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inode.c

/*
 *  linux/fs/isofs/inode.c
 *
 *  (C) 1991  Linus Torvalds - minix filesystem
 *      1992, 1993, 1994  Eric Youngdale Modified for ISO 9660 filesystem.
 *      1994  Eberhard Mönkeberg - multi session handling.
 *      1995  Mark Dobie - allow mounting of some weird VideoCDs and PhotoCDs.
 *    1997  Gordon Chaffee - Joliet CDs
 *    1998  Eric Lammerts - ISO 9660 Level 3
 *    2004  Paul Serice - Inode Support pushed out from 4GB to 128GB
 *    2004  Paul Serice - NFS Export Operations
 */

#include <linux/init.h>
#include <linux/module.h>

#include <linux/slab.h>
#include <linux/nls.h>
#include <linux/ctype.h>
#include <linux/smp_lock.h>
#include <linux/statfs.h>
#include <linux/cdrom.h>
#include <linux/parser.h>

#include "isofs.h"
#include "zisofs.h"

#define BEQUIET

static int isofs_hashi(struct dentry *parent, struct qstr *qstr);
static int isofs_hash(struct dentry *parent, struct qstr *qstr);
static int isofs_dentry_cmpi(struct dentry *dentry, struct qstr *a, struct qstr *b);
static int isofs_dentry_cmp(struct dentry *dentry, struct qstr *a, struct qstr *b);

#ifdef CONFIG_JOLIET
static int isofs_hashi_ms(struct dentry *parent, struct qstr *qstr);
static int isofs_hash_ms(struct dentry *parent, struct qstr *qstr);
static int isofs_dentry_cmpi_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
static int isofs_dentry_cmp_ms(struct dentry *dentry, struct qstr *a, struct qstr *b);
#endif

static void isofs_put_super(struct super_block *sb)
{
      struct isofs_sb_info *sbi = ISOFS_SB(sb);
#ifdef CONFIG_JOLIET
      if (sbi->s_nls_iocharset) {
            unload_nls(sbi->s_nls_iocharset);
            sbi->s_nls_iocharset = NULL;
      }
#endif

      kfree(sbi);
      sb->s_fs_info = NULL;
      return;
}

static void isofs_read_inode(struct inode *);
static int isofs_statfs (struct dentry *, struct kstatfs *);

static struct kmem_cache *isofs_inode_cachep;

static struct inode *isofs_alloc_inode(struct super_block *sb)
{
      struct iso_inode_info *ei;
      ei = kmem_cache_alloc(isofs_inode_cachep, GFP_KERNEL);
      if (!ei)
            return NULL;
      return &ei->vfs_inode;
}

static void isofs_destroy_inode(struct inode *inode)
{
      kmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));
}

static void init_once(struct kmem_cache *cachep, void *foo)
{
      struct iso_inode_info *ei = foo;

      inode_init_once(&ei->vfs_inode);
}

static int init_inodecache(void)
{
      isofs_inode_cachep = kmem_cache_create("isofs_inode_cache",
                              sizeof(struct iso_inode_info),
                              0, (SLAB_RECLAIM_ACCOUNT|
                              SLAB_MEM_SPREAD),
                              init_once);
      if (isofs_inode_cachep == NULL)
            return -ENOMEM;
      return 0;
}

static void destroy_inodecache(void)
{
      kmem_cache_destroy(isofs_inode_cachep);
}

static int isofs_remount(struct super_block *sb, int *flags, char *data)
{
      /* we probably want a lot more here */
      *flags |= MS_RDONLY;
      return 0;
}

static const struct super_operations isofs_sops = {
      .alloc_inode      = isofs_alloc_inode,
      .destroy_inode    = isofs_destroy_inode,
      .read_inode = isofs_read_inode,
      .put_super  = isofs_put_super,
      .statfs           = isofs_statfs,
      .remount_fs = isofs_remount,
};


static struct dentry_operations isofs_dentry_ops[] = {
      {
            .d_hash           = isofs_hash,
            .d_compare  = isofs_dentry_cmp,
      },
      {
            .d_hash           = isofs_hashi,
            .d_compare  = isofs_dentry_cmpi,
      },
#ifdef CONFIG_JOLIET
      {
            .d_hash           = isofs_hash_ms,
            .d_compare  = isofs_dentry_cmp_ms,
      },
      {
            .d_hash           = isofs_hashi_ms,
            .d_compare  = isofs_dentry_cmpi_ms,
      },
#endif
};

struct iso9660_options{
      char map;
      char rock;
      char joliet;
      char cruft;
      char hide;
      char showassoc;
      char nocompress;
      unsigned char check;
      unsigned int blocksize;
      mode_t mode;
      gid_t gid;
      uid_t uid;
      char *iocharset;
      unsigned char utf8;
      /* LVE */
      s32 session;
      s32 sbsector;
};

/*
 * Compute the hash for the isofs name corresponding to the dentry.
 */
static int
isofs_hash_common(struct dentry *dentry, struct qstr *qstr, int ms)
{
      const char *name;
      int len;

      len = qstr->len;
      name = qstr->name;
      if (ms) {
            while (len && name[len-1] == '.')
                  len--;
      }

      qstr->hash = full_name_hash(name, len);

      return 0;
}

/*
 * Compute the hash for the isofs name corresponding to the dentry.
 */
static int
isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms)
{
      const char *name;
      int len;
      char c;
      unsigned long hash;

      len = qstr->len;
      name = qstr->name;
      if (ms) {
            while (len && name[len-1] == '.')
                  len--;
      }

      hash = init_name_hash();
      while (len--) {
            c = tolower(*name++);
            hash = partial_name_hash(c, hash);
      }
      qstr->hash = end_name_hash(hash);

      return 0;
}

/*
 * Case insensitive compare of two isofs names.
 */
static int isofs_dentry_cmpi_common(struct dentry *dentry, struct qstr *a,
                        struct qstr *b, int ms)
{
      int alen, blen;

      /* A filename cannot end in '.' or we treat it like it has none */
      alen = a->len;
      blen = b->len;
      if (ms) {
            while (alen && a->name[alen-1] == '.')
                  alen--;
            while (blen && b->name[blen-1] == '.')
                  blen--;
      }
      if (alen == blen) {
            if (strnicmp(a->name, b->name, alen) == 0)
                  return 0;
      }
      return 1;
}

/*
 * Case sensitive compare of two isofs names.
 */
static int isofs_dentry_cmp_common(struct dentry *dentry, struct qstr *a,
                              struct qstr *b, int ms)
{
      int alen, blen;

      /* A filename cannot end in '.' or we treat it like it has none */
      alen = a->len;
      blen = b->len;
      if (ms) {
            while (alen && a->name[alen-1] == '.')
                  alen--;
            while (blen && b->name[blen-1] == '.')
                  blen--;
      }
      if (alen == blen) {
            if (strncmp(a->name, b->name, alen) == 0)
                  return 0;
      }
      return 1;
}

static int
isofs_hash(struct dentry *dentry, struct qstr *qstr)
{
      return isofs_hash_common(dentry, qstr, 0);
}

static int
isofs_hashi(struct dentry *dentry, struct qstr *qstr)
{
      return isofs_hashi_common(dentry, qstr, 0);
}

static int
isofs_dentry_cmp(struct dentry *dentry,struct qstr *a,struct qstr *b)
{
      return isofs_dentry_cmp_common(dentry, a, b, 0);
}

static int
isofs_dentry_cmpi(struct dentry *dentry,struct qstr *a,struct qstr *b)
{
      return isofs_dentry_cmpi_common(dentry, a, b, 0);
}

#ifdef CONFIG_JOLIET
static int
isofs_hash_ms(struct dentry *dentry, struct qstr *qstr)
{
      return isofs_hash_common(dentry, qstr, 1);
}

static int
isofs_hashi_ms(struct dentry *dentry, struct qstr *qstr)
{
      return isofs_hashi_common(dentry, qstr, 1);
}

static int
isofs_dentry_cmp_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
{
      return isofs_dentry_cmp_common(dentry, a, b, 1);
}

static int
isofs_dentry_cmpi_ms(struct dentry *dentry,struct qstr *a,struct qstr *b)
{
      return isofs_dentry_cmpi_common(dentry, a, b, 1);
}
#endif

enum {
      Opt_block, Opt_check_r, Opt_check_s, Opt_cruft, Opt_gid, Opt_ignore,
      Opt_iocharset, Opt_map_a, Opt_map_n, Opt_map_o, Opt_mode, Opt_nojoliet,
      Opt_norock, Opt_sb, Opt_session, Opt_uid, Opt_unhide, Opt_utf8, Opt_err,
      Opt_nocompress, Opt_hide, Opt_showassoc,
};

static match_table_t tokens = {
      {Opt_norock, "norock"},
      {Opt_nojoliet, "nojoliet"},
      {Opt_unhide, "unhide"},
      {Opt_hide, "hide"},
      {Opt_showassoc, "showassoc"},
      {Opt_cruft, "cruft"},
      {Opt_utf8, "utf8"},
      {Opt_iocharset, "iocharset=%s"},
      {Opt_map_a, "map=acorn"},
      {Opt_map_a, "map=a"},
      {Opt_map_n, "map=normal"},
      {Opt_map_n, "map=n"},
      {Opt_map_o, "map=off"},
      {Opt_map_o, "map=o"},
      {Opt_session, "session=%u"},
      {Opt_sb, "sbsector=%u"},
      {Opt_check_r, "check=relaxed"},
      {Opt_check_r, "check=r"},
      {Opt_check_s, "check=strict"},
      {Opt_check_s, "check=s"},
      {Opt_uid, "uid=%u"},
      {Opt_gid, "gid=%u"},
      {Opt_mode, "mode=%u"},
      {Opt_block, "block=%u"},
      {Opt_ignore, "conv=binary"},
      {Opt_ignore, "conv=b"},
      {Opt_ignore, "conv=text"},
      {Opt_ignore, "conv=t"},
      {Opt_ignore, "conv=mtext"},
      {Opt_ignore, "conv=m"},
      {Opt_ignore, "conv=auto"},
      {Opt_ignore, "conv=a"},
      {Opt_nocompress, "nocompress"},
      {Opt_err, NULL}
};

static int parse_options(char *options, struct iso9660_options *popt)
{
      char *p;
      int option;

      popt->map = 'n';
      popt->rock = 'y';
      popt->joliet = 'y';
      popt->cruft = 'n';
      popt->hide = 'n';
      popt->showassoc = 'n';
      popt->check = 'u';            /* unset */
      popt->nocompress = 0;
      popt->blocksize = 1024;
      popt->mode = S_IRUGO | S_IXUGO; /*
                               * r-x for all.  The disc could
                               * be shared with DOS machines so
                               * virtually anything could be
                               * a valid executable.
                               */
      popt->gid = 0;
      popt->uid = 0;
      popt->iocharset = NULL;
      popt->utf8 = 0;
      popt->session=-1;
      popt->sbsector=-1;
      if (!options)
            return 1;

      while ((p = strsep(&options, ",")) != NULL) {
            int token;
            substring_t args[MAX_OPT_ARGS];
            unsigned n;

            if (!*p)
                  continue;

            token = match_token(p, tokens, args);
            switch (token) {
            case Opt_norock:
                  popt->rock = 'n';
                  break;
            case Opt_nojoliet:
                  popt->joliet = 'n';
                  break;
            case Opt_hide:
                  popt->hide = 'y';
                  break;
            case Opt_unhide:
            case Opt_showassoc:
                  popt->showassoc = 'y';
                  break;
            case Opt_cruft:
                  popt->cruft = 'y';
                  break;
            case Opt_utf8:
                  popt->utf8 = 1;
                  break;
#ifdef CONFIG_JOLIET
            case Opt_iocharset:
                  popt->iocharset = match_strdup(&args[0]);
                  break;
#endif
            case Opt_map_a:
                  popt->map = 'a';
                  break;
            case Opt_map_o:
                  popt->map = 'o';
                  break;
            case Opt_map_n:
                  popt->map = 'n';
                  break;
            case Opt_session:
                  if (match_int(&args[0], &option))
                        return 0;
                  n = option;
                  if (n > 99)
                        return 0;
                  popt->session = n + 1;
                  break;
            case Opt_sb:
                  if (match_int(&args[0], &option))
                        return 0;
                  popt->sbsector = option;
                  break;
            case Opt_check_r:
                  popt->check = 'r';
                  break;
            case Opt_check_s:
                  popt->check = 's';
                  break;
            case Opt_ignore:
                  break;
            case Opt_uid:
                  if (match_int(&args[0], &option))
                        return 0;
                  popt->uid = option;
                  break;
            case Opt_gid:
                  if (match_int(&args[0], &option))
                        return 0;
                  popt->gid = option;
                  break;
            case Opt_mode:
                  if (match_int(&args[0], &option))
                        return 0;
                  popt->mode = option;
                  break;
            case Opt_block:
                  if (match_int(&args[0], &option))
                        return 0;
                  n = option;
                  if (n != 512 && n != 1024 && n != 2048)
                        return 0;
                  popt->blocksize = n;
                  break;
            case Opt_nocompress:
                  popt->nocompress = 1;
                  break;
            default:
                  return 0;
            }
      }
      return 1;
}

/*
 * look if the driver can tell the multi session redirection value
 *
 * don't change this if you don't know what you do, please!
 * Multisession is legal only with XA disks.
 * A non-XA disk with more than one volume descriptor may do it right, but
 * usually is written in a nowhere standardized "multi-partition" manner.
 * Multisession uses absolute addressing (solely the first frame of the whole
 * track is #0), multi-partition uses relative addressing (each first frame of
 * each track is #0), and a track is not a session.
 *
 * A broken CDwriter software or drive firmware does not set new standards,
 * at least not if conflicting with the existing ones.
 *
 * emoenke@gwdg.de
 */
#define WE_OBEY_THE_WRITTEN_STANDARDS 1

static unsigned int isofs_get_last_session(struct super_block *sb, s32 session)
{
      struct cdrom_multisession ms_info;
      unsigned int vol_desc_start;
      struct block_device *bdev = sb->s_bdev;
      int i;

      vol_desc_start=0;
      ms_info.addr_format=CDROM_LBA;
      if(session >= 0 && session <= 99) {
            struct cdrom_tocentry Te;
            Te.cdte_track=session;
            Te.cdte_format=CDROM_LBA;
            i = ioctl_by_bdev(bdev, CDROMREADTOCENTRY, (unsigned long) &Te);
            if (!i) {
                  printk(KERN_DEBUG "ISOFS: Session %d start %d type %d\n",
                        session, Te.cdte_addr.lba,
                        Te.cdte_ctrl&CDROM_DATA_TRACK);
                  if ((Te.cdte_ctrl&CDROM_DATA_TRACK) == 4)
                        return Te.cdte_addr.lba;
            }

            printk(KERN_ERR "ISOFS: Invalid session number or type of track\n");
      }
      i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long) &ms_info);
      if (session > 0)
            printk(KERN_ERR "ISOFS: Invalid session number\n");
#if 0
      printk(KERN_DEBUG "isofs.inode: CDROMMULTISESSION: rc=%d\n",i);
      if (i==0) {
            printk(KERN_DEBUG "isofs.inode: XA disk: %s\n",ms_info.xa_flag?"yes":"no");
            printk(KERN_DEBUG "isofs.inode: vol_desc_start = %d\n", ms_info.addr.lba);
      }
#endif
      if (i==0)
#if WE_OBEY_THE_WRITTEN_STANDARDS
            if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
#endif
                  vol_desc_start=ms_info.addr.lba;
      return vol_desc_start;
}

/*
 * Initialize the superblock and read the root inode.
 *
 * Note: a check_disk_change() has been done immediately prior
 * to this call, so we don't need to check again.
 */
static int isofs_fill_super(struct super_block *s, void *data, int silent)
{
      struct buffer_head *bh = NULL, *pri_bh = NULL;
      struct hs_primary_descriptor *h_pri = NULL;
      struct iso_primary_descriptor *pri = NULL;
      struct iso_supplementary_descriptor *sec = NULL;
      struct iso_directory_record *rootp;
      struct inode *inode;
      struct iso9660_options opt;
      struct isofs_sb_info *sbi;
      unsigned long first_data_zone;
      int joliet_level = 0;
      int iso_blknum, block;
      int orig_zonesize;
      int table;
      unsigned int vol_desc_start;

      sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
      if (!sbi)
            return -ENOMEM;
      s->s_fs_info = sbi;

      if (!parse_options((char *)data, &opt))
            goto out_freesbi;

      /*
       * First of all, get the hardware blocksize for this device.
       * If we don't know what it is, or the hardware blocksize is
       * larger than the blocksize the user specified, then use
       * that value.
       */
      /*
       * What if bugger tells us to go beyond page size?
       */
      opt.blocksize = sb_min_blocksize(s, opt.blocksize);

      sbi->s_high_sierra = 0; /* default is iso9660 */

      vol_desc_start = (opt.sbsector != -1) ?
            opt.sbsector : isofs_get_last_session(s,opt.session);

      for (iso_blknum = vol_desc_start+16;
            iso_blknum < vol_desc_start+100; iso_blknum++) {
            struct hs_volume_descriptor *hdp;
            struct iso_volume_descriptor  *vdp;

            block = iso_blknum << (ISOFS_BLOCK_BITS - s->s_blocksize_bits);
            if (!(bh = sb_bread(s, block)))
                  goto out_no_read;

            vdp = (struct iso_volume_descriptor *)bh->b_data;
            hdp = (struct hs_volume_descriptor *)bh->b_data;

            /*
             * Due to the overlapping physical location of the descriptors,
             * ISO CDs can match hdp->id==HS_STANDARD_ID as well. To ensure
             * proper identification in this case, we first check for ISO.
             */
            if (strncmp (vdp->id, ISO_STANDARD_ID, sizeof vdp->id) == 0) {
                  if (isonum_711(vdp->type) == ISO_VD_END)
                        break;
                  if (isonum_711(vdp->type) == ISO_VD_PRIMARY) {
                        if (pri == NULL) {
                              pri = (struct iso_primary_descriptor *)vdp;
                              /* Save the buffer in case we need it ... */
                              pri_bh = bh;
                              bh = NULL;
                        }
                  }
#ifdef CONFIG_JOLIET
                  else if (isonum_711(vdp->type) == ISO_VD_SUPPLEMENTARY) {
                        sec = (struct iso_supplementary_descriptor *)vdp;
                        if (sec->escape[0] == 0x25 && sec->escape[1] == 0x2f) {
                              if (opt.joliet == 'y') {
                                    if (sec->escape[2] == 0x40)
                                          joliet_level = 1;
                                    else if (sec->escape[2] == 0x43)
                                          joliet_level = 2;
                                    else if (sec->escape[2] == 0x45)
                                          joliet_level = 3;

                                    printk(KERN_DEBUG "ISO 9660 Extensions: "
                                          "Microsoft Joliet Level %d\n",
                                          joliet_level);
                              }
                              goto root_found;
                        } else {
                        /* Unknown supplementary volume descriptor */
                        sec = NULL;
                        }
                  }
#endif
            } else {
                  if (strncmp (hdp->id, HS_STANDARD_ID, sizeof hdp->id) == 0) {
                        if (isonum_711(hdp->type) != ISO_VD_PRIMARY)
                              goto out_freebh;

                        sbi->s_high_sierra = 1;
                        opt.rock = 'n';
                        h_pri = (struct hs_primary_descriptor *)vdp;
                        goto root_found;
                  }
            }

            /* Just skip any volume descriptors we don't recognize */

            brelse(bh);
            bh = NULL;
      }
      /*
       * If we fall through, either no volume descriptor was found,
       * or else we passed a primary descriptor looking for others.
       */
      if (!pri)
            goto out_unknown_format;
      brelse(bh);
      bh = pri_bh;
      pri_bh = NULL;

root_found:

      if (joliet_level && (pri == NULL || opt.rock == 'n')) {
            /* This is the case of Joliet with the norock mount flag.
             * A disc with both Joliet and Rock Ridge is handled later
             */
            pri = (struct iso_primary_descriptor *) sec;
      }

      if(sbi->s_high_sierra){
            rootp = (struct iso_directory_record *) h_pri->root_directory_record;
            sbi->s_nzones = isonum_733(h_pri->volume_space_size);
            sbi->s_log_zone_size = isonum_723(h_pri->logical_block_size);
            sbi->s_max_size = isonum_733(h_pri->volume_space_size);
      } else {
            if (!pri)
                  goto out_freebh;
            rootp = (struct iso_directory_record *) pri->root_directory_record;
            sbi->s_nzones = isonum_733(pri->volume_space_size);
            sbi->s_log_zone_size = isonum_723(pri->logical_block_size);
            sbi->s_max_size = isonum_733(pri->volume_space_size);
      }

      sbi->s_ninodes = 0; /* No way to figure this out easily */

      orig_zonesize = sbi->s_log_zone_size;
      /*
       * If the zone size is smaller than the hardware sector size,
       * this is a fatal error.  This would occur if the disc drive
       * had sectors that were 2048 bytes, but the filesystem had
       * blocks that were 512 bytes (which should only very rarely
       * happen.)
       */
      if (orig_zonesize < opt.blocksize)
            goto out_bad_size;

      /* RDE: convert log zone size to bit shift */
      switch (sbi->s_log_zone_size) {
      case  512: sbi->s_log_zone_size =  9; break;
      case 1024: sbi->s_log_zone_size = 10; break;
      case 2048: sbi->s_log_zone_size = 11; break;

      default:
            goto out_bad_zone_size;
      }

      s->s_magic = ISOFS_SUPER_MAGIC;
      s->s_maxbytes = 0xffffffff; /* We can handle files up to 4 GB */

      /*
       * The CDROM is read-only, has no nodes (devices) on it, and since
       * all of the files appear to be owned by root, we really do not want
       * to allow suid.  (suid or devices will not show up unless we have
       * Rock Ridge extensions)
       */

      s->s_flags |= MS_RDONLY /* | MS_NODEV | MS_NOSUID */;

      /* Set this for reference. Its not currently used except on write
         which we don't have .. */

      first_data_zone = isonum_733(rootp->extent) +
                    isonum_711(rootp->ext_attr_length);
      sbi->s_firstdatazone = first_data_zone;
#ifndef BEQUIET
      printk(KERN_DEBUG "ISOFS: Max size:%ld   Log zone size:%ld\n",
            sbi->s_max_size, 1UL << sbi->s_log_zone_size);
      printk(KERN_DEBUG "ISOFS: First datazone:%ld\n", sbi->s_firstdatazone);
      if(sbi->s_high_sierra)
            printk(KERN_DEBUG "ISOFS: Disc in High Sierra format.\n");
#endif

      /*
       * If the Joliet level is set, we _may_ decide to use the
       * secondary descriptor, but can't be sure until after we
       * read the root inode. But before reading the root inode
       * we may need to change the device blocksize, and would
       * rather release the old buffer first. So, we cache the
       * first_data_zone value from the secondary descriptor.
       */
      if (joliet_level) {
            pri = (struct iso_primary_descriptor *) sec;
            rootp = (struct iso_directory_record *)
                  pri->root_directory_record;
            first_data_zone = isonum_733(rootp->extent) +
                        isonum_711(rootp->ext_attr_length);
      }

      /*
       * We're all done using the volume descriptor, and may need
       * to change the device blocksize, so release the buffer now.
       */
      brelse(pri_bh);
      brelse(bh);

      /*
       * Force the blocksize to 512 for 512 byte sectors.  The file
       * read primitives really get it wrong in a bad way if we don't
       * do this.
       *
       * Note - we should never be setting the blocksize to something
       * less than the hardware sector size for the device.  If we
       * do, we would end up having to read larger buffers and split
       * out portions to satisfy requests.
       *
       * Note2- the idea here is that we want to deal with the optimal
       * zonesize in the filesystem.  If we have it set to something less,
       * then we have horrible problems with trying to piece together
       * bits of adjacent blocks in order to properly read directory
       * entries.  By forcing the blocksize in this way, we ensure
       * that we will never be required to do this.
       */
      sb_set_blocksize(s, orig_zonesize);

      sbi->s_nls_iocharset = NULL;

#ifdef CONFIG_JOLIET
      if (joliet_level && opt.utf8 == 0) {
            char *p = opt.iocharset ? opt.iocharset : CONFIG_NLS_DEFAULT;
            sbi->s_nls_iocharset = load_nls(p);
            if (! sbi->s_nls_iocharset) {
                  /* Fail only if explicit charset specified */
                  if (opt.iocharset)
                        goto out_freesbi;
                  sbi->s_nls_iocharset = load_nls_default();
            }
      }
#endif
      s->s_op = &isofs_sops;
      s->s_export_op = &isofs_export_ops;
      sbi->s_mapping = opt.map;
      sbi->s_rock = (opt.rock == 'y' ? 2 : 0);
      sbi->s_rock_offset = -1; /* initial offset, will guess until SP is found*/
      sbi->s_cruft = opt.cruft;
      sbi->s_hide = opt.hide;
      sbi->s_showassoc = opt.showassoc;
      sbi->s_uid = opt.uid;
      sbi->s_gid = opt.gid;
      sbi->s_utf8 = opt.utf8;
      sbi->s_nocompress = opt.nocompress;
      /*
       * It would be incredibly stupid to allow people to mark every file
       * on the disk as suid, so we merely allow them to set the default
       * permissions.
       */
      sbi->s_mode = opt.mode & 0777;

      /*
       * Read the root inode, which _may_ result in changing
       * the s_rock flag. Once we have the final s_rock value,
       * we then decide whether to use the Joliet descriptor.
       */
      inode = isofs_iget(s, sbi->s_firstdatazone, 0);

      /*
       * If this disk has both Rock Ridge and Joliet on it, then we
       * want to use Rock Ridge by default.  This can be overridden
       * by using the norock mount option.  There is still one other
       * possibility that is not taken into account: a Rock Ridge
       * CD with Unicode names.  Until someone sees such a beast, it
       * will not be supported.
       */
      if (sbi->s_rock == 1) {
            joliet_level = 0;
      } else if (joliet_level) {
            sbi->s_rock = 0;
            if (sbi->s_firstdatazone != first_data_zone) {
                  sbi->s_firstdatazone = first_data_zone;
                  printk(KERN_DEBUG
                        "ISOFS: changing to secondary root\n");
                  iput(inode);
                  inode = isofs_iget(s, sbi->s_firstdatazone, 0);
            }
      }

      if (opt.check == 'u') {
            /* Only Joliet is case insensitive by default */
            if (joliet_level)
                  opt.check = 'r';
            else
                  opt.check = 's';
      }
      sbi->s_joliet_level = joliet_level;

      /* check the root inode */
      if (!inode)
            goto out_no_root;
      if (!inode->i_op)
            goto out_bad_root;

      /* Make sure the root inode is a directory */
      if (!S_ISDIR(inode->i_mode)) {
            printk(KERN_WARNING
                  "isofs_fill_super: root inode is not a directory. "
                  "Corrupted media?\n");
            goto out_iput;
      }

      /* get the root dentry */
      s->s_root = d_alloc_root(inode);
      if (!(s->s_root))
            goto out_no_root;

      table = 0;
      if (joliet_level)
            table += 2;
      if (opt.check == 'r')
            table++;
      s->s_root->d_op = &isofs_dentry_ops[table];

      kfree(opt.iocharset);

      return 0;

      /*
       * Display error messages and free resources.
       */
out_bad_root:
      printk(KERN_WARNING "%s: root inode not initialized\n", __func__);
      goto out_iput;
out_no_root:
      printk(KERN_WARNING "%s: get root inode failed\n", __func__);
out_iput:
      iput(inode);
#ifdef CONFIG_JOLIET
      if (sbi->s_nls_iocharset)
            unload_nls(sbi->s_nls_iocharset);
#endif
      goto out_freesbi;
out_no_read:
      printk(KERN_WARNING "%s: bread failed, dev=%s, iso_blknum=%d, block=%d\n",
            __func__, s->s_id, iso_blknum, block);
      goto out_freesbi;
out_bad_zone_size:
      printk(KERN_WARNING "ISOFS: Bad logical zone size %ld\n",
            sbi->s_log_zone_size);
      goto out_freebh;
out_bad_size:
      printk(KERN_WARNING "ISOFS: Logical zone size(%d) < hardware blocksize(%u)\n",
            orig_zonesize, opt.blocksize);
      goto out_freebh;
out_unknown_format:
      if (!silent)
            printk(KERN_WARNING "ISOFS: Unable to identify CD-ROM format.\n");

out_freebh:
      brelse(bh);
out_freesbi:
      kfree(opt.iocharset);
      kfree(sbi);
      s->s_fs_info = NULL;
      return -EINVAL;
}

static int isofs_statfs (struct dentry *dentry, struct kstatfs *buf)
{
      struct super_block *sb = dentry->d_sb;

      buf->f_type = ISOFS_SUPER_MAGIC;
      buf->f_bsize = sb->s_blocksize;
      buf->f_blocks = (ISOFS_SB(sb)->s_nzones
            << (ISOFS_SB(sb)->s_log_zone_size - sb->s_blocksize_bits));
      buf->f_bfree = 0;
      buf->f_bavail = 0;
      buf->f_files = ISOFS_SB(sb)->s_ninodes;
      buf->f_ffree = 0;
      buf->f_namelen = NAME_MAX;
      return 0;
}

/*
 * Get a set of blocks; filling in buffer_heads if already allocated
 * or getblk() if they are not.  Returns the number of blocks inserted
 * (0 == error.)
 */
int isofs_get_blocks(struct inode *inode, sector_t iblock_s,
                 struct buffer_head **bh, unsigned long nblocks)
{
      unsigned long b_off;
      unsigned offset, sect_size;
      unsigned int firstext;
      unsigned long nextblk, nextoff;
      long iblock = (long)iblock_s;
      int section, rv;
      struct iso_inode_info *ei = ISOFS_I(inode);

      lock_kernel();

      rv = 0;
      if (iblock < 0 || iblock != iblock_s) {
            printk(KERN_DEBUG "%s: block number too large\n", __func__);
            goto abort;
      }

      b_off = iblock;

      offset = 0;
      firstext = ei->i_first_extent;
      sect_size = ei->i_section_size >> ISOFS_BUFFER_BITS(inode);
      nextblk = ei->i_next_section_block;
      nextoff = ei->i_next_section_offset;
      section = 0;

      while (nblocks) {
            /* If we are *way* beyond the end of the file, print a message.
             * Access beyond the end of the file up to the next page boundary
             * is normal, however because of the way the page cache works.
             * In this case, we just return 0 so that we can properly fill
             * the page with useless information without generating any
             * I/O errors.
             */
            if (b_off > ((inode->i_size + PAGE_CACHE_SIZE - 1) >> ISOFS_BUFFER_BITS(inode))) {
                  printk(KERN_DEBUG "%s: block >= EOF (%ld, %ld)\n",
                        __func__, iblock, (unsigned long) inode->i_size);
                  goto abort;
            }

            /* On the last section, nextblk == 0, section size is likely to
             * exceed sect_size by a partial block, and access beyond the
             * end of the file will reach beyond the section size, too.
             */
            while (nextblk && (b_off >= (offset + sect_size))) {
                  struct inode *ninode;

                  offset += sect_size;
                  ninode = isofs_iget(inode->i_sb, nextblk, nextoff);
                  if (!ninode)
                        goto abort;
                  firstext  = ISOFS_I(ninode)->i_first_extent;
                  sect_size = ISOFS_I(ninode)->i_section_size >> ISOFS_BUFFER_BITS(ninode);
                  nextblk   = ISOFS_I(ninode)->i_next_section_block;
                  nextoff   = ISOFS_I(ninode)->i_next_section_offset;
                  iput(ninode);

                  if (++section > 100) {
                        printk(KERN_DEBUG "%s: More than 100 file sections ?!?"
                              " aborting...\n", __func__);
                        printk(KERN_DEBUG "%s: block=%ld firstext=%u sect_size=%u "
                              "nextblk=%lu nextoff=%lu\n", __func__,
                              iblock, firstext, (unsigned) sect_size,
                              nextblk, nextoff);
                        goto abort;
                  }
            }

            if (*bh) {
                  map_bh(*bh, inode->i_sb, firstext + b_off - offset);
            } else {
                  *bh = sb_getblk(inode->i_sb, firstext+b_off-offset);
                  if (!*bh)
                        goto abort;
            }
            bh++; /* Next buffer head */
            b_off++;    /* Next buffer offset */
            nblocks--;
            rv++;
      }

abort:
      unlock_kernel();
      return rv;
}

/*
 * Used by the standard interfaces.
 */
static int isofs_get_block(struct inode *inode, sector_t iblock,
                struct buffer_head *bh_result, int create)
{
      if (create) {
            printk(KERN_DEBUG "%s: Kernel tries to allocate a block\n", __func__);
            return -EROFS;
      }

      return isofs_get_blocks(inode, iblock, &bh_result, 1) ? 0 : -EIO;
}

static int isofs_bmap(struct inode *inode, sector_t block)
{
      struct buffer_head dummy;
      int error;

      dummy.b_state = 0;
      dummy.b_blocknr = -1000;
      error = isofs_get_block(inode, block, &dummy, 0);
      if (!error)
            return dummy.b_blocknr;
      return 0;
}

struct buffer_head *isofs_bread(struct inode *inode, sector_t block)
{
      sector_t blknr = isofs_bmap(inode, block);
      if (!blknr)
            return NULL;
      return sb_bread(inode->i_sb, blknr);
}

static int isofs_readpage(struct file *file, struct page *page)
{
      return block_read_full_page(page,isofs_get_block);
}

static sector_t _isofs_bmap(struct address_space *mapping, sector_t block)
{
      return generic_block_bmap(mapping,block,isofs_get_block);
}

static const struct address_space_operations isofs_aops = {
      .readpage = isofs_readpage,
      .sync_page = block_sync_page,
      .bmap = _isofs_bmap
};

static inline void test_and_set_uid(uid_t *p, uid_t value)
{
      if (value)
            *p = value;
}

static inline void test_and_set_gid(gid_t *p, gid_t value)
{
        if (value)
                *p = value;
}

static int isofs_read_level3_size(struct inode *inode)
{
      unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
      int high_sierra = ISOFS_SB(inode->i_sb)->s_high_sierra;
      struct buffer_head *bh = NULL;
      unsigned long block, offset, block_saved, offset_saved;
      int i = 0;
      int more_entries = 0;
      struct iso_directory_record *tmpde = NULL;
      struct iso_inode_info *ei = ISOFS_I(inode);

      inode->i_size = 0;

      /* The first 16 blocks are reserved as the System Area.  Thus,
       * no inodes can appear in block 0.  We use this to flag that
       * this is the last section. */
      ei->i_next_section_block = 0;
      ei->i_next_section_offset = 0;

      block = ei->i_iget5_block;
      offset = ei->i_iget5_offset;

      do {
            struct iso_directory_record *de;
            unsigned int de_len;

            if (!bh) {
                  bh = sb_bread(inode->i_sb, block);
                  if (!bh)
                        goto out_noread;
            }
            de = (struct iso_directory_record *) (bh->b_data + offset);
            de_len = *(unsigned char *) de;

            if (de_len == 0) {
                  brelse(bh);
                  bh = NULL;
                  ++block;
                  offset = 0;
                  continue;
            }

            block_saved = block;
            offset_saved = offset;
            offset += de_len;

            /* Make sure we have a full directory entry */
            if (offset >= bufsize) {
                  int slop = bufsize - offset + de_len;
                  if (!tmpde) {
                        tmpde = kmalloc(256, GFP_KERNEL);
                        if (!tmpde)
                              goto out_nomem;
                  }
                  memcpy(tmpde, de, slop);
                  offset &= bufsize - 1;
                  block++;
                  brelse(bh);
                  bh = NULL;
                  if (offset) {
                        bh = sb_bread(inode->i_sb, block);
                        if (!bh)
                              goto out_noread;
                        memcpy((void *)tmpde+slop, bh->b_data, offset);
                  }
                  de = tmpde;
            }

            inode->i_size += isonum_733(de->size);
            if (i == 1) {
                  ei->i_next_section_block = block_saved;
                  ei->i_next_section_offset = offset_saved;
            }

            more_entries = de->flags[-high_sierra] & 0x80;

            i++;
            if (i > 100)
                  goto out_toomany;
      } while (more_entries);
out:
      kfree(tmpde);
      if (bh)
            brelse(bh);
      return 0;

out_nomem:
      if (bh)
            brelse(bh);
      return -ENOMEM;

out_noread:
      printk(KERN_INFO "ISOFS: unable to read i-node block %lu\n", block);
      kfree(tmpde);
      return -EIO;

out_toomany:
      printk(KERN_INFO "%s: More than 100 file sections ?!?, aborting...\n"
            "isofs_read_level3_size: inode=%lu\n",
            __func__, inode->i_ino);
      goto out;
}

static void isofs_read_inode(struct inode *inode)
{
      struct super_block *sb = inode->i_sb;
      struct isofs_sb_info *sbi = ISOFS_SB(sb);
      unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
      unsigned long block;
      int high_sierra = sbi->s_high_sierra;
      struct buffer_head *bh = NULL;
      struct iso_directory_record *de;
      struct iso_directory_record *tmpde = NULL;
      unsigned int de_len;
      unsigned long offset;
      struct iso_inode_info *ei = ISOFS_I(inode);

      block = ei->i_iget5_block;
      bh = sb_bread(inode->i_sb, block);
      if (!bh)
            goto out_badread;

      offset = ei->i_iget5_offset;

      de = (struct iso_directory_record *) (bh->b_data + offset);
      de_len = *(unsigned char *) de;

      if (offset + de_len > bufsize) {
            int frag1 = bufsize - offset;

            tmpde = kmalloc(de_len, GFP_KERNEL);
            if (tmpde == NULL) {
                  printk(KERN_INFO "%s: out of memory\n", __func__);
                  goto fail;
            }
            memcpy(tmpde, bh->b_data + offset, frag1);
            brelse(bh);
            bh = sb_bread(inode->i_sb, ++block);
            if (!bh)
                  goto out_badread;
            memcpy((char *)tmpde+frag1, bh->b_data, de_len - frag1);
            de = tmpde;
      }

      inode->i_ino = isofs_get_ino(ei->i_iget5_block,
                              ei->i_iget5_offset,
                              ISOFS_BUFFER_BITS(inode));

      /* Assume it is a normal-format file unless told otherwise */
      ei->i_file_format = isofs_file_normal;

      if (de->flags[-high_sierra] & 2) {
            inode->i_mode = S_IRUGO | S_IXUGO | S_IFDIR;
            inode->i_nlink = 1;     /*
                               * Set to 1.  We know there are 2, but
                               * the find utility tries to optimize
                               * if it is 2, and it screws up.  It is
                               * easier to give 1 which tells find to
                               * do it the hard way.
                               */
      } else {
            /* Everybody gets to read the file. */
            inode->i_mode = sbi->s_mode;
            inode->i_nlink = 1;
            inode->i_mode |= S_IFREG;
      }
      inode->i_uid = sbi->s_uid;
      inode->i_gid = sbi->s_gid;
      inode->i_blocks = 0;

      ei->i_format_parm[0] = 0;
      ei->i_format_parm[1] = 0;
      ei->i_format_parm[2] = 0;

      ei->i_section_size = isonum_733(de->size);
      if (de->flags[-high_sierra] & 0x80) {
            if(isofs_read_level3_size(inode))
                  goto fail;
      } else {
            ei->i_next_section_block = 0;
            ei->i_next_section_offset = 0;
            inode->i_size = isonum_733(de->size);
      }

      /*
       * Some dipshit decided to store some other bit of information
       * in the high byte of the file length.  Truncate size in case
       * this CDROM was mounted with the cruft option.
       */

      if (sbi->s_cruft == 'y')
            inode->i_size &= 0x00ffffff;

      if (de->interleave[0]) {
            printk(KERN_DEBUG "ISOFS: Interleaved files not (yet) supported.\n");
            inode->i_size = 0;
      }

      /* I have no idea what file_unit_size is used for, so
         we will flag it for now */
      if (de->file_unit_size[0] != 0) {
            printk(KERN_DEBUG "ISOFS: File unit size != 0 for ISO file (%ld).\n",
                  inode->i_ino);
      }

      /* I have no idea what other flag bits are used for, so
         we will flag it for now */
#ifdef DEBUG
      if((de->flags[-high_sierra] & ~2)!= 0){
            printk(KERN_DEBUG "ISOFS: Unusual flag settings for ISO file "
                        "(%ld %x).\n",
                  inode->i_ino, de->flags[-high_sierra]);
      }
#endif

      inode->i_mtime.tv_sec =
      inode->i_atime.tv_sec =
      inode->i_ctime.tv_sec = iso_date(de->date, high_sierra);
      inode->i_mtime.tv_nsec =
      inode->i_atime.tv_nsec =
      inode->i_ctime.tv_nsec = 0;

      ei->i_first_extent = (isonum_733(de->extent) +
                  isonum_711(de->ext_attr_length));

      /* Set the number of blocks for stat() - should be done before RR */
      inode->i_blocks = (inode->i_size + 511) >> 9;

      /*
       * Now test for possible Rock Ridge extensions which will override
       * some of these numbers in the inode structure.
       */

      if (!high_sierra) {
            parse_rock_ridge_inode(de, inode);
            /* if we want uid/gid set, override the rock ridge setting */
            test_and_set_uid(&inode->i_uid, sbi->s_uid);
            test_and_set_gid(&inode->i_gid, sbi->s_gid);
      }

      /* Install the inode operations vector */
      if (S_ISREG(inode->i_mode)) {
            inode->i_fop = &generic_ro_fops;
            switch (ei->i_file_format) {
#ifdef CONFIG_ZISOFS
            case isofs_file_compressed:
                  inode->i_data.a_ops = &zisofs_aops;
                  break;
#endif
            default:
                  inode->i_data.a_ops = &isofs_aops;
                  break;
            }
      } else if (S_ISDIR(inode->i_mode)) {
            inode->i_op = &isofs_dir_inode_operations;
            inode->i_fop = &isofs_dir_operations;
      } else if (S_ISLNK(inode->i_mode)) {
            inode->i_op = &page_symlink_inode_operations;
            inode->i_data.a_ops = &isofs_symlink_aops;
      } else
            /* XXX - parse_rock_ridge_inode() had already set i_rdev. */
            init_special_inode(inode, inode->i_mode, inode->i_rdev);

out:
      kfree(tmpde);
      if (bh)
            brelse(bh);
      return;

out_badread:
      printk(KERN_WARNING "ISOFS: unable to read i-node block\n");
fail:
      make_bad_inode(inode);
      goto out;
}

struct isofs_iget5_callback_data {
      unsigned long block;
      unsigned long offset;
};

static int isofs_iget5_test(struct inode *ino, void *data)
{
      struct iso_inode_info *i = ISOFS_I(ino);
      struct isofs_iget5_callback_data *d =
            (struct isofs_iget5_callback_data*)data;
      return (i->i_iget5_block == d->block)
            && (i->i_iget5_offset == d->offset);
}

static int isofs_iget5_set(struct inode *ino, void *data)
{
      struct iso_inode_info *i = ISOFS_I(ino);
      struct isofs_iget5_callback_data *d =
            (struct isofs_iget5_callback_data*)data;
      i->i_iget5_block = d->block;
      i->i_iget5_offset = d->offset;
      return 0;
}

/* Store, in the inode's containing structure, the block and block
 * offset that point to the underlying meta-data for the inode.  The
 * code below is otherwise similar to the iget() code in
 * include/linux/fs.h */
struct inode *isofs_iget(struct super_block *sb,
                   unsigned long block,
                   unsigned long offset)
{
      unsigned long hashval;
      struct inode *inode;
      struct isofs_iget5_callback_data data;

      if (offset >= 1ul << sb->s_blocksize_bits)
            return NULL;

      data.block = block;
      data.offset = offset;

      hashval = (block << sb->s_blocksize_bits) | offset;

      inode = iget5_locked(sb, hashval, &isofs_iget5_test,
                        &isofs_iget5_set, &data);

      if (inode && (inode->i_state & I_NEW)) {
            sb->s_op->read_inode(inode);
            unlock_new_inode(inode);
      }

      return inode;
}

static int isofs_get_sb(struct file_system_type *fs_type,
      int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
      return get_sb_bdev(fs_type, flags, dev_name, data, isofs_fill_super,
                        mnt);
}

static struct file_system_type iso9660_fs_type = {
      .owner            = THIS_MODULE,
      .name       = "iso9660",
      .get_sb           = isofs_get_sb,
      .kill_sb    = kill_block_super,
      .fs_flags   = FS_REQUIRES_DEV,
};

static int __init init_iso9660_fs(void)
{
      int err = init_inodecache();
      if (err)
            goto out;
#ifdef CONFIG_ZISOFS
      err = zisofs_init();
      if (err)
            goto out1;
#endif
      err = register_filesystem(&iso9660_fs_type);
      if (err)
            goto out2;
      return 0;
out2:
#ifdef CONFIG_ZISOFS
      zisofs_cleanup();
out1:
#endif
      destroy_inodecache();
out:
      return err;
}

static void __exit exit_iso9660_fs(void)
{
        unregister_filesystem(&iso9660_fs_type);
#ifdef CONFIG_ZISOFS
      zisofs_cleanup();
#endif
      destroy_inodecache();
}

module_init(init_iso9660_fs)
module_exit(exit_iso9660_fs)
MODULE_LICENSE("GPL");
/* Actual filesystem name is iso9660, as requested in filesystems.c */
MODULE_ALIAS("iso9660");

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