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/* libdiskfs implementation of fs.defs: dir_unlink
Copyright (C) 1992, 1993, 1994, 1995 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"
#include "fs_S.h"
#include <hurd/fsys.h>
/* Implement dir_unlink as described in <hurd/fs.defs>. */
kern_return_t
diskfs_S_dir_unlink (struct protid *dircred,
char *name)
{
struct node *dnp;
struct node *np;
struct dirstat *ds = alloca (diskfs_dirstat_size);
error_t error;
if (!dircred)
return EOPNOTSUPP;
dnp = dircred->po->np;
if (diskfs_readonly)
return EROFS;
retry:
mutex_lock (&dnp->lock);
error = diskfs_lookup (dnp, name, REMOVE, &np, ds, dircred);
if (error == EAGAIN)
error = EISDIR;
if (error)
{
diskfs_drop_dirstat (dnp, ds);
mutex_unlock (&dnp->lock);
return error;
}
/* This isn't the BSD behavior, but it is Posix compliant and saves
us on several race conditions.*/
if (S_ISDIR(np->dn_stat.st_mode))
{
if (np == dnp) /* gotta catch '.' */
diskfs_nrele (np);
else
diskfs_nput (np);
diskfs_drop_dirstat (dnp, ds);
mutex_unlock (&dnp->lock);
return EISDIR;
}
mutex_lock (&np->translator.lock);
if (np->translator.control != MACH_PORT_NULL)
{
mach_port_t control;
/* There is a running active translator here. Give it a push.
If it squeaks, then return an error. If it consents, then
clear the active translator spec (unless it's been changed
in the interim) and repeat the lookup above. */
control = np->translator.control;
mach_port_mod_refs (mach_task_self (), control, MACH_PORT_RIGHT_SEND, 1);
mutex_unlock (&np->translator.lock);
diskfs_drop_dirstat (dnp, ds);
mutex_unlock (&dnp->lock);
mutex_unlock (&np->lock);
error = fsys_goaway (control, FSYS_GOAWAY_UNLINK);
if (error)
return error;
mutex_lock (&np->lock);
mutex_lock (&np->translator.lock);
if (np->translator.control == control)
fshelp_translator_drop (&np->translator);
mutex_unlock (&np->translator.lock);
diskfs_nput (np);
mach_port_deallocate (mach_task_self (), control);
goto retry;
}
mutex_unlock (&np->translator.lock);
error = diskfs_dirremove (dnp, ds);
if (diskfs_synchronous)
diskfs_node_update (dnp, 1);
if (error)
{
diskfs_nput (np);
mutex_unlock (&dnp->lock);
return error;
}
np->dn_stat.st_nlink--;
np->dn_set_ctime = 1;
if (diskfs_synchronous)
diskfs_node_update (np, 1);
/* This check is necessary because we might get here on an error while
checking the mode on something which happens to be `.'. */
if (np == dnp)
diskfs_nrele (np);
else
diskfs_nput (np);
mutex_unlock (&dnp->lock);
return error;
}
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