lib/libvtreefs/link.c

   1 /* VTreeFS - link.c - by Alen Stojanov and David van Moolenbroek */
   2
   3 #include "inc.h"
   4
   5 /*===========================================================================*
   6  *                              fs_rdlink                                    *
   7  *===========================================================================*/
   8 int fs_rdlink(void)
   9 {
  10         /* Retrieve symbolic link target.
  11          */
  12         char path[PATH_MAX];
  13         struct inode *node;
  14         size_t len;
  15         int r;
  16
  17         if ((node = find_inode(fs_m_in.REQ_INODE_NR)) == NULL)
  18                 return EINVAL;
  19
  20         /* Call the rdlink hook. */
  21         assert(vtreefs_hooks->rdlink_hook != NULL);
  22         assert(!is_inode_deleted(node));        /* symlinks cannot be opened */
  23
  24         r = vtreefs_hooks->rdlink_hook(node, path, sizeof(path),
  25                 get_inode_cbdata(node));
  26         if (r != OK) return r;
  27
  28         len = strlen(path);
  29         assert(len > 0 && len < sizeof(path));
  30
  31         if (len > fs_m_in.REQ_MEM_SIZE)
  32                 len = fs_m_in.REQ_MEM_SIZE;
  33
  34         /* Copy out the result. */
  35         r = sys_safecopyto(fs_m_in.m_source, fs_m_in.REQ_GRANT, 0,
  36                 (vir_bytes) path, len, D);
  37         if (r != OK) return r;
  38
  39         fs_m_out.RES_NBYTES = len;
  40         return OK;
  41 }