servers/mfs/stadir.c

   1 #include "fs.h"
   2 #include <string.h>
   3 #include <assert.h>
   4 #include <sys/stat.h>
   5 #include <sys/statfs.h>
   6 #include <sys/statvfs.h>
   7 #include "inode.h"
   8 #include "super.h"
   9 #include <minix/vfsif.h>
  10
  11 /*===========================================================================*
  12  *                              estimate_blocks                              *
  13  *===========================================================================*/
  14 static blkcnt_t estimate_blocks(struct inode *rip)
  15 {
  16 /* Return the number of 512-byte blocks used by this file. This includes space
  17  * used by data zones and indirect blocks (actually also zones). Reading in all
  18  * indirect blocks is too costly for a stat call, so we disregard holes and
  19  * return a conservative estimation.
  20  */
  21   blkcnt_t zones, sindirs, dindirs, nr_indirs, sq_indirs;
  22   unsigned int zone_size;
  23
  24   /* Compute the number of zones used by the file. */
  25   zone_size = rip->i_sp->s_block_size << rip->i_sp->s_log_zone_size;
  26
  27   zones = (blkcnt_t) ((rip->i_size + zone_size - 1) / zone_size);
  28
  29   /* Compute the number of indirect blocks needed for that zone count. */
  30   nr_indirs = (blkcnt_t) rip->i_nindirs;
  31   sq_indirs = nr_indirs * nr_indirs;
  32
  33   sindirs = (zones - (blkcnt_t) rip->i_ndzones + nr_indirs - 1) / nr_indirs;
  34   dindirs = (sindirs - 1 + sq_indirs - 1) / sq_indirs;
  35
  36   /* Return the number of 512-byte blocks corresponding to the number of data
  37    * zones and indirect blocks.
  38    */
  39   return (zones + sindirs + dindirs) * (blkcnt_t) (zone_size / 512);
  40 }
  41
  42 /*===========================================================================*
  43  *                              stat_inode                                   *
  44  *===========================================================================*/
  45 static int stat_inode(
  46   register struct inode *rip,   /* pointer to inode to stat */
  47   endpoint_t who_e,             /* Caller endpoint */
  48   cp_grant_id_t gid             /* grant for the stat buf */
  49 )
  50 {
  51 /* Common code for stat and fstat system calls. */
  52
  53   struct stat statbuf;
  54   mode_t mo;
  55   int r, s;
  56
  57   /* Update the atime, ctime, and mtime fields in the inode, if need be. */
  58   if (rip->i_update) update_times(rip);
  59
  60   /* Fill in the statbuf struct. */
  61   mo = rip->i_mode & I_TYPE;
  62
  63   /* true iff special */
  64   s = (mo == I_CHAR_SPECIAL || mo == I_BLOCK_SPECIAL);
  65
  66   memset(&statbuf, 0, sizeof(struct stat));
  67
  68   statbuf.st_dev = rip->i_dev;
  69   statbuf.st_ino = rip->i_num;
  70   statbuf.st_mode = rip->i_mode;
  71   statbuf.st_nlink = rip->i_nlinks;
  72   statbuf.st_uid = rip->i_uid;
  73   statbuf.st_gid = rip->i_gid;
  74   statbuf.st_rdev = (s ? (dev_t) rip->i_zone[0] : NO_DEV);
  75   statbuf.st_size = rip->i_size;
  76   statbuf.st_atime = rip->i_atime;
  77   statbuf.st_mtime = rip->i_mtime;
  78   statbuf.st_ctime = rip->i_ctime;
  79   statbuf.st_blksize = lmfs_fs_block_size();
  80   statbuf.st_blocks = estimate_blocks(rip);
  81
  82   /* Copy the struct to user space. */
  83   r = sys_safecopyto(who_e, gid, (vir_bytes) 0, (vir_bytes) &statbuf,
  84                 (size_t) sizeof(statbuf));
  85
  86   return(r);
  87 }
  88
  89 /*===========================================================================*
  90  *                              fs_fstatfs                                   *
  91  *===========================================================================*/
  92 int fs_fstatfs()
  93 {
  94   struct statfs st;
  95   struct inode *rip;
  96   int r;
  97
  98   if((rip = find_inode(fs_dev, ROOT_INODE)) == NULL)
  99           return(EINVAL);
 100
 101   st.f_bsize = rip->i_sp->s_block_size;
 102
 103   /* Copy the struct to user space. */
 104   r = sys_safecopyto(fs_m_in.m_source, (cp_grant_id_t) fs_m_in.REQ_GRANT,
 105                      (vir_bytes) 0, (vir_bytes) &st, (size_t) sizeof(st));
 106
 107   return(r);
 108 }
 109
 110
 111 /*===========================================================================*
 112  *                              fs_statvfs                                   *
 113  *===========================================================================*/
 114 int fs_statvfs()
 115 {
 116   struct statvfs st;
 117   struct super_block *sp;
 118   int r, scale;
 119   u32_t used;
 120
 121   sp = get_super(fs_dev);
 122
 123   scale = sp->s_log_zone_size;
 124
 125   fs_blockstats((u32_t *) &st.f_blocks, (u32_t *) &st.f_bfree, &used);
 126   st.f_bavail = st.f_bfree;
 127
 128   st.f_bsize =  sp->s_block_size << scale;
 129   st.f_frsize = sp->s_block_size;
 130   st.f_files = sp->s_ninodes;
 131   st.f_ffree = count_free_bits(sp, IMAP);
 132   st.f_favail = st.f_ffree;
 133   st.f_fsid = fs_dev;
 134   st.f_flag = (sp->s_rd_only == 1 ? ST_RDONLY : 0);
 135   st.f_namemax = MFS_DIRSIZ;
 136
 137   /* Copy the struct to user space. */
 138   r = sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT, 0, (vir_bytes) &st,
 139                      (phys_bytes) sizeof(st));
 140
 141   return(r);
 142 }
 143
 144 /*===========================================================================*
 145  *                             fs_stat                                       *
 146  *===========================================================================*/
 147 int fs_stat()
 148 {
 149   register int r;              /* return value */
 150   register struct inode *rip;  /* target inode */
 151
 152   if ((rip = get_inode(fs_dev, (ino_t) fs_m_in.REQ_INODE_NR)) == NULL)
 153         return(EINVAL);
 154
 155   r = stat_inode(rip, fs_m_in.m_source, (cp_grant_id_t) fs_m_in.REQ_GRANT);
 156   put_inode(rip);               /* release the inode */
 157   return(r);
 158 }
 159