Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
[pandora-kernel.git] / fs / udf / directory.c
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/buffer_head.h>
20
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, block;
30         struct buffer_head *tmp, *bha[16];
31         struct udf_inode_info *iinfo = UDF_I(dir);
32
33         fibh->soffset = fibh->eoffset;
34
35         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
36                 fi = udf_get_fileident(iinfo->i_ext.i_data -
37                                        (iinfo->i_efe ?
38                                         sizeof(struct extendedFileEntry) :
39                                         sizeof(struct fileEntry)),
40                                        dir->i_sb->s_blocksize,
41                                        &(fibh->eoffset));
42                 if (!fi)
43                         return NULL;
44
45                 *nf_pos += fibh->eoffset - fibh->soffset;
46
47                 memcpy((uint8_t *)cfi, (uint8_t *)fi,
48                        sizeof(struct fileIdentDesc));
49
50                 return fi;
51         }
52
53         if (fibh->eoffset == dir->i_sb->s_blocksize) {
54                 int lextoffset = epos->offset;
55                 unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
56
57                 if (udf_next_aext(dir, epos, eloc, elen, 1) !=
58                     (EXT_RECORDED_ALLOCATED >> 30))
59                         return NULL;
60
61                 block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
62
63                 (*offset)++;
64
65                 if ((*offset << blocksize_bits) >= *elen)
66                         *offset = 0;
67                 else
68                         epos->offset = lextoffset;
69
70                 brelse(fibh->sbh);
71                 fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
72                 if (!fibh->sbh)
73                         return NULL;
74                 fibh->soffset = fibh->eoffset = 0;
75
76                 if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
77                         i = 16 >> (blocksize_bits - 9);
78                         if (i + *offset > (*elen >> blocksize_bits))
79                                 i = (*elen >> blocksize_bits)-*offset;
80                         for (num = 0; i > 0; i--) {
81                                 block = udf_get_lb_pblock(dir->i_sb, eloc,
82                                                           *offset + i);
83                                 tmp = udf_tgetblk(dir->i_sb, block);
84                                 if (tmp && !buffer_uptodate(tmp) &&
85                                                 !buffer_locked(tmp))
86                                         bha[num++] = tmp;
87                                 else
88                                         brelse(tmp);
89                         }
90                         if (num) {
91                                 ll_rw_block(READA, num, bha);
92                                 for (i = 0; i < num; i++)
93                                         brelse(bha[i]);
94                         }
95                 }
96         } else if (fibh->sbh != fibh->ebh) {
97                 brelse(fibh->sbh);
98                 fibh->sbh = fibh->ebh;
99         }
100
101         fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
102                                &(fibh->eoffset));
103
104         if (!fi)
105                 return NULL;
106
107         *nf_pos += fibh->eoffset - fibh->soffset;
108
109         if (fibh->eoffset <= dir->i_sb->s_blocksize) {
110                 memcpy((uint8_t *)cfi, (uint8_t *)fi,
111                        sizeof(struct fileIdentDesc));
112         } else if (fibh->eoffset > dir->i_sb->s_blocksize) {
113                 int lextoffset = epos->offset;
114
115                 if (udf_next_aext(dir, epos, eloc, elen, 1) !=
116                     (EXT_RECORDED_ALLOCATED >> 30))
117                         return NULL;
118
119                 block = udf_get_lb_pblock(dir->i_sb, eloc, *offset);
120
121                 (*offset)++;
122
123                 if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
124                         *offset = 0;
125                 else
126                         epos->offset = lextoffset;
127
128                 fibh->soffset -= dir->i_sb->s_blocksize;
129                 fibh->eoffset -= dir->i_sb->s_blocksize;
130
131                 fibh->ebh = udf_tread(dir->i_sb, block);
132                 if (!fibh->ebh)
133                         return NULL;
134
135                 if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
136                         int fi_len;
137
138                         memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
139                         memcpy((uint8_t *)cfi - fibh->soffset,
140                                fibh->ebh->b_data,
141                                sizeof(struct fileIdentDesc) + fibh->soffset);
142
143                         fi_len = (sizeof(struct fileIdentDesc) +
144                                   cfi->lengthFileIdent +
145                                   le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;
146
147                         *nf_pos += fi_len - (fibh->eoffset - fibh->soffset);
148                         fibh->eoffset = fibh->soffset + fi_len;
149                 } else {
150                         memcpy((uint8_t *)cfi, (uint8_t *)fi,
151                                sizeof(struct fileIdentDesc));
152                 }
153         }
154         return fi;
155 }
156
157 struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
158 {
159         struct fileIdentDesc *fi;
160         int lengthThisIdent;
161         uint8_t *ptr;
162         int padlen;
163
164         if ((!buffer) || (!offset)) {
165                 udf_debug("invalidparms, buffer=%p, offset=%p\n",
166                           buffer, offset);
167                 return NULL;
168         }
169
170         ptr = buffer;
171
172         if ((*offset > 0) && (*offset < bufsize))
173                 ptr += *offset;
174         fi = (struct fileIdentDesc *)ptr;
175         if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
176                 udf_debug("0x%x != TAG_IDENT_FID\n",
177                           le16_to_cpu(fi->descTag.tagIdent));
178                 udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
179                           *offset, (unsigned long)sizeof(struct fileIdentDesc),
180                           bufsize);
181                 return NULL;
182         }
183         if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
184                 lengthThisIdent = sizeof(struct fileIdentDesc);
185         else
186                 lengthThisIdent = sizeof(struct fileIdentDesc) +
187                         fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
188
189         /* we need to figure padding, too! */
190         padlen = lengthThisIdent % UDF_NAME_PAD;
191         if (padlen)
192                 lengthThisIdent += (UDF_NAME_PAD - padlen);
193         *offset = *offset + lengthThisIdent;
194
195         return fi;
196 }
197
198 struct short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
199                               int inc)
200 {
201         struct short_ad *sa;
202
203         if ((!ptr) || (!offset)) {
204                 pr_err("%s: invalidparms\n", __func__);
205                 return NULL;
206         }
207
208         if ((*offset + sizeof(struct short_ad)) > maxoffset)
209                 return NULL;
210         else {
211                 sa = (struct short_ad *)ptr;
212                 if (sa->extLength == 0)
213                         return NULL;
214         }
215
216         if (inc)
217                 *offset += sizeof(struct short_ad);
218         return sa;
219 }
220
221 struct long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
222 {
223         struct long_ad *la;
224
225         if ((!ptr) || (!offset)) {
226                 pr_err("%s: invalidparms\n", __func__);
227                 return NULL;
228         }
229
230         if ((*offset + sizeof(struct long_ad)) > maxoffset)
231                 return NULL;
232         else {
233                 la = (struct long_ad *)ptr;
234                 if (la->extLength == 0)
235                         return NULL;
236         }
237
238         if (inc)
239                 *offset += sizeof(struct long_ad);
240         return la;
241 }