[PATCH] ufs: zeroize the rest of block in truncate
[linux-2.6.git] / fs / ufs / util.c
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
17 struct 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;
40 failed:
41         for (j = 0; j < i; j++)
42                 brelse (ubh->bh[j]);
43         kfree(ubh);
44         return NULL;
45 }
46
47 struct 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);
65 failed:
66         for (j = 0; j < i; j++)
67                 brelse (USPI_UBH(uspi)->bh[j]);
68         return NULL;
69 }
70
71 void 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
81 void 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
92 void 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
101 void 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
115 void 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
123 void 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
132 void 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  
141 int 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
152 void _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
168 void _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
184 dev_t
185 ufs_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
211 void
212 ufs_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
247 struct 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_cache_page(mapping, index,
255                                        (filler_t*)mapping->a_ops->readpage,
256                                        NULL);
257
258                 if (IS_ERR(page)) {
259                         printk(KERN_ERR "ufs_change_blocknr: "
260                                "read_cache_page error: ino %lu, index: %lu\n",
261                                mapping->host->i_ino, index);
262                         goto out;
263                 }
264
265                 lock_page(page);
266
267                 if (unlikely(page->mapping == NULL)) {
268                         /* Truncate got there first */
269                         unlock_page(page);
270                         page_cache_release(page);
271                         page = NULL;
272                         goto out;
273                 }
274
275                 if (!PageUptodate(page) || PageError(page)) {
276                         unlock_page(page);
277                         page_cache_release(page);
278
279                         printk(KERN_ERR "ufs_change_blocknr: "
280                                "can not read page: ino %lu, index: %lu\n",
281                                mapping->host->i_ino, index);
282
283                         page = ERR_PTR(-EIO);
284                 }
285         }
286 out:
287         return page;
288 }