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 */
27
28 #include "udfdecl.h"
29 #include <linux/fs.h>
30 #include <asm/uaccess.h>
31 #include <linux/kernel.h>
32 #include <linux/string.h> /* memset */
33 #include <linux/capability.h>
34 #include <linux/errno.h>
35 #include <linux/pagemap.h>
36 #include <linux/buffer_head.h>
37 #include <linux/aio.h>
38
39 #include "udf_i.h"
40 #include "udf_sb.h"
41
__udf_adinicb_readpage(struct page * page)42 static void __udf_adinicb_readpage(struct page *page)
43 {
44 struct inode *inode = page->mapping->host;
45 char *kaddr;
46 struct udf_inode_info *iinfo = UDF_I(inode);
47
48 kaddr = kmap(page);
49 memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
50 memset(kaddr + inode->i_size, 0, PAGE_CACHE_SIZE - inode->i_size);
51 flush_dcache_page(page);
52 SetPageUptodate(page);
53 kunmap(page);
54 }
55
udf_adinicb_readpage(struct file * file,struct page * page)56 static int udf_adinicb_readpage(struct file *file, struct page *page)
57 {
58 BUG_ON(!PageLocked(page));
59 __udf_adinicb_readpage(page);
60 unlock_page(page);
61
62 return 0;
63 }
64
udf_adinicb_writepage(struct page * page,struct writeback_control * wbc)65 static int udf_adinicb_writepage(struct page *page,
66 struct writeback_control *wbc)
67 {
68 struct inode *inode = page->mapping->host;
69 char *kaddr;
70 struct udf_inode_info *iinfo = UDF_I(inode);
71
72 BUG_ON(!PageLocked(page));
73
74 kaddr = kmap(page);
75 memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
76 mark_inode_dirty(inode);
77 SetPageUptodate(page);
78 kunmap(page);
79 unlock_page(page);
80
81 return 0;
82 }
83
udf_adinicb_write_begin(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned flags,struct page ** pagep,void ** fsdata)84 static int udf_adinicb_write_begin(struct file *file,
85 struct address_space *mapping, loff_t pos,
86 unsigned len, unsigned flags, struct page **pagep,
87 void **fsdata)
88 {
89 struct page *page;
90
91 if (WARN_ON_ONCE(pos >= PAGE_CACHE_SIZE))
92 return -EIO;
93 page = grab_cache_page_write_begin(mapping, 0, flags);
94 if (!page)
95 return -ENOMEM;
96 *pagep = page;
97
98 if (!PageUptodate(page) && len != PAGE_CACHE_SIZE)
99 __udf_adinicb_readpage(page);
100 return 0;
101 }
102
udf_adinicb_write_end(struct file * file,struct address_space * mapping,loff_t pos,unsigned len,unsigned copied,struct page * page,void * fsdata)103 static int udf_adinicb_write_end(struct file *file,
104 struct address_space *mapping,
105 loff_t pos, unsigned len, unsigned copied,
106 struct page *page, void *fsdata)
107 {
108 struct inode *inode = mapping->host;
109 unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
110 char *kaddr;
111 struct udf_inode_info *iinfo = UDF_I(inode);
112
113 kaddr = kmap_atomic(page);
114 memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
115 kaddr + offset, copied);
116 kunmap_atomic(kaddr);
117
118 return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
119 }
120
121 const struct address_space_operations udf_adinicb_aops = {
122 .readpage = udf_adinicb_readpage,
123 .writepage = udf_adinicb_writepage,
124 .write_begin = udf_adinicb_write_begin,
125 .write_end = udf_adinicb_write_end,
126 };
127
udf_file_aio_write(struct kiocb * iocb,const struct iovec * iov,unsigned long nr_segs,loff_t ppos)128 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
129 unsigned long nr_segs, loff_t ppos)
130 {
131 ssize_t retval;
132 struct file *file = iocb->ki_filp;
133 struct inode *inode = file->f_path.dentry->d_inode;
134 int err, pos;
135 size_t count = iocb->ki_left;
136 struct udf_inode_info *iinfo = UDF_I(inode);
137
138 down_write(&iinfo->i_data_sem);
139 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
140 if (file->f_flags & O_APPEND)
141 pos = inode->i_size;
142 else
143 pos = ppos;
144
145 if (inode->i_sb->s_blocksize <
146 (udf_file_entry_alloc_offset(inode) +
147 pos + count)) {
148 err = udf_expand_file_adinicb(inode);
149 if (err) {
150 udf_debug("udf_expand_adinicb: err=%d\n", err);
151 return err;
152 }
153 } else {
154 if (pos + count > inode->i_size)
155 iinfo->i_lenAlloc = pos + count;
156 else
157 iinfo->i_lenAlloc = inode->i_size;
158 up_write(&iinfo->i_data_sem);
159 }
160 } else
161 up_write(&iinfo->i_data_sem);
162
163 retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
164 if (retval > 0)
165 mark_inode_dirty(inode);
166
167 return retval;
168 }
169
udf_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)170 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
171 {
172 struct inode *inode = filp->f_dentry->d_inode;
173 long old_block, new_block;
174 int result = -EINVAL;
175
176 if (inode_permission(inode, MAY_READ) != 0) {
177 udf_debug("no permission to access inode %lu\n", inode->i_ino);
178 result = -EPERM;
179 goto out;
180 }
181
182 if (!arg) {
183 udf_debug("invalid argument to udf_ioctl\n");
184 result = -EINVAL;
185 goto out;
186 }
187
188 switch (cmd) {
189 case UDF_GETVOLIDENT:
190 if (copy_to_user((char __user *)arg,
191 UDF_SB(inode->i_sb)->s_volume_ident, 32))
192 result = -EFAULT;
193 else
194 result = 0;
195 goto out;
196 case UDF_RELOCATE_BLOCKS:
197 if (!capable(CAP_SYS_ADMIN)) {
198 result = -EACCES;
199 goto out;
200 }
201 if (get_user(old_block, (long __user *)arg)) {
202 result = -EFAULT;
203 goto out;
204 }
205 result = udf_relocate_blocks(inode->i_sb,
206 old_block, &new_block);
207 if (result == 0)
208 result = put_user(new_block, (long __user *)arg);
209 goto out;
210 case UDF_GETEASIZE:
211 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
212 goto out;
213 case UDF_GETEABLOCK:
214 result = copy_to_user((char __user *)arg,
215 UDF_I(inode)->i_ext.i_data,
216 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
217 goto out;
218 }
219
220 out:
221 return result;
222 }
223
udf_release_file(struct inode * inode,struct file * filp)224 static int udf_release_file(struct inode *inode, struct file *filp)
225 {
226 if (filp->f_mode & FMODE_WRITE) {
227 down_write(&UDF_I(inode)->i_data_sem);
228 udf_discard_prealloc(inode);
229 udf_truncate_tail_extent(inode);
230 up_write(&UDF_I(inode)->i_data_sem);
231 }
232 return 0;
233 }
234
235 const struct file_operations udf_file_operations = {
236 .read = do_sync_read,
237 .aio_read = generic_file_aio_read,
238 .unlocked_ioctl = udf_ioctl,
239 .open = generic_file_open,
240 .mmap = generic_file_mmap,
241 .write = do_sync_write,
242 .aio_write = udf_file_aio_write,
243 .release = udf_release_file,
244 .fsync = generic_file_fsync,
245 .splice_read = generic_file_splice_read,
246 .llseek = generic_file_llseek,
247 };
248
udf_setattr(struct dentry * dentry,struct iattr * attr)249 static int udf_setattr(struct dentry *dentry, struct iattr *attr)
250 {
251 struct inode *inode = dentry->d_inode;
252 int error;
253
254 error = inode_change_ok(inode, attr);
255 if (error)
256 return error;
257
258 if ((attr->ia_valid & ATTR_SIZE) &&
259 attr->ia_size != i_size_read(inode)) {
260 error = udf_setsize(inode, attr->ia_size);
261 if (error)
262 return error;
263 }
264
265 setattr_copy(inode, attr);
266 mark_inode_dirty(inode);
267 return 0;
268 }
269
270 const struct inode_operations udf_file_inode_operations = {
271 .setattr = udf_setattr,
272 };
273