253 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * file.c4 *5 * PURPOSE6 * File handling routines for the OSTA-UDF(tm) filesystem.7 *8 * COPYRIGHT9 * (C) 1998-1999 Dave Boynton10 * (C) 1998-2004 Ben Fennema11 * (C) 1999-2000 Stelias Computing Inc12 *13 * HISTORY14 *15 * 10/02/98 dgb Attempt to integrate into udf.o16 * 10/07/98 Switched to using generic_readpage, etc., like isofs17 * And it works!18 * 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but19 * ICBTAG_FLAG_AD_IN_ICB.20 * 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c21 * 05/12/99 Preliminary file write support22 */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 37static 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 else64 end = PAGE_SIZE;65 err = __block_write_begin(folio, 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);73out_dirty:74 folio_mark_dirty(folio);75 folio_wait_stable(folio);76out_unlock:77 filemap_invalidate_unlock_shared(mapping);78 sb_end_pagefault(inode->i_sb);79 return ret;80}81 82static 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 88static 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);112out: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 128long 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 174static 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_size180 * 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 192static 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 200const 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 213static 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 filemap_invalidate_lock(inode->i_mapping);236 error = udf_setsize(inode, attr->ia_size);237 filemap_invalidate_unlock(inode->i_mapping);238 if (error)239 return error;240 }241 242 if (attr->ia_valid & ATTR_MODE)243 udf_update_extra_perms(inode, attr->ia_mode);244 245 setattr_copy(&nop_mnt_idmap, inode, attr);246 mark_inode_dirty(inode);247 return 0;248}249 250const struct inode_operations udf_file_inode_operations = {251 .setattr = udf_setattr,252};253