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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/*
* dir.c
*
* PURPOSE
* Directory handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-2004 Ben Fennema
*
* HISTORY
*
* 10/05/98 dgb Split directory operations into its own file
* Implemented directory reads via do_udf_readdir
* 10/06/98 Made directory operations work!
* 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG
* 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
* across blocks.
* 12/12/98 Split out the lookup code to namei.c. bulk of directory
* code now in directory.c:udf_fileident_read.
*/
#include "udfdecl.h"
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/bio.h>
#include <linux/iversion.h>
#include "udf_i.h"
#include "udf_sb.h"
static int udf_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *dir = file_inode(file);
struct udf_inode_info *iinfo = UDF_I(dir);
struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
struct fileIdentDesc *fi = NULL;
struct fileIdentDesc cfi;
udf_pblk_t block, iblock;
loff_t nf_pos, emit_pos = 0;
int flen;
unsigned char *fname = NULL, *copy_name = NULL;
unsigned char *nameptr;
uint16_t liu;
uint8_t lfi;
loff_t size = udf_ext0_offset(dir) + dir->i_size;
struct buffer_head *tmp, *bha[16];
struct kernel_lb_addr eloc;
uint32_t elen;
sector_t offset;
int i, num, ret = 0;
struct extent_position epos = { NULL, 0, {0, 0} };
struct super_block *sb = dir->i_sb;
bool pos_valid = false;
if (ctx->pos == 0) {
if (!dir_emit_dot(file, ctx))
return 0;
ctx->pos = 1;
}
nf_pos = (ctx->pos - 1) << 2;
if (nf_pos >= size)
goto out;
/*
* Something changed since last readdir (either lseek was called or dir
* changed)? We need to verify the position correctly points at the
* beginning of some dir entry so that the directory parsing code does
* not get confused. Since UDF does not have any reliable way of
* identifying beginning of dir entry (names are under user control),
* we need to scan the directory from the beginning.
*/
if (!inode_eq_iversion(dir, file->f_version)) {
emit_pos = nf_pos;
nf_pos = 0;
} else {
pos_valid = true;
}
fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
if (!fname) {
ret = -ENOMEM;
goto out;
}
if (nf_pos == 0)
nf_pos = udf_ext0_offset(dir);
fibh.soffset = fibh.eoffset = nf_pos & (sb->s_blocksize - 1);
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
if (inode_bmap(dir, nf_pos >> sb->s_blocksize_bits,
&epos, &eloc, &elen, &offset)
!= (EXT_RECORDED_ALLOCATED >> 30)) {
ret = -ENOENT;
goto out;
}
block = udf_get_lb_pblock(sb, &eloc, offset);
if ((++offset << sb->s_blocksize_bits) < elen) {
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
epos.offset -= sizeof(struct short_ad);
else if (iinfo->i_alloc_type ==
ICBTAG_FLAG_AD_LONG)
epos.offset -= sizeof(struct long_ad);
} else {
offset = 0;
}
if (!(fibh.sbh = fibh.ebh = udf_tread(sb, block))) {
ret = -EIO;
goto out;
}
if (!(offset & ((16 >> (sb->s_blocksize_bits - 9)) - 1))) {
i = 16 >> (sb->s_blocksize_bits - 9);
if (i + offset > (elen >> sb->s_blocksize_bits))
i = (elen >> sb->s_blocksize_bits) - offset;
for (num = 0; i > 0; i--) {
block = udf_get_lb_pblock(sb, &eloc, offset + i);
tmp = udf_tgetblk(sb, block);
if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
bha[num++] = tmp;
else
brelse(tmp);
}
if (num) {
ll_rw_block(REQ_OP_READ | REQ_RAHEAD, num, bha);
for (i = 0; i < num; i++)
brelse(bha[i]);
}
}
}
while (nf_pos < size) {
struct kernel_lb_addr tloc;
loff_t cur_pos = nf_pos;
/* Update file position only if we got past the current one */
if (nf_pos >= emit_pos) {
ctx->pos = (nf_pos >> 2) + 1;
pos_valid = true;
}
fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
&elen, &offset);
if (!fi)
goto out;
/* Still not at offset where user asked us to read from? */
if (cur_pos < emit_pos)
continue;
liu = le16_to_cpu(cfi.lengthOfImpUse);
lfi = cfi.lengthFileIdent;
if (fibh.sbh == fibh.ebh) {
nameptr = udf_get_fi_ident(fi);
} else {
int poffset; /* Unpaded ending offset */
poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
if (poffset >= lfi) {
nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
} else {
if (!copy_name) {
copy_name = kmalloc(UDF_NAME_LEN,
GFP_NOFS);
if (!copy_name) {
ret = -ENOMEM;
goto out;
}
}
nameptr = copy_name;
memcpy(nameptr, udf_get_fi_ident(fi),
lfi - poffset);
memcpy(nameptr + lfi - poffset,
fibh.ebh->b_data, poffset);
}
}
if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
continue;
}
if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
continue;
}
if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
if (!dir_emit_dotdot(file, ctx))
goto out;
continue;
}
flen = udf_get_filename(sb, nameptr, lfi, fname, UDF_NAME_LEN);
if (flen < 0)
continue;
tloc = lelb_to_cpu(cfi.icb.extLocation);
iblock = udf_get_lb_pblock(sb, &tloc, 0);
if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN))
goto out;
} /* end while */
ctx->pos = (nf_pos >> 2) + 1;
pos_valid = true;
out:
if (pos_valid)
file->f_version = inode_query_iversion(dir);
if (fibh.sbh != fibh.ebh)
brelse(fibh.ebh);
brelse(fibh.sbh);
brelse(epos.bh);
kfree(fname);
kfree(copy_name);
return ret;
}
/* readdir and lookup functions */
const struct file_operations udf_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = udf_readdir,
.unlocked_ioctl = udf_ioctl,
.fsync = generic_file_fsync,
};
|
