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/udf_fs.h> 31 #include <asm/uaccess.h> 32 #include <linux/kernel.h> 33 #include <linux/string.h> /* memset */ 34 #include <linux/capability.h> 35 #include <linux/errno.h> 36 #include <linux/smp_lock.h> 37 #include <linux/pagemap.h> 38 #include <linux/buffer_head.h> 39 40 #include "udf_i.h" 41 #include "udf_sb.h" 42 43 static int udf_adinicb_readpage(struct file *file, struct page * page) 44 { 45 struct inode *inode = page->mapping->host; 46 char *kaddr; 47 48 BUG_ON(!PageLocked(page)); 49 50 kaddr = kmap(page); 51 memset(kaddr, 0, PAGE_CACHE_SIZE); 52 memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size); 53 flush_dcache_page(page); 54 SetPageUptodate(page); 55 kunmap(page); 56 unlock_page(page); 57 return 0; 58 } 59 60 static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc) 61 { 62 struct inode *inode = page->mapping->host; 63 char *kaddr; 64 65 BUG_ON(!PageLocked(page)); 66 67 kaddr = kmap(page); 68 memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size); 69 mark_inode_dirty(inode); 70 SetPageUptodate(page); 71 kunmap(page); 72 unlock_page(page); 73 return 0; 74 } 75 76 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to) 77 { 78 kmap(page); 79 return 0; 80 } 81 82 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to) 83 { 84 struct inode *inode = page->mapping->host; 85 char *kaddr = page_address(page); 86 87 memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset, 88 kaddr + offset, to - offset); 89 mark_inode_dirty(inode); 90 SetPageUptodate(page); 91 kunmap(page); 92 /* only one page here */ 93 if (to > inode->i_size) 94 inode->i_size = to; 95 return 0; 96 } 97 98 struct address_space_operations udf_adinicb_aops = { 99 .readpage = udf_adinicb_readpage, 100 .writepage = udf_adinicb_writepage, 101 .sync_page = block_sync_page, 102 .prepare_write = udf_adinicb_prepare_write, 103 .commit_write = udf_adinicb_commit_write, 104 }; 105 106 static ssize_t udf_file_write(struct file * file, const char __user * buf, 107 size_t count, loff_t *ppos) 108 { 109 ssize_t retval; 110 struct inode *inode = file->f_dentry->d_inode; 111 int err, pos; 112 113 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) 114 { 115 if (file->f_flags & O_APPEND) 116 pos = inode->i_size; 117 else 118 pos = *ppos; 119 120 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) + 121 pos + count)) 122 { 123 udf_expand_file_adinicb(inode, pos + count, &err); 124 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) 125 { 126 udf_debug("udf_expand_adinicb: err=%d\n", err); 127 return err; 128 } 129 } 130 else 131 { 132 if (pos + count > inode->i_size) 133 UDF_I_LENALLOC(inode) = pos + count; 134 else 135 UDF_I_LENALLOC(inode) = inode->i_size; 136 } 137 } 138 139 retval = generic_file_write(file, buf, count, ppos); 140 141 if (retval > 0) 142 mark_inode_dirty(inode); 143 return retval; 144 } 145 146 /* 147 * udf_ioctl 148 * 149 * PURPOSE 150 * Issue an ioctl. 151 * 152 * DESCRIPTION 153 * Optional - sys_ioctl() will return -ENOTTY if this routine is not 154 * available, and the ioctl cannot be handled without filesystem help. 155 * 156 * sys_ioctl() handles these ioctls that apply only to regular files: 157 * FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD 158 * These ioctls are also handled by sys_ioctl(): 159 * FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC 160 * All other ioctls are passed to the filesystem. 161 * 162 * Refer to sys_ioctl() in fs/ioctl.c 163 * sys_ioctl() -> . 164 * 165 * PRE-CONDITIONS 166 * inode Pointer to inode that ioctl was issued on. 167 * filp Pointer to file that ioctl was issued on. 168 * cmd The ioctl command. 169 * arg The ioctl argument [can be interpreted as a 170 * user-space pointer if desired]. 171 * 172 * POST-CONDITIONS 173 * <return> Success (>=0) or an error code (<=0) that 174 * sys_ioctl() will return. 175 * 176 * HISTORY 177 * July 1, 1997 - Andrew E. Mileski 178 * Written, tested, and released. 179 */ 180 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, 181 unsigned long arg) 182 { 183 int result = -EINVAL; 184 185 if ( file_permission(filp, MAY_READ) != 0 ) 186 { 187 udf_debug("no permission to access inode %lu\n", 188 inode->i_ino); 189 return -EPERM; 190 } 191 192 if ( !arg ) 193 { 194 udf_debug("invalid argument to udf_ioctl\n"); 195 return -EINVAL; 196 } 197 198 switch (cmd) 199 { 200 case UDF_GETVOLIDENT: 201 return copy_to_user((char __user *)arg, 202 UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0; 203 case UDF_RELOCATE_BLOCKS: 204 { 205 long old, new; 206 207 if (!capable(CAP_SYS_ADMIN)) return -EACCES; 208 if (get_user(old, (long __user *)arg)) return -EFAULT; 209 if ((result = udf_relocate_blocks(inode->i_sb, 210 old, &new)) == 0) 211 result = put_user(new, (long __user *)arg); 212 213 return result; 214 } 215 case UDF_GETEASIZE: 216 result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg); 217 break; 218 219 case UDF_GETEABLOCK: 220 result = copy_to_user((char __user *)arg, UDF_I_DATA(inode), 221 UDF_I_LENEATTR(inode)) ? -EFAULT : 0; 222 break; 223 } 224 225 return result; 226 } 227 228 /* 229 * udf_release_file 230 * 231 * PURPOSE 232 * Called when all references to the file are closed 233 * 234 * DESCRIPTION 235 * Discard prealloced blocks 236 * 237 * HISTORY 238 * 239 */ 240 static int udf_release_file(struct inode * inode, struct file * filp) 241 { 242 if (filp->f_mode & FMODE_WRITE) 243 { 244 lock_kernel(); 245 udf_discard_prealloc(inode); 246 unlock_kernel(); 247 } 248 return 0; 249 } 250 251 struct file_operations udf_file_operations = { 252 .read = generic_file_read, 253 .ioctl = udf_ioctl, 254 .open = generic_file_open, 255 .mmap = generic_file_mmap, 256 .write = udf_file_write, 257 .release = udf_release_file, 258 .fsync = udf_fsync_file, 259 .sendfile = generic_file_sendfile, 260 }; 261 262 struct inode_operations udf_file_inode_operations = { 263 .truncate = udf_truncate, 264 }; 265