Merge remote-tracking branch 'lsk/v3.10/topic/of' into linux-linaro-lsk
[firefly-linux-kernel-4.4.55.git] / fs / hpfs / map.c
1 /*
2  *  linux/fs/hpfs/map.c
3  *
4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5  *
6  *  mapping structures to memory with some minimal checks
7  */
8
9 #include "hpfs_fn.h"
10
11 __le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh)
12 {
13         return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);
14 }
15
16 __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,
17                          struct quad_buffer_head *qbh, char *id)
18 {
19         secno sec;
20         unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;
21         if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {
22                 hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);
23                 return NULL;
24         }
25         sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);
26         if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) {
27                 hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);
28                 return NULL;
29         }
30         return hpfs_map_4sectors(s, sec, qbh, 4);
31 }
32
33 /*
34  * Load first code page into kernel memory, return pointer to 256-byte array,
35  * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are
36  * lowercasing table
37  */
38
39 unsigned char *hpfs_load_code_page(struct super_block *s, secno cps)
40 {
41         struct buffer_head *bh;
42         secno cpds;
43         unsigned cpi;
44         unsigned char *ptr;
45         unsigned char *cp_table;
46         int i;
47         struct code_page_data *cpd;
48         struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);
49         if (!cp) return NULL;
50         if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) {
51                 printk("HPFS: Code page directory magic doesn't match (magic = %08x)\n", le32_to_cpu(cp->magic));
52                 brelse(bh);
53                 return NULL;
54         }
55         if (!le32_to_cpu(cp->n_code_pages)) {
56                 printk("HPFS: n_code_pages == 0\n");
57                 brelse(bh);
58                 return NULL;
59         }
60         cpds = le32_to_cpu(cp->array[0].code_page_data);
61         cpi = le16_to_cpu(cp->array[0].index);
62         brelse(bh);
63
64         if (cpi >= 3) {
65                 printk("HPFS: Code page index out of array\n");
66                 return NULL;
67         }
68         
69         if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;
70         if (le16_to_cpu(cpd->offs[cpi]) > 0x178) {
71                 printk("HPFS: Code page index out of sector\n");
72                 brelse(bh);
73                 return NULL;
74         }
75         ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6;
76         if (!(cp_table = kmalloc(256, GFP_KERNEL))) {
77                 printk("HPFS: out of memory for code page table\n");
78                 brelse(bh);
79                 return NULL;
80         }
81         memcpy(cp_table, ptr, 128);
82         brelse(bh);
83
84         /* Try to build lowercasing table from uppercasing one */
85
86         for (i=128; i<256; i++) cp_table[i]=i;
87         for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)
88                 cp_table[cp_table[i-128]] = i;
89         
90         return cp_table;
91 }
92
93 __le32 *hpfs_load_bitmap_directory(struct super_block *s, secno bmp)
94 {
95         struct buffer_head *bh;
96         int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;
97         int i;
98         __le32 *b;
99         if (!(b = kmalloc(n * 512, GFP_KERNEL))) {
100                 printk("HPFS: can't allocate memory for bitmap directory\n");
101                 return NULL;
102         }       
103         for (i=0;i<n;i++) {
104                 __le32 *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);
105                 if (!d) {
106                         kfree(b);
107                         return NULL;
108                 }
109                 memcpy((char *)b + 512 * i, d, 512);
110                 brelse(bh);
111         }
112         return b;
113 }
114
115 /*
116  * Load fnode to memory
117  */
118
119 struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp)
120 {
121         struct fnode *fnode;
122         if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {
123                 return NULL;
124         }
125         if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {
126                 if (hpfs_sb(s)->sb_chk) {
127                         struct extended_attribute *ea;
128                         struct extended_attribute *ea_end;
129                         if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) {
130                                 hpfs_error(s, "bad magic on fnode %08lx",
131                                         (unsigned long)ino);
132                                 goto bail;
133                         }
134                         if (!fnode_is_dir(fnode)) {
135                                 if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
136                                     (bp_internal(&fnode->btree) ? 12 : 8)) {
137                                         hpfs_error(s,
138                                            "bad number of nodes in fnode %08lx",
139                                             (unsigned long)ino);
140                                         goto bail;
141                                 }
142                                 if (le16_to_cpu(fnode->btree.first_free) !=
143                                     8 + fnode->btree.n_used_nodes * (bp_internal(&fnode->btree) ? 8 : 12)) {
144                                         hpfs_error(s,
145                                             "bad first_free pointer in fnode %08lx",
146                                             (unsigned long)ino);
147                                         goto bail;
148                                 }
149                         }
150                         if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 ||
151                            le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) {
152                                 hpfs_error(s,
153                                         "bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",
154                                         (unsigned long)ino,
155                                         le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));
156                                 goto bail;
157                         }
158                         ea = fnode_ea(fnode);
159                         ea_end = fnode_end_ea(fnode);
160                         while (ea != ea_end) {
161                                 if (ea > ea_end) {
162                                         hpfs_error(s, "bad EA in fnode %08lx",
163                                                 (unsigned long)ino);
164                                         goto bail;
165                                 }
166                                 ea = next_ea(ea);
167                         }
168                 }
169         }
170         return fnode;
171         bail:
172         brelse(*bhp);
173         return NULL;
174 }
175
176 struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp)
177 {
178         struct anode *anode;
179         if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;
180         if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))
181                 if (hpfs_sb(s)->sb_chk) {
182                         if (le32_to_cpu(anode->magic) != ANODE_MAGIC) {
183                                 hpfs_error(s, "bad magic on anode %08x", ano);
184                                 goto bail;
185                         }
186                         if (le32_to_cpu(anode->self) != ano) {
187                                 hpfs_error(s, "self pointer invalid on anode %08x", ano);
188                                 goto bail;
189                         }
190                         if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
191                             (bp_internal(&anode->btree) ? 60 : 40)) {
192                                 hpfs_error(s, "bad number of nodes in anode %08x", ano);
193                                 goto bail;
194                         }
195                         if (le16_to_cpu(anode->btree.first_free) !=
196                             8 + anode->btree.n_used_nodes * (bp_internal(&anode->btree) ? 8 : 12)) {
197                                 hpfs_error(s, "bad first_free pointer in anode %08x", ano);
198                                 goto bail;
199                         }
200                 }
201         return anode;
202         bail:
203         brelse(*bhp);
204         return NULL;
205 }
206
207 /*
208  * Load dnode to memory and do some checks
209  */
210
211 struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno,
212                              struct quad_buffer_head *qbh)
213 {
214         struct dnode *dnode;
215         if (hpfs_sb(s)->sb_chk) {
216                 if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;
217                 if (secno & 3) {
218                         hpfs_error(s, "dnode %08x not byte-aligned", secno);
219                         return NULL;
220                 }       
221         }
222         if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))
223                 if (hpfs_sb(s)->sb_chk) {
224                         unsigned p, pp = 0;
225                         unsigned char *d = (unsigned char *)dnode;
226                         int b = 0;
227                         if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) {
228                                 hpfs_error(s, "bad magic on dnode %08x", secno);
229                                 goto bail;
230                         }
231                         if (le32_to_cpu(dnode->self) != secno)
232                                 hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self));
233                         /* Check dirents - bad dirents would cause infinite
234                            loops or shooting to memory */
235                         if (le32_to_cpu(dnode->first_free) > 2048) {
236                                 hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free));
237                                 goto bail;
238                         }
239                         for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) {
240                                 struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p);
241                                 if (le16_to_cpu(de->length) > 292 || (le16_to_cpu(de->length) < 32) || (le16_to_cpu(de->length) & 3) || p + le16_to_cpu(de->length) > 2048) {
242                                         hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
243                                         goto bail;
244                                 }
245                                 if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) {
246                                         if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & MS_RDONLY) goto ok;
247                                         hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);
248                                         goto bail;
249                                 }
250                                 ok:
251                                 if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down;
252                                 if (de->down) if (de_down_pointer(de) < 0x10) {
253                                         hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);
254                                         goto bail;
255                                 }
256                                 pp = p;
257                                 
258                         }
259                         if (p != le32_to_cpu(dnode->first_free)) {
260                                 hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);
261                                 goto bail;
262                         }
263                         if (d[pp + 30] != 1 || d[pp + 31] != 255) {
264                                 hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);
265                                 goto bail;
266                         }
267                         if (b == 3) printk("HPFS: warning: unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n", secno);
268                 }
269         return dnode;
270         bail:
271         hpfs_brelse4(qbh);
272         return NULL;
273 }
274
275 dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino)
276 {
277         struct buffer_head *bh;
278         struct fnode *fnode;
279         dnode_secno dno;
280
281         fnode = hpfs_map_fnode(s, ino, &bh);
282         if (!fnode)
283                 return 0;
284
285         dno = le32_to_cpu(fnode->u.external[0].disk_secno);
286         brelse(bh);
287         return dno;
288 }