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_CACHE_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_CACHE_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) && len != PAGE_CACHE_SIZE) 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 loff_t offset) 104 { 105 /* Fallback to buffered I/O. */ 106 return 0; 107 } 108 109 const struct address_space_operations udf_adinicb_aops = { 110 .readpage = udf_adinicb_readpage, 111 .writepage = udf_adinicb_writepage, 112 .write_begin = udf_adinicb_write_begin, 113 .write_end = simple_write_end, 114 .direct_IO = udf_adinicb_direct_IO, 115 }; 116 117 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 118 { 119 ssize_t retval; 120 struct file *file = iocb->ki_filp; 121 struct inode *inode = file_inode(file); 122 struct udf_inode_info *iinfo = UDF_I(inode); 123 int err; 124 125 mutex_lock(&inode->i_mutex); 126 127 retval = generic_write_checks(iocb, from); 128 if (retval <= 0) 129 goto out; 130 131 down_write(&iinfo->i_data_sem); 132 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { 133 loff_t end = iocb->ki_pos + iov_iter_count(from); 134 135 if (inode->i_sb->s_blocksize < 136 (udf_file_entry_alloc_offset(inode) + end)) { 137 err = udf_expand_file_adinicb(inode); 138 if (err) { 139 mutex_unlock(&inode->i_mutex); 140 udf_debug("udf_expand_adinicb: err=%d\n", err); 141 return err; 142 } 143 } else { 144 iinfo->i_lenAlloc = max(end, inode->i_size); 145 up_write(&iinfo->i_data_sem); 146 } 147 } else 148 up_write(&iinfo->i_data_sem); 149 150 retval = __generic_file_write_iter(iocb, from); 151 out: 152 mutex_unlock(&inode->i_mutex); 153 154 if (retval > 0) { 155 ssize_t err; 156 157 mark_inode_dirty(inode); 158 err = generic_write_sync(file, iocb->ki_pos - retval, retval); 159 if (err < 0) 160 retval = err; 161 } 162 163 return retval; 164 } 165 166 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 167 { 168 struct inode *inode = file_inode(filp); 169 long old_block, new_block; 170 int result = -EINVAL; 171 172 if (inode_permission(inode, MAY_READ) != 0) { 173 udf_debug("no permission to access inode %lu\n", inode->i_ino); 174 result = -EPERM; 175 goto out; 176 } 177 178 if (!arg) { 179 udf_debug("invalid argument to udf_ioctl\n"); 180 result = -EINVAL; 181 goto out; 182 } 183 184 switch (cmd) { 185 case UDF_GETVOLIDENT: 186 if (copy_to_user((char __user *)arg, 187 UDF_SB(inode->i_sb)->s_volume_ident, 32)) 188 result = -EFAULT; 189 else 190 result = 0; 191 goto out; 192 case UDF_RELOCATE_BLOCKS: 193 if (!capable(CAP_SYS_ADMIN)) { 194 result = -EPERM; 195 goto out; 196 } 197 if (get_user(old_block, (long __user *)arg)) { 198 result = -EFAULT; 199 goto out; 200 } 201 result = udf_relocate_blocks(inode->i_sb, 202 old_block, &new_block); 203 if (result == 0) 204 result = put_user(new_block, (long __user *)arg); 205 goto out; 206 case UDF_GETEASIZE: 207 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); 208 goto out; 209 case UDF_GETEABLOCK: 210 result = copy_to_user((char __user *)arg, 211 UDF_I(inode)->i_ext.i_data, 212 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; 213 goto out; 214 } 215 216 out: 217 return result; 218 } 219 220 static int udf_release_file(struct inode *inode, struct file *filp) 221 { 222 if (filp->f_mode & FMODE_WRITE && 223 atomic_read(&inode->i_writecount) == 1) { 224 /* 225 * Grab i_mutex to avoid races with writes changing i_size 226 * while we are running. 227 */ 228 mutex_lock(&inode->i_mutex); 229 down_write(&UDF_I(inode)->i_data_sem); 230 udf_discard_prealloc(inode); 231 udf_truncate_tail_extent(inode); 232 up_write(&UDF_I(inode)->i_data_sem); 233 mutex_unlock(&inode->i_mutex); 234 } 235 return 0; 236 } 237 238 const struct file_operations udf_file_operations = { 239 .read_iter = generic_file_read_iter, 240 .unlocked_ioctl = udf_ioctl, 241 .open = generic_file_open, 242 .mmap = generic_file_mmap, 243 .write_iter = udf_file_write_iter, 244 .release = udf_release_file, 245 .fsync = generic_file_fsync, 246 .splice_read = generic_file_splice_read, 247 .llseek = generic_file_llseek, 248 }; 249 250 static int udf_setattr(struct dentry *dentry, struct iattr *attr) 251 { 252 struct inode *inode = d_inode(dentry); 253 int error; 254 255 error = inode_change_ok(inode, attr); 256 if (error) 257 return error; 258 259 if ((attr->ia_valid & ATTR_SIZE) && 260 attr->ia_size != i_size_read(inode)) { 261 error = udf_setsize(inode, attr->ia_size); 262 if (error) 263 return error; 264 } 265 266 setattr_copy(inode, attr); 267 mark_inode_dirty(inode); 268 return 0; 269 } 270 271 const struct inode_operations udf_file_inode_operations = { 272 .setattr = udf_setattr, 273 }; 274