1 /*
2 * directory.c
3 *
4 * PURPOSE
5 * Directory related functions
6 *
7 * COPYRIGHT
8 * This file is distributed under the terms of the GNU General Public
9 * License (GPL). Copies of the GPL can be obtained from:
10 * ftp://prep.ai.mit.edu/pub/gnu/GPL
11 * Each contributing author retains all rights to their own work.
12 */
13
14 #include "udfdecl.h"
15 #include "udf_i.h"
16
17 #include <linux/fs.h>
18 #include <linux/string.h>
19 #include <linux/bio.h>
20
udf_fileident_read(struct inode * dir,loff_t * nf_pos,struct udf_fileident_bh * fibh,struct fileIdentDesc * cfi,struct extent_position * epos,struct kernel_lb_addr * eloc,uint32_t * elen,sector_t * offset)21 struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
22 struct udf_fileident_bh *fibh,
23 struct fileIdentDesc *cfi,
24 struct extent_position *epos,
25 struct kernel_lb_addr *eloc, uint32_t *elen,
26 sector_t *offset)
27 {
28 struct fileIdentDesc *fi;
29 int i, num;
30 udf_pblk_t block;
31 struct buffer_head *tmp, *bha[16];
32 struct udf_inode_info *iinfo = UDF_I(dir);
33
34 fibh->soffset = fibh->eoffset;
35
36 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
37 fi = udf_get_fileident(iinfo->i_ext.i_data -
38 (iinfo->i_efe ?
39 sizeof(struct extendedFileEntry) :
40 sizeof(struct fileEntry)),
41 dir->i_sb->s_blocksize,
42 &(fibh->eoffset));
43 if (!fi)
44 return NULL;
45
46 *nf_pos += fibh->eoffset - fibh->soffset;
47
48 memcpy((uint8_t *)cfi, (uint8_t *)fi,
49 sizeof(struct fileIdentDesc));
50
51 return fi;
52 }
53
54 if (fibh->eoffset == dir->i_sb->s_blocksize) {
55 uint32_t lextoffset = epos->offset;
56 unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
57
58 if (udf_next_aext(dir, epos, eloc, elen, 1) !=
59 (EXT_RECORDED_ALLOCATED >> 30))
60 return NULL;
61
62 block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
63
64 (*offset)++;
65
66 if ((*offset << blocksize_bits) >= *elen)
67 *offset = 0;
68 else
69 epos->offset = lextoffset;
70
71 brelse(fibh->sbh);
72 fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
73 if (!fibh->sbh)
74 return NULL;
75 fibh->soffset = fibh->eoffset = 0;
76
77 if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
78 i = 16 >> (blocksize_bits - 9);
79 if (i + *offset > (*elen >> blocksize_bits))
80 i = (*elen >> blocksize_bits)-*offset;
81 for (num = 0; i > 0; i--) {
82 block = udf_get_lb_pblock(dir->i_sb, eloc,
83 *offset + i);
84 tmp = udf_tgetblk(dir->i_sb, block);
85 if (tmp && !buffer_uptodate(tmp) &&
86 !buffer_locked(tmp))
87 bha[num++] = tmp;
88 else
89 brelse(tmp);
90 }
91 if (num) {
92 ll_rw_block(REQ_OP_READ, REQ_RAHEAD, num, bha);
93 for (i = 0; i < num; i++)
94 brelse(bha[i]);
95 }
96 }
97 } else if (fibh->sbh != fibh->ebh) {
98 brelse(fibh->sbh);
99 fibh->sbh = fibh->ebh;
100 }
101
102 fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
103 &(fibh->eoffset));
104
105 if (!fi)
106 return NULL;
107
108 *nf_pos += fibh->eoffset - fibh->soffset;
109
110 if (fibh->eoffset <= dir->i_sb->s_blocksize) {
111 memcpy((uint8_t *)cfi, (uint8_t *)fi,
112 sizeof(struct fileIdentDesc));
113 } else if (fibh->eoffset > dir->i_sb->s_blocksize) {
114 uint32_t lextoffset = epos->offset;
115
116 if (udf_next_aext(dir, epos, eloc, elen, 1) !=
117 (EXT_RECORDED_ALLOCATED >> 30))
118 return NULL;
119
120 block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
121
122 (*offset)++;
123
124 if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
125 *offset = 0;
126 else
127 epos->offset = lextoffset;
128
129 fibh->soffset -= dir->i_sb->s_blocksize;
130 fibh->eoffset -= dir->i_sb->s_blocksize;
131
132 fibh->ebh = udf_tread(dir->i_sb, block);
133 if (!fibh->ebh)
134 return NULL;
135
136 if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
137 int fi_len;
138
139 memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
140 memcpy((uint8_t *)cfi - fibh->soffset,
141 fibh->ebh->b_data,
142 sizeof(struct fileIdentDesc) + fibh->soffset);
143
144 fi_len = udf_dir_entry_len(cfi);
145 *nf_pos += fi_len - (fibh->eoffset - fibh->soffset);
146 fibh->eoffset = fibh->soffset + fi_len;
147 } else {
148 memcpy((uint8_t *)cfi, (uint8_t *)fi,
149 sizeof(struct fileIdentDesc));
150 }
151 }
152 /* Got last entry outside of dir size - fs is corrupted! */
153 if (*nf_pos > dir->i_size)
154 return NULL;
155 return fi;
156 }
157
udf_get_fileident(void * buffer,int bufsize,int * offset)158 struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
159 {
160 struct fileIdentDesc *fi;
161 int lengthThisIdent;
162 uint8_t *ptr;
163 int padlen;
164
165 if ((!buffer) || (!offset)) {
166 udf_debug("invalidparms, buffer=%p, offset=%p\n",
167 buffer, offset);
168 return NULL;
169 }
170
171 ptr = buffer;
172
173 if ((*offset > 0) && (*offset < bufsize))
174 ptr += *offset;
175 fi = (struct fileIdentDesc *)ptr;
176 if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
177 udf_debug("0x%x != TAG_IDENT_FID\n",
178 le16_to_cpu(fi->descTag.tagIdent));
179 udf_debug("offset: %d sizeof: %lu bufsize: %d\n",
180 *offset, (unsigned long)sizeof(struct fileIdentDesc),
181 bufsize);
182 return NULL;
183 }
184 if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
185 lengthThisIdent = sizeof(struct fileIdentDesc);
186 else
187 lengthThisIdent = sizeof(struct fileIdentDesc) +
188 fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
189
190 /* we need to figure padding, too! */
191 padlen = lengthThisIdent % UDF_NAME_PAD;
192 if (padlen)
193 lengthThisIdent += (UDF_NAME_PAD - padlen);
194 *offset = *offset + lengthThisIdent;
195
196 return fi;
197 }
198
udf_get_fileshortad(uint8_t * ptr,int maxoffset,uint32_t * offset,int inc)199 struct short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
200 int inc)
201 {
202 struct short_ad *sa;
203
204 if ((!ptr) || (!offset)) {
205 pr_err("%s: invalidparms\n", __func__);
206 return NULL;
207 }
208
209 if ((*offset + sizeof(struct short_ad)) > maxoffset)
210 return NULL;
211 else {
212 sa = (struct short_ad *)ptr;
213 if (sa->extLength == 0)
214 return NULL;
215 }
216
217 if (inc)
218 *offset += sizeof(struct short_ad);
219 return sa;
220 }
221
udf_get_filelongad(uint8_t * ptr,int maxoffset,uint32_t * offset,int inc)222 struct long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
223 {
224 struct long_ad *la;
225
226 if ((!ptr) || (!offset)) {
227 pr_err("%s: invalidparms\n", __func__);
228 return NULL;
229 }
230
231 if ((*offset + sizeof(struct long_ad)) > maxoffset)
232 return NULL;
233 else {
234 la = (struct long_ad *)ptr;
235 if (la->extLength == 0)
236 return NULL;
237 }
238
239 if (inc)
240 *offset += sizeof(struct long_ad);
241 return la;
242 }
243