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// SPDX-License-Identifier: GPL-2.0-only
/*
* file.c
*
* PURPOSE
* File handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* (C) 1998-1999 Dave Boynton
* (C) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 10/02/98 dgb Attempt to integrate into udf.o
* 10/07/98 Switched to using generic_readpage, etc., like isofs
* And it works!
* 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
* ICBTAG_FLAG_AD_IN_ICB.
* 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
* 05/12/99 Preliminary file write support
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/string.h> /* memset */
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include "udf_i.h"
#include "udf_sb.h"
static vm_fault_t udf_page_mkwrite(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct inode *inode = file_inode(vma->vm_file);
struct address_space *mapping = inode->i_mapping;
struct folio *folio = page_folio(vmf->page);
loff_t size;
unsigned int end;
vm_fault_t ret = VM_FAULT_LOCKED;
int err;
sb_start_pagefault(inode->i_sb);
file_update_time(vma->vm_file);
filemap_invalidate_lock_shared(mapping);
folio_lock(folio);
size = i_size_read(inode);
if (folio->mapping != inode->i_mapping || folio_pos(folio) >= size) {
folio_unlock(folio);
ret = VM_FAULT_NOPAGE;
goto out_unlock;
}
/* Space is already allocated for in-ICB file */
if (UDF_I(inode)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
goto out_dirty;
if (folio->index == size >> PAGE_SHIFT)
end = size & ~PAGE_MASK;
else
end = PAGE_SIZE;
err = __block_write_begin(&folio->page, 0, end, udf_get_block);
if (err) {
folio_unlock(folio);
ret = vmf_fs_error(err);
goto out_unlock;
}
block_commit_write(&folio->page, 0, end);
out_dirty:
folio_mark_dirty(folio);
folio_wait_stable(folio);
out_unlock:
filemap_invalidate_unlock_shared(mapping);
sb_end_pagefault(inode->i_sb);
return ret;
}
static const struct vm_operations_struct udf_file_vm_ops = {
.fault = filemap_fault,
.map_pages = filemap_map_pages,
.page_mkwrite = udf_page_mkwrite,
};
static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
ssize_t retval;
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct udf_inode_info *iinfo = UDF_I(inode);
inode_lock(inode);
retval = generic_write_checks(iocb, from);
if (retval <= 0)
goto out;
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
iocb->ki_pos + iov_iter_count(from))) {
filemap_invalidate_lock(inode->i_mapping);
retval = udf_expand_file_adinicb(inode);
filemap_invalidate_unlock(inode->i_mapping);
if (retval)
goto out;
}
retval = __generic_file_write_iter(iocb, from);
out:
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0) {
down_write(&iinfo->i_data_sem);
iinfo->i_lenAlloc = inode->i_size;
up_write(&iinfo->i_data_sem);
}
inode_unlock(inode);
if (retval > 0) {
mark_inode_dirty(inode);
retval = generic_write_sync(iocb, retval);
}
return retval;
}
long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
long old_block, new_block;
int result;
if (file_permission(filp, MAY_READ) != 0) {
udf_debug("no permission to access inode %lu\n", inode->i_ino);
return -EPERM;
}
if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
(cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
udf_debug("invalid argument to udf_ioctl\n");
return -EINVAL;
}
switch (cmd) {
case UDF_GETVOLIDENT:
if (copy_to_user((char __user *)arg,
UDF_SB(inode->i_sb)->s_volume_ident, 32))
return -EFAULT;
return 0;
case UDF_RELOCATE_BLOCKS:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (get_user(old_block, (long __user *)arg))
return -EFAULT;
result = udf_relocate_blocks(inode->i_sb,
old_block, &new_block);
if (result == 0)
result = put_user(new_block, (long __user *)arg);
return result;
case UDF_GETEASIZE:
return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
case UDF_GETEABLOCK:
return copy_to_user((char __user *)arg,
UDF_I(inode)->i_data,
UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static int udf_release_file(struct inode *inode, struct file *filp)
{
if (filp->f_mode & FMODE_WRITE &&
atomic_read(&inode->i_writecount) == 1) {
/*
* Grab i_mutex to avoid races with writes changing i_size
* while we are running.
*/
inode_lock(inode);
down_write(&UDF_I(inode)->i_data_sem);
udf_discard_prealloc(inode);
udf_truncate_tail_extent(inode);
up_write(&UDF_I(inode)->i_data_sem);
inode_unlock(inode);
}
return 0;
}
static int udf_file_mmap(struct file *file, struct vm_area_struct *vma)
{
file_accessed(file);
vma->vm_ops = &udf_file_vm_ops;
return 0;
}
const struct file_operations udf_file_operations = {
.read_iter = generic_file_read_iter,
.unlocked_ioctl = udf_ioctl,
.open = generic_file_open,
.mmap = udf_file_mmap,
.write_iter = udf_file_write_iter,
.release = udf_release_file,
.fsync = generic_file_fsync,
.splice_read = filemap_splice_read,
.splice_write = iter_file_splice_write,
.llseek = generic_file_llseek,
};
static int udf_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct super_block *sb = inode->i_sb;
int error;
error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
if (error)
return error;
if ((attr->ia_valid & ATTR_UID) &&
UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) &&
!uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid))
return -EPERM;
if ((attr->ia_valid & ATTR_GID) &&
UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) &&
!gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid))
return -EPERM;
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode)) {
filemap_invalidate_lock(inode->i_mapping);
error = udf_setsize(inode, attr->ia_size);
filemap_invalidate_unlock(inode->i_mapping);
if (error)
return error;
}
if (attr->ia_valid & ATTR_MODE)
udf_update_extra_perms(inode, attr->ia_mode);
setattr_copy(&nop_mnt_idmap, inode, attr);
mark_inode_dirty(inode);
return 0;
}
const struct inode_operations udf_file_inode_operations = {
.setattr = udf_setattr,
};
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