| 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 | mark_inode_dirty(inode); |
| 156 | err = generic_write_sync(file, iocb->ki_pos - retval, retval); |
| 157 | if (err < 0) |
| 158 | retval = err; |
| 159 | } |
| 160 | |
| 161 | return retval; |
| 162 | } |
| 163 | |
| 164 | long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
| 165 | { |
| 166 | struct inode *inode = file_inode(filp); |
| 167 | long old_block, new_block; |
| 168 | int result = -EINVAL; |
| 169 | |
| 170 | if (inode_permission(inode, MAY_READ) != 0) { |
| 171 | udf_debug("no permission to access inode %lu\n", inode->i_ino); |
| 172 | result = -EPERM; |
| 173 | goto out; |
| 174 | } |
| 175 | |
| 176 | if (!arg) { |
| 177 | udf_debug("invalid argument to udf_ioctl\n"); |
| 178 | result = -EINVAL; |
| 179 | goto out; |
| 180 | } |
| 181 | |
| 182 | switch (cmd) { |
| 183 | case UDF_GETVOLIDENT: |
| 184 | if (copy_to_user((char __user *)arg, |
| 185 | UDF_SB(inode->i_sb)->s_volume_ident, 32)) |
| 186 | result = -EFAULT; |
| 187 | else |
| 188 | result = 0; |
| 189 | goto out; |
| 190 | case UDF_RELOCATE_BLOCKS: |
| 191 | if (!capable(CAP_SYS_ADMIN)) { |
| 192 | result = -EPERM; |
| 193 | goto out; |
| 194 | } |
| 195 | if (get_user(old_block, (long __user *)arg)) { |
| 196 | result = -EFAULT; |
| 197 | goto out; |
| 198 | } |
| 199 | result = udf_relocate_blocks(inode->i_sb, |
| 200 | old_block, &new_block); |
| 201 | if (result == 0) |
| 202 | result = put_user(new_block, (long __user *)arg); |
| 203 | goto out; |
| 204 | case UDF_GETEASIZE: |
| 205 | result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); |
| 206 | goto out; |
| 207 | case UDF_GETEABLOCK: |
| 208 | result = copy_to_user((char __user *)arg, |
| 209 | UDF_I(inode)->i_ext.i_data, |
| 210 | UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; |
| 211 | goto out; |
| 212 | } |
| 213 | |
| 214 | out: |
| 215 | return result; |
| 216 | } |
| 217 | |
| 218 | static int udf_release_file(struct inode *inode, struct file *filp) |
| 219 | { |
| 220 | if (filp->f_mode & FMODE_WRITE && |
| 221 | atomic_read(&inode->i_writecount) == 1) { |
| 222 | /* |
| 223 | * Grab i_mutex to avoid races with writes changing i_size |
| 224 | * while we are running. |
| 225 | */ |
| 226 | mutex_lock(&inode->i_mutex); |
| 227 | down_write(&UDF_I(inode)->i_data_sem); |
| 228 | udf_discard_prealloc(inode); |
| 229 | udf_truncate_tail_extent(inode); |
| 230 | up_write(&UDF_I(inode)->i_data_sem); |
| 231 | mutex_unlock(&inode->i_mutex); |
| 232 | } |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | const struct file_operations udf_file_operations = { |
| 237 | .read_iter = generic_file_read_iter, |
| 238 | .unlocked_ioctl = udf_ioctl, |
| 239 | .open = generic_file_open, |
| 240 | .mmap = generic_file_mmap, |
| 241 | .write_iter = udf_file_write_iter, |
| 242 | .release = udf_release_file, |
| 243 | .fsync = generic_file_fsync, |
| 244 | .splice_read = generic_file_splice_read, |
| 245 | .llseek = generic_file_llseek, |
| 246 | }; |
| 247 | |
| 248 | static int udf_setattr(struct dentry *dentry, struct iattr *attr) |
| 249 | { |
| 250 | struct inode *inode = d_inode(dentry); |
| 251 | int error; |
| 252 | |
| 253 | error = inode_change_ok(inode, attr); |
| 254 | if (error) |
| 255 | return error; |
| 256 | |
| 257 | if ((attr->ia_valid & ATTR_SIZE) && |
| 258 | attr->ia_size != i_size_read(inode)) { |
| 259 | error = udf_setsize(inode, attr->ia_size); |
| 260 | if (error) |
| 261 | return error; |
| 262 | } |
| 263 | |
| 264 | setattr_copy(inode, attr); |
| 265 | mark_inode_dirty(inode); |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | const struct inode_operations udf_file_inode_operations = { |
| 270 | .setattr = udf_setattr, |
| 271 | }; |