ia64/linux-2.6.18-xen.hg

view fs/udf/file.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /*
2 * file.c
3 *
4 * PURPOSE
5 * File handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * COPYRIGHT
8 * This file is distributed under the terms of the GNU General Public
9 * License (GPL). Copies of the GPL can be obtained from:
10 * ftp://prep.ai.mit.edu/pub/gnu/GPL
11 * Each contributing author retains all rights to their own work.
12 *
13 * (C) 1998-1999 Dave Boynton
14 * (C) 1998-2004 Ben Fennema
15 * (C) 1999-2000 Stelias Computing Inc
16 *
17 * HISTORY
18 *
19 * 10/02/98 dgb Attempt to integrate into udf.o
20 * 10/07/98 Switched to using generic_readpage, etc., like isofs
21 * And it works!
22 * 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
23 * ICBTAG_FLAG_AD_IN_ICB.
24 * 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
25 * 05/12/99 Preliminary file write support
26 */
28 #include "udfdecl.h"
29 #include <linux/fs.h>
30 #include <linux/udf_fs.h>
31 #include <asm/uaccess.h>
32 #include <linux/kernel.h>
33 #include <linux/string.h> /* memset */
34 #include <linux/capability.h>
35 #include <linux/errno.h>
36 #include <linux/smp_lock.h>
37 #include <linux/pagemap.h>
38 #include <linux/buffer_head.h>
40 #include "udf_i.h"
41 #include "udf_sb.h"
43 static int udf_adinicb_readpage(struct file *file, struct page * page)
44 {
45 struct inode *inode = page->mapping->host;
46 char *kaddr;
48 BUG_ON(!PageLocked(page));
50 kaddr = kmap(page);
51 memset(kaddr, 0, PAGE_CACHE_SIZE);
52 memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
53 flush_dcache_page(page);
54 SetPageUptodate(page);
55 kunmap(page);
56 unlock_page(page);
57 return 0;
58 }
60 static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc)
61 {
62 struct inode *inode = page->mapping->host;
63 char *kaddr;
65 BUG_ON(!PageLocked(page));
67 kaddr = kmap(page);
68 memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
69 mark_inode_dirty(inode);
70 SetPageUptodate(page);
71 kunmap(page);
72 unlock_page(page);
73 return 0;
74 }
76 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
77 {
78 kmap(page);
79 return 0;
80 }
82 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
83 {
84 struct inode *inode = page->mapping->host;
85 char *kaddr = page_address(page);
87 memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
88 kaddr + offset, to - offset);
89 mark_inode_dirty(inode);
90 SetPageUptodate(page);
91 kunmap(page);
92 /* only one page here */
93 if (to > inode->i_size)
94 inode->i_size = to;
95 return 0;
96 }
98 const struct address_space_operations udf_adinicb_aops = {
99 .readpage = udf_adinicb_readpage,
100 .writepage = udf_adinicb_writepage,
101 .sync_page = block_sync_page,
102 .prepare_write = udf_adinicb_prepare_write,
103 .commit_write = udf_adinicb_commit_write,
104 };
106 static ssize_t udf_file_write(struct file * file, const char __user * buf,
107 size_t count, loff_t *ppos)
108 {
109 ssize_t retval;
110 struct inode *inode = file->f_dentry->d_inode;
111 int err, pos;
113 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
114 {
115 if (file->f_flags & O_APPEND)
116 pos = inode->i_size;
117 else
118 pos = *ppos;
120 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
121 pos + count))
122 {
123 udf_expand_file_adinicb(inode, pos + count, &err);
124 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
125 {
126 udf_debug("udf_expand_adinicb: err=%d\n", err);
127 return err;
128 }
129 }
130 else
131 {
132 if (pos + count > inode->i_size)
133 UDF_I_LENALLOC(inode) = pos + count;
134 else
135 UDF_I_LENALLOC(inode) = inode->i_size;
136 }
137 }
139 retval = generic_file_write(file, buf, count, ppos);
141 if (retval > 0)
142 mark_inode_dirty(inode);
143 return retval;
144 }
146 /*
147 * udf_ioctl
148 *
149 * PURPOSE
150 * Issue an ioctl.
151 *
152 * DESCRIPTION
153 * Optional - sys_ioctl() will return -ENOTTY if this routine is not
154 * available, and the ioctl cannot be handled without filesystem help.
155 *
156 * sys_ioctl() handles these ioctls that apply only to regular files:
157 * FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
158 * These ioctls are also handled by sys_ioctl():
159 * FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
160 * All other ioctls are passed to the filesystem.
161 *
162 * Refer to sys_ioctl() in fs/ioctl.c
163 * sys_ioctl() -> .
164 *
165 * PRE-CONDITIONS
166 * inode Pointer to inode that ioctl was issued on.
167 * filp Pointer to file that ioctl was issued on.
168 * cmd The ioctl command.
169 * arg The ioctl argument [can be interpreted as a
170 * user-space pointer if desired].
171 *
172 * POST-CONDITIONS
173 * <return> Success (>=0) or an error code (<=0) that
174 * sys_ioctl() will return.
175 *
176 * HISTORY
177 * July 1, 1997 - Andrew E. Mileski
178 * Written, tested, and released.
179 */
180 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
181 unsigned long arg)
182 {
183 int result = -EINVAL;
185 if ( file_permission(filp, MAY_READ) != 0 )
186 {
187 udf_debug("no permission to access inode %lu\n",
188 inode->i_ino);
189 return -EPERM;
190 }
192 if ( !arg )
193 {
194 udf_debug("invalid argument to udf_ioctl\n");
195 return -EINVAL;
196 }
198 switch (cmd)
199 {
200 case UDF_GETVOLIDENT:
201 return copy_to_user((char __user *)arg,
202 UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
203 case UDF_RELOCATE_BLOCKS:
204 {
205 long old, new;
207 if (!capable(CAP_SYS_ADMIN)) return -EACCES;
208 if (get_user(old, (long __user *)arg)) return -EFAULT;
209 if ((result = udf_relocate_blocks(inode->i_sb,
210 old, &new)) == 0)
211 result = put_user(new, (long __user *)arg);
213 return result;
214 }
215 case UDF_GETEASIZE:
216 result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
217 break;
219 case UDF_GETEABLOCK:
220 result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
221 UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
222 break;
223 }
225 return result;
226 }
228 /*
229 * udf_release_file
230 *
231 * PURPOSE
232 * Called when all references to the file are closed
233 *
234 * DESCRIPTION
235 * Discard prealloced blocks
236 *
237 * HISTORY
238 *
239 */
240 static int udf_release_file(struct inode * inode, struct file * filp)
241 {
242 if (filp->f_mode & FMODE_WRITE)
243 {
244 lock_kernel();
245 udf_discard_prealloc(inode);
246 unlock_kernel();
247 }
248 return 0;
249 }
251 const struct file_operations udf_file_operations = {
252 .read = generic_file_read,
253 .ioctl = udf_ioctl,
254 .open = generic_file_open,
255 .mmap = generic_file_mmap,
256 .write = udf_file_write,
257 .release = udf_release_file,
258 .fsync = udf_fsync_file,
259 .sendfile = generic_file_sendfile,
260 };
262 struct inode_operations udf_file_inode_operations = {
263 .truncate = udf_truncate,
264 };