1 /*
2 * file.c
3 *
4 * PURPOSE
5 * File handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * CONTACTS
8 * E-mail regarding any portion of the Linux UDF file system should be
9 * directed to the development team mailing list (run by majordomo):
10 * linux_udf@hootie.lvld.hp.com
11 *
12 * COPYRIGHT
13 * This file is distributed under the terms of the GNU General Public
14 * License (GPL). Copies of the GPL can be obtained from:
15 * ftp://prep.ai.mit.edu/pub/gnu/GPL
16 * Each contributing author retains all rights to their own work.
17 *
18 * (C) 1998-1999 Dave Boynton
19 * (C) 1998-2000 Ben Fennema
20 * (C) 1999-2000 Stelias Computing Inc
21 *
22 * HISTORY
23 *
24 * 10/02/98 dgb Attempt to integrate into udf.o
25 * 10/07/98 Switched to using generic_readpage, etc., like isofs
26 * And it works!
27 * 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
28 * ICB_FLAG_AD_IN_ICB.
29 * 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
30 * 05/12/99 Preliminary file write support
31 */
32
33 #include "udfdecl.h"
34 #include <linux/fs.h>
35 #include <linux/udf_fs.h>
36 #include <asm/uaccess.h>
37 #include <linux/kernel.h>
38 #include <linux/string.h> /* memset */
39 #include <linux/errno.h>
40 #include <linux/locks.h>
41 #include <linux/smp_lock.h>
42
43 #include "udf_i.h"
44 #include "udf_sb.h"
45
46 static int udf_adinicb_readpage(struct file *file, struct page * page)
47 {
48 struct inode *inode = page->mapping->host;
49
50 struct buffer_head *bh;
51 int block;
52 char *kaddr;
53
54 if (!PageLocked(page))
55 PAGE_BUG(page);
56
57 kaddr = kmap(page);
58 memset(kaddr, 0, PAGE_CACHE_SIZE);
59 block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);
60 bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize);
61 memcpy(kaddr, bh->b_data + udf_ext0_offset(inode), inode->i_size);
62 brelse(bh);
63 flush_dcache_page(page);
64 SetPageUptodate(page);
65 kunmap(page);
66 UnlockPage(page);
67 return 0;
68 }
69
70 static int udf_adinicb_writepage(struct page *page)
71 {
72 struct inode *inode = page->mapping->host;
73
74 struct buffer_head *bh;
75 int block;
76 char *kaddr;
77
78 if (!PageLocked(page))
79 PAGE_BUG(page);
80
81 kaddr = kmap(page);
82 block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);
83 bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize);
84 memcpy(bh->b_data + udf_ext0_offset(inode), kaddr, inode->i_size);
85 mark_buffer_dirty(bh);
86 brelse(bh);
87 SetPageUptodate(page);
88 kunmap(page);
89 return 0;
90 }
91
92 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
93 {
94 kmap(page);
95 return 0;
96 }
97
98 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
99 {
100 struct inode *inode = page->mapping->host;
101
102 struct buffer_head *bh;
103 int block;
104 char *kaddr = page_address(page);
105
106 block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);
107 bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize);
108 memcpy(bh->b_data + udf_file_entry_alloc_offset(inode) + offset,
109 kaddr + offset, to-offset);
110 mark_buffer_dirty(bh);
111 brelse(bh);
112 SetPageUptodate(page);
113 kunmap(page);
114 /* only one page here */
115 if (to > inode->i_size)
116 inode->i_size = to;
117 return 0;
118 }
119
120 struct address_space_operations udf_adinicb_aops = {
121 readpage: udf_adinicb_readpage,
122 writepage: udf_adinicb_writepage,
123 sync_page: block_sync_page,
124 prepare_write: udf_adinicb_prepare_write,
125 commit_write: udf_adinicb_commit_write,
126 };
127
128 static ssize_t udf_file_write(struct file * file, const char * buf,
129 size_t count, loff_t *ppos)
130 {
131 ssize_t retval;
132 struct inode *inode = file->f_dentry->d_inode;
133 int err, pos;
134
135 if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_IN_ICB)
136 {
137 if (file->f_flags & O_APPEND)
138 pos = inode->i_size;
139 else
140 pos = *ppos;
141
142 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
143 pos + count))
144 {
145 udf_expand_file_adinicb(inode, pos + count, &err);
146 if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_IN_ICB)
147 {
148 udf_debug("udf_expand_adinicb: err=%d\n", err);
149 return err;
150 }
151 }
152 else
153 {
154 if (pos + count > inode->i_size)
155 UDF_I_LENALLOC(inode) = pos + count;
156 else
157 UDF_I_LENALLOC(inode) = inode->i_size;
158 }
159 }
160
161 retval = generic_file_write(file, buf, count, ppos);
162
163 if (retval > 0)
164 {
165 UDF_I_UCTIME(inode) = UDF_I_UMTIME(inode) = CURRENT_UTIME;
166 mark_inode_dirty(inode);
167 }
168 return retval;
169 }
170
171 /*
172 * udf_ioctl
173 *
174 * PURPOSE
175 * Issue an ioctl.
176 *
177 * DESCRIPTION
178 * Optional - sys_ioctl() will return -ENOTTY if this routine is not
179 * available, and the ioctl cannot be handled without filesystem help.
180 *
181 * sys_ioctl() handles these ioctls that apply only to regular files:
182 * FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
183 * These ioctls are also handled by sys_ioctl():
184 * FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
185 * All other ioctls are passed to the filesystem.
186 *
187 * Refer to sys_ioctl() in fs/ioctl.c
188 * sys_ioctl() -> .
189 *
190 * PRE-CONDITIONS
191 * inode Pointer to inode that ioctl was issued on.
192 * filp Pointer to file that ioctl was issued on.
193 * cmd The ioctl command.
194 * arg The ioctl argument [can be interpreted as a
195 * user-space pointer if desired].
196 *
197 * POST-CONDITIONS
198 * <return> Success (>=0) or an error code (<=0) that
199 * sys_ioctl() will return.
200 *
201 * HISTORY
202 * July 1, 1997 - Andrew E. Mileski
203 * Written, tested, and released.
204 */
205 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
206 unsigned long arg)
207 {
208 int result = -1;
209 struct buffer_head *bh = NULL;
210 Uint16 ident;
211 long_ad eaicb;
212 Uint8 *ea = NULL;
213
214 if ( permission(inode, MAY_READ) != 0 )
215 {
216 udf_debug("no permission to access inode %lu\n",
217 inode->i_ino);
218 return -EPERM;
219 }
220
221 if ( !arg )
222 {
223 udf_debug("invalid argument to udf_ioctl\n");
224 return -EINVAL;
225 }
226
227 /* first, do ioctls that don't need to udf_read */
228 switch (cmd)
229 {
230 case UDF_GETVOLIDENT:
231 if ( (result == verify_area(VERIFY_WRITE, (char *)arg, 32)) == 0)
232 result = copy_to_user((char *)arg, UDF_SB_VOLIDENT(inode->i_sb), 32);
233 return result;
234
235 }
236
237 /* ok, we need to read the inode */
238 bh = udf_read_ptagged(inode->i_sb, UDF_I_LOCATION(inode), 0, &ident);
239
240 if (!bh || (ident != TID_FILE_ENTRY && ident != TID_EXTENDED_FILE_ENTRY))
241 {
242 udf_debug("bread failed (ino=%ld) or ident (%d) != TID_(EXTENDED_)FILE_ENTRY",
243 inode->i_ino, ident);
244 return -EFAULT;
245 }
246
247 if (UDF_I_EXTENDED_FE(inode) == 0)
248 {
249 struct FileEntry *fe;
250
251 fe = (struct FileEntry *)bh->b_data;
252 eaicb = lela_to_cpu(fe->extendedAttrICB);
253 if (UDF_I_LENEATTR(inode))
254 ea = fe->extendedAttr;
255 }
256 else
257 {
258 struct ExtendedFileEntry *efe;
259
260 efe = (struct ExtendedFileEntry *)bh->b_data;
261 eaicb = lela_to_cpu(efe->extendedAttrICB);
262 if (UDF_I_LENEATTR(inode))
263 ea = efe->extendedAttr;
264 }
265
266 switch (cmd)
267 {
268 case UDF_GETEASIZE:
269 if ( (result = verify_area(VERIFY_WRITE, (char *)arg, 4)) == 0)
270 result = put_user(UDF_I_LENEATTR(inode), (int *)arg);
271 break;
272
273 case UDF_GETEABLOCK:
274 if ( (result = verify_area(VERIFY_WRITE, (char *)arg, UDF_I_LENEATTR(inode))) == 0)
275 result = copy_to_user((char *)arg, ea, UDF_I_LENEATTR(inode));
276 break;
277
278 default:
279 udf_debug("ino=%ld, cmd=%d\n", inode->i_ino, cmd);
280 break;
281 }
282
283 udf_release_data(bh);
284 return result;
285 }
286
287 /*
288 * udf_release_file
289 *
290 * PURPOSE
291 * Called when all references to the file are closed
292 *
293 * DESCRIPTION
294 * Discard prealloced blocks
295 *
296 * HISTORY
297 *
298 */
299 static int udf_release_file(struct inode * inode, struct file * filp)
300 {
301 if (filp->f_mode & FMODE_WRITE) {
302 lock_kernel();
303 udf_discard_prealloc(inode);
304 unlock_kernel();
305 }
306 return 0;
307 }
308
309 /*
310 * udf_open_file
311 *
312 * PURPOSE
313 * Called when an inode is about to be open.
314 *
315 * DESCRIPTION
316 * Use this to disallow opening RW large files on 32 bit systems.
317 * On 64 bit systems we force on O_LARGEFILE in sys_open.
318 *
319 * HISTORY
320 *
321 */
322 static int udf_open_file(struct inode * inode, struct file * filp)
323 {
324 if ((inode->i_size & 0xFFFFFFFF00000000ULL) && !(filp->f_flags & O_LARGEFILE))
325 return -EFBIG;
326 return 0;
327 }
328
329 struct file_operations udf_file_operations = {
330 read: generic_file_read,
331 ioctl: udf_ioctl,
332 open: udf_open_file,
333 mmap: generic_file_mmap,
334 write: udf_file_write,
335 release: udf_release_file,
336 fsync: udf_sync_file,
337 };
338
339 struct inode_operations udf_file_inode_operations = {
340 truncate: udf_truncate,
341 };
342
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.