271 строка
6.4 KiB
C
271 строка
6.4 KiB
C
/*
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* file.c
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*
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* PURPOSE
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* File handling routines for the OSTA-UDF(tm) filesystem.
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*
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* CONTACTS
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* E-mail regarding any portion of the Linux UDF file system should be
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* directed to the development team mailing list (run by majordomo):
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* linux_udf@hpesjro.fc.hp.com
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*
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* COPYRIGHT
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* This file is distributed under the terms of the GNU General Public
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* License (GPL). Copies of the GPL can be obtained from:
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* ftp://prep.ai.mit.edu/pub/gnu/GPL
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* Each contributing author retains all rights to their own work.
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*
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* (C) 1998-1999 Dave Boynton
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* (C) 1998-2004 Ben Fennema
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* (C) 1999-2000 Stelias Computing Inc
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*
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* HISTORY
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*
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* 10/02/98 dgb Attempt to integrate into udf.o
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* 10/07/98 Switched to using generic_readpage, etc., like isofs
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* And it works!
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* 12/06/98 blf Added udf_file_read. uses generic_file_read for all cases but
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* ICBTAG_FLAG_AD_IN_ICB.
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* 04/06/99 64 bit file handling on 32 bit systems taken from ext2 file.c
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* 05/12/99 Preliminary file write support
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*/
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#include "udfdecl.h"
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#include <linux/fs.h>
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#include <linux/udf_fs.h>
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#include <asm/uaccess.h>
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#include <linux/kernel.h>
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#include <linux/string.h> /* memset */
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#include <linux/errno.h>
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#include <linux/smp_lock.h>
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#include <linux/pagemap.h>
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#include <linux/buffer_head.h>
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#include "udf_i.h"
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#include "udf_sb.h"
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static int udf_adinicb_readpage(struct file *file, struct page * page)
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{
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struct inode *inode = page->mapping->host;
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char *kaddr;
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if (!PageLocked(page))
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PAGE_BUG(page);
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kaddr = kmap(page);
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memset(kaddr, 0, PAGE_CACHE_SIZE);
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memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
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flush_dcache_page(page);
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SetPageUptodate(page);
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kunmap(page);
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unlock_page(page);
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return 0;
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}
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static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc)
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{
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struct inode *inode = page->mapping->host;
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char *kaddr;
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if (!PageLocked(page))
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PAGE_BUG(page);
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kaddr = kmap(page);
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memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
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mark_inode_dirty(inode);
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SetPageUptodate(page);
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kunmap(page);
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unlock_page(page);
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return 0;
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}
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static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
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{
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kmap(page);
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return 0;
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}
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static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
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{
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struct inode *inode = page->mapping->host;
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char *kaddr = page_address(page);
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memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
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kaddr + offset, to - offset);
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mark_inode_dirty(inode);
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SetPageUptodate(page);
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kunmap(page);
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/* only one page here */
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if (to > inode->i_size)
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inode->i_size = to;
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return 0;
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}
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struct address_space_operations udf_adinicb_aops = {
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.readpage = udf_adinicb_readpage,
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.writepage = udf_adinicb_writepage,
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.sync_page = block_sync_page,
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.prepare_write = udf_adinicb_prepare_write,
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.commit_write = udf_adinicb_commit_write,
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};
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static ssize_t udf_file_write(struct file * file, const char __user * buf,
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size_t count, loff_t *ppos)
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{
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ssize_t retval;
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struct inode *inode = file->f_dentry->d_inode;
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int err, pos;
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
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{
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if (file->f_flags & O_APPEND)
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pos = inode->i_size;
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else
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pos = *ppos;
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if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
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pos + count))
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{
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udf_expand_file_adinicb(inode, pos + count, &err);
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if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
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{
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udf_debug("udf_expand_adinicb: err=%d\n", err);
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return err;
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}
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}
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else
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{
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if (pos + count > inode->i_size)
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UDF_I_LENALLOC(inode) = pos + count;
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else
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UDF_I_LENALLOC(inode) = inode->i_size;
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}
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}
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retval = generic_file_write(file, buf, count, ppos);
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if (retval > 0)
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mark_inode_dirty(inode);
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return retval;
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}
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/*
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* udf_ioctl
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*
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* PURPOSE
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* Issue an ioctl.
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*
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* DESCRIPTION
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* Optional - sys_ioctl() will return -ENOTTY if this routine is not
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* available, and the ioctl cannot be handled without filesystem help.
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*
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* sys_ioctl() handles these ioctls that apply only to regular files:
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* FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
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* These ioctls are also handled by sys_ioctl():
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* FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
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* All other ioctls are passed to the filesystem.
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*
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* Refer to sys_ioctl() in fs/ioctl.c
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* sys_ioctl() -> .
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*
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* PRE-CONDITIONS
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* inode Pointer to inode that ioctl was issued on.
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* filp Pointer to file that ioctl was issued on.
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* cmd The ioctl command.
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* arg The ioctl argument [can be interpreted as a
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* user-space pointer if desired].
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*
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* POST-CONDITIONS
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* <return> Success (>=0) or an error code (<=0) that
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* sys_ioctl() will return.
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*
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* HISTORY
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* July 1, 1997 - Andrew E. Mileski
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* Written, tested, and released.
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*/
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int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
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unsigned long arg)
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{
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int result = -EINVAL;
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if ( permission(inode, MAY_READ, NULL) != 0 )
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{
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udf_debug("no permission to access inode %lu\n",
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inode->i_ino);
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return -EPERM;
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}
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if ( !arg )
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{
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udf_debug("invalid argument to udf_ioctl\n");
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return -EINVAL;
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}
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switch (cmd)
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{
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case UDF_GETVOLIDENT:
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return copy_to_user((char __user *)arg,
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UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
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case UDF_RELOCATE_BLOCKS:
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{
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long old, new;
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if (!capable(CAP_SYS_ADMIN)) return -EACCES;
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if (get_user(old, (long __user *)arg)) return -EFAULT;
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if ((result = udf_relocate_blocks(inode->i_sb,
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old, &new)) == 0)
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result = put_user(new, (long __user *)arg);
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return result;
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}
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case UDF_GETEASIZE:
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result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
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break;
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case UDF_GETEABLOCK:
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result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
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UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
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break;
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}
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return result;
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}
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/*
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* udf_release_file
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*
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* PURPOSE
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* Called when all references to the file are closed
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*
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* DESCRIPTION
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* Discard prealloced blocks
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*
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* HISTORY
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*
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*/
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static int udf_release_file(struct inode * inode, struct file * filp)
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{
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if (filp->f_mode & FMODE_WRITE)
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{
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lock_kernel();
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udf_discard_prealloc(inode);
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unlock_kernel();
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}
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return 0;
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}
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struct file_operations udf_file_operations = {
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.read = generic_file_read,
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.ioctl = udf_ioctl,
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.open = generic_file_open,
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.mmap = generic_file_mmap,
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.write = udf_file_write,
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.release = udf_release_file,
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.fsync = udf_fsync_file,
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.sendfile = generic_file_sendfile,
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};
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struct inode_operations udf_file_inode_operations = {
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.truncate = udf_truncate,
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};
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