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/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 ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb, 104 struct iov_iter *iter, 105 loff_t offset) 106 { 107 /* Fallback to buffered I/O. */ 108 return 0; 109 } 110 111 const struct address_space_operations udf_adinicb_aops = { 112 .readpage = udf_adinicb_readpage, 113 .writepage = udf_adinicb_writepage, 114 .write_begin = udf_adinicb_write_begin, 115 .write_end = simple_write_end, 116 .direct_IO = udf_adinicb_direct_IO, 117 }; 118 119 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 120 { 121 ssize_t retval; 122 struct file *file = iocb->ki_filp; 123 struct inode *inode = file_inode(file); 124 int err, pos; 125 size_t count = iocb->ki_nbytes; 126 struct udf_inode_info *iinfo = UDF_I(inode); 127 128 mutex_lock(&inode->i_mutex); 129 down_write(&iinfo->i_data_sem); 130 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { 131 if (file->f_flags & O_APPEND) 132 pos = inode->i_size; 133 else 134 pos = iocb->ki_pos; 135 136 if (inode->i_sb->s_blocksize < 137 (udf_file_entry_alloc_offset(inode) + 138 pos + count)) { 139 err = udf_expand_file_adinicb(inode); 140 if (err) { 141 mutex_unlock(&inode->i_mutex); 142 udf_debug("udf_expand_adinicb: err=%d\n", err); 143 return err; 144 } 145 } else { 146 if (pos + count > inode->i_size) 147 iinfo->i_lenAlloc = pos + count; 148 else 149 iinfo->i_lenAlloc = inode->i_size; 150 up_write(&iinfo->i_data_sem); 151 } 152 } else 153 up_write(&iinfo->i_data_sem); 154 155 retval = __generic_file_write_iter(iocb, from); 156 mutex_unlock(&inode->i_mutex); 157 158 if (retval > 0) { 159 ssize_t err; 160 161 mark_inode_dirty(inode); 162 err = generic_write_sync(file, iocb->ki_pos - retval, retval); 163 if (err < 0) 164 retval = err; 165 } 166 167 return retval; 168 } 169 170 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 171 { 172 struct inode *inode = file_inode(filp); 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 = -EPERM; 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 } 223 224 static int udf_release_file(struct inode *inode, struct file *filp) 225 { 226 if (filp->f_mode & FMODE_WRITE && 227 atomic_read(&inode->i_writecount) > 1) { 228 /* 229 * Grab i_mutex to avoid races with writes changing i_size 230 * while we are running. 231 */ 232 mutex_lock(&inode->i_mutex); 233 down_write(&UDF_I(inode)->i_data_sem); 234 udf_discard_prealloc(inode); 235 udf_truncate_tail_extent(inode); 236 up_write(&UDF_I(inode)->i_data_sem); 237 mutex_unlock(&inode->i_mutex); 238 } 239 return 0; 240 } 241 242 const struct file_operations udf_file_operations = { 243 .read = new_sync_read, 244 .read_iter = generic_file_read_iter, 245 .unlocked_ioctl = udf_ioctl, 246 .open = generic_file_open, 247 .mmap = generic_file_mmap, 248 .write = new_sync_write, 249 .write_iter = udf_file_write_iter, 250 .release = udf_release_file, 251 .fsync = generic_file_fsync, 252 .splice_read = generic_file_splice_read, 253 .llseek = generic_file_llseek, 254 }; 255 256 static int udf_setattr(struct dentry *dentry, struct iattr *attr) 257 { 258 struct inode *inode = dentry->d_inode; 259 int error; 260 261 error = inode_change_ok(inode, attr); 262 if (error) 263 return error; 264 265 if ((attr->ia_valid & ATTR_SIZE) && 266 attr->ia_size != i_size_read(inode)) { 267 error = udf_setsize(inode, attr->ia_size); 268 if (error) 269 return error; 270 } 271 272 setattr_copy(inode, attr); 273 mark_inode_dirty(inode); 274 return 0; 275 } 276 277 const struct inode_operations udf_file_inode_operations = { 278 .setattr = udf_setattr, 279 }; 280