linux/fs/udf/file.c
Christoph Hellwig e259221763 fs: simplify the generic_write_sync prototype
The kiocb already has the new position, so use that.  The only interesting
case is AIO, where we currently don't bother updating ki_pos.  We're about
to free the kiocb after we're done, so we might as well update it to make
everyone's life simpler.

While we're at it also return the bytes written argument passed in if
we were successful so that the boilerplate error switch code in the
callers can go away.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00

269 lines
6.4 KiB
C

/*
* file.c
*
* PURPOSE
* File handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (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 void __udf_adinicb_readpage(struct page *page)
{
struct inode *inode = page->mapping->host;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
kaddr = kmap(page);
memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
memset(kaddr + inode->i_size, 0, PAGE_SIZE - inode->i_size);
flush_dcache_page(page);
SetPageUptodate(page);
kunmap(page);
}
static int udf_adinicb_readpage(struct file *file, struct page *page)
{
BUG_ON(!PageLocked(page));
__udf_adinicb_readpage(page);
unlock_page(page);
return 0;
}
static int udf_adinicb_writepage(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
BUG_ON(!PageLocked(page));
kaddr = kmap(page);
memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
mark_inode_dirty(inode);
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
}
static int udf_adinicb_write_begin(struct file *file,
struct address_space *mapping, loff_t pos,
unsigned len, unsigned flags, struct page **pagep,
void **fsdata)
{
struct page *page;
if (WARN_ON_ONCE(pos >= PAGE_SIZE))
return -EIO;
page = grab_cache_page_write_begin(mapping, 0, flags);
if (!page)
return -ENOMEM;
*pagep = page;
if (!PageUptodate(page) && len != PAGE_SIZE)
__udf_adinicb_readpage(page);
return 0;
}
static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
/* Fallback to buffered I/O. */
return 0;
}
const struct address_space_operations udf_adinicb_aops = {
.readpage = udf_adinicb_readpage,
.writepage = udf_adinicb_writepage,
.write_begin = udf_adinicb_write_begin,
.write_end = simple_write_end,
.direct_IO = udf_adinicb_direct_IO,
};
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);
int err;
inode_lock(inode);
retval = generic_write_checks(iocb, from);
if (retval <= 0)
goto out;
down_write(&iinfo->i_data_sem);
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
loff_t end = iocb->ki_pos + iov_iter_count(from);
if (inode->i_sb->s_blocksize <
(udf_file_entry_alloc_offset(inode) + end)) {
err = udf_expand_file_adinicb(inode);
if (err) {
inode_unlock(inode);
udf_debug("udf_expand_adinicb: err=%d\n", err);
return err;
}
} else {
iinfo->i_lenAlloc = max(end, inode->i_size);
up_write(&iinfo->i_data_sem);
}
} else
up_write(&iinfo->i_data_sem);
retval = __generic_file_write_iter(iocb, from);
out:
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 = -EINVAL;
if (inode_permission(inode, MAY_READ) != 0) {
udf_debug("no permission to access inode %lu\n", inode->i_ino);
result = -EPERM;
goto out;
}
if (!arg) {
udf_debug("invalid argument to udf_ioctl\n");
result = -EINVAL;
goto out;
}
switch (cmd) {
case UDF_GETVOLIDENT:
if (copy_to_user((char __user *)arg,
UDF_SB(inode->i_sb)->s_volume_ident, 32))
result = -EFAULT;
else
result = 0;
goto out;
case UDF_RELOCATE_BLOCKS:
if (!capable(CAP_SYS_ADMIN)) {
result = -EPERM;
goto out;
}
if (get_user(old_block, (long __user *)arg)) {
result = -EFAULT;
goto out;
}
result = udf_relocate_blocks(inode->i_sb,
old_block, &new_block);
if (result == 0)
result = put_user(new_block, (long __user *)arg);
goto out;
case UDF_GETEASIZE:
result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
goto out;
case UDF_GETEABLOCK:
result = copy_to_user((char __user *)arg,
UDF_I(inode)->i_ext.i_data,
UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
goto out;
}
out:
return result;
}
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;
}
const struct file_operations udf_file_operations = {
.read_iter = generic_file_read_iter,
.unlocked_ioctl = udf_ioctl,
.open = generic_file_open,
.mmap = generic_file_mmap,
.write_iter = udf_file_write_iter,
.release = udf_release_file,
.fsync = generic_file_fsync,
.splice_read = generic_file_splice_read,
.llseek = generic_file_llseek,
};
static int udf_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
int error;
error = inode_change_ok(inode, attr);
if (error)
return error;
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode)) {
error = udf_setsize(inode, attr->ia_size);
if (error)
return error;
}
setattr_copy(inode, attr);
mark_inode_dirty(inode);
return 0;
}
const struct inode_operations udf_file_inode_operations = {
.setattr = udf_setattr,
};