xref: /openbmc/linux/fs/udf/directory.c (revision 1ed161718a8f763130e6e349f2bbb1b764e6c5b3)
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 #if 0
22 static uint8_t *udf_filead_read(struct inode *dir, uint8_t *tmpad,
23 				uint8_t ad_size, kernel_lb_addr fe_loc,
24 				int *pos, int *offset, struct buffer_head **bh,
25 				int *error)
26 {
27 	int loffset = *offset;
28 	int block;
29 	uint8_t *ad;
30 	int remainder;
31 
32 	*error = 0;
33 
34 	ad = (uint8_t *)(*bh)->b_data + *offset;
35 	*offset += ad_size;
36 
37 	if (!ad) {
38 		brelse(*bh);
39 		*error = 1;
40 		return NULL;
41 	}
42 
43 	if (*offset == dir->i_sb->s_blocksize) {
44 		brelse(*bh);
45 		block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
46 		if (!block)
47 			return NULL;
48 		*bh = udf_tread(dir->i_sb, block);
49 		if (!*bh)
50 			return NULL;
51 	} else if (*offset > dir->i_sb->s_blocksize) {
52 		ad = tmpad;
53 
54 		remainder = dir->i_sb->s_blocksize - loffset;
55 		memcpy((uint8_t *)ad, (*bh)->b_data + loffset, remainder);
56 
57 		brelse(*bh);
58 		block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
59 		if (!block)
60 			return NULL;
61 		(*bh) = udf_tread(dir->i_sb, block);
62 		if (!*bh)
63 			return NULL;
64 
65 		memcpy((uint8_t *)ad + remainder, (*bh)->b_data,
66 			ad_size - remainder);
67 		*offset = ad_size - remainder;
68 	}
69 
70 	return ad;
71 }
72 #endif
73 
74 struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
75 					 struct udf_fileident_bh *fibh,
76 					 struct fileIdentDesc *cfi,
77 					 struct extent_position *epos,
78 					 kernel_lb_addr *eloc, uint32_t *elen,
79 					 sector_t *offset)
80 {
81 	struct fileIdentDesc *fi;
82 	int i, num, block;
83 	struct buffer_head *tmp, *bha[16];
84 	struct udf_inode_info *iinfo = UDF_I(dir);
85 
86 	fibh->soffset = fibh->eoffset;
87 
88 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
89 		fi = udf_get_fileident(iinfo->i_ext.i_data -
90 				       (iinfo->i_efe ?
91 					sizeof(struct extendedFileEntry) :
92 					sizeof(struct fileEntry)),
93 				       dir->i_sb->s_blocksize,
94 				       &(fibh->eoffset));
95 		if (!fi)
96 			return NULL;
97 
98 		*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
99 
100 		memcpy((uint8_t *)cfi, (uint8_t *)fi,
101 		       sizeof(struct fileIdentDesc));
102 
103 		return fi;
104 	}
105 
106 	if (fibh->eoffset == dir->i_sb->s_blocksize) {
107 		int lextoffset = epos->offset;
108 		unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
109 
110 		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
111 		    (EXT_RECORDED_ALLOCATED >> 30))
112 			return NULL;
113 
114 		block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);
115 
116 		(*offset)++;
117 
118 		if ((*offset << blocksize_bits) >= *elen)
119 			*offset = 0;
120 		else
121 			epos->offset = lextoffset;
122 
123 		brelse(fibh->sbh);
124 		fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
125 		if (!fibh->sbh)
126 			return NULL;
127 		fibh->soffset = fibh->eoffset = 0;
128 
129 		if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
130 			i = 16 >> (blocksize_bits - 9);
131 			if (i + *offset > (*elen >> blocksize_bits))
132 				i = (*elen >> blocksize_bits)-*offset;
133 			for (num = 0; i > 0; i--) {
134 				block = udf_get_lb_pblock(dir->i_sb, *eloc,
135 							  *offset + i);
136 				tmp = udf_tgetblk(dir->i_sb, block);
137 				if (tmp && !buffer_uptodate(tmp) &&
138 						!buffer_locked(tmp))
139 					bha[num++] = tmp;
140 				else
141 					brelse(tmp);
142 			}
143 			if (num) {
144 				ll_rw_block(READA, num, bha);
145 				for (i = 0; i < num; i++)
146 					brelse(bha[i]);
147 			}
148 		}
149 	} else if (fibh->sbh != fibh->ebh) {
150 		brelse(fibh->sbh);
151 		fibh->sbh = fibh->ebh;
152 	}
153 
154 	fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
155 			       &(fibh->eoffset));
156 
157 	if (!fi)
158 		return NULL;
159 
160 	*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
161 
162 	if (fibh->eoffset <= dir->i_sb->s_blocksize) {
163 		memcpy((uint8_t *)cfi, (uint8_t *)fi,
164 		       sizeof(struct fileIdentDesc));
165 	} else if (fibh->eoffset > dir->i_sb->s_blocksize) {
166 		int lextoffset = epos->offset;
167 
168 		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
169 		    (EXT_RECORDED_ALLOCATED >> 30))
170 			return NULL;
171 
172 		block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);
173 
174 		(*offset)++;
175 
176 		if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
177 			*offset = 0;
178 		else
179 			epos->offset = lextoffset;
180 
181 		fibh->soffset -= dir->i_sb->s_blocksize;
182 		fibh->eoffset -= dir->i_sb->s_blocksize;
183 
184 		fibh->ebh = udf_tread(dir->i_sb, block);
185 		if (!fibh->ebh)
186 			return NULL;
187 
188 		if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
189 			int fi_len;
190 
191 			memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
192 			memcpy((uint8_t *)cfi - fibh->soffset,
193 			       fibh->ebh->b_data,
194 			       sizeof(struct fileIdentDesc) + fibh->soffset);
195 
196 			fi_len = (sizeof(struct fileIdentDesc) +
197 				  cfi->lengthFileIdent +
198 				  le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;
199 
200 			*nf_pos += (fi_len - (fibh->eoffset - fibh->soffset))
201 					>> 2;
202 			fibh->eoffset = fibh->soffset + fi_len;
203 		} else {
204 			memcpy((uint8_t *)cfi, (uint8_t *)fi,
205 			       sizeof(struct fileIdentDesc));
206 		}
207 	}
208 	return fi;
209 }
210 
211 struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
212 {
213 	struct fileIdentDesc *fi;
214 	int lengthThisIdent;
215 	uint8_t *ptr;
216 	int padlen;
217 
218 	if ((!buffer) || (!offset)) {
219 		udf_debug("invalidparms\n, buffer=%p, offset=%p\n", buffer,
220 			  offset);
221 		return NULL;
222 	}
223 
224 	ptr = buffer;
225 
226 	if ((*offset > 0) && (*offset < bufsize))
227 		ptr += *offset;
228 	fi = (struct fileIdentDesc *)ptr;
229 	if (fi->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FID)) {
230 		udf_debug("0x%x != TAG_IDENT_FID\n",
231 			  le16_to_cpu(fi->descTag.tagIdent));
232 		udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
233 			  *offset, (unsigned long)sizeof(struct fileIdentDesc),
234 			  bufsize);
235 		return NULL;
236 	}
237 	if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
238 		lengthThisIdent = sizeof(struct fileIdentDesc);
239 	else
240 		lengthThisIdent = sizeof(struct fileIdentDesc) +
241 			fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
242 
243 	/* we need to figure padding, too! */
244 	padlen = lengthThisIdent % UDF_NAME_PAD;
245 	if (padlen)
246 		lengthThisIdent += (UDF_NAME_PAD - padlen);
247 	*offset = *offset + lengthThisIdent;
248 
249 	return fi;
250 }
251 
252 #if 0
253 static extent_ad *udf_get_fileextent(void *buffer, int bufsize, int *offset)
254 {
255 	extent_ad *ext;
256 	struct fileEntry *fe;
257 	uint8_t *ptr;
258 
259 	if ((!buffer) || (!offset)) {
260 		printk(KERN_ERR "udf: udf_get_fileextent() invalidparms\n");
261 		return NULL;
262 	}
263 
264 	fe = (struct fileEntry *)buffer;
265 
266 	if (fe->descTag.tagIdent != cpu_to_le16(TAG_IDENT_FE)) {
267 		udf_debug("0x%x != TAG_IDENT_FE\n",
268 			  le16_to_cpu(fe->descTag.tagIdent));
269 		return NULL;
270 	}
271 
272 	ptr = (uint8_t *)(fe->extendedAttr) +
273 		le32_to_cpu(fe->lengthExtendedAttr);
274 
275 	if ((*offset > 0) && (*offset < le32_to_cpu(fe->lengthAllocDescs)))
276 		ptr += *offset;
277 
278 	ext = (extent_ad *)ptr;
279 
280 	*offset = *offset + sizeof(extent_ad);
281 	return ext;
282 }
283 #endif
284 
285 short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, uint32_t *offset,
286 			      int inc)
287 {
288 	short_ad *sa;
289 
290 	if ((!ptr) || (!offset)) {
291 		printk(KERN_ERR "udf: udf_get_fileshortad() invalidparms\n");
292 		return NULL;
293 	}
294 
295 	if ((*offset + sizeof(short_ad)) > maxoffset)
296 		return NULL;
297 	else {
298 		sa = (short_ad *)ptr;
299 		if (sa->extLength == 0)
300 			return NULL;
301 	}
302 
303 	if (inc)
304 		*offset += sizeof(short_ad);
305 	return sa;
306 }
307 
308 long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, uint32_t *offset, int inc)
309 {
310 	long_ad *la;
311 
312 	if ((!ptr) || (!offset)) {
313 		printk(KERN_ERR "udf: udf_get_filelongad() invalidparms\n");
314 		return NULL;
315 	}
316 
317 	if ((*offset + sizeof(long_ad)) > maxoffset)
318 		return NULL;
319 	else {
320 		la = (long_ad *)ptr;
321 		if (la->extLength == 0)
322 			return NULL;
323 	}
324 
325 	if (inc)
326 		*offset += sizeof(long_ad);
327 	return la;
328 }
329