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
|
/* Access to file layout information
Copyright (C) 1996 Free Software Foundation, Inc.
Written by Miles Bader <miles@gnu.ai.mit.edu>
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 <string.h>
#include <netinet/in.h> /* htonl */
#include <hurd/store.h>
#include "ext2fs.h"
error_t
diskfs_S_file_get_storage_info (struct protid *cred,
mach_port_t **ports,
mach_msg_type_name_t *ports_type,
mach_msg_type_number_t *num_ports,
int **ints, mach_msg_type_number_t *num_ints,
off_t **offsets,
mach_msg_type_number_t *num_offsets,
char **data, mach_msg_type_number_t *data_len)
{
error_t err = 0;
unsigned num_fs_blocks;
struct store *file_store;
struct store_run *runs, *run = 0;
block_t index = 0;
size_t num_runs = 0, runs_alloced = 10;
struct node *node = cred->po->np;
runs = malloc (runs_alloced * sizeof (struct store_run));
if (! runs)
return ENOMEM;
mutex_lock (&node->lock);
/* NUM_FS_BLOCKS counts down the blocks in the file that we've not
enumerated yet; when it hits zero, we can stop. */
if (node->dn_stat.st_size < node->dn_stat.st_blocks * 512)
/* The value indicated by st_blocks is too big (because it includes
indirect blocks), so use the size of the file. */
num_fs_blocks =
(node->dn_stat.st_size + block_size - 1) >> log2_block_size;
else
num_fs_blocks = node->dn_stat.st_blocks >> log2_stat_blocks_per_fs_block;
while (num_fs_blocks-- > 0)
{
block_t block;
err = ext2_getblk (node, index++, 0, &block);
if (err == EINVAL)
/* Either a hole, or past the end of the file. */
{
block = 0;
err = 0;
}
else if (err)
break;
block <<= log2_dev_blocks_per_fs_block;
if (num_runs == 0
|| ((block && run->start >= 0) /* Neither is a hole and... */
? (block != run->start + run->length) /* BLOCK doesn't follow RUN */
: (block || run->start >= 0))) /* or one is, but not both */
/* Add a new run. */
{
if (num_runs == runs_alloced)
/* Make some more space in RUNS. */
{
struct store_run *new;
runs_alloced *= 2;
new = realloc (runs, runs_alloced * sizeof (struct store_run));
if (! new)
{
err = ENOMEM;
break;
}
runs = new;
}
run = runs + num_runs++;
run->start = block ?: -1; /* -1 means a hole in OFFSETS */
run->length = 0; /* will get extended just below */
}
/* Increase the size of the current run by one filesystem block. */
run->length += 1 << log2_dev_blocks_per_fs_block;
}
mutex_unlock (&node->lock);
if (! err)
err = store_clone (store, &file_store);
if (! err)
{
err = store_remap (file_store, runs, num_runs, &file_store);
if (!err
&& !idvec_contains (cred->user->uids, 0)
&& !store_is_securely_returnable (file_store, cred->po->openstat))
{
err = store_set_flags (file_store, STORE_INACTIVE);
if (err == EINVAL)
err = EACCES;
}
if (! err)
{
*ports_type = MACH_MSG_TYPE_COPY_SEND;
err = store_return (file_store, ports, num_ports, ints, num_ints,
offsets, num_offsets, data, data_len);
}
store_free (file_store);
}
free (runs);
return err;
}
|
