Merge tag 'pull-tmpfile' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[platform/kernel/linux-starfive.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         loff_t isize = i_size_read(inode);
47
48         /*
49          * We have to be careful here as truncate can change i_size under us.
50          * So just sample it once and use the same value everywhere.
51          */
52         kaddr = kmap_atomic(page);
53         memcpy(kaddr, iinfo->i_data + iinfo->i_lenEAttr, isize);
54         memset(kaddr + isize, 0, PAGE_SIZE - isize);
55         flush_dcache_page(page);
56         SetPageUptodate(page);
57         kunmap_atomic(kaddr);
58 }
59
60 static int udf_adinicb_read_folio(struct file *file, struct folio *folio)
61 {
62         BUG_ON(!folio_test_locked(folio));
63         __udf_adinicb_readpage(&folio->page);
64         folio_unlock(folio);
65
66         return 0;
67 }
68
69 static int udf_adinicb_writepage(struct page *page,
70                                  struct writeback_control *wbc)
71 {
72         struct inode *inode = page->mapping->host;
73         char *kaddr;
74         struct udf_inode_info *iinfo = UDF_I(inode);
75
76         BUG_ON(!PageLocked(page));
77
78         kaddr = kmap_atomic(page);
79         memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
80         SetPageUptodate(page);
81         kunmap_atomic(kaddr);
82         mark_inode_dirty(inode);
83         unlock_page(page);
84
85         return 0;
86 }
87
88 static int udf_adinicb_write_begin(struct file *file,
89                         struct address_space *mapping, loff_t pos,
90                         unsigned len, struct page **pagep,
91                         void **fsdata)
92 {
93         struct page *page;
94
95         if (WARN_ON_ONCE(pos >= PAGE_SIZE))
96                 return -EIO;
97         page = grab_cache_page_write_begin(mapping, 0);
98         if (!page)
99                 return -ENOMEM;
100         *pagep = page;
101
102         if (!PageUptodate(page))
103                 __udf_adinicb_readpage(page);
104         return 0;
105 }
106
107 static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
108 {
109         /* Fallback to buffered I/O. */
110         return 0;
111 }
112
113 static int udf_adinicb_write_end(struct file *file, struct address_space *mapping,
114                                  loff_t pos, unsigned len, unsigned copied,
115                                  struct page *page, void *fsdata)
116 {
117         struct inode *inode = page->mapping->host;
118         loff_t last_pos = pos + copied;
119         if (last_pos > inode->i_size)
120                 i_size_write(inode, last_pos);
121         set_page_dirty(page);
122         unlock_page(page);
123         put_page(page);
124         return copied;
125 }
126
127 const struct address_space_operations udf_adinicb_aops = {
128         .dirty_folio    = block_dirty_folio,
129         .invalidate_folio = block_invalidate_folio,
130         .read_folio     = udf_adinicb_read_folio,
131         .writepage      = udf_adinicb_writepage,
132         .write_begin    = udf_adinicb_write_begin,
133         .write_end      = udf_adinicb_write_end,
134         .direct_IO      = udf_adinicb_direct_IO,
135 };
136
137 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
138 {
139         ssize_t retval;
140         struct file *file = iocb->ki_filp;
141         struct inode *inode = file_inode(file);
142         struct udf_inode_info *iinfo = UDF_I(inode);
143         int err;
144
145         inode_lock(inode);
146
147         retval = generic_write_checks(iocb, from);
148         if (retval <= 0)
149                 goto out;
150
151         down_write(&iinfo->i_data_sem);
152         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
153                 loff_t end = iocb->ki_pos + iov_iter_count(from);
154
155                 if (inode->i_sb->s_blocksize <
156                                 (udf_file_entry_alloc_offset(inode) + end)) {
157                         err = udf_expand_file_adinicb(inode);
158                         if (err) {
159                                 inode_unlock(inode);
160                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
161                                 return err;
162                         }
163                 } else {
164                         iinfo->i_lenAlloc = max(end, inode->i_size);
165                         up_write(&iinfo->i_data_sem);
166                 }
167         } else
168                 up_write(&iinfo->i_data_sem);
169
170         retval = __generic_file_write_iter(iocb, from);
171 out:
172         inode_unlock(inode);
173
174         if (retval > 0) {
175                 mark_inode_dirty(inode);
176                 retval = generic_write_sync(iocb, retval);
177         }
178
179         return retval;
180 }
181
182 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
183 {
184         struct inode *inode = file_inode(filp);
185         long old_block, new_block;
186         int result;
187
188         if (file_permission(filp, MAY_READ) != 0) {
189                 udf_debug("no permission to access inode %lu\n", inode->i_ino);
190                 return -EPERM;
191         }
192
193         if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
194                      (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
195                 udf_debug("invalid argument to udf_ioctl\n");
196                 return -EINVAL;
197         }
198
199         switch (cmd) {
200         case UDF_GETVOLIDENT:
201                 if (copy_to_user((char __user *)arg,
202                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
203                         return -EFAULT;
204                 return 0;
205         case UDF_RELOCATE_BLOCKS:
206                 if (!capable(CAP_SYS_ADMIN))
207                         return -EPERM;
208                 if (get_user(old_block, (long __user *)arg))
209                         return -EFAULT;
210                 result = udf_relocate_blocks(inode->i_sb,
211                                                 old_block, &new_block);
212                 if (result == 0)
213                         result = put_user(new_block, (long __user *)arg);
214                 return result;
215         case UDF_GETEASIZE:
216                 return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
217         case UDF_GETEABLOCK:
218                 return copy_to_user((char __user *)arg,
219                                     UDF_I(inode)->i_data,
220                                     UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
221         default:
222                 return -ENOIOCTLCMD;
223         }
224
225         return 0;
226 }
227
228 static int udf_release_file(struct inode *inode, struct file *filp)
229 {
230         if (filp->f_mode & FMODE_WRITE &&
231             atomic_read(&inode->i_writecount) == 1) {
232                 /*
233                  * Grab i_mutex to avoid races with writes changing i_size
234                  * while we are running.
235                  */
236                 inode_lock(inode);
237                 down_write(&UDF_I(inode)->i_data_sem);
238                 udf_discard_prealloc(inode);
239                 udf_truncate_tail_extent(inode);
240                 up_write(&UDF_I(inode)->i_data_sem);
241                 inode_unlock(inode);
242         }
243         return 0;
244 }
245
246 const struct file_operations udf_file_operations = {
247         .read_iter              = generic_file_read_iter,
248         .unlocked_ioctl         = udf_ioctl,
249         .open                   = generic_file_open,
250         .mmap                   = generic_file_mmap,
251         .write_iter             = udf_file_write_iter,
252         .release                = udf_release_file,
253         .fsync                  = generic_file_fsync,
254         .splice_read            = generic_file_splice_read,
255         .splice_write           = iter_file_splice_write,
256         .llseek                 = generic_file_llseek,
257 };
258
259 static int udf_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
260                        struct iattr *attr)
261 {
262         struct inode *inode = d_inode(dentry);
263         struct super_block *sb = inode->i_sb;
264         int error;
265
266         error = setattr_prepare(&init_user_ns, dentry, attr);
267         if (error)
268                 return error;
269
270         if ((attr->ia_valid & ATTR_UID) &&
271             UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) &&
272             !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid))
273                 return -EPERM;
274         if ((attr->ia_valid & ATTR_GID) &&
275             UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) &&
276             !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid))
277                 return -EPERM;
278
279         if ((attr->ia_valid & ATTR_SIZE) &&
280             attr->ia_size != i_size_read(inode)) {
281                 error = udf_setsize(inode, attr->ia_size);
282                 if (error)
283                         return error;
284         }
285
286         if (attr->ia_valid & ATTR_MODE)
287                 udf_update_extra_perms(inode, attr->ia_mode);
288
289         setattr_copy(&init_user_ns, inode, attr);
290         mark_inode_dirty(inode);
291         return 0;
292 }
293
294 const struct inode_operations udf_file_inode_operations = {
295         .setattr                = udf_setattr,
296 };