minix/lib/libsffs/mount.c

   1 /* This file contains mount and unmount functionality.
   2  *
   3  * The entry points into this file are:
   4  *   do_mount           perform the READSUPER file system call
   5  *   do_unmount         perform the UNMOUNT file system call
   6  *
   7  * Created:
   8  *   April 2009 (D.C. van Moolenbroek)
   9  */
  10
  11 #include "inc.h"
  12
  13 /*===========================================================================*
  14  *                              do_mount                                     *
  15  *===========================================================================*/
  16 int do_mount(dev_t __unused dev, unsigned int flags,
  17         struct fsdriver_node *root_node, unsigned int *res_flags)
  18 {
  19 /* Mount the file system.
  20  */
  21   char path[PATH_MAX];
  22   struct inode *ino;
  23   struct sffs_attr attr;
  24   int r;
  25
  26   dprintf(("%s: mount (dev %"PRIx64", flags %x)\n", sffs_name, dev, flags));
  27
  28   if (flags & REQ_ISROOT) {
  29         printf("%s: attempt to mount as root device\n", sffs_name);
  30
  31         return EINVAL;
  32   }
  33
  34   read_only = !!(flags & REQ_RDONLY);
  35
  36   init_dentry();
  37   ino = init_inode();
  38
  39   attr.a_mask = SFFS_ATTR_MODE | SFFS_ATTR_SIZE;
  40
  41   /* We cannot continue if we fail to get the properties of the root inode at
  42    * all, because we cannot guess the details of the root node to return to
  43    * VFS. Print a (hopefully) helpful error message, and abort the mount.
  44    */
  45   if ((r = verify_inode(ino, path, &attr)) != OK) {
  46         if (r == EAGAIN)
  47                 printf("%s: shared folders disabled\n", sffs_name);
  48         else if (sffs_params->p_prefix[0] && (r == ENOENT || r == EACCES))
  49                 printf("%s: unable to access the given prefix directory\n",
  50                         sffs_name);
  51         else
  52                 printf("%s: unable to access shared folders\n", sffs_name);
  53
  54         return r;
  55   }
  56
  57   root_node->fn_ino_nr = INODE_NR(ino);
  58   root_node->fn_mode = get_mode(ino, attr.a_mode);
  59   root_node->fn_size = attr.a_size;
  60   root_node->fn_uid = sffs_params->p_uid;
  61   root_node->fn_gid = sffs_params->p_gid;
  62   root_node->fn_dev = NO_DEV;
  63
  64   *res_flags = RES_64BIT;
  65
  66   return OK;
  67 }
  68
  69 /*===========================================================================*
  70  *                              do_unmount                                   *
  71  *===========================================================================*/
  72 void do_unmount(void)
  73 {
  74 /* Unmount the file system.
  75  */
  76   struct inode *ino;
  77
  78   dprintf(("%s: unmount\n", sffs_name));
  79
  80   /* Decrease the reference count of the root inode. */
  81   if ((ino = find_inode(ROOT_INODE_NR)) == NULL)
  82         return;
  83
  84   put_inode(ino);
  85
  86   /* There should not be any referenced inodes anymore now. */
  87   if (have_used_inode())
  88         printf("%s: in-use inodes left at unmount time!\n", sffs_name);
  89 }