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