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; 180 181 if (inode_permission(inode, MAY_READ) != 0) { 182 udf_debug("no permission to access inode %lu\n", inode->i_ino); 183 return -EPERM; 184 } 185 186 if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || 187 (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { 188 udf_debug("invalid argument to udf_ioctl\n"); 189 return -EINVAL; 190 } 191 192 switch (cmd) { 193 case UDF_GETVOLIDENT: 194 if (copy_to_user((char __user *)arg, 195 UDF_SB(inode->i_sb)->s_volume_ident, 32)) 196 return -EFAULT; 197 return 0; 198 case UDF_RELOCATE_BLOCKS: 199 if (!capable(CAP_SYS_ADMIN)) 200 return -EPERM; 201 if (get_user(old_block, (long __user *)arg)) 202 return -EFAULT; 203 result = udf_relocate_blocks(inode->i_sb, 204 old_block, &new_block); 205 if (result == 0) 206 result = put_user(new_block, (long __user *)arg); 207 return result; 208 case UDF_GETEASIZE: 209 return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); 210 case UDF_GETEABLOCK: 211 return copy_to_user((char __user *)arg, 212 UDF_I(inode)->i_ext.i_data, 213 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; 214 default: 215 return -ENOIOCTLCMD; 216 } 217 218 return 0; 219 } 220 221 static int udf_release_file(struct inode *inode, struct file *filp) 222 { 223 if (filp->f_mode & FMODE_WRITE && 224 atomic_read(&inode->i_writecount) == 1) { 225 /* 226 * Grab i_mutex to avoid races with writes changing i_size 227 * while we are running. 228 */ 229 inode_lock(inode); 230 down_write(&UDF_I(inode)->i_data_sem); 231 udf_discard_prealloc(inode); 232 udf_truncate_tail_extent(inode); 233 up_write(&UDF_I(inode)->i_data_sem); 234 inode_unlock(inode); 235 } 236 return 0; 237 } 238 239 const struct file_operations udf_file_operations = { 240 .read_iter = generic_file_read_iter, 241 .unlocked_ioctl = udf_ioctl, 242 .open = generic_file_open, 243 .mmap = generic_file_mmap, 244 .write_iter = udf_file_write_iter, 245 .release = udf_release_file, 246 .fsync = generic_file_fsync, 247 .splice_read = generic_file_splice_read, 248 .llseek = generic_file_llseek, 249 }; 250 251 static int udf_setattr(struct dentry *dentry, struct iattr *attr) 252 { 253 struct inode *inode = d_inode(dentry); 254 int error; 255 256 error = setattr_prepare(dentry, attr); 257 if (error) 258 return error; 259 260 if ((attr->ia_valid & ATTR_SIZE) && 261 attr->ia_size != i_size_read(inode)) { 262 error = udf_setsize(inode, attr->ia_size); 263 if (error) 264 return error; 265 } 266 267 setattr_copy(inode, attr); 268 mark_inode_dirty(inode); 269 return 0; 270 } 271 272 const struct inode_operations udf_file_inode_operations = { 273 .setattr = udf_setattr, 274 }; 275