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/buffer_head.h>
12
13#include "ufs_fs.h"
14#include "ufs.h"
15#include "swab.h"
16#include "util.h"
17
18struct ufs_buffer_head * _ubh_bread_ (struct ufs_sb_private_info * uspi,
19	struct super_block *sb, u64 fragment, u64 size)
20{
21	struct ufs_buffer_head * ubh;
22	unsigned i, j ;
23	u64  count = 0;
24	if (size & ~uspi->s_fmask)
25		return NULL;
26	count = size >> uspi->s_fshift;
27	if (count > UFS_MAXFRAG)
28		return NULL;
29	ubh = kmalloc (sizeof (struct ufs_buffer_head), GFP_NOFS);
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_sync_block(struct ufs_buffer_head *ubh)
116{
117	if (ubh) {
118		unsigned i;
119
120		for (i = 0; i < ubh->count; i++)
121			write_dirty_buffer(ubh->bh[i], WRITE);
122
123		for (i = 0; i < ubh->count; i++)
124			wait_on_buffer(ubh->bh[i]);
125	}
126}
127
128void ubh_bforget (struct ufs_buffer_head * ubh)
129{
130	unsigned i;
131	if (!ubh)
132		return;
133	for ( i = 0; i < ubh->count; i++ ) if ( ubh->bh[i] )
134		bforget (ubh->bh[i]);
135}
136
137int ubh_buffer_dirty (struct ufs_buffer_head * ubh)
138{
139	unsigned i;
140	unsigned result = 0;
141	if (!ubh)
142		return 0;
143	for ( i = 0; i < ubh->count; i++ )
144		result |= buffer_dirty(ubh->bh[i]);
145	return result;
146}
147
148void _ubh_ubhcpymem_(struct ufs_sb_private_info * uspi,
149	unsigned char * mem, struct ufs_buffer_head * ubh, unsigned size)
150{
151	unsigned len, bhno;
152	if (size > (ubh->count << uspi->s_fshift))
153		size = ubh->count << uspi->s_fshift;
154	bhno = 0;
155	while (size) {
156		len = min_t(unsigned int, size, uspi->s_fsize);
157		memcpy (mem, ubh->bh[bhno]->b_data, len);
158		mem += uspi->s_fsize;
159		size -= len;
160		bhno++;
161	}
162}
163
164void _ubh_memcpyubh_(struct ufs_sb_private_info * uspi,
165	struct ufs_buffer_head * ubh, unsigned char * mem, unsigned size)
166{
167	unsigned len, bhno;
168	if (size > (ubh->count << uspi->s_fshift))
169		size = ubh->count << uspi->s_fshift;
170	bhno = 0;
171	while (size) {
172		len = min_t(unsigned int, size, uspi->s_fsize);
173		memcpy (ubh->bh[bhno]->b_data, mem, len);
174		mem += uspi->s_fsize;
175		size -= len;
176		bhno++;
177	}
178}
179
180dev_t
181ufs_get_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi)
182{
183	__u32 fs32;
184	dev_t dev;
185
186	if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
187		fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[1]);
188	else
189		fs32 = fs32_to_cpu(sb, ufsi->i_u1.i_data[0]);
190	switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
191	case UFS_ST_SUNx86:
192	case UFS_ST_SUN:
193		if ((fs32 & 0xffff0000) == 0 ||
194		    (fs32 & 0xffff0000) == 0xffff0000)
195			dev = old_decode_dev(fs32 & 0x7fff);
196		else
197			dev = MKDEV(sysv_major(fs32), sysv_minor(fs32));
198		break;
199
200	default:
201		dev = old_decode_dev(fs32);
202		break;
203	}
204	return dev;
205}
206
207void
208ufs_set_inode_dev(struct super_block *sb, struct ufs_inode_info *ufsi, dev_t dev)
209{
210	__u32 fs32;
211
212	switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
213	case UFS_ST_SUNx86:
214	case UFS_ST_SUN:
215		fs32 = sysv_encode_dev(dev);
216		if ((fs32 & 0xffff8000) == 0) {
217			fs32 = old_encode_dev(dev);
218		}
219		break;
220
221	default:
222		fs32 = old_encode_dev(dev);
223		break;
224	}
225	if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
226		ufsi->i_u1.i_data[1] = cpu_to_fs32(sb, fs32);
227	else
228		ufsi->i_u1.i_data[0] = cpu_to_fs32(sb, fs32);
229}
230
231/**
232 * ufs_get_locked_page() - locate, pin and lock a pagecache page, if not exist
233 * read it from disk.
234 * @mapping: the address_space to search
235 * @index: the page index
236 *
237 * Locates the desired pagecache page, if not exist we'll read it,
238 * locks it, increments its reference
239 * count and returns its address.
240 *
241 */
242
243struct page *ufs_get_locked_page(struct address_space *mapping,
244				 pgoff_t index)
245{
246	struct page *page;
247
248	page = find_lock_page(mapping, index);
249	if (!page) {
250		page = read_mapping_page(mapping, index, NULL);
251
252		if (IS_ERR(page)) {
253			printk(KERN_ERR "ufs_change_blocknr: "
254			       "read_mapping_page error: ino %lu, index: %lu\n",
255			       mapping->host->i_ino, index);
256			goto out;
257		}
258
259		lock_page(page);
260
261		if (unlikely(page->mapping == NULL)) {
262			/* Truncate got there first */
263			unlock_page(page);
264			page_cache_release(page);
265			page = NULL;
266			goto out;
267		}
268
269		if (!PageUptodate(page) || PageError(page)) {
270			unlock_page(page);
271			page_cache_release(page);
272
273			printk(KERN_ERR "ufs_change_blocknr: "
274			       "can not read page: ino %lu, index: %lu\n",
275			       mapping->host->i_ino, index);
276
277			page = ERR_PTR(-EIO);
278		}
279	}
280out:
281	return page;
282}
283