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/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
#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:
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 (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 ;
}
reiserfs_write_lock(inode->i_sb);
/* we need to make sure nobody is changing the file size beneath
** us
*/
down(&inode->i_sem) ;
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:
up(&inode->i_sem) ;
reiserfs_write_unlock(inode->i_sb);
return retval;
}
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