Subversion Repositories test_project

/*

 * 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 <linux/aio.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_write_end(struct file *file,

                        struct address_space *mapping,

                        loff_t pos, unsigned len, unsigned copied,

                        struct page *page, void *fsdata)

{

        struct inode *inode = mapping->host;

        unsigned offset = pos & (PAGE_CACHE_SIZE - 1);

        char *kaddr;

        kaddr = kmap_atomic(page, KM_USER0);

        memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,

                kaddr + offset, copied);

        kunmap_atomic(kaddr, KM_USER0);

        return simple_write_end(file, mapping, pos, len, copied, page, fsdata);

}

const struct address_space_operations udf_adinicb_aops = {

        .readpage       = udf_adinicb_readpage,

        .writepage      = udf_adinicb_writepage,

        .sync_page      = block_sync_page,

        .write_begin = simple_write_begin,

        .write_end = udf_adinicb_write_end,

};

static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,

                                  unsigned long nr_segs, loff_t ppos)

{

        ssize_t retval;

        struct file *file = iocb->ki_filp;

        struct inode *inode = file->f_path.dentry->d_inode;

        int err, pos;

        size_t count = iocb->ki_left;

        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_aio_write(iocb, iov, nr_segs, 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)

{

        long old_block, new_block;

        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:

                if (!capable(CAP_SYS_ADMIN))

                        return -EACCES;

                if (get_user(old_block, (long __user *)arg))

                        return -EFAULT;

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

                                                  old_block, &new_block)) == 0)

                        result = put_user(new_block, (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                   = do_sync_read,

        .aio_read               = generic_file_aio_read,

        .ioctl                  = udf_ioctl,

        .open                   = generic_file_open,

        .mmap                   = generic_file_mmap,

        .write                  = do_sync_write,

        .aio_write              = udf_file_aio_write,

        .release                = udf_release_file,

        .fsync                  = udf_fsync_file,

        .splice_read            = generic_file_splice_read,

};

const struct inode_operations udf_file_inode_operations = {

        .truncate = udf_truncate,

};