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/pagemap.h> 32 #include <linux/uio.h> 33 34 #include "udf_i.h" 35 #include "udf_sb.h" 36 37 static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf) 38 { 39 struct vm_area_struct *vma = vmf->vma; 40 struct inode *inode = file_inode(vma->vm_file); 41 struct address_space *mapping = inode->i_mapping; 42 struct folio *folio = page_folio(vmf->page); 43 loff_t size; 44 unsigned int end; 45 vm_fault_t ret = VM_FAULT_LOCKED; 46 int err; 47 48 sb_start_pagefault(inode->i_sb); 49 file_update_time(vma->vm_file); 50 filemap_invalidate_lock_shared(mapping); 51 folio_lock(folio); 52 size = i_size_read(inode); 53 if (folio->mapping != inode->i_mapping || folio_pos(folio) >= size) { 54 folio_unlock(folio); 55 ret = VM_FAULT_NOPAGE; 56 goto out_unlock; 57 } 58 /* Space is already allocated for in-ICB file */ 59 if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) 60 goto out_dirty; 61 if (folio->index == size >> PAGE_SHIFT) 62 end = size & ~PAGE_MASK; 63 else 64 end = PAGE_SIZE; 65 err = __block_write_begin(&folio->page, 0, end, udf_get_block); 66 if (err) { 67 folio_unlock(folio); 68 ret = vmf_fs_error(err); 69 goto out_unlock; 70 } 71 72 block_commit_write(&folio->page, 0, end); 73 out_dirty: 74 folio_mark_dirty(folio); 75 folio_wait_stable(folio); 76 out_unlock: 77 filemap_invalidate_unlock_shared(mapping); 78 sb_end_pagefault(inode->i_sb); 79 return ret; 80 } 81 82 static const struct vm_operations_struct udf_file_vm_ops = { 83 .fault = filemap_fault, 84 .map_pages = filemap_map_pages, 85 .page_mkwrite = udf_page_mkwrite, 86 }; 87 88 static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 89 { 90 ssize_t retval; 91 struct file *file = iocb->ki_filp; 92 struct inode *inode = file_inode(file); 93 struct udf_inode_info *iinfo = UDF_I(inode); 94 95 inode_lock(inode); 96 97 retval = generic_write_checks(iocb, from); 98 if (retval <= 0) 99 goto out; 100 101 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && 102 inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) + 103 iocb->ki_pos + iov_iter_count(from))) { 104 filemap_invalidate_lock(inode->i_mapping); 105 retval = udf_expand_file_adinicb(inode); 106 filemap_invalidate_unlock(inode->i_mapping); 107 if (retval) 108 goto out; 109 } 110 111 retval = __generic_file_write_iter(iocb, from); 112 out: 113 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) { 114 down_write(&iinfo->i_data_sem); 115 iinfo->i_lenAlloc = inode->i_size; 116 up_write(&iinfo->i_data_sem); 117 } 118 inode_unlock(inode); 119 120 if (retval > 0) { 121 mark_inode_dirty(inode); 122 retval = generic_write_sync(iocb, retval); 123 } 124 125 return retval; 126 } 127 128 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 129 { 130 struct inode *inode = file_inode(filp); 131 long old_block, new_block; 132 int result; 133 134 if (file_permission(filp, MAY_READ) != 0) { 135 udf_debug("no permission to access inode %lu\n", inode->i_ino); 136 return -EPERM; 137 } 138 139 if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) || 140 (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) { 141 udf_debug("invalid argument to udf_ioctl\n"); 142 return -EINVAL; 143 } 144 145 switch (cmd) { 146 case UDF_GETVOLIDENT: 147 if (copy_to_user((char __user *)arg, 148 UDF_SB(inode->i_sb)->s_volume_ident, 32)) 149 return -EFAULT; 150 return 0; 151 case UDF_RELOCATE_BLOCKS: 152 if (!capable(CAP_SYS_ADMIN)) 153 return -EPERM; 154 if (get_user(old_block, (long __user *)arg)) 155 return -EFAULT; 156 result = udf_relocate_blocks(inode->i_sb, 157 old_block, &new_block); 158 if (result == 0) 159 result = put_user(new_block, (long __user *)arg); 160 return result; 161 case UDF_GETEASIZE: 162 return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg); 163 case UDF_GETEABLOCK: 164 return copy_to_user((char __user *)arg, 165 UDF_I(inode)->i_data, 166 UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0; 167 default: 168 return -ENOIOCTLCMD; 169 } 170 171 return 0; 172 } 173 174 static int udf_release_file(struct inode *inode, struct file *filp) 175 { 176 if (filp->f_mode & FMODE_WRITE && 177 atomic_read(&inode->i_writecount) == 1) { 178 /* 179 * Grab i_mutex to avoid races with writes changing i_size 180 * while we are running. 181 */ 182 inode_lock(inode); 183 down_write(&UDF_I(inode)->i_data_sem); 184 udf_discard_prealloc(inode); 185 udf_truncate_tail_extent(inode); 186 up_write(&UDF_I(inode)->i_data_sem); 187 inode_unlock(inode); 188 } 189 return 0; 190 } 191 192 static int udf_file_mmap(struct file *file, struct vm_area_struct *vma) 193 { 194 file_accessed(file); 195 vma->vm_ops = &udf_file_vm_ops; 196 197 return 0; 198 } 199 200 const struct file_operations udf_file_operations = { 201 .read_iter = generic_file_read_iter, 202 .unlocked_ioctl = udf_ioctl, 203 .open = generic_file_open, 204 .mmap = udf_file_mmap, 205 .write_iter = udf_file_write_iter, 206 .release = udf_release_file, 207 .fsync = generic_file_fsync, 208 .splice_read = filemap_splice_read, 209 .splice_write = iter_file_splice_write, 210 .llseek = generic_file_llseek, 211 }; 212 213 static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 214 struct iattr *attr) 215 { 216 struct inode *inode = d_inode(dentry); 217 struct super_block *sb = inode->i_sb; 218 int error; 219 220 error = setattr_prepare(&nop_mnt_idmap, dentry, attr); 221 if (error) 222 return error; 223 224 if ((attr->ia_valid & ATTR_UID) && 225 UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) && 226 !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid)) 227 return -EPERM; 228 if ((attr->ia_valid & ATTR_GID) && 229 UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) && 230 !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid)) 231 return -EPERM; 232 233 if ((attr->ia_valid & ATTR_SIZE) && 234 attr->ia_size != i_size_read(inode)) { 235 error = udf_setsize(inode, attr->ia_size); 236 if (error) 237 return error; 238 } 239 240 if (attr->ia_valid & ATTR_MODE) 241 udf_update_extra_perms(inode, attr->ia_mode); 242 243 setattr_copy(&nop_mnt_idmap, inode, attr); 244 mark_inode_dirty(inode); 245 return 0; 246 } 247 248 const struct inode_operations udf_file_inode_operations = { 249 .setattr = udf_setattr, 250 }; 251