1/*
2 *  linux/fs/ufs/util.c
3 *
4 * Copyright (C) 1998
5 * Daniel Pirkl <daniel.pirkl@email.cz>
6 * Charles University, Faculty of Mathematics and Physics
7 */
8
9#include <linux/string.h>
10#include <linux/slab.h>
11#include <linux/ufs_fs.h>
12#include <linux/buffer_head.h>
13
14#include "swab.h"
15#include "util.h"
16
17struct ufs_buffer_head * _ubh_bread_ (struct ufs_sb_private_info * uspi,
18	struct super_block *sb, u64 fragment, u64 size)
19{
20	struct ufs_buffer_head * ubh;
21	unsigned i, j ;
22	u64  count = 0;
23	if (size & ~uspi->s_fmask)
24		return NULL;
25	count = size >> uspi->s_fshift;
26	if (count > UFS_MAXFRAG)
27		return NULL;
28	ubh = (struct ufs_buffer_head *)
29		kmalloc (sizeof (struct ufs_buffer_head), GFP_KERNEL);
30	if (!ubh)
31		return NULL;
32	ubh->fragment = fragment;
33	ubh->count = count;
34	for (i = 0; i < count; i++)
35		if (!(ubh->bh[i] = sb_bread(sb, fragment + i)))
36			goto failed;
37	for (; i < UFS_MAXFRAG; i++)
38		ubh->bh[i] = NULL;
39	return ubh;
40failed:
41	for (j = 0; j < i; j++)
42		brelse (ubh->bh[j]);
43	kfree(ubh);
44	return NULL;
45}
46
47struct ufs_buffer_head * ubh_bread_uspi (struct ufs_sb_private_info * uspi,
48	struct super_block *sb, u64 fragment, u64 size)
49{
50	unsigned i, j;
51	u64 count = 0;
52	if (size & ~uspi->s_fmask)
53		return NULL;
54	count = size >> uspi->s_fshift;
55	if (count <= 0 || count > UFS_MAXFRAG)
56		return NULL;
57	USPI_UBH(uspi)->fragment = fragment;
58	USPI_UBH(uspi)->count = count;
59	for (i = 0; i < count; i++)
60		if (!(USPI_UBH(uspi)->bh[i] = sb_bread(sb, fragment + i)))
61			goto failed;
62	for (; i < UFS_MAXFRAG; i++)
63		USPI_UBH(uspi)->bh[i] = NULL;
64	return USPI_UBH(uspi);
65failed:
66	for (j = 0; j < i; j++)
67		brelse (USPI_UBH(uspi)->bh[j]);
68	return NULL;
69}
70
71void ubh_brelse (struct ufs_buffer_head * ubh)
72{
73	unsigned i;
74	if (!ubh)
75		return;
76	for (i = 0; i < ubh->count; i++)
77		brelse (ubh->bh[i]);
78	kfree (ubh);
79}
80
81void ubh_brelse_uspi (struct ufs_sb_private_info * uspi)
82{
83	unsigned i;
84	if (!USPI_UBH(uspi))
85		return;
86	for ( i = 0; i < USPI_UBH(uspi)->count; i++ ) {
87		brelse (USPI_UBH(uspi)->bh[i]);
88		USPI_UBH(uspi)->bh[i] = NULL;
89	}
90}
91
92void ubh_mark_buffer_dirty (struct ufs_buffer_head * ubh)
93{
94	unsigned i;
95	if (!ubh)
96		return;
97	for ( i = 0; i < ubh->count; i++ )
98		mark_buffer_dirty (ubh->bh[i]);
99}
100
101void ubh_mark_buffer_uptodate (struct ufs_buffer_head * ubh, int flag)
102{
103	unsigned i;
104	if (!ubh)
105		return;
106	if (flag) {
107		for ( i = 0; i < ubh->count; i++ )
108			set_buffer_uptodate (ubh->bh[i]);
109	} else {
110		for ( i = 0; i < ubh->count; i++ )
111			clear_buffer_uptodate (ubh->bh[i]);
112	}
113}
114
115void ubh_ll_rw_block(int rw, struct ufs_buffer_head *ubh)
116{
117	if (!ubh)
118		return;
119
120	ll_rw_block(rw, ubh->count, ubh->bh);
121}
122
123void ubh_wait_on_buffer (struct ufs_buffer_head * ubh)
124{
125	unsigned i;
126	if (!ubh)
127		return;
128	for ( i = 0; i < ubh->count; i++ )
129		wait_on_buffer (ubh->bh[i]);
130}
131
132void ubh_bforget (struct ufs_buffer_head * ubh)
133{
134	unsigned i;
135	if (!ubh)
136		return;
137	for ( i = 0; i < ubh->count; i++ ) if ( ubh->bh[i] )
138		bforget (ubh->bh[i]);
139}
140
141int ubh_buffer_dirty (struct ufs_buffer_head * ubh)
142{
143	unsigned i;
144	unsigned result = 0;
145	if (!ubh)
146		return 0;
147	for ( i = 0; i < ubh->count; i++ )
148		result |= buffer_dirty(ubh->bh[i]);
149	return result;
150}
151
152void _ubh_ubhcpymem_(struct ufs_sb_private_info * uspi,
153	unsigned char * mem, struct ufs_buffer_head * ubh, unsigned size)
154{
155	unsigned len, bhno;
156	if (size > (ubh->count << uspi->s_fshift))
157		size = ubh->count << uspi->s_fshift;
158	bhno = 0;
159	while (size) {
160		len = min_t(unsigned int, size, uspi->s_fsize);
161		memcpy (mem, ubh->bh[bhno]->b_data, len);
162		mem += uspi->s_fsize;
163		size -= len;
164		bhno++;
165	}
166}
167
168void _ubh_memcpyubh_(struct ufs_sb_private_info * uspi,
169	struct ufs_buffer_head * ubh, unsigned char * mem, unsigned size)
170{
171	unsigned len, bhno;
172	if (size > (ubh->count << uspi->s_fshift))
173		size = ubh->count << uspi->s_fshift;
174	bhno = 0;
175	while (size) {
176		len = min_t(unsigned int, size, uspi->s_fsize);
177		memcpy (ubh->bh[bhno]->b_data, mem, len);
178		mem += uspi->s_fsize;
179		size -= len;
180		bhno++;
181	}
182}
183
184dev_t
185ufs_get_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi)
186{
187	__u32 fs32;
188	dev_t dev;
189
190	if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
191		fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[1]);
192	else
193		fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[0]);
194	switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
195	case UFS_ST_SUNx86:
196	case UFS_ST_SUN:
197		if ((fs32 & 0xffff0000) == 0 ||
198		    (fs32 & 0xffff0000) == 0xffff0000)
199			dev = old_decode_dev(fs32 & 0x7fff);
200		else
201			dev = MKDEV(sysv_major(fs32), sysv_minor(fs32));
202		break;
203
204	default:
205		dev = old_decode_dev(fs32);
206		break;
207	}
208	return dev;
209}
210
211void
212ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev)
213{
214	__u32 fs32;
215
216	switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
217	case UFS_ST_SUNx86:
218	case UFS_ST_SUN:
219		fs32 = sysv_encode_dev(dev);
220		if ((fs32 & 0xffff8000) == 0) {
221			fs32 = old_encode_dev(dev);
222		}
223		break;
224
225	default:
226		fs32 = old_encode_dev(dev);
227		break;
228	}
229	if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
230		ufsi->i_u1.i_data[1] = cpu_to_fs32(sb, fs32);
231	else
232		ufsi->i_u1.i_data[0] = cpu_to_fs32(sb, fs32);
233}
234
235/**
236 * ufs_get_locked_page() - locate, pin and lock a pagecache page, if not exist
237 * read it from disk.
238 * @mapping: the address_space to search
239 * @index: the page index
240 *
241 * Locates the desired pagecache page, if not exist we'll read it,
242 * locks it, increments its reference
243 * count and returns its address.
244 *
245 */
246
247struct page *ufs_get_locked_page(struct address_space *mapping,
248				 pgoff_t index)
249{
250	struct page *page;
251
252	page = find_lock_page(mapping, index);
253	if (!page) {
254		page = read_mapping_page(mapping, index, NULL);
255
256		if (IS_ERR(page)) {
257			printk(KERN_ERR "ufs_change_blocknr: "
258			       "read_mapping_page error: ino %lu, index: %lu\n",
259			       mapping->host->i_ino, index);
260			goto out;
261		}
262
263		lock_page(page);
264
265		if (unlikely(page->mapping == NULL)) {
266			/* Truncate got there first */
267			unlock_page(page);
268			page_cache_release(page);
269			page = NULL;
270			goto out;
271		}
272
273		if (!PageUptodate(page) || PageError(page)) {
274			unlock_page(page);
275			page_cache_release(page);
276
277			printk(KERN_ERR "ufs_change_blocknr: "
278			       "can not read page: ino %lu, index: %lu\n",
279			       mapping->host->i_ino, index);
280
281			page = ERR_PTR(-EIO);
282		}
283	}
284out:
285	return page;
286}
287