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root/fs/udf/dir.c

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DEFINITIONS

This source file includes following definitions.
  1. do_udf_readdir
  2. udf_readdir

/*
 * dir.c
 *
 * PURPOSE
 *  Directory 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) 1998-2004 Ben Fennema
 *
 * HISTORY
 *
 *  10/05/98 dgb  Split directory operations into its own file
 *                Implemented directory reads via do_udf_readdir
 *  10/06/98      Made directory operations work!
 *  11/17/98      Rewrote directory to support ICBTAG_FLAG_AD_LONG
 *  11/25/98 blf  Rewrote directory handling (readdir+lookup) to support reading
 *                across blocks.
 *  12/12/98      Split out the lookup code to namei.c. bulk of directory
 *                code now in directory.c:udf_fileident_read.
 */

#include "udfdecl.h"

#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>

#include "udf_i.h"
#include "udf_sb.h"

static int do_udf_readdir(struct inode *dir, struct file *filp,
                          filldir_t filldir, void *dirent)
{
        struct udf_fileident_bh fibh = { .sbh = NULL, .ebh = NULL};
        struct fileIdentDesc *fi = NULL;
        struct fileIdentDesc cfi;
        int block, iblock;
        loff_t nf_pos = (filp->f_pos - 1) << 2;
        int flen;
        char *fname = NULL;
        char *nameptr;
        uint16_t liu;
        uint8_t lfi;
        loff_t size = udf_ext0_offset(dir) + dir->i_size;
        struct buffer_head *tmp, *bha[16];
        kernel_lb_addr eloc;
        uint32_t elen;
        sector_t offset;
        int i, num, ret = 0;
        unsigned int dt_type;
        struct extent_position epos = { NULL, 0, {0, 0} };
        struct udf_inode_info *iinfo;

        if (nf_pos >= size)
                goto out;

        fname = kmalloc(UDF_NAME_LEN, GFP_NOFS);
        if (!fname) {
                ret = -ENOMEM;
                goto out;
        }

        if (nf_pos == 0)
                nf_pos = udf_ext0_offset(dir);

        fibh.soffset = fibh.eoffset = nf_pos & (dir->i_sb->s_blocksize - 1);
        iinfo = UDF_I(dir);
        if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
                if (inode_bmap(dir, nf_pos >> dir->i_sb->s_blocksize_bits,
                    &epos, &eloc, &elen, &offset)
                    != (EXT_RECORDED_ALLOCATED >> 30)) {
                        ret = -ENOENT;
                        goto out;
                }
                block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
                if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
                        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
                                epos.offset -= sizeof(short_ad);
                        else if (iinfo->i_alloc_type ==
                                        ICBTAG_FLAG_AD_LONG)
                                epos.offset -= sizeof(long_ad);
                } else {
                        offset = 0;
                }

                if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block))) {
                        ret = -EIO;
                        goto out;
                }

                if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9)) - 1))) {
                        i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
                        if (i + offset > (elen >> dir->i_sb->s_blocksize_bits))
                                i = (elen >> dir->i_sb->s_blocksize_bits) - offset;
                        for (num = 0; i > 0; i--) {
                                block = udf_get_lb_pblock(dir->i_sb, eloc, offset + i);
                                tmp = udf_tgetblk(dir->i_sb, block);
                                if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
                                        bha[num++] = tmp;
                                else
                                        brelse(tmp);
                        }
                        if (num) {
                                ll_rw_block(READA, num, bha);
                                for (i = 0; i < num; i++)
                                        brelse(bha[i]);
                        }
                }
        }

        while (nf_pos < size) {
                filp->f_pos = (nf_pos >> 2) + 1;

                fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &epos, &eloc,
                                        &elen, &offset);
                if (!fi)
                        goto out;

                liu = le16_to_cpu(cfi.lengthOfImpUse);
                lfi = cfi.lengthFileIdent;

                if (fibh.sbh == fibh.ebh) {
                        nameptr = fi->fileIdent + liu;
                } else {
                        int poffset;    /* Unpaded ending offset */

                        poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;

                        if (poffset >= lfi) {
                                nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
                        } else {
                                nameptr = fname;
                                memcpy(nameptr, fi->fileIdent + liu,
                                       lfi - poffset);
                                memcpy(nameptr + lfi - poffset,
                                       fibh.ebh->b_data, poffset);
                        }
                }

                if ((cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0) {
                        if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE))
                                continue;
                }

                if ((cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0) {
                        if (!UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE))
                                continue;
                }

                if (cfi.fileCharacteristics & FID_FILE_CHAR_PARENT) {
                        iblock = parent_ino(filp->f_path.dentry);
                        flen = 2;
                        memcpy(fname, "..", flen);
                        dt_type = DT_DIR;
                } else {
                        kernel_lb_addr tloc = lelb_to_cpu(cfi.icb.extLocation);

                        iblock = udf_get_lb_pblock(dir->i_sb, tloc, 0);
                        flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
                        dt_type = DT_UNKNOWN;
                }

                if (flen && filldir(dirent, fname, flen, filp->f_pos,
                                    iblock, dt_type) < 0)
                        goto out;
        } /* end while */

        filp->f_pos = (nf_pos >> 2) + 1;

out:
        if (fibh.sbh != fibh.ebh)
                brelse(fibh.ebh);
        brelse(fibh.sbh);
        brelse(epos.bh);
        kfree(fname);

        return ret;
}

static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
        struct inode *dir = filp->f_path.dentry->d_inode;
        int result;

        lock_kernel();

        if (filp->f_pos == 0) {
                if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0) {
                        unlock_kernel();
                        return 0;
                }
                filp->f_pos++;
        }

        result = do_udf_readdir(dir, filp, filldir, dirent);
        unlock_kernel();
        return result;
}

/* readdir and lookup functions */
const struct file_operations udf_dir_operations = {
        .read                   = generic_read_dir,
        .readdir                = udf_readdir,
        .ioctl                  = udf_ioctl,
        .fsync                  = udf_fsync_file,
};

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