#include "fs.h"
#include <string.h>
#include <assert.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/statvfs.h>
#include "inode.h"
#include "super.h"
#include <minix/vfsif.h>

PRIVATE int copy_new_to_old_stat(endpoint_t who_e,
	cp_grant_id_t gid, struct stat *st)
{
	struct minix_prev_stat prevst;

  	memset(&prevst, 0, sizeof(prevst));

	prevst.st_dev = st->st_dev;
	prevst.st_ino = st->st_ino;
	prevst.st_mode = st->st_mode;
	prevst.st_uid = (short) st->st_uid;
	prevst.st_gid = (short) st->st_gid;
	prevst.st_size = st->st_size;
	prevst.st_rdev = st->st_rdev;

	return sys_safecopyto(who_e, gid, (vir_bytes) 0, (vir_bytes) &prevst,
  		(size_t) sizeof(prevst), D);
}

/*===========================================================================*
 *				stat_inode				     *
 *===========================================================================*/
PRIVATE int stat_inode(
  register struct inode *rip,	/* pointer to inode to stat */
  endpoint_t who_e,		/* Caller endpoint */
  cp_grant_id_t gid		/* grant for the stat buf */
)
{
/* Common code for stat and fstat system calls. */

  struct stat statbuf;
  mode_t mo;
  int r, s;
  u32_t blocks; /* The unit of this is 512 */

  /* Update the atime, ctime, and mtime fields in the inode, if need be. */
  if (rip->i_update) update_times(rip);

  /* Fill in the statbuf struct. */
  mo = rip->i_mode & I_TYPE;

  /* true iff special */
  s = (mo == I_CHAR_SPECIAL || mo == I_BLOCK_SPECIAL);

  blocks = rip->i_size / 512;
  if (rip->i_size % 512 != 0)
	blocks += 1;

  memset(&statbuf, 0, sizeof(struct stat));

  statbuf.st_dev = rip->i_dev;
  statbuf.st_ino = rip->i_num;
  statbuf.st_mode = rip->i_mode;
  statbuf.st_nlink = rip->i_nlinks;
  statbuf.st_uid = rip->i_uid;
  statbuf.st_gid = rip->i_gid;
  statbuf.st_rdev = (s ? (dev_t) rip->i_zone[0] : NO_DEV);
  statbuf.st_size = rip->i_size;
  statbuf.st_atime = rip->i_atime;
  statbuf.st_mtime = rip->i_mtime;
  statbuf.st_ctime = rip->i_ctime;
  statbuf.st_blksize = fs_block_size;
  statbuf.st_blocks = blocks;

  /* Copy the struct to user space. */
  r = sys_safecopyto(who_e, gid, (vir_bytes) 0, (vir_bytes) &statbuf,
  		(size_t) sizeof(statbuf), D);

  /* Fallback for older VFS (old stat) */
  if(r != OK) {
  	r = copy_new_to_old_stat(who_e, gid, &statbuf);
	if(r == OK) printf("MFS: old vfs stat fallback ok\n");
	else	printf("MFS: old vfs stat fallback failed\n");
  }
  
  return(r);
}

/*===========================================================================*
 *				fs_fstatfs				     *
 *===========================================================================*/
PUBLIC int fs_fstatfs()
{
  struct statfs st;
  struct inode *rip;
  int r;

  if((rip = find_inode(fs_dev, ROOT_INODE)) == NULL)
	  return(EINVAL);
   
  st.f_bsize = rip->i_sp->s_block_size;
  
  /* Copy the struct to user space. */
  r = sys_safecopyto(fs_m_in.m_source, (cp_grant_id_t) fs_m_in.REQ_GRANT,
  		     (vir_bytes) 0, (vir_bytes) &st, (size_t) sizeof(st), D);
  
  return(r);
}


/*===========================================================================*
 *				fs_statvfs				     *
 *===========================================================================*/
PUBLIC int fs_statvfs()
{
  struct statvfs st;
  struct super_block *sp;
  int r, scale;
  u32_t used;

  sp = get_super(fs_dev);

  scale = sp->s_log_zone_size;

  blockstats((u32_t *) &st.f_blocks, (u32_t *) &st.f_bfree, &used);
  st.f_bavail = st.f_bfree;

  st.f_bsize =  sp->s_block_size << scale;
  st.f_frsize = sp->s_block_size;
  st.f_files = sp->s_ninodes;
  st.f_ffree = count_free_bits(sp, IMAP);
  st.f_favail = st.f_ffree;
  st.f_fsid = fs_dev;
  st.f_flag = (sp->s_rd_only == 1 ? ST_RDONLY : 0);
  st.f_namemax = MFS_DIRSIZ;

  /* Copy the struct to user space. */
  r = sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT, 0, (vir_bytes) &st,
		     (phys_bytes) sizeof(st), D);
  
  return(r);
}

/*===========================================================================*
 *                             fs_stat					     *
 *===========================================================================*/
PUBLIC int fs_stat()
{
  register int r;              /* return value */
  register struct inode *rip;  /* target inode */

  if ((rip = get_inode(fs_dev, (ino_t) fs_m_in.REQ_INODE_NR)) == NULL)
	return(EINVAL);
  
  r = stat_inode(rip, fs_m_in.m_source, (cp_grant_id_t) fs_m_in.REQ_GRANT);
  put_inode(rip);		/* release the inode */
  return(r);
}