xref: /openbmc/linux/fs/udf/directory.c (revision c21b37f6)
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 		if (!(*bh = udf_tread(dir->i_sb, block)))
49 			return NULL;
50 	} else if (*offset > dir->i_sb->s_blocksize) {
51 		ad = tmpad;
52 
53 		remainder = dir->i_sb->s_blocksize - loffset;
54 		memcpy((uint8_t *)ad, (*bh)->b_data + loffset, remainder);
55 
56 		brelse(*bh);
57 		block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
58 		if (!block)
59 			return NULL;
60 		if (!((*bh) = udf_tread(dir->i_sb, block)))
61 			return NULL;
62 
63 		memcpy((uint8_t *)ad + remainder, (*bh)->b_data, ad_size - remainder);
64 		*offset = ad_size - remainder;
65 	}
66 
67 	return ad;
68 }
69 #endif
70 
71 struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t * nf_pos,
72 					 struct udf_fileident_bh *fibh,
73 					 struct fileIdentDesc *cfi,
74 					 struct extent_position *epos,
75 					 kernel_lb_addr * eloc, uint32_t * elen,
76 					 sector_t * offset)
77 {
78 	struct fileIdentDesc *fi;
79 	int i, num, block;
80 	struct buffer_head *tmp, *bha[16];
81 
82 	fibh->soffset = fibh->eoffset;
83 
84 	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
85 		fi = udf_get_fileident(UDF_I_DATA(dir) -
86 				       (UDF_I_EFE(dir) ?
87 					sizeof(struct extendedFileEntry) :
88 					sizeof(struct fileEntry)),
89 				       dir->i_sb->s_blocksize, &(fibh->eoffset));
90 		if (!fi)
91 			return NULL;
92 
93 		*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
94 
95 		memcpy((uint8_t *)cfi, (uint8_t *)fi,
96 		       sizeof(struct fileIdentDesc));
97 
98 		return fi;
99 	}
100 
101 	if (fibh->eoffset == dir->i_sb->s_blocksize) {
102 		int lextoffset = epos->offset;
103 
104 		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
105 		    (EXT_RECORDED_ALLOCATED >> 30))
106 			return NULL;
107 
108 		block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);
109 
110 		(*offset)++;
111 
112 		if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
113 			*offset = 0;
114 		else
115 			epos->offset = lextoffset;
116 
117 		brelse(fibh->sbh);
118 		if (!(fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block)))
119 			return NULL;
120 		fibh->soffset = fibh->eoffset = 0;
121 
122 		if (!(*offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
123 			i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
124 			if (i + *offset > (*elen >> dir->i_sb->s_blocksize_bits))
125 				i = (*elen >> dir->i_sb->s_blocksize_bits)-*offset;
126 			for (num = 0; i > 0; i--) {
127 				block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset + i);
128 				tmp = udf_tgetblk(dir->i_sb, block);
129 				if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
130 					bha[num++] = tmp;
131 				else
132 					brelse(tmp);
133 			}
134 			if (num) {
135 				ll_rw_block(READA, num, bha);
136 				for (i = 0; i < num; i++)
137 					brelse(bha[i]);
138 			}
139 		}
140 	} else if (fibh->sbh != fibh->ebh) {
141 		brelse(fibh->sbh);
142 		fibh->sbh = fibh->ebh;
143 	}
144 
145 	fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
146 			       &(fibh->eoffset));
147 
148 	if (!fi)
149 		return NULL;
150 
151 	*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
152 
153 	if (fibh->eoffset <= dir->i_sb->s_blocksize) {
154 		memcpy((uint8_t *)cfi, (uint8_t *)fi,
155 		       sizeof(struct fileIdentDesc));
156 	} else if (fibh->eoffset > dir->i_sb->s_blocksize) {
157 		int lextoffset = epos->offset;
158 
159 		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
160 		    (EXT_RECORDED_ALLOCATED >> 30))
161 			return NULL;
162 
163 		block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);
164 
165 		(*offset)++;
166 
167 		if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
168 			*offset = 0;
169 		else
170 			epos->offset = lextoffset;
171 
172 		fibh->soffset -= dir->i_sb->s_blocksize;
173 		fibh->eoffset -= dir->i_sb->s_blocksize;
174 
175 		if (!(fibh->ebh = udf_tread(dir->i_sb, block)))
176 			return NULL;
177 
178 		if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
179 			int fi_len;
180 
181 			memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
182 			memcpy((uint8_t *)cfi - fibh->soffset, fibh->ebh->b_data,
183 			       sizeof(struct fileIdentDesc) + fibh->soffset);
184 
185 			fi_len = (sizeof(struct fileIdentDesc) + cfi->lengthFileIdent +
186 				  le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;
187 
188 			*nf_pos += ((fi_len - (fibh->eoffset - fibh->soffset)) >> 2);
189 			fibh->eoffset = fibh->soffset + fi_len;
190 		} else {
191 			memcpy((uint8_t *)cfi, (uint8_t *)fi,
192 			       sizeof(struct fileIdentDesc));
193 		}
194 	}
195 	return fi;
196 }
197 
198 struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
199 {
200 	struct fileIdentDesc *fi;
201 	int lengthThisIdent;
202 	uint8_t *ptr;
203 	int padlen;
204 
205 	if ((!buffer) || (!offset)) {
206 		udf_debug("invalidparms\n, buffer=%p, offset=%p\n", buffer,
207 			  offset);
208 		return NULL;
209 	}
210 
211 	ptr = buffer;
212 
213 	if ((*offset > 0) && (*offset < bufsize)) {
214 		ptr += *offset;
215 	}
216 	fi = (struct fileIdentDesc *)ptr;
217 	if (le16_to_cpu(fi->descTag.tagIdent) != TAG_IDENT_FID) {
218 		udf_debug("0x%x != TAG_IDENT_FID\n",
219 			  le16_to_cpu(fi->descTag.tagIdent));
220 		udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
221 			  *offset, (unsigned long)sizeof(struct fileIdentDesc),
222 			  bufsize);
223 		return NULL;
224 	}
225 	if ((*offset + sizeof(struct fileIdentDesc)) > bufsize) {
226 		lengthThisIdent = sizeof(struct fileIdentDesc);
227 	} else {
228 		lengthThisIdent = sizeof(struct fileIdentDesc) +
229 			fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
230 	}
231 
232 	/* we need to figure padding, too! */
233 	padlen = lengthThisIdent % UDF_NAME_PAD;
234 	if (padlen)
235 		lengthThisIdent += (UDF_NAME_PAD - padlen);
236 	*offset = *offset + lengthThisIdent;
237 
238 	return fi;
239 }
240 
241 #if 0
242 static extent_ad *udf_get_fileextent(void *buffer, int bufsize, int *offset)
243 {
244 	extent_ad *ext;
245 	struct fileEntry *fe;
246 	uint8_t *ptr;
247 
248 	if ((!buffer) || (!offset)) {
249 		printk(KERN_ERR "udf: udf_get_fileextent() invalidparms\n");
250 		return NULL;
251 	}
252 
253 	fe = (struct fileEntry *)buffer;
254 
255 	if (le16_to_cpu(fe->descTag.tagIdent) != TAG_IDENT_FE) {
256 		udf_debug("0x%x != TAG_IDENT_FE\n",
257 			  le16_to_cpu(fe->descTag.tagIdent));
258 		return NULL;
259 	}
260 
261 	ptr = (uint8_t *)(fe->extendedAttr) + le32_to_cpu(fe->lengthExtendedAttr);
262 
263 	if ((*offset > 0) && (*offset < le32_to_cpu(fe->lengthAllocDescs))) {
264 		ptr += *offset;
265 	}
266 
267 	ext = (extent_ad *)ptr;
268 
269 	*offset = *offset + sizeof(extent_ad);
270 	return ext;
271 }
272 #endif
273 
274 short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, int *offset,
275 			      int inc)
276 {
277 	short_ad *sa;
278 
279 	if ((!ptr) || (!offset)) {
280 		printk(KERN_ERR "udf: udf_get_fileshortad() invalidparms\n");
281 		return NULL;
282 	}
283 
284 	if ((*offset < 0) || ((*offset + sizeof(short_ad)) > maxoffset))
285 		return NULL;
286 	else if ((sa = (short_ad *)ptr)->extLength == 0)
287 		return NULL;
288 
289 	if (inc)
290 		*offset += sizeof(short_ad);
291 	return sa;
292 }
293 
294 long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, int *offset, int inc)
295 {
296 	long_ad *la;
297 
298 	if ((!ptr) || (!offset)) {
299 		printk(KERN_ERR "udf: udf_get_filelongad() invalidparms\n");
300 		return NULL;
301 	}
302 
303 	if ((*offset < 0) || ((*offset + sizeof(long_ad)) > maxoffset))
304 		return NULL;
305 	else if ((la = (long_ad *)ptr)->extLength == 0)
306 		return NULL;
307 
308 	if (inc)
309 		*offset += sizeof(long_ad);
310 	return la;
311 }
312