1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * file.c 4 * 5 * PURPOSE 6 * File handling routines for the OSTA-UDF(tm) filesystem. 7 * 8 * COPYRIGHT 9 * (C) 1998-1999 Dave Boynton 10 * (C) 1998-2004 Ben Fennema 11 * (C) 1999-2000 Stelias Computing Inc 12 * 13 * HISTORY 14 * 15 * 10/02/98 dgb Attempt to integrate into udf.o 16 * 10/07/98 Switched to using generic_readpage, etc., like isofs 17 * And it works! 18 * 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but 19 * ICBTAG_FLAG_AD_IN_ICB. 20 * 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c 21 * 05/12/99 Preliminary file write support 22 */ 23 24 #include "udfdecl.h" 25 #include <linux/fs.h> 26 #include <linux/uaccess.h> 27 #include <linux/kernel.h> 28 #include <linux/string.h> /* memset */ 29 #include <linux/capability.h> 30 #include <linux/errno.h> 31 #include <linux/filelock.h> 32 #include <linux/pagemap.h> 33 #include <linux/uio.h> 34 35 #include "udf_i.h" 36 #include "udf_sb.h" 37 38 static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf) 39 { 40 struct vm_area_struct *vma = vmf->vma; 41 struct inode *inode = file_inode(vma->vm_file); 42 struct address_space *mapping = inode->i_mapping; 43 struct folio *folio = page_folio(vmf->page); 44 loff_t size; 45 unsigned int end; 46 vm_fault_t ret = VM_FAULT_LOCKED; 47 int err; 48 49 sb_start_pagefault(inode->i_sb); 50 file_update_time(vma->vm_file); 51 filemap_invalidate_lock_shared(mapping); 52 folio_lock(folio); 53 size = i_size_read(inode); 54 if (folio->mapping != inode->i_mapping || folio_pos(folio) >= size) { 55 folio_unlock(folio); 56 ret = VM_FAULT_NOPAGE; 57 goto out_unlock; 58 } 59 /* Space is already allocated for in-ICB file */ 60 if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) 61 goto out_dirty; 62 if (folio->index == size >> PAGE_SHIFT) 63 end = size & ~PAGE_MASK; 64 else 65 end = PAGE_SIZE; 66 err = __block_write_begin(folio, 0, end, udf_get_block); 67 if (err) { 68 folio_unlock(folio); 69 ret = vmf_fs_error(err); 70 goto out_unlock; 71 } 72 73 block_commit_write(folio, 0, end); 74 out_dirty: 75 folio_mark_dirty(folio); 76 folio_wait_stable(folio); 77 out_unlock: 78 filemap_invalidate_unlock_shared(mapping); 79 sb_end_pagefault(inode->i_sb); 80 return ret; 81 } 82 83 static const struct vm_operations_struct udf_file_vm_ops = { 84 .fault = filemap_fault, 85 .map_pages = filemap_map_pages, 86 .page_mkwrite = udf_page_mkwrite, 87 }; 88 89 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 90 { 91 ssize_t retval; 92 struct file *file = iocb->ki_filp; 93 struct inode *inode = file_inode(file); 94 struct udf_inode_info *iinfo = UDF_I(inode); 95 96 inode_lock(inode); 97 98 retval = generic_write_checks(iocb, from); 99 if (retval <= 0) 100 goto out; 101 102 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && 103 inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) + 104 iocb->ki_pos + iov_iter_count(from))) { 105 filemap_invalidate_lock(inode->i_mapping); 106 retval = udf_expand_file_adinicb(inode); 107 filemap_invalidate_unlock(inode->i_mapping); 108 if (retval) 109 goto out; 110 } 111 112 retval = __generic_file_write_iter(iocb, from); 113 out: 114 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) { 115 down_write(&iinfo->i_data_sem); 116 iinfo->i_lenAlloc = inode->i_size; 117 up_write(&iinfo->i_data_sem); 118 } 119 inode_unlock(inode); 120 121 if (retval > 0) { 122 mark_inode_dirty(inode); 123 retval = generic_write_sync(iocb, retval); 124 } 125 126 return retval; 127 } 128 129 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 130 { 131 struct inode *inode = file_inode(filp); 132 long old_block, new_block; 133 int result; 134 135 if (file_permission(filp, MAY_READ) != 0) { 136 udf_debug("no permission to access inode %lu\n", inode->i_ino); 137 return -EPERM; 138 } 139 140 if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || 141 (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { 142 udf_debug("invalid argument to udf_ioctl\n"); 143 return -EINVAL; 144 } 145 146 switch (cmd) { 147 case UDF_GETVOLIDENT: 148 if (copy_to_user((char __user *)arg, 149 UDF_SB(inode->i_sb)->s_volume_ident, 32)) 150 return -EFAULT; 151 return 0; 152 case UDF_RELOCATE_BLOCKS: 153 if (!capable(CAP_SYS_ADMIN)) 154 return -EPERM; 155 if (get_user(old_block, (long __user *)arg)) 156 return -EFAULT; 157 result = udf_relocate_blocks(inode->i_sb, 158 old_block, &new_block); 159 if (result == 0) 160 result = put_user(new_block, (long __user *)arg); 161 return result; 162 case UDF_GETEASIZE: 163 return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); 164 case UDF_GETEABLOCK: 165 return copy_to_user((char __user *)arg, 166 UDF_I(inode)->i_data, 167 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; 168 default: 169 return -ENOIOCTLCMD; 170 } 171 172 return 0; 173 } 174 175 static int udf_release_file(struct inode *inode, struct file *filp) 176 { 177 if (filp->f_mode & FMODE_WRITE && 178 atomic_read(&inode->i_writecount) == 1) { 179 /* 180 * Grab i_mutex to avoid races with writes changing i_size 181 * while we are running. 182 */ 183 inode_lock(inode); 184 down_write(&UDF_I(inode)->i_data_sem); 185 udf_discard_prealloc(inode); 186 udf_truncate_tail_extent(inode); 187 up_write(&UDF_I(inode)->i_data_sem); 188 inode_unlock(inode); 189 } 190 return 0; 191 } 192 193 static int udf_file_mmap(struct file *file, struct vm_area_struct *vma) 194 { 195 file_accessed(file); 196 vma->vm_ops = &udf_file_vm_ops; 197 198 return 0; 199 } 200 201 const struct file_operations udf_file_operations = { 202 .read_iter = generic_file_read_iter, 203 .unlocked_ioctl = udf_ioctl, 204 .open = generic_file_open, 205 .mmap = udf_file_mmap, 206 .write_iter = udf_file_write_iter, 207 .release = udf_release_file, 208 .fsync = generic_file_fsync, 209 .splice_read = filemap_splice_read, 210 .splice_write = iter_file_splice_write, 211 .llseek = generic_file_llseek, 212 .setlease = generic_setlease, 213 }; 214 215 static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 216 struct iattr *attr) 217 { 218 struct inode *inode = d_inode(dentry); 219 struct super_block *sb = inode->i_sb; 220 int error; 221 222 error = setattr_prepare(&nop_mnt_idmap, dentry, attr); 223 if (error) 224 return error; 225 226 if ((attr->ia_valid & ATTR_UID) && 227 UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && 228 !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid)) 229 return -EPERM; 230 if ((attr->ia_valid & ATTR_GID) && 231 UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && 232 !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid)) 233 return -EPERM; 234 235 if ((attr->ia_valid & ATTR_SIZE) && 236 attr->ia_size != i_size_read(inode)) { 237 filemap_invalidate_lock(inode->i_mapping); 238 error = udf_setsize(inode, attr->ia_size); 239 filemap_invalidate_unlock(inode->i_mapping); 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