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/fs/adfs/dir_fplus.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 265 lines | 200 code | 48 blank | 17 comment | 44 complexity | ee7b372b916d75c16117a4624a44e456 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  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 > sizeof(dir->bh)/sizeof(dir->bh[0])) {
 59		/* this directory is too big for fixed bh set, must allocate */
 60		struct buffer_head **bh_fplus =
 61			kzalloc(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"
 83					" offset %d, mapped block %X",
 84					id, blk, block);
 85			goto out;
 86		}
 87
 88		dir->nr_buffers += 1;
 89	}
 90
 91	t = (struct adfs_bigdirtail *)
 92		(dir->bh_fplus[size - 1]->b_data + (sb->s_blocksize - 8));
 93
 94	if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
 95	    t->bigdirendmasseq != h->startmasseq ||
 96	    t->reserved[0] != 0 || t->reserved[1] != 0) {
 97		printk(KERN_WARNING "adfs: dir object %X has "
 98					"malformed dir end\n", id);
 99		goto out;
100	}
101
102	dir->parent_id = le32_to_cpu(h->bigdirparent);
103	dir->sb = sb;
104	return 0;
105
106out:
107	if (dir->bh_fplus) {
108		for (i = 0; i < dir->nr_buffers; i++)
109			brelse(dir->bh_fplus[i]);
110
111		if (&dir->bh[0] != dir->bh_fplus)
112			kfree(dir->bh_fplus);
113
114		dir->bh_fplus = NULL;
115	}
116
117	dir->nr_buffers = 0;
118	dir->sb = NULL;
119	return ret;
120}
121
122static int
123adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
124{
125	struct adfs_bigdirheader *h =
126		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
127	int ret = -ENOENT;
128
129	if (fpos <= le32_to_cpu(h->bigdirentries)) {
130		dir->pos = fpos;
131		ret = 0;
132	}
133
134	return ret;
135}
136
137static void
138dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
139{
140	struct super_block *sb = dir->sb;
141	unsigned int buffer, partial, remainder;
142
143	buffer = offset >> sb->s_blocksize_bits;
144	offset &= sb->s_blocksize - 1;
145
146	partial = sb->s_blocksize - offset;
147
148	if (partial >= len)
149		memcpy(to, dir->bh_fplus[buffer]->b_data + offset, len);
150	else {
151		char *c = (char *)to;
152
153		remainder = len - partial;
154
155		memcpy(c,
156			dir->bh_fplus[buffer]->b_data + offset,
157			partial);
158
159		memcpy(c + partial,
160			dir->bh_fplus[buffer + 1]->b_data,
161			remainder);
162	}
163}
164
165static int
166adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
167{
168	struct adfs_bigdirheader *h =
169		(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
170	struct adfs_bigdirentry bde;
171	unsigned int offset;
172	int i, ret = -ENOENT;
173
174	if (dir->pos >= le32_to_cpu(h->bigdirentries))
175		goto out;
176
177	offset = offsetof(struct adfs_bigdirheader, bigdirname);
178	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
179	offset += dir->pos * sizeof(struct adfs_bigdirentry);
180
181	dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
182
183	obj->loadaddr = le32_to_cpu(bde.bigdirload);
184	obj->execaddr = le32_to_cpu(bde.bigdirexec);
185	obj->size     = le32_to_cpu(bde.bigdirlen);
186	obj->file_id  = le32_to_cpu(bde.bigdirindaddr);
187	obj->attr     = le32_to_cpu(bde.bigdirattr);
188	obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
189
190	offset = offsetof(struct adfs_bigdirheader, bigdirname);
191	offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
192	offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
193	offset += le32_to_cpu(bde.bigdirobnameptr);
194
195	dir_memcpy(dir, offset, obj->name, obj->name_len);
196	for (i = 0; i < obj->name_len; i++)
197		if (obj->name[i] == '/')
198			obj->name[i] = '.';
199
200	obj->filetype = -1;
201
202	/*
203	 * object is a file and is filetyped and timestamped?
204	 * RISC OS 12-bit filetype is stored in load_address[19:8]
205	 */
206	if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
207		(0xfff00000 == (0xfff00000 & obj->loadaddr))) {
208		obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
209
210		/* optionally append the ,xyz hex filetype suffix */
211		if (ADFS_SB(dir->sb)->s_ftsuffix)
212			obj->name_len +=
213				append_filetype_suffix(
214					&obj->name[obj->name_len],
215					obj->filetype);
216	}
217
218	dir->pos += 1;
219	ret = 0;
220out:
221	return ret;
222}
223
224static int
225adfs_fplus_sync(struct adfs_dir *dir)
226{
227	int err = 0;
228	int i;
229
230	for (i = dir->nr_buffers - 1; i >= 0; i--) {
231		struct buffer_head *bh = dir->bh_fplus[i];
232		sync_dirty_buffer(bh);
233		if (buffer_req(bh) && !buffer_uptodate(bh))
234			err = -EIO;
235	}
236
237	return err;
238}
239
240static void
241adfs_fplus_free(struct adfs_dir *dir)
242{
243	int i;
244
245	if (dir->bh_fplus) {
246		for (i = 0; i < dir->nr_buffers; i++)
247			brelse(dir->bh_fplus[i]);
248
249		if (&dir->bh[0] != dir->bh_fplus)
250			kfree(dir->bh_fplus);
251
252		dir->bh_fplus = NULL;
253	}
254
255	dir->nr_buffers = 0;
256	dir->sb = NULL;
257}
258
259struct adfs_dir_ops adfs_fplus_dir_ops = {
260	.read		= adfs_fplus_read,
261	.setpos		= adfs_fplus_setpos,
262	.getnext	= adfs_fplus_getnext,
263	.sync		= adfs_fplus_sync,
264	.free		= adfs_fplus_free
265};