servers/mfs/mount.c

   1 #include "fs.h"
   2 #include <fcntl.h>
   3 #include <string.h>
   4 #include <minix/com.h>
   5 #include <sys/stat.h>
   6 #include "buf.h"
   7 #include "inode.h"
   8 #include "super.h"
   9 #include "drivers.h"
  10 #include <minix/ds.h>
  11 #include <minix/vfsif.h>
  12
  13
  14 /*===========================================================================*
  15  *                              fs_readsuper                                 *
  16  *===========================================================================*/
  17 PUBLIC int fs_readsuper()
  18 {
  19 /* This function reads the superblock of the partition, gets the root inode
  20  * and sends back the details of them. Note, that the FS process does not
  21  * know the index of the vmnt object which refers to it, whenever the pathname
  22  * lookup leaves a partition an ELEAVEMOUNT error is transferred back
  23  * so that the VFS knows that it has to find the vnode on which this FS
  24  * process' partition is mounted on.
  25  */
  26   struct inode *root_ip;
  27   cp_grant_id_t label_gid;
  28   size_t label_len;
  29   int r = OK;
  30   endpoint_t driver_e;
  31   int readonly, isroot;
  32
  33   fs_dev    = fs_m_in.REQ_DEV;
  34   label_gid = fs_m_in.REQ_GRANT;
  35   label_len = fs_m_in.REQ_PATH_LEN;
  36   readonly  = (fs_m_in.REQ_FLAGS & REQ_RDONLY) ? 1 : 0;
  37   isroot    = (fs_m_in.REQ_FLAGS & REQ_ISROOT) ? 1 : 0;
  38
  39   if (label_len > sizeof(fs_dev_label))
  40         return(EINVAL);
  41
  42   r = sys_safecopyfrom(fs_m_in.m_source, label_gid, 0,
  43                        (vir_bytes)fs_dev_label, label_len, D);
  44   if (r != OK) {
  45         printf("%s:%d fs_readsuper: safecopyfrom failed: %d\n",
  46                __FILE__, __LINE__, r);
  47         return(EINVAL);
  48   }
  49
  50   r= ds_retrieve_label_endpt(fs_dev_label, &driver_e);
  51   if (r != OK)
  52   {
  53         printf("mfs:fs_readsuper: ds_retrieve_label_endpt failed for '%s': %d\n",
  54                 fs_dev_label, r);
  55         return EINVAL;
  56   }
  57
  58   /* Map the driver endpoint for this major */
  59   driver_endpoints[(fs_dev >> MAJOR) & BYTE].driver_e =  driver_e;
  60   use_getuptime2 = TRUE; /* Should be removed with old getuptime call. */
  61   vfs_slink_storage = (char *)0xdeadbeef;       /* Should be removed together
  62                                                  * with old lookup code.
  63                                                  */;
  64
  65   /* Open the device the file system lives on. */
  66   if (dev_open(driver_e, fs_dev, driver_e,
  67         readonly ? R_BIT : (R_BIT|W_BIT)) != OK) {
  68         return(EINVAL);
  69   }
  70
  71   /* Fill in the super block. */
  72   superblock.s_dev = fs_dev;    /* read_super() needs to know which dev */
  73   r = read_super(&superblock);
  74
  75   /* Is it recognized as a Minix filesystem? */
  76   if (r != OK) {
  77         superblock.s_dev = NO_DEV;
  78         dev_close(driver_e, fs_dev);
  79         return(r);
  80   }
  81
  82   set_blocksize(superblock.s_block_size);
  83
  84   /* Get the root inode of the mounted file system. */
  85   if( (root_ip = get_inode(fs_dev, ROOT_INODE)) == NIL_INODE)  {
  86           printf("MFS: couldn't get root inode\n");
  87           superblock.s_dev = NO_DEV;
  88           dev_close(driver_e, fs_dev);
  89           return(EINVAL);
  90   }
  91
  92   if(root_ip != NIL_INODE && root_ip->i_mode == 0) {
  93           printf("%s:%d zero mode for root inode?\n", __FILE__, __LINE__);
  94           put_inode(root_ip);
  95           superblock.s_dev = NO_DEV;
  96           dev_close(driver_e, fs_dev);
  97           return(EINVAL);
  98   }
  99
 100   superblock.s_rd_only = readonly;
 101   superblock.s_is_root = isroot;
 102
 103   /* Root inode properties */
 104   fs_m_out.RES_INODE_NR = root_ip->i_num;
 105   fs_m_out.RES_MODE = root_ip->i_mode;
 106   fs_m_out.RES_FILE_SIZE_LO = root_ip->i_size;
 107   fs_m_out.RES_UID = root_ip->i_uid;
 108   fs_m_out.RES_GID = root_ip->i_gid;
 109
 110   return(r);
 111 }
 112
 113
 114 /*===========================================================================*
 115  *                              fs_mountpoint                                *
 116  *===========================================================================*/
 117 PUBLIC int fs_mountpoint()
 118 {
 119 /* This function looks up the mount point, it checks the condition whether
 120  * the partition can be mounted on the inode or not.
 121  */
 122   register struct inode *rip;
 123   int r = OK;
 124   mode_t bits;
 125
 126   /* Temporarily open the file. */
 127   if( (rip = get_inode(fs_dev, fs_m_in.REQ_INODE_NR)) == NIL_INODE)
 128           return(EINVAL);
 129
 130
 131   if(rip->i_mountpoint) r = EBUSY;
 132
 133   /* It may not be special. */
 134   bits = rip->i_mode & I_TYPE;
 135   if (bits == I_BLOCK_SPECIAL || bits == I_CHAR_SPECIAL) r = ENOTDIR;
 136
 137   put_inode(rip);
 138
 139   if(r == OK) rip->i_mountpoint = TRUE;
 140
 141   return(r);
 142 }
 143
 144
 145 /*===========================================================================*
 146  *                              fs_unmount                                   *
 147  *===========================================================================*/
 148 PUBLIC int fs_unmount()
 149 {
 150 /* Unmount a file system by device number. */
 151   int count;
 152   struct inode *rip, *root_ip;
 153
 154   if(superblock.s_dev != fs_dev) return(EINVAL);
 155
 156   /* See if the mounted device is busy.  Only 1 inode using it should be
 157    * open --the root inode-- and that inode only 1 time. */
 158   count = 0;
 159   for (rip = &inode[0]; rip < &inode[NR_INODES]; rip++)
 160           if (rip->i_count > 0 && rip->i_dev == fs_dev) count += rip->i_count;
 161
 162   if ((root_ip = find_inode(fs_dev, ROOT_INODE)) == NIL_INODE) {
 163         printf("MFS: couldn't find root inode. Unmount failed.\n");
 164         panic("MFS: couldn't find root inode: %d", EINVAL);
 165         return(EINVAL);
 166   }
 167
 168   if (count > 1) return(EBUSY); /* can't umount a busy file system */
 169   put_inode(root_ip);
 170
 171   /* force any cached blocks out of memory */
 172   (void) fs_sync();
 173
 174   /* Close the device the file system lives on. */
 175   dev_close(driver_endpoints[(fs_dev >> MAJOR) & BYTE].driver_e, fs_dev);
 176
 177   /* Finish off the unmount. */
 178   superblock.s_dev = NO_DEV;
 179   unmountdone = TRUE;
 180
 181   return(OK);
 182 }
 183