1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/* libdiskfs implementation of fs.defs: dir_link
Copyright (C) 1992,93,94,95,96,97,99 Free Software Foundation, Inc.
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 *dircred,
struct protid *filecred,
char *name,
int excl)
{
struct node *np; /* node being linked */
struct node *tnp; /* node being deleted implicitly */
struct node *dnp; /* directory of new entry */
struct dirstat *ds = alloca (diskfs_dirstat_size);
error_t err;
if (!dircred)
return EOPNOTSUPP;
if (diskfs_check_readonly ())
return EROFS;
if (!filecred)
return EXDEV;
np = filecred->po->np;
pthread_mutex_lock (&np->lock);
if (S_ISDIR (np->dn_stat.st_mode))
{
pthread_mutex_unlock (&np->lock);
return EPERM;
}
pthread_mutex_unlock (&np->lock);
dnp = dircred->po->np;
pthread_mutex_lock (&dnp->lock);
/* Lookup new location */
err = diskfs_lookup (dnp, name, RENAME, &tnp, ds, dircred);
if (!err && excl)
{
err = EEXIST;
diskfs_nput (tnp);
}
if (err && err != ENOENT)
{
if (err == EAGAIN)
err = EINVAL;
diskfs_drop_dirstat (dnp, ds);
pthread_mutex_unlock (&dnp->lock);
return err;
}
if (np == tnp)
{
diskfs_drop_dirstat (dnp, ds);
pthread_mutex_unlock (&dnp->lock);
pthread_mutex_unlock (&tnp->lock);
mach_port_deallocate (mach_task_self (), filecred->pi.port_right);
return 0;
}
if (tnp && S_ISDIR (tnp->dn_stat.st_mode))
{
diskfs_drop_dirstat (dnp, ds);
pthread_mutex_unlock (&dnp->lock);
pthread_mutex_unlock (&tnp->lock);
return EISDIR;
}
/* Create new entry for NP */
/* This is safe because NP is not a directory (thus not DNP) and
not TNP and is a leaf. */
pthread_mutex_lock (&np->lock);
/* Increment link count */
if (np->dn_stat.st_nlink == diskfs_link_max - 1)
{
diskfs_drop_dirstat (dnp, ds);
pthread_mutex_unlock (&np->lock);
pthread_mutex_unlock (&dnp->lock);
return EMLINK;
}
np->dn_stat.st_nlink++;
np->dn_set_ctime = 1;
diskfs_node_update (np, diskfs_synchronous);
/* Attach it */
if (tnp)
{
assert_backtrace (!excl);
err = diskfs_dirrewrite (dnp, tnp, np, name, ds);
if (!err)
{
/* Deallocate link on TNP */
tnp->dn_stat.st_nlink--;
tnp->dn_set_ctime = 1;
if (diskfs_synchronous)
diskfs_node_update (tnp, 1);
}
diskfs_nput (tnp);
}
else
err = diskfs_direnter (dnp, name, np, ds, dircred);
if (diskfs_synchronous)
diskfs_node_update (dnp, 1);
pthread_mutex_unlock (&dnp->lock);
pthread_mutex_unlock (&np->lock);
if (!err)
/* MiG won't do this for us, which it ought to. */
mach_port_deallocate (mach_task_self (), filecred->pi.port_right);
return err;
}
|
