servers/hgfs/mount.c

   1 /* This file contains mount and unmount functionality.
   2  *
   3  * The entry points into this file are:
   4  *   do_readsuper       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_readsuper                                 *
  15  *===========================================================================*/
  16 PUBLIC int do_readsuper()
  17 {
  18 /* Mount the file system.
  19  */
  20   char path[PATH_MAX];
  21   struct inode *ino;
  22   struct hgfs_attr attr;
  23   int r;
  24
  25   dprintf(("HGFS: readsuper (dev %x, flags %x)\n",
  26         (dev_t) m_in.REQ_DEV, m_in.REQ_FLAGS));
  27
  28   if (m_in.REQ_FLAGS & REQ_ISROOT) {
  29         printf("HGFS: attempt to mount as root device\n");
  30
  31         return EINVAL;
  32   }
  33
  34   state.read_only = !!(m_in.REQ_FLAGS & REQ_RDONLY);
  35   state.dev = m_in.REQ_DEV;
  36
  37   init_dentry();
  38   ino = init_inode();
  39
  40   attr.a_mask = HGFS_ATTR_MODE | HGFS_ATTR_SIZE;
  41
  42   /* We cannot continue if we fail to get the properties of the root inode at
  43    * all, because we cannot guess the details of the root node to return to
  44    * VFS. Print a (hopefully) helpful error message, and abort the mount.
  45    */
  46   if ((r = verify_inode(ino, path, &attr)) != OK) {
  47         if (r == EAGAIN)
  48                 printf("HGFS: shared folders disabled\n");
  49         else if (opt.prefix[0] && (r == ENOENT || r == EACCES))
  50                 printf("HGFS: unable to access the given prefix directory\n");
  51         else
  52                 printf("HGFS: unable to access shared folders\n");
  53
  54         return r;
  55   }
  56
  57   m_out.RES_INODE_NR = INODE_NR(ino);
  58   m_out.RES_MODE = get_mode(ino, attr.a_mode);
  59   m_out.RES_FILE_SIZE_HI = ex64hi(attr.a_size);
  60   m_out.RES_FILE_SIZE_LO = ex64lo(attr.a_size);
  61   m_out.RES_UID = opt.uid;
  62   m_out.RES_GID = opt.gid;
  63   m_out.RES_DEV = NO_DEV;
  64
  65   state.mounted = TRUE;
  66
  67   return OK;
  68 }
  69
  70 /*===========================================================================*
  71  *                              do_unmount                                   *
  72  *===========================================================================*/
  73 PUBLIC int do_unmount()
  74 {
  75 /* Unmount the file system.
  76  */
  77   struct inode *ino;
  78
  79   dprintf(("HGFS: do_unmount\n"));
  80
  81   /* Decrease the reference count of the root inode. */
  82   if ((ino = find_inode(ROOT_INODE_NR)) == NIL_INODE)
  83         return EINVAL;
  84
  85   put_inode(ino);
  86
  87   /* There should not be any referenced inodes anymore now. */
  88   if (have_used_inode())
  89         printf("HGFS: in-use inodes left at unmount time!\n");
  90
  91   state.mounted = FALSE;
  92
  93   return OK;
  94 }