udf: fix ioctl errors
[sfrench/cifs-2.6.git] / fs / udf / file.c
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 <linux/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/uio.h>
37
38 #include "udf_i.h"
39 #include "udf_sb.h"
40
41 static void __udf_adinicb_readpage(struct page *page)
42 {
43         struct inode *inode = page->mapping->host;
44         char *kaddr;
45         struct udf_inode_info *iinfo = UDF_I(inode);
46
47         kaddr = kmap(page);
48         memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
49         memset(kaddr + inode->i_size, 0, PAGE_SIZE - inode->i_size);
50         flush_dcache_page(page);
51         SetPageUptodate(page);
52         kunmap(page);
53 }
54
55 static int udf_adinicb_readpage(struct file *file, struct page *page)
56 {
57         BUG_ON(!PageLocked(page));
58         __udf_adinicb_readpage(page);
59         unlock_page(page);
60
61         return 0;
62 }
63
64 static int udf_adinicb_writepage(struct page *page,
65                                  struct writeback_control *wbc)
66 {
67         struct inode *inode = page->mapping->host;
68         char *kaddr;
69         struct udf_inode_info *iinfo = UDF_I(inode);
70
71         BUG_ON(!PageLocked(page));
72
73         kaddr = kmap(page);
74         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
75         mark_inode_dirty(inode);
76         SetPageUptodate(page);
77         kunmap(page);
78         unlock_page(page);
79
80         return 0;
81 }
82
83 static int udf_adinicb_write_begin(struct file *file,
84                         struct address_space *mapping, loff_t pos,
85                         unsigned len, unsigned flags, struct page **pagep,
86                         void **fsdata)
87 {
88         struct page *page;
89
90         if (WARN_ON_ONCE(pos >= PAGE_SIZE))
91                 return -EIO;
92         page = grab_cache_page_write_begin(mapping, 0, flags);
93         if (!page)
94                 return -ENOMEM;
95         *pagep = page;
96
97         if (!PageUptodate(page))
98                 __udf_adinicb_readpage(page);
99         return 0;
100 }
101
102 static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
103 {
104         /* Fallback to buffered I/O. */
105         return 0;
106 }
107
108 static int udf_adinicb_write_end(struct file *file, struct address_space *mapping,
109                                  loff_t pos, unsigned len, unsigned copied,
110                                  struct page *page, void *fsdata)
111 {
112         struct inode *inode = page->mapping->host;
113         loff_t last_pos = pos + copied;
114         if (last_pos > inode->i_size)
115                 i_size_write(inode, last_pos);
116         set_page_dirty(page);
117         unlock_page(page);
118         put_page(page);
119         return copied;
120 }
121
122 const struct address_space_operations udf_adinicb_aops = {
123         .readpage       = udf_adinicb_readpage,
124         .writepage      = udf_adinicb_writepage,
125         .write_begin    = udf_adinicb_write_begin,
126         .write_end      = udf_adinicb_write_end,
127         .direct_IO      = udf_adinicb_direct_IO,
128 };
129
130 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
131 {
132         ssize_t retval;
133         struct file *file = iocb->ki_filp;
134         struct inode *inode = file_inode(file);
135         struct udf_inode_info *iinfo = UDF_I(inode);
136         int err;
137
138         inode_lock(inode);
139
140         retval = generic_write_checks(iocb, from);
141         if (retval <= 0)
142                 goto out;
143
144         down_write(&iinfo->i_data_sem);
145         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
146                 loff_t end = iocb->ki_pos + iov_iter_count(from);
147
148                 if (inode->i_sb->s_blocksize <
149                                 (udf_file_entry_alloc_offset(inode) + end)) {
150                         err = udf_expand_file_adinicb(inode);
151                         if (err) {
152                                 inode_unlock(inode);
153                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
154                                 return err;
155                         }
156                 } else {
157                         iinfo->i_lenAlloc = max(end, 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_write_iter(iocb, from);
164 out:
165         inode_unlock(inode);
166
167         if (retval > 0) {
168                 mark_inode_dirty(inode);
169                 retval = generic_write_sync(iocb, retval);
170         }
171
172         return retval;
173 }
174
175 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
176 {
177         struct inode *inode = file_inode(filp);
178         long old_block, new_block;
179         int result = -EINVAL;
180
181         if (inode_permission(inode, MAY_READ) != 0) {
182                 udf_debug("no permission to access inode %lu\n", inode->i_ino);
183                 result = -EPERM;
184                 goto out;
185         }
186
187         if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
188                      (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
189                 udf_debug("invalid argument to udf_ioctl\n");
190                 result = -EINVAL;
191                 goto out;
192         }
193
194         switch (cmd) {
195         case UDF_GETVOLIDENT:
196                 if (copy_to_user((char __user *)arg,
197                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
198                         result = -EFAULT;
199                 else
200                         result = 0;
201                 goto out;
202         case UDF_RELOCATE_BLOCKS:
203                 if (!capable(CAP_SYS_ADMIN)) {
204                         result = -EPERM;
205                         goto out;
206                 }
207                 if (get_user(old_block, (long __user *)arg)) {
208                         result = -EFAULT;
209                         goto out;
210                 }
211                 result = udf_relocate_blocks(inode->i_sb,
212                                                 old_block, &new_block);
213                 if (result == 0)
214                         result = put_user(new_block, (long __user *)arg);
215                 goto out;
216         case UDF_GETEASIZE:
217                 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
218                 goto out;
219         case UDF_GETEABLOCK:
220                 result = copy_to_user((char __user *)arg,
221                                       UDF_I(inode)->i_ext.i_data,
222                                       UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
223                 goto out;
224         default:
225                 return -ENOIOCTLCMD;
226         }
227
228 out:
229         return result;
230 }
231
232 static int udf_release_file(struct inode *inode, struct file *filp)
233 {
234         if (filp->f_mode & FMODE_WRITE &&
235             atomic_read(&inode->i_writecount) == 1) {
236                 /*
237                  * Grab i_mutex to avoid races with writes changing i_size
238                  * while we are running.
239                  */
240                 inode_lock(inode);
241                 down_write(&UDF_I(inode)->i_data_sem);
242                 udf_discard_prealloc(inode);
243                 udf_truncate_tail_extent(inode);
244                 up_write(&UDF_I(inode)->i_data_sem);
245                 inode_unlock(inode);
246         }
247         return 0;
248 }
249
250 const struct file_operations udf_file_operations = {
251         .read_iter              = generic_file_read_iter,
252         .unlocked_ioctl         = udf_ioctl,
253         .open                   = generic_file_open,
254         .mmap                   = generic_file_mmap,
255         .write_iter             = udf_file_write_iter,
256         .release                = udf_release_file,
257         .fsync                  = generic_file_fsync,
258         .splice_read            = generic_file_splice_read,
259         .llseek                 = generic_file_llseek,
260 };
261
262 static int udf_setattr(struct dentry *dentry, struct iattr *attr)
263 {
264         struct inode *inode = d_inode(dentry);
265         int error;
266
267         error = setattr_prepare(dentry, attr);
268         if (error)
269                 return error;
270
271         if ((attr->ia_valid & ATTR_SIZE) &&
272             attr->ia_size != i_size_read(inode)) {
273                 error = udf_setsize(inode, attr->ia_size);
274                 if (error)
275                         return error;
276         }
277
278         setattr_copy(inode, attr);
279         mark_inode_dirty(inode);
280         return 0;
281 }
282
283 const struct inode_operations udf_file_inode_operations = {
284         .setattr                = udf_setattr,
285 };