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 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 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 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 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 } 102 103 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 static ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb, 122 struct iov_iter *iter, 123 loff_t offset) 124 { 125 /* Fallback to buffered I/O. */ 126 return 0; 127 } 128 129 const struct address_space_operations udf_adinicb_aops = { 130 .readpage = udf_adinicb_readpage, 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 int err, pos; 143 size_t count = iocb->ki_nbytes; 144 struct udf_inode_info *iinfo = UDF_I(inode); 145 146 mutex_lock(&inode->i_mutex); 147 down_write(&iinfo->i_data_sem); 148 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { 149 if (file->f_flags & O_APPEND) 150 pos = inode->i_size; 151 else 152 pos = iocb->ki_pos; 153 154 if (inode->i_sb->s_blocksize < 155 (udf_file_entry_alloc_offset(inode) + 156 pos + count)) { 157 err = udf_expand_file_adinicb(inode); 158 if (err) { 159 mutex_unlock(&inode->i_mutex); 160 udf_debug("udf_expand_adinicb: err=%d\n", err); 161 return err; 162 } 163 } else { 164 if (pos + count > inode->i_size) 165 iinfo->i_lenAlloc = pos + count; 166 else 167 iinfo->i_lenAlloc = inode->i_size; 168 up_write(&iinfo->i_data_sem); 169 } 170 } else 171 up_write(&iinfo->i_data_sem); 172 173 retval = __generic_file_write_iter(iocb, from); 174 mutex_unlock(&inode->i_mutex); 175 176 if (retval > 0) { 177 ssize_t err; 178 179 mark_inode_dirty(inode); 180 err = generic_write_sync(file, iocb->ki_pos - retval, retval); 181 if (err < 0) 182 retval = err; 183 } 184 185 return retval; 186 } 187 188 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 189 { 190 struct inode *inode = file_inode(filp); 191 long old_block, new_block; 192 int result = -EINVAL; 193 194 if (inode_permission(inode, MAY_READ) != 0) { 195 udf_debug("no permission to access inode %lu\n", inode->i_ino); 196 result = -EPERM; 197 goto out; 198 } 199 200 if (!arg) { 201 udf_debug("invalid argument to udf_ioctl\n"); 202 result = -EINVAL; 203 goto out; 204 } 205 206 switch (cmd) { 207 case UDF_GETVOLIDENT: 208 if (copy_to_user((char __user *)arg, 209 UDF_SB(inode->i_sb)->s_volume_ident, 32)) 210 result = -EFAULT; 211 else 212 result = 0; 213 goto out; 214 case UDF_RELOCATE_BLOCKS: 215 if (!capable(CAP_SYS_ADMIN)) { 216 result = -EPERM; 217 goto out; 218 } 219 if (get_user(old_block, (long __user *)arg)) { 220 result = -EFAULT; 221 goto out; 222 } 223 result = udf_relocate_blocks(inode->i_sb, 224 old_block, &new_block); 225 if (result == 0) 226 result = put_user(new_block, (long __user *)arg); 227 goto out; 228 case UDF_GETEASIZE: 229 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); 230 goto out; 231 case UDF_GETEABLOCK: 232 result = copy_to_user((char __user *)arg, 233 UDF_I(inode)->i_ext.i_data, 234 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; 235 goto out; 236 } 237 238 out: 239 return result; 240 } 241 242 static int udf_release_file(struct inode *inode, struct file *filp) 243 { 244 if (filp->f_mode & FMODE_WRITE) { 245 down_write(&UDF_I(inode)->i_data_sem); 246 udf_discard_prealloc(inode); 247 udf_truncate_tail_extent(inode); 248 up_write(&UDF_I(inode)->i_data_sem); 249 } 250 return 0; 251 } 252 253 const struct file_operations udf_file_operations = { 254 .read = new_sync_read, 255 .read_iter = generic_file_read_iter, 256 .unlocked_ioctl = udf_ioctl, 257 .open = generic_file_open, 258 .mmap = generic_file_mmap, 259 .write = new_sync_write, 260 .write_iter = udf_file_write_iter, 261 .release = udf_release_file, 262 .fsync = generic_file_fsync, 263 .splice_read = generic_file_splice_read, 264 .llseek = generic_file_llseek, 265 }; 266 267 static int udf_setattr(struct dentry *dentry, struct iattr *attr) 268 { 269 struct inode *inode = dentry->d_inode; 270 int error; 271 272 error = inode_change_ok(inode, attr); 273 if (error) 274 return error; 275 276 if ((attr->ia_valid & ATTR_SIZE) && 277 attr->ia_size != i_size_read(inode)) { 278 error = udf_setsize(inode, attr->ia_size); 279 if (error) 280 return error; 281 } 282 283 setattr_copy(inode, attr); 284 mark_inode_dirty(inode); 285 return 0; 286 } 287 288 const struct inode_operations udf_file_inode_operations = { 289 .setattr = udf_setattr, 290 }; 291