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/*

 * file.c

 *

 * PURPOSE

 *  File handling routines for the OSTA-UDF(tm) filesystem.

 *

 * CONTACTS

 *  E-mail regarding any portion of the Linux UDF file system should be

 *  directed to the development team mailing list (run by majordomo):

 *    linux_udf@hpesjro.fc.hp.com

 *

 * 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) 1998-2001 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/errno.h>

#include <linux/locks.h>

#include <linux/smp_lock.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;

        struct buffer_head *bh;

        int block;

        char *kaddr;

        int err = 0;

        if (!PageLocked(page))

                PAGE_BUG(page);

        kaddr = kmap(page);

        memset(kaddr, 0, PAGE_CACHE_SIZE);

        block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);

        bh = sb_bread(inode->i_sb, block);

        if (!bh)

        {

                SetPageError(page);

                err = -EIO;

                goto out;

        }

        memcpy(kaddr, bh->b_data + udf_ext0_offset(inode), inode->i_size);

        brelse(bh);

        flush_dcache_page(page);

        SetPageUptodate(page);

out:

        kunmap(page);

        UnlockPage(page);

        return err;

}

static int udf_adinicb_writepage(struct page *page)

{

        struct inode *inode = page->mapping->host;

        struct buffer_head *bh;

        int block;

        char *kaddr;

        int err = 0;

        if (!PageLocked(page))

                PAGE_BUG(page);

        kaddr = kmap(page);

        block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);

        bh = sb_bread(inode->i_sb, block);

        if (!bh)

        {

                SetPageError(page);

                err = -EIO;

                goto out;

        }

        memcpy(bh->b_data + udf_ext0_offset(inode), kaddr, inode->i_size);

        mark_buffer_dirty(bh);

        brelse(bh);

        SetPageUptodate(page);

out:

        kunmap(page);

        UnlockPage(page);

        return err;

}

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;

        struct buffer_head *bh;

        int block;

        char *kaddr = page_address(page);

        int err = 0;

        block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);

        bh = sb_bread(inode->i_sb, block);

        if (!bh)

        {

                SetPageError(page);

                err = -EIO;

                goto out;

        }

        memcpy(bh->b_data + udf_file_entry_alloc_offset(inode) + offset,

                kaddr + offset, to - offset);

        mark_buffer_dirty(bh);

        brelse(bh);

        SetPageUptodate(page);

out:

        kunmap(page);

        /* only one page here */

        if (to > inode->i_size)

                inode->i_size = to;

        return err;

}

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 * 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)

        {

                UDF_I_UCTIME(inode) = UDF_I_UMTIME(inode) = CURRENT_UTIME;

                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;

        struct buffer_head *bh = NULL;

        long_ad eaicb;

        uint8_t *ea = NULL;

        if ( permission(inode, 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;

        }

        /* first, do ioctls that don't need to udf_read */

        switch (cmd)

        {

                case UDF_GETVOLIDENT:

                        return copy_to_user((char *)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 *)arg)) return -EFAULT;

                        if ((result = udf_relocate_blocks(inode->i_sb,

                                        old, &new)) == 0)

                                result = put_user(new, (long *)arg);

                        return result;

                }

        }

        /* ok, we need to read the inode */

        bh = udf_tread(inode->i_sb,

                udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0));

        if (!bh)

        {

                udf_debug("bread failed (inode=%ld)\n", inode->i_ino);

                return -EIO;

        }

        if (UDF_I_EXTENDED_FE(inode) == 0)

        {

                struct fileEntry *fe;

                fe = (struct fileEntry *)bh->b_data;

                eaicb = lela_to_cpu(fe->extendedAttrICB);

                if (UDF_I_LENEATTR(inode))

                        ea = fe->extendedAttr;

        }

        else

        {

                struct extendedFileEntry *efe;

                efe = (struct extendedFileEntry *)bh->b_data;

                eaicb = lela_to_cpu(efe->extendedAttrICB);

                if (UDF_I_LENEATTR(inode))

                        ea = efe->extendedAttr;

        }

        switch (cmd)

        {

                case UDF_GETEASIZE:

                        result = put_user(UDF_I_LENEATTR(inode), (int *)arg);

                        break;

                case UDF_GETEABLOCK:

                        result = copy_to_user((char *)arg, ea,

                                UDF_I_LENEATTR(inode)) ? -EFAULT : 0;

                        break;

        }

        udf_release_data(bh);

        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;

}

/*

 * udf_open_file

 *

 * PURPOSE

 *  Called when an inode is about to be open.

 *

 * DESCRIPTION

 *  Use this to disallow opening RW large files on 32 bit systems.

 *  On 64 bit systems we force on O_LARGEFILE in sys_open.

 *

 * HISTORY

 *

 */

static int udf_open_file(struct inode * inode, struct file * filp)

{

        if ((inode->i_size & 0xFFFFFFFF80000000ULL) && !(filp->f_flags & O_LARGEFILE))

                return -EFBIG;

        return 0;

}

struct file_operations udf_file_operations = {

        read:                   generic_file_read,

        ioctl:                  udf_ioctl,

        open:                   udf_open_file,

        mmap:                   generic_file_mmap,

        write:                  udf_file_write,

        release:                udf_release_file,

        fsync:                  udf_fsync_file,

};

struct inode_operations udf_file_inode_operations = {

        truncate:               udf_truncate,

};