfs_ea_read(struct super_block *s, secno a, int ano, unsigned pos,
  	    unsigned len, char *buf)
  {
  	struct buffer_head *bh;
  	char *data;
  	secno sec;
  	unsigned l;
  	while (len) {
  		if (ano) {
  			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
  				return -1;
  		} else sec = a + (pos >> 9);
  		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #1")) return -1;
  		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
  			return -1;
  		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
  		memcpy(buf, data + (pos & 0x1ff), l);
  		brelse(bh);
  		buf += l; pos += l; len -= l;
  	}
  	return 0;
  }
  
  int hpfs_ea_write(struct super_block *s, secno a, int ano, unsigned pos,

  	     unsigned len, const char *buf)

  {
  	struct buffer_head *bh;
  	char *data;
  	secno sec;
  	unsigned l;
  	while (len) {
  		if (ano) {
  			if ((sec = anode_lookup(s, a, pos >> 9)) == -1)
  				return -1;
  		} else sec = a + (pos >> 9);
  		if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, sec, 1, "ea #2")) return -1;
  		if (!(data = hpfs_map_sector(s, sec, &bh, (len - 1) >> 9)))
  			return -1;
  		l = 0x200 - (pos & 0x1ff); if (l > len) l = len;
  		memcpy(data + (pos & 0x1ff), buf, l);
  		mark_buffer_dirty(bh);
  		brelse(bh);
  		buf += l; pos += l; len -= l;
  	}
  	return 0;
  }
  
  void hpfs_ea_remove(struct super_block *s, secno a, int ano, unsigned len)
  {
  	struct anode *anode;
  	struct buffer_head *bh;
  	if (ano) {
  		if (!(anode = hpfs_map_anode(s, a, &bh))) return;
  		hpfs_remove_btree(s, &anode->btree);
  		brelse(bh);
  		hpfs_free_sectors(s, a, 1);
  	} else hpfs_free_sectors(s, a, (len + 511) >> 9);
  }
  
  /* Truncate allocation tree. Doesn't join anodes - I hope it doesn't matter */
  
  void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
  {
  	struct fnode *fnode;
  	struct anode *anode;
  	struct buffer_head *bh;
  	struct bplus_header *btree;
  	anode_secno node = f;
  	int i, j, nodes;
  	int c1, c2 = 0;
  	if (fno) {
  		if (!(fnode = hpfs_map_fnode(s, f, &bh))) return;
  		btree = &fnode->btree;
  	} else {
  		if (!(anode = hpfs_map_anode(s, f, &bh))) return;
  		btree = &anode->btree;
  	}
  	if (!secs) {
  		hpfs_remove_btree(s, btree);
  		if (fno) {
  			btree->n_free_nodes = 8;
  			btree->n_used_nodes = 0;

  			btree->first_free = cpu_to_le16(8);

  			btree->internal = 0;
  			mark_buffer_dirty(bh);
  		} else hpfs_free_sectors(s, f, 1);
  		brelse(bh);
  		return;
  	}
  	while (btree->internal) {
  		nodes = btree->n_used_nodes + btree->n_free_nodes;
  		for (i = 0; i < btree->n_used_nodes; i++)

  			if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;

  		brelse(bh);
  		hpfs_error(s, "internal btree %08x doesn't end with -1", node);
  		return;
  		f:
  		for (j = i + 1; j < btree->n_used_nodes; j++)

  			hpfs_ea_remove(s, le32_to_cpu(btree->u.internal[j].down), 1, 0);

  		btree->n_used_nodes = i + 1;
  		btree->n_free_nodes = nodes - btree->n_used_nodes;

  		btree->first_free = cpu_to_le16(8 + 8 * btree->n_used_nodes);

  		mark_buffer_dirty(bh);

  		if (btree->u.internal[i].file_secno == cpu_to_le32(secs)) {

  			brelse(bh);
  			return;
  		}

  		node = le32_to_cpu(btree->u.internal[i].down);

  		brelse(bh);
  		if (hpfs_sb(s)->sb_chk)
  			if (hpfs_stop_cycles(s, node, &c1, &c2, "hpfs_truncate_btree"))
  				return;
  		if (!(anode = hpfs_map_anode(s, node, &bh))) return;
  		btree = &anode->btree;
  	}	
  	nodes = btree->n_used_nodes + btree->n_free_nodes;
  	for (i = 0; i < btree->n_used_nodes; i++)

  		if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) >= secs) goto ff;

  	brelse(bh);
  	return;
  	ff:

  	if (secs <= le32_to_cpu(btree->u.external[i].file_secno)) {

  		hpfs_error(s, "there is an allocation error in file %08x, sector %08x", f, secs);
  		if (i) i--;
  	}

  	else if (le32_to_cpu(btree->u.external[i].file_secno) + le32_to_cpu(btree->u.external[i].length) > secs) {
  		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[i].disk_secno) + secs -
  			le32_to_cpu(btree->u.external[i].file_secno), le32_to_cpu(btree->u.external[i].length)
  			- secs + le32_to_cpu(btree->u.external[i].file_secno)); /* I hope gcc optimizes this :-) */
  		btree->u.external[i].length = cpu_to_le32(secs - le32_to_cpu(btree->u.external[i].file_secno));

  	}
  	for (j = i + 1; j < btree->n_used_nodes; j++)

  		hpfs_free_sectors(s, le32_to_cpu(btree->u.external[j].disk_secno), le32_to_cpu(btree->u.external[j].length));

  	btree->n_used_nodes = i + 1;
  	btree->n_free_nodes = nodes - btree->n_used_nodes;

  	btree->first_free = cpu_to_le16(8 + 12 * btree->n_used_nodes);

  	mark_buffer_dirty(bh);
  	brelse(bh);
  }
  
  /* Remove file or directory and it's eas - note that directory must
     be empty when this is called. */
  
  void hpfs_remove_fnode(struct super_block *s, fnode_secno fno)
  {
  	struct buffer_head *bh;
  	struct fnode *fnode;
  	struct extended_attribute *ea;
  	struct extended_attribute *ea_end;
  	if (!(fnode = hpfs_map_fnode(s, fno, &bh))) return;
  	if (!fnode->dirflag) hpfs_remove_btree(s, &fnode->btree);

  	else hpfs_remove_dtree(s, le32_to_cpu(fnode->u.external[0].disk_secno));

  	ea_end = fnode_end_ea(fnode);
  	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
  		if (ea->indirect)
  			hpfs_ea_remove(s, ea_sec(ea), ea->anode, ea_len(ea));

  	hpfs_ea_ext_remove(s, le32_to_cpu(fnode->ea_secno), fnode->ea_anode, le32_to_cpu(fnode->ea_size_l));

  	brelse(bh);
  	hpfs_free_sectors(s, fno, 1);
  }