diff options
Diffstat (limited to 'libdiskfs/io-readable.c')
-rw-r--r-- | libdiskfs/io-readable.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/libdiskfs/io-readable.c b/libdiskfs/io-readable.c new file mode 100644 index 00000000..481b5b67 --- /dev/null +++ b/libdiskfs/io-readable.c @@ -0,0 +1,43 @@ +/* + Copyright (C) 1994 Free Software Foundation + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include "priv.h" + +/* Implement io_readable as described in <hurd/io.defs>. */ +error_t +diskfs_S_io_readable (struct protid *cred, + int *amount) +{ + struct node *np; + error_t err; + + if (!cred) + return EOPNOTSUPP; + + if (!(cred->po->openstat & O_READ)) + return EINVAL; + + np = cred->po->np; + + mutex_lock (&np->lock); + err = ioserver_get_conch (&np->i_conch); + if (!err) + *amount = np->dn_stat.st_size - cred->po->filepointer; + + mutex_unlock (&np->lock); + return err; +} |