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/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/reiserfs_fs.h>
#include <linux/time.h>
#include <asm/uaccess.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
static int reiserfs_unpack(struct inode *inode, struct file *filp);
/*
** reiserfs_ioctl - handler for ioctl for inode
** supported commands:
** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
** and prevent packing file (argument arg has to be non-zero)
** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
** 3) That's all for a while ...
*/
int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
unsigned long arg)
{
unsigned int flags;
switch (cmd) {
case REISERFS_IOC_UNPACK:
if (S_ISREG(inode->i_mode)) {
if (arg)
return reiserfs_unpack(inode, filp);
else
return 0;
} else
return -ENOTTY;
/* following two cases are taken from fs/ext2/ioctl.c by Remy
Card (card@masi.ibp.fr) */
case REISERFS_IOC_GETFLAGS:
if (!reiserfs_attrs(inode->i_sb))
return -ENOTTY;
flags = REISERFS_I(inode)->i_attrs;
i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
return put_user(flags, (int __user *)arg);
case REISERFS_IOC_SETFLAGS:{
if (!reiserfs_attrs(inode->i_sb))
return -ENOTTY;
if (IS_RDONLY(inode))
return -EROFS;
if ((current->fsuid != inode->i_uid)
&& !capable(CAP_FOWNER))
return -EPERM;
if (get_user(flags, (int __user *)arg))
return -EFAULT;
if (((flags ^ REISERFS_I(inode)->
i_attrs) & (REISERFS_IMMUTABLE_FL |
REISERFS_APPEND_FL))
&& !capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
if ((flags & REISERFS_NOTAIL_FL) &&
S_ISREG(inode->i_mode)) {
int result;
result = reiserfs_unpack(inode, filp);
if (result)
return result;
}
sd_attrs_to_i_attrs(flags, inode);
REISERFS_I(inode)->i_attrs = flags;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return 0;
}
case REISERFS_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *)arg);
case REISERFS_IOC_SETVERSION:
if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
if (get_user(inode->i_generation, (int __user *)arg))
return -EFAULT;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return 0;
default:
return -ENOTTY;
}
}
/*
** reiserfs_unpack
** Function try to convert tail from direct item into indirect.
** It set up nopack attribute in the REISERFS_I(inode)->nopack
*/
static int reiserfs_unpack(struct inode *inode, struct file *filp)
{
int retval = 0;
int index;
struct page *page;
struct address_space *mapping;
unsigned long write_from;
unsigned long blocksize = inode->i_sb->s_blocksize;
if (inode->i_size == 0) {
REISERFS_I(inode)->i_flags |= i_nopack_mask;
return 0;
}
/* ioctl already done */
if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
return 0;
}
/* we need to make sure nobody is changing the file size beneath
** us
*/
mutex_lock(&inode->i_mutex);
reiserfs_write_lock(inode->i_sb);
write_from = inode->i_size & (blocksize - 1);
/* if we are on a block boundary, we are already unpacked. */
if (write_from == 0) {
REISERFS_I(inode)->i_flags |= i_nopack_mask;
goto out;
}
/* we unpack by finding the page with the tail, and calling
** reiserfs_prepare_write on that page. This will force a
** reiserfs_get_block to unpack the tail for us.
*/
index = inode->i_size >> PAGE_CACHE_SHIFT;
mapping = inode->i_mapping;
page = grab_cache_page(mapping, index);
retval = -ENOMEM;
if (!page) {
goto out;
}
retval =
mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
if (retval)
goto out_unlock;
/* conversion can change page contents, must flush */
flush_dcache_page(page);
retval =
mapping->a_ops->commit_write(NULL, page, write_from, write_from);
REISERFS_I(inode)->i_flags |= i_nopack_mask;
out_unlock:
unlock_page(page);
page_cache_release(page);
out:
mutex_unlock(&inode->i_mutex);
reiserfs_write_unlock(inode->i_sb);
return retval;
}
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