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/* libdiskfs implementation of fs.defs: dir_link
Copyright (C) 1992, 1993, 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"
#include "fs_S.h"
/* Implement dir_link as described in <hurd/fs.defs>. */
kern_return_t
diskfs_S_dir_link (struct protid *filecred,
struct protid *dircred,
char *name)
{
struct node *np;
struct node *dnp;
struct dirstat *ds = alloca (diskfs_dirstat_size);
error_t error;
if (!filecred)
return EOPNOTSUPP;
np = filecred->po->np;
if (diskfs_readonly)
return EROFS;
if (!dircred)
return EXDEV;
dnp = dircred->po->np;
mutex_lock (&dnp->lock);
/* This lock is safe since a non-directory is inherently a leaf */
/* XXX But we don't know yet that it is a non-directory */
mutex_lock (&np->lock);
if (S_ISDIR (np->dn_stat.st_mode))
{
error = EISDIR;
goto out;
}
else if (np->dn_stat.st_nlink == diskfs_link_max - 1)
{
error = EMLINK;
goto out;
}
error = diskfs_lookup (dnp, name, CREATE, 0, ds, dircred);
if (error == EAGAIN)
error = EEXIST;
if (!error)
error = EEXIST;
if (error != ENOENT)
{
diskfs_drop_dirstat (dnp, ds);
goto out;
}
np->dn_stat.st_nlink++;
np->dn_set_ctime = 1;
diskfs_node_update (np, 1);
error = diskfs_direnter (dnp, name, np, ds, dircred);
if (error)
{
np->dn_stat.st_nlink--;
np->dn_set_ctime = 1;
}
out:
mutex_unlock (&dnp->lock);
mutex_unlock (&np->lock);
return error;
}
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