linux/fs/udf/file.c
Christoph Hellwig f5e54d6e53 [PATCH] mark address_space_operations const
Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28 14:59:04 -07:00

265 lines
6.3 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/udf_fs.h>
#include <asm/uaccess.h>
#include <linux/kernel.h>
#include <linux/string.h> /* memset */
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <linux/pagemap.h>
#include <linux/buffer_head.h>
#include "udf_i.h"
#include "udf_sb.h"
static int udf_adinicb_readpage(struct file *file, struct page * page)
{
struct inode *inode = page->mapping->host;
char *kaddr;
BUG_ON(!PageLocked(page));
kaddr = kmap(page);
memset(kaddr, 0, PAGE_CACHE_SIZE);
memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
flush_dcache_page(page);
SetPageUptodate(page);
kunmap(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;
BUG_ON(!PageLocked(page));
kaddr = kmap(page);
memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
mark_inode_dirty(inode);
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
}
static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
{
kmap(page);
return 0;
}
static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
{
struct inode *inode = page->mapping->host;
char *kaddr = page_address(page);
memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
kaddr + offset, to - offset);
mark_inode_dirty(inode);
SetPageUptodate(page);
kunmap(page);
/* only one page here */
if (to > inode->i_size)
inode->i_size = to;
return 0;
}
const struct address_space_operations udf_adinicb_aops = {
.readpage = udf_adinicb_readpage,
.writepage = udf_adinicb_writepage,
.sync_page = block_sync_page,
.prepare_write = udf_adinicb_prepare_write,
.commit_write = udf_adinicb_commit_write,
};
static ssize_t udf_file_write(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
ssize_t retval;
struct inode *inode = file->f_dentry->d_inode;
int err, pos;
if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
{
if (file->f_flags & O_APPEND)
pos = inode->i_size;
else
pos = *ppos;
if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
pos + count))
{
udf_expand_file_adinicb(inode, pos + count, &err);
if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
{
udf_debug("udf_expand_adinicb: err=%d\n", err);
return err;
}
}
else
{
if (pos + count > inode->i_size)
UDF_I_LENALLOC(inode) = pos + count;
else
UDF_I_LENALLOC(inode) = inode->i_size;
}
}
retval = generic_file_write(file, buf, count, ppos);
if (retval > 0)
mark_inode_dirty(inode);
return retval;
}
/*
* udf_ioctl
*
* PURPOSE
* Issue an ioctl.
*
* DESCRIPTION
* Optional - sys_ioctl() will return -ENOTTY if this routine is not
* available, and the ioctl cannot be handled without filesystem help.
*
* sys_ioctl() handles these ioctls that apply only to regular files:
* FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
* These ioctls are also handled by sys_ioctl():
* FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
* All other ioctls are passed to the filesystem.
*
* Refer to sys_ioctl() in fs/ioctl.c
* sys_ioctl() -> .
*
* PRE-CONDITIONS
* inode Pointer to inode that ioctl was issued on.
* filp Pointer to file that ioctl was issued on.
* cmd The ioctl command.
* arg The ioctl argument [can be interpreted as a
* user-space pointer if desired].
*
* POST-CONDITIONS
* <return> Success (>=0) or an error code (<=0) that
* sys_ioctl() will return.
*
* HISTORY
* July 1, 1997 - Andrew E. Mileski
* Written, tested, and released.
*/
int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
unsigned long arg)
{
int result = -EINVAL;
if ( file_permission(filp, MAY_READ) != 0 )
{
udf_debug("no permission to access inode %lu\n",
inode->i_ino);
return -EPERM;
}
if ( !arg )
{
udf_debug("invalid argument to udf_ioctl\n");
return -EINVAL;
}
switch (cmd)
{
case UDF_GETVOLIDENT:
return copy_to_user((char __user *)arg,
UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
case UDF_RELOCATE_BLOCKS:
{
long old, new;
if (!capable(CAP_SYS_ADMIN)) return -EACCES;
if (get_user(old, (long __user *)arg)) return -EFAULT;
if ((result = udf_relocate_blocks(inode->i_sb,
old, &new)) == 0)
result = put_user(new, (long __user *)arg);
return result;
}
case UDF_GETEASIZE:
result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
break;
case UDF_GETEABLOCK:
result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
break;
}
return result;
}
/*
* udf_release_file
*
* PURPOSE
* Called when all references to the file are closed
*
* DESCRIPTION
* Discard prealloced blocks
*
* HISTORY
*
*/
static int udf_release_file(struct inode * inode, struct file * filp)
{
if (filp->f_mode & FMODE_WRITE)
{
lock_kernel();
udf_discard_prealloc(inode);
unlock_kernel();
}
return 0;
}
const struct file_operations udf_file_operations = {
.read = generic_file_read,
.ioctl = udf_ioctl,
.open = generic_file_open,
.mmap = generic_file_mmap,
.write = udf_file_write,
.release = udf_release_file,
.fsync = udf_fsync_file,
.sendfile = generic_file_sendfile,
};
struct inode_operations udf_file_inode_operations = {
.truncate = udf_truncate,
};