1/*
2 *  linux/fs/adfs/dir_fplus.c
3 *
4 *  Copyright (C) 1997-1999 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/buffer_head.h>
11#include <linux/slab.h>
12#include "adfs.h"
13#include "dir_fplus.h"
14
15static int
16adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
17{
18	struct adfs_bigdirheader *h;
19	struct adfs_bigdirtail *t;
20	unsigned long block;
21	unsigned int blk, size;
22	int i, ret = -EIO;
23
24	dir->nr_buffers = 0;
25
26	/* start off using fixed bh set - only alloc for big dirs */
27	dir->bh_fplus = &dir->bh[0];
28
29	block = __adfs_block_map(sb, id, 0);
30	if (!block) {
31		adfs_error(sb, "dir object %X has a hole at offset 0", id);
32		goto out;
33	}
34
35	dir->bh_fplus[0] = sb_bread(sb, block);
36	if (!dir->bh_fplus[0])
37		goto out;
38	dir->nr_buffers += 1;
39
40	h = (struct adfs_bigdirheader *)dir->bh_fplus[0]->b_data;
41	size = le32_to_cpu(h->bigdirsize);
42	if (size != sz) {
43		printk(KERN_WARNING "adfs: adfs_fplus_read:"
44					" directory header size %X\n"
45					" does not match directory size %X\n",
46					size, sz);
47	}
48
49	if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
50	    h->bigdirversion[2] != 0 || size & 2047 ||
51	    h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) {
52		printk(KERN_WARNING "adfs: dir object %X has"
53					" malformed dir header\n", id);
54		goto out;
55	}
56
57	size >>= sb->s_blocksize_bits;
58	if (size > ARRAY_SIZE(dir->bh)) {
59		/* this directory is too big for fixed bh set, must allocate */
60		struct buffer_head **bh_fplus =
61			kcalloc(size, sizeof(struct buffer_head *),
62				GFP_KERNEL);
63		if (!bh_fplus) {
64			adfs_error(sb, "not enough memory for"
65					" dir object %X (%d blocks)", id, size);
66			goto out;
67		}
68		dir->bh_fplus = bh_fplus;
69		/* copy over the pointer to the block that we've already read */
70		dir->bh_fplus[0] = dir->bh[0];
71	}
72
73	for (blk = 1; blk < size; blk++) {
74		block = __adfs_block_map(sb, id, blk);
75		if (!block) {
76			adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
77			goto out;
78		}
79
80		dir->bh_fplus[blk] = sb_bread(sb, block);
81		if (!dir->bh_fplus[blk]) {
82			adfs_error(sb,	"dir object %x failed read for offset %d, mapped block %lX",
83				   id, blk, block);
84			goto out;
85		}
86
87		dir->nr_buffers += 1;
88	}
89
90	t = (struct adfs_bigdirtail *)
91		(dir->bh_fplus[size - 1]->b_data + (sb->s_blocksize - 8));
92
93	if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
94	    t->bigdirendmasseq != h->startmasseq ||
95	    t->reserved[0] != 0 || t->reserved[1] != 0) {
96		printk(KERN_WARNING "adfs: dir object %X has "
97					"malformed dir end\n", id);
98		goto out;
99	}
100
101	dir->parent_id = le32_to_cpu(h->bigdirparent);
102	dir->sb = sb;
103	return 0;
104
105out:
106	if (dir->bh_fplus) {
107		for (i = 0; i < dir->nr_buffers; i++)
108			brelse(dir->bh_fplus[i]);
109
110		if (&dir->bh[0] != dir->bh_fplus)
111			kfree(dir->bh_fplus);
112
113		dir->bh_fplus = NULL;
114	}
115
116	dir->nr_buffers = 0;
117	dir->sb = NULL;
118	return ret;
119}
120
121static int
122adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
123{
124	struct adfs_bigdirheader *h =
125		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
126	int ret = -ENOENT;
127
128	if (fpos <= le32_to_cpu(h->bigdirentries)) {
129		dir->pos = fpos;
130		ret = 0;
131	}
132
133	return ret;
134}
135
136static void
137dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
138{
139	struct super_block *sb = dir->sb;
140	unsigned int buffer, partial, remainder;
141
142	buffer = offset >> sb->s_blocksize_bits;
143	offset &= sb->s_blocksize - 1;
144
145	partial = sb->s_blocksize - offset;
146
147	if (partial >= len)
148		memcpy(to, dir->bh_fplus[buffer]->b_data + offset, len);
149	else {
150		char *c = (char *)to;
151
152		remainder = len - partial;
153
154		memcpy(c,
155			dir->bh_fplus[buffer]->b_data + offset,
156			partial);
157
158		memcpy(c + partial,
159			dir->bh_fplus[buffer + 1]->b_data,
160			remainder);
161	}
162}
163
164static int
165adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
166{
167	struct adfs_bigdirheader *h =
168		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
169	struct adfs_bigdirentry bde;
170	unsigned int offset;
171	int i, ret = -ENOENT;
172
173	if (dir->pos >= le32_to_cpu(h->bigdirentries))
174		goto out;
175
176	offset = offsetof(struct adfs_bigdirheader, bigdirname);
177	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
178	offset += dir->pos * sizeof(struct adfs_bigdirentry);
179
180	dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
181
182	obj->loadaddr = le32_to_cpu(bde.bigdirload);
183	obj->execaddr = le32_to_cpu(bde.bigdirexec);
184	obj->size     = le32_to_cpu(bde.bigdirlen);
185	obj->file_id  = le32_to_cpu(bde.bigdirindaddr);
186	obj->attr     = le32_to_cpu(bde.bigdirattr);
187	obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
188
189	offset = offsetof(struct adfs_bigdirheader, bigdirname);
190	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
191	offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
192	offset += le32_to_cpu(bde.bigdirobnameptr);
193
194	dir_memcpy(dir, offset, obj->name, obj->name_len);
195	for (i = 0; i < obj->name_len; i++)
196		if (obj->name[i] == '/')
197			obj->name[i] = '.';
198
199	obj->filetype = -1;
200
201	/*
202	 * object is a file and is filetyped and timestamped?
203	 * RISC OS 12-bit filetype is stored in load_address[19:8]
204	 */
205	if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
206		(0xfff00000 == (0xfff00000 & obj->loadaddr))) {
207		obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
208
209		/* optionally append the ,xyz hex filetype suffix */
210		if (ADFS_SB(dir->sb)->s_ftsuffix)
211			obj->name_len +=
212				append_filetype_suffix(
213					&obj->name[obj->name_len],
214					obj->filetype);
215	}
216
217	dir->pos += 1;
218	ret = 0;
219out:
220	return ret;
221}
222
223static int
224adfs_fplus_sync(struct adfs_dir *dir)
225{
226	int err = 0;
227	int i;
228
229	for (i = dir->nr_buffers - 1; i >= 0; i--) {
230		struct buffer_head *bh = dir->bh_fplus[i];
231		sync_dirty_buffer(bh);
232		if (buffer_req(bh) && !buffer_uptodate(bh))
233			err = -EIO;
234	}
235
236	return err;
237}
238
239static void
240adfs_fplus_free(struct adfs_dir *dir)
241{
242	int i;
243
244	if (dir->bh_fplus) {
245		for (i = 0; i < dir->nr_buffers; i++)
246			brelse(dir->bh_fplus[i]);
247
248		if (&dir->bh[0] != dir->bh_fplus)
249			kfree(dir->bh_fplus);
250
251		dir->bh_fplus = NULL;
252	}
253
254	dir->nr_buffers = 0;
255	dir->sb = NULL;
256}
257
258struct adfs_dir_ops adfs_fplus_dir_ops = {
259	.read		= adfs_fplus_read,
260	.setpos		= adfs_fplus_setpos,
261	.getnext	= adfs_fplus_getnext,
262	.sync		= adfs_fplus_sync,
263	.free		= adfs_fplus_free
264};
265