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 vm_fault_t udf_page_mkwrite(struct vm_fault *vmf) 42 { 43 struct vm_area_struct *vma = vmf->vma; 44 struct inode *inode = file_inode(vma->vm_file); 45 struct address_space *mapping = inode->i_mapping; 46 struct page *page = vmf->page; 47 loff_t size; 48 unsigned int end; 49 vm_fault_t ret = VM_FAULT_LOCKED; 50 int err; 51 52 sb_start_pagefault(inode->i_sb); 53 file_update_time(vma->vm_file); 54 filemap_invalidate_lock_shared(mapping); 55 lock_page(page); 56 size = i_size_read(inode); 57 if (page->mapping != inode->i_mapping || page_offset(page) >= size) { 58 unlock_page(page); 59 ret = VM_FAULT_NOPAGE; 60 goto out_unlock; 61 } 62 /* Space is already allocated for in-ICB file */ 63 if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) 64 goto out_dirty; 65 if (page->index == size >> PAGE_SHIFT) 66 end = size & ~PAGE_MASK; 67 else 68 end = PAGE_SIZE; 69 err = __block_write_begin(page, 0, end, udf_get_block); 70 if (!err) 71 err = block_commit_write(page, 0, end); 72 if (err < 0) { 73 unlock_page(page); 74 ret = block_page_mkwrite_return(err); 75 goto out_unlock; 76 } 77 out_dirty: 78 set_page_dirty(page); 79 wait_for_stable_page(page); 80 out_unlock: 81 filemap_invalidate_unlock_shared(mapping); 82 sb_end_pagefault(inode->i_sb); 83 return ret; 84 } 85 86 static const struct vm_operations_struct udf_file_vm_ops = { 87 .fault = filemap_fault, 88 .map_pages = filemap_map_pages, 89 .page_mkwrite = udf_page_mkwrite, 90 }; 91 92 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 93 { 94 ssize_t retval; 95 struct file *file = iocb->ki_filp; 96 struct inode *inode = file_inode(file); 97 struct udf_inode_info *iinfo = UDF_I(inode); 98 99 inode_lock(inode); 100 101 retval = generic_write_checks(iocb, from); 102 if (retval <= 0) 103 goto out; 104 105 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && 106 inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) + 107 iocb->ki_pos + iov_iter_count(from))) { 108 filemap_invalidate_lock(inode->i_mapping); 109 retval = udf_expand_file_adinicb(inode); 110 filemap_invalidate_unlock(inode->i_mapping); 111 if (retval) 112 goto out; 113 } 114 115 retval = __generic_file_write_iter(iocb, from); 116 out: 117 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) { 118 down_write(&iinfo->i_data_sem); 119 iinfo->i_lenAlloc = inode->i_size; 120 up_write(&iinfo->i_data_sem); 121 } 122 inode_unlock(inode); 123 124 if (retval > 0) { 125 mark_inode_dirty(inode); 126 retval = generic_write_sync(iocb, retval); 127 } 128 129 return retval; 130 } 131 132 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 133 { 134 struct inode *inode = file_inode(filp); 135 long old_block, new_block; 136 int result; 137 138 if (file_permission(filp, MAY_READ) != 0) { 139 udf_debug("no permission to access inode %lu\n", inode->i_ino); 140 return -EPERM; 141 } 142 143 if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || 144 (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { 145 udf_debug("invalid argument to udf_ioctl\n"); 146 return -EINVAL; 147 } 148 149 switch (cmd) { 150 case UDF_GETVOLIDENT: 151 if (copy_to_user((char __user *)arg, 152 UDF_SB(inode->i_sb)->s_volume_ident, 32)) 153 return -EFAULT; 154 return 0; 155 case UDF_RELOCATE_BLOCKS: 156 if (!capable(CAP_SYS_ADMIN)) 157 return -EPERM; 158 if (get_user(old_block, (long __user *)arg)) 159 return -EFAULT; 160 result = udf_relocate_blocks(inode->i_sb, 161 old_block, &new_block); 162 if (result == 0) 163 result = put_user(new_block, (long __user *)arg); 164 return result; 165 case UDF_GETEASIZE: 166 return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); 167 case UDF_GETEABLOCK: 168 return copy_to_user((char __user *)arg, 169 UDF_I(inode)->i_data, 170 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; 171 default: 172 return -ENOIOCTLCMD; 173 } 174 175 return 0; 176 } 177 178 static int udf_release_file(struct inode *inode, struct file *filp) 179 { 180 if (filp->f_mode & FMODE_WRITE && 181 atomic_read(&inode->i_writecount) == 1) { 182 /* 183 * Grab i_mutex to avoid races with writes changing i_size 184 * while we are running. 185 */ 186 inode_lock(inode); 187 down_write(&UDF_I(inode)->i_data_sem); 188 udf_discard_prealloc(inode); 189 udf_truncate_tail_extent(inode); 190 up_write(&UDF_I(inode)->i_data_sem); 191 inode_unlock(inode); 192 } 193 return 0; 194 } 195 196 static int udf_file_mmap(struct file *file, struct vm_area_struct *vma) 197 { 198 file_accessed(file); 199 vma->vm_ops = &udf_file_vm_ops; 200 201 return 0; 202 } 203 204 const struct file_operations udf_file_operations = { 205 .read_iter = generic_file_read_iter, 206 .unlocked_ioctl = udf_ioctl, 207 .open = generic_file_open, 208 .mmap = udf_file_mmap, 209 .write_iter = udf_file_write_iter, 210 .release = udf_release_file, 211 .fsync = generic_file_fsync, 212 .splice_read = generic_file_splice_read, 213 .splice_write = iter_file_splice_write, 214 .llseek = generic_file_llseek, 215 }; 216 217 static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 218 struct iattr *attr) 219 { 220 struct inode *inode = d_inode(dentry); 221 struct super_block *sb = inode->i_sb; 222 int error; 223 224 error = setattr_prepare(&nop_mnt_idmap, dentry, attr); 225 if (error) 226 return error; 227 228 if ((attr->ia_valid & ATTR_UID) && 229 UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && 230 !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid)) 231 return -EPERM; 232 if ((attr->ia_valid & ATTR_GID) && 233 UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && 234 !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid)) 235 return -EPERM; 236 237 if ((attr->ia_valid & ATTR_SIZE) && 238 attr->ia_size != i_size_read(inode)) { 239 error = udf_setsize(inode, attr->ia_size); 240 if (error) 241 return error; 242 } 243 244 if (attr->ia_valid & ATTR_MODE) 245 udf_update_extra_perms(inode, attr->ia_mode); 246 247 setattr_copy(&nop_mnt_idmap, inode, attr); 248 mark_inode_dirty(inode); 249 return 0; 250 } 251 252 const struct inode_operations udf_file_inode_operations = { 253 .setattr = udf_setattr, 254 }; 255