text: /*-
   * Copyright (c) 2001, 2002 Scott Long <scottl@freebsd.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * $FreeBSD: soc2013/dpl/head/sys/fs/udf/udf_vnops.c 249483 2013-03-14 20:28:26Z kib $
   */
  
  /* udf_vnops.c */
  /* Take care of the vnode side of things */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/namei.h>
  #include <sys/kernel.h>
  #include <sys/malloc.h>
  #include <sys/stat.h>
  #include <sys/bio.h>
  #include <sys/conf.h>
  #include <sys/buf.h>
  #include <sys/iconv.h>
  #include <sys/mount.h>
  #include <sys/vnode.h>
  #include <sys/dirent.h>
  #include <sys/queue.h>
  #include <sys/unistd.h>
  #include <sys/endian.h>
  
  #include <vm/uma.h>
  
  #include <fs/udf/ecma167-udf.h>
  #include <fs/udf/osta.h>
  #include <fs/udf/udf.h>
  #include <fs/udf/udf_mount.h>
  
  extern struct iconv_functions *udf_iconv;
  
  static vop_access_t	udf_access;
  static vop_getattr_t	udf_getattr;
  static vop_open_t	udf_open;
  static vop_ioctl_t	udf_ioctl;
  static vop_pathconf_t	udf_pathconf;
  static vop_print_t	udf_print;
  static vop_read_t	udf_read;
  static vop_readdir_t	udf_readdir;
  static vop_readlink_t	udf_readlink;
  static vop_setattr_t	udf_setattr;
  static vop_strategy_t	udf_strategy;
  static vop_bmap_t	udf_bmap;
  static vop_cachedlookup_t	udf_lookup;
  static vop_reclaim_t	udf_reclaim;
  static vop_vptofh_t	udf_vptofh;
  static int udf_readatoffset(struct udf_node *node, int *size, off_t offset,
      struct buf **bp, uint8_t **data);
  static int udf_bmap_internal(struct udf_node *node, off_t offset,
      daddr_t *sector, uint32_t *max_size);
  
  static struct vop_vector udf_vnodeops = {
  	.vop_default =		&default_vnodeops,
  
  	.vop_access =		udf_access,
  	.vop_bmap =		udf_bmap,
  	.vop_cachedlookup =	udf_lookup,
  	.vop_getattr =		udf_getattr,
  	.vop_ioctl =		udf_ioctl,
  	.vop_lookup =		vfs_cache_lookup,
  	.vop_open =		udf_open,
  	.vop_pathconf =		udf_pathconf,
  	.vop_print =		udf_print,
  	.vop_read =		udf_read,
  	.vop_readdir =		udf_readdir,
  	.vop_readlink =		udf_readlink,
  	.vop_reclaim =		udf_reclaim,
  	.vop_setattr =		udf_setattr,
  	.vop_strategy =		udf_strategy,
  	.vop_vptofh =		udf_vptofh,
  };
  
  struct vop_vector udf_fifoops = {
  	.vop_default =		&fifo_specops,
  	.vop_access =		udf_access,
  	.vop_getattr =		udf_getattr,
  	.vop_print =		udf_print,
  	.vop_reclaim =		udf_reclaim,
  	.vop_setattr =		udf_setattr,
  	.vop_vptofh =		udf_vptofh,
  };
  
  static MALLOC_DEFINE(M_UDFFID, "udf_fid", "UDF FileId structure");
  static MALLOC_DEFINE(M_UDFDS, "udf_ds", "UDF Dirstream structure");
  
  #define UDF_INVALID_BMAP	-1
  
  int
  udf_allocv(struct mount *mp, struct vnode **vpp, struct thread *td)
  {
  	int error;
  	struct vnode *vp;
  
  	error = getnewvnode("udf", mp, &udf_vnodeops, &vp);
  	if (error) {
  		printf("udf_allocv: failed to allocate new vnode\n");
  		return (error);
  	}
  
  	*vpp = vp;
  	return (0);
  }
  
  /* Convert file entry permission (5 bits per owner/group/user) to a mode_t */
  static mode_t
  udf_permtomode(struct udf_node *node)
  {
  	uint32_t perm;
  	uint16_t flags;
  	mode_t mode;
  
  	perm = le32toh(node->fentry->perm);
  	flags = le16toh(node->fentry->icbtag.flags);
  
  	mode = perm & UDF_FENTRY_PERM_USER_MASK;
  	mode |= ((perm & UDF_FENTRY_PERM_GRP_MASK) >> 2);
  	mode |= ((perm & UDF_FENTRY_PERM_OWNER_MASK) >> 4);
  	mode |= ((flags & UDF_ICB_TAG_FLAGS_STICKY) << 4);
  	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETGID) << 6);
  	mode |= ((flags & UDF_ICB_TAG_FLAGS_SETUID) << 8);
  
  	return (mode);
  }
  
  static int
  udf_access(struct vop_access_args *a)
  {
  	struct vnode *vp;
  	struct udf_node *node;
  	accmode_t accmode;
  	mode_t mode;
  
  	vp = a->a_vp;
  	node = VTON(vp);
  	accmode = a->a_accmode;
  
  	if (accmode & VWRITE) {
  		switch (vp->v_type) {
  		case VDIR:
  		case VLNK:
  		case VREG:
  			return (EROFS);
  			/* NOT REACHED */
  		default:
  			break;
  		}
  	}
  
  	mode = udf_permtomode(node);
  
  	return (vaccess(vp->v_type, mode, node->fentry->uid, node->fentry->gid,
  	    accmode, a->a_cred, NULL));
  }
  
  static int
  udf_open(struct vop_open_args *ap) {
  	struct udf_node *np = VTON(ap->a_vp);
  	off_t fsize;
  
  	fsize = le64toh(np->fentry->inf_len);
  	vnode_create_vobject(ap->a_vp, fsize, ap->a_td);
  	return 0;
  }
  
  static const int mon_lens[2][12] = {
  	{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334},
  	{0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}
  };
  
  static int
  udf_isaleapyear(int year)
  {
  	int i;
  
  	i = (year % 4) ? 0 : 1;
  	i &= (year % 100) ? 1 : 0;
  	i |= (year % 400) ? 0 : 1;
  
  	return i;
  }
  
  /*
   * Timezone calculation compliments of Julian Elischer <julian@elischer.org>.
   */
  static void
  udf_timetotimespec(struct timestamp *time, struct timespec *t)
  {
  	int i, lpyear, daysinyear, year, startyear;
  	union {
  		uint16_t	u_tz_offset;
  		int16_t		s_tz_offset;
  	} tz;
  
  	/*
  	 * DirectCD seems to like using bogus year values.
  	 * Don't trust time->month as it will be used for an array index.
  	 */
  	year = le16toh(time->year);
  	if (year < 1970 || time->month < 1 || time->month > 12) {
  		t->tv_sec = 0;
  		t->tv_nsec = 0;
  		return;
  	}
  
  	/* Calculate the time and day */
  	t->tv_sec = time->second;
  	t->tv_sec += time->minute * 60;
  	t->tv_sec += time->hour * 3600;
  	t->tv_sec += (time->day - 1) * 3600 * 24;
  
  	/* Calculate the month */
  	lpyear = udf_isaleapyear(year);
  	t->tv_sec += mon_lens[lpyear][time->month - 1] * 3600 * 24;
  
  	/* Speed up the calculation */
  	startyear = 1970;
  	if (year > 2009) {
  		t->tv_sec += 1262304000;
  		startyear += 40;
  	} else if (year > 1999) {
  		t->tv_sec += 946684800;
  		startyear += 30;
  	} else if (year > 1989) {
  		t->tv_sec += 631152000;
  		startyear += 20;
  	} else if (year > 1979) {
  		t->tv_sec += 315532800;
  		startyear += 10;
  	}
  
  	daysinyear = (year - startyear) * 365;
  	for (i = startyear; i < year; i++)
  		daysinyear += udf_isaleapyear(i);
  	t->tv_sec += daysinyear * 3600 * 24;
  
  	/* Calculate microseconds */
  	t->tv_nsec = time->centisec * 10000 + time->hund_usec * 100 +
  	    time->usec;
  
  	/*
  	 * Calculate the time zone.  The timezone is 12 bit signed 2's
  	 * complement, so we gotta do some extra magic to handle it right.
  	 */
  	tz.u_tz_offset = le16toh(time->type_tz);
  	tz.u_tz_offset &= 0x0fff;
  	if (tz.u_tz_offset & 0x0800)
  		tz.u_tz_offset |= 0xf000;	/* extend the sign to 16 bits */
  	if ((le16toh(time->type_tz) & 0x1000) && (tz.s_tz_offset != -2047))
  		t->tv_sec -= tz.s_tz_offset * 60;
  
  	return;
  }
  
  static int
  udf_getattr(struct vop_getattr_args *a)
  {
  	struct vnode *vp;
  	struct udf_node *node;
  	struct vattr *vap;
  	struct file_entry *fentry;
  	struct timespec ts;
  
  	ts.tv_sec = 0;
  
  	vp = a->a_vp;
  	vap = a->a_vap;
  	node = VTON(vp);
  	fentry = node->fentry;
  
  	vap->va_fsid = dev2udev(node->udfmp->im_dev);
  	vap->va_fileid = node->hash_id;
  	vap->va_mode = udf_permtomode(node);
  	vap->va_nlink = le16toh(fentry->link_cnt);
  	/*
  	 * XXX The spec says that -1 is valid for uid/gid and indicates an
  	 * invalid uid/gid.  How should this be represented?
  	 */
  	vap->va_uid = (le32toh(fentry->uid) == -1) ? 0 : le32toh(fentry->uid);
  	vap->va_gid = (le32toh(fentry->gid) == -1) ? 0 : le32toh(fentry->gid);
  	udf_timetotimespec(&fentry->atime, &vap->va_atime);
  	udf_timetotimespec(&fentry->mtime, &vap->va_mtime);
  	vap->va_ctime = vap->va_mtime; /* XXX Stored as an Extended Attribute */
  	vap->va_rdev = NODEV;
  	if (vp->v_type & VDIR) {
  		/*
  		 * Directories that are recorded within their ICB will show
  		 * as having 0 blocks recorded.  Since tradition dictates
  		 * that directories consume at least one logical block,
  		 * make it appear so.
  		 */
  		if (fentry->logblks_rec != 0) {
  			vap->va_size =
  			    le64toh(fentry->logblks_rec) * node->udfmp->bsize;
  		} else {
  			vap->va_size = node->udfmp->bsize;
  		}
  	} else {
  		vap->va_size = le64toh(fentry->inf_len);
  	}
  	vap->va_flags = 0;
  	vap->va_gen = 1;
  	vap->va_blocksize = node->udfmp->bsize;
  	vap->va_bytes = le64toh(fentry->inf_len);
  	vap->va_type = vp->v_type;
  	vap->va_filerev = 0; /* XXX */
  	return (0);
  }
  
  static int
  udf_setattr(struct vop_setattr_args *a)
  {
  	struct vnode *vp;
  	struct vattr *vap;
  
  	vp = a->a_vp;
  	vap = a->a_vap;
  	if (vap->va_flags != (u_long)VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
  	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
  	    vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL)
  		return (EROFS);
  	if (vap->va_size != (u_quad_t)VNOVAL) {
  		switch (vp->v_type) {
  		case VDIR:
  			return (EISDIR);
  		case VLNK:
  		case VREG:
  			return (EROFS);
  		case VCHR:
  		case VBLK:
  		case VSOCK:
  		case VFIFO:
  		case VNON:
  		case VBAD:
  		case VMARKER:
  			return (0);
  		}
  	}
  	return (0);
  }
  
  /*
   * File specific ioctls.
   */
  static int
  udf_ioctl(struct vop_ioctl_args *a)
  {
  	printf("%s called\n", __func__);
  	return (ENOTTY);
  }
  
  /*
   * I'm not sure that this has much value in a read-only filesystem, but
   * cd9660 has it too.
   */
  static int
  udf_pathconf(struct vop_pathconf_args *a)
  {
  
  	switch (a->a_name) {
  	case _PC_LINK_MAX:
  		*a->a_retval = 65535;
  		return (0);
  	case _PC_NAME_MAX:
  		*a->a_retval = NAME_MAX;
  		return (0);
  	case _PC_PATH_MAX:
  		*a->a_retval = PATH_MAX;
  		return (0);
  	case _PC_NO_TRUNC:
  		*a->a_retval = 1;
  		return (0);
  	default:
  		return (EINVAL);
  	}
  }
  
  static int
  udf_print(struct vop_print_args *ap)
  {
  	struct vnode *vp = ap->a_vp;
  	struct udf_node *node = VTON(vp);
  
  	printf("    ino %lu, on dev %s", (u_long)node->hash_id,
  	    devtoname(node->udfmp->im_dev));
  	if (vp->v_type == VFIFO)
  		fifo_printinfo(vp);
  	printf("\n");
  	return (0);
  }
  
  #define lblkno(udfmp, loc)	((loc) >> (udfmp)->bshift)
  #define blkoff(udfmp, loc)	((loc) & (udfmp)->bmask)
  #define lblktosize(udfmp, blk)	((blk) << (udfmp)->bshift)
  
  static inline int
  is_data_in_fentry(const struct udf_node *node)
  {
  	const struct file_entry *fentry = node->fentry;
  
  	return ((le16toh(fentry->icbtag.flags) & 0x7) == 3);
  }
  
  static int
  udf_read(struct vop_read_args *ap)
  {
  	struct vnode *vp = ap->a_vp;
  	struct uio *uio = ap->a_uio;
  	struct udf_node *node = VTON(vp);
  	struct udf_mnt *udfmp;
  	struct file_entry *fentry;
  	struct buf *bp;
  	uint8_t *data;
  	daddr_t lbn, rablock;
  	off_t diff, fsize;
  	ssize_t n;
  	int error = 0;
  	long size, on;
  
  	if (uio->uio_resid == 0)
  		return (0);
  	if (uio->uio_offset < 0)
  		return (EINVAL);
  
  	if (is_data_in_fentry(node)) {
  		fentry = node->fentry;
  		data = &fentry->data[le32toh(fentry->l_ea)];
  		fsize = le32toh(fentry->l_ad);
  
  		n = uio->uio_resid;
  		diff = fsize - uio->uio_offset;
  		if (diff <= 0)
  			return (0);
  		if (diff < n)
  			n = diff;
  		error = uiomove(data + uio->uio_offset, (int)n, uio);
  		return (error);
  	}
  
  	fsize = le64toh(node->fentry->inf_len);
  	udfmp = node->udfmp;
  	do {
  		lbn = lblkno(udfmp, uio->uio_offset);
  		on = blkoff(udfmp, uio->uio_offset);
  		n = min((u_int)(udfmp->bsize - on),
  			uio->uio_resid);
  		diff = fsize - uio->uio_offset;
  		if (diff <= 0)
  			return (0);
  		if (diff < n)
  			n = diff;
  		size = udfmp->bsize;
  		rablock = lbn + 1;
  		if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
  			if (lblktosize(udfmp, rablock) < fsize) {
  				error = cluster_read(vp, fsize, lbn, size,
  				    NOCRED, uio->uio_resid,
  				    (ap->a_ioflag >> 16), 0, &bp);
  			} else {
  				error = bread(vp, lbn, size, NOCRED, &bp);
  			}
  		} else {
  			error = bread(vp, lbn, size, NOCRED, &bp);
  		}
  		n = min(n, size - bp->b_resid);
  		if (error) {
  			brelse(bp);
  			return (error);
  		}
  
  		error = uiomove(bp->b_data + on, (int)n, uio);
  		brelse(bp);
  	} while (error == 0 && uio->uio_resid > 0 && n != 0);
  	return (error);
  }
  
  /*
   * Call the OSTA routines to translate the name from a CS0 dstring to a
   * 16-bit Unicode String.  Hooks need to be placed in here to translate from
   * Unicode to the encoding that the kernel/user expects.  Return the length
   * of the translated string.
   */
  static int
  udf_transname(char *cs0string, char *destname, int len, struct udf_mnt *udfmp)
  {
  	unicode_t *transname;
  	char *unibuf, *unip;
  	int i, destlen;
  	ssize_t unilen = 0;
  	size_t destleft = MAXNAMLEN;
  
  	/* Convert 16-bit Unicode to destname */
  	if (udfmp->im_flags & UDFMNT_KICONV && udf_iconv) {
  		/* allocate a buffer big enough to hold an 8->16 bit expansion */
  		unibuf = uma_zalloc(udf_zone_trans, M_WAITOK);
  		unip = unibuf;
  		if ((unilen = (ssize_t)udf_UncompressUnicodeByte(len, cs0string, unibuf)) == -1) {
  			printf("udf: Unicode translation failed\n");
  			uma_zfree(udf_zone_trans, unibuf);
  			return 0;
  		}
  
  		while (unilen > 0 && destleft > 0) {
  			udf_iconv->conv(udfmp->im_d2l, (const char **)&unibuf,
  				(size_t *)&unilen, (char **)&destname, &destleft);
  			/* Unconverted character found */
  			if (unilen > 0 && destleft > 0) {
  				*destname++ = '?';
  				destleft--;
  				unibuf += 2;
  				unilen -= 2;
  			}
  		}
  		uma_zfree(udf_zone_trans, unip);
  		*destname = '\0';
  		destlen = MAXNAMLEN - (int)destleft;
  	} else {
  		/* allocate a buffer big enough to hold an 8->16 bit expansion */
  		transname = uma_zalloc(udf_zone_trans, M_WAITOK);
  
  		if ((unilen = (ssize_t)udf_UncompressUnicode(len, cs0string, transname)) == -1) {
  			printf("udf: Unicode translation failed\n");
  			uma_zfree(udf_zone_trans, transname);
  			return 0;
  		}
  
  		for (i = 0; i < unilen ; i++) {
  			if (transname[i] & 0xff00) {
  				destname[i] = '.';	/* Fudge the 16bit chars */
  			} else {
  				destname[i] = transname[i] & 0xff;
  			}
  		}
  		uma_zfree(udf_zone_trans, transname);
  		destname[unilen] = 0;
  		destlen = (int)unilen;
  	}
  
  	return (destlen);
  }
  
  /*
   * Compare a CS0 dstring with a name passed in from the VFS layer.  Return
   * 0 on a successful match, nonzero otherwise.  Unicode work may need to be done
   * here also.
   */
  static int
  udf_cmpname(char *cs0string, char *cmpname, int cs0len, int cmplen, struct udf_mnt *udfmp)
  {
  	char *transname;
  	int error = 0;
  
  	/* This is overkill, but not worth creating a new zone */
  	transname = uma_zalloc(udf_zone_trans, M_WAITOK);
  
  	cs0len = udf_transname(cs0string, transname, cs0len, udfmp);
  
  	/* Easy check.  If they aren't the same length, they aren't equal */
  	if ((cs0len == 0) || (cs0len != cmplen))
  		error = -1;
  	else
  		error = bcmp(transname, cmpname, cmplen);
  
  	uma_zfree(udf_zone_trans, transname);
  	return (error);
  }
  
  struct udf_uiodir {
  	struct dirent *dirent;
  	u_long *cookies;
  	int ncookies;
  	int acookies;
  	int eofflag;
  };
  
  static int
  udf_uiodir(struct udf_uiodir *uiodir, int de_size, struct uio *uio, long cookie)
  {
  	if (uiodir->cookies != NULL) {
  		if (++uiodir->acookies > uiodir->ncookies) {
  			uiodir->eofflag = 0;
  			return (-1);
  		}
  		*uiodir->cookies++ = cookie;
  	}
  
  	if (uio->uio_resid < de_size) {
  		uiodir->eofflag = 0;
  		return (-1);
  	}
  
  	return (uiomove(uiodir->dirent, de_size, uio));
  }
  
  static struct udf_dirstream *
  udf_opendir(struct udf_node *node, int offset, int fsize, struct udf_mnt *udfmp)
  {
  	struct udf_dirstream *ds;
  
  	ds = uma_zalloc(udf_zone_ds, M_WAITOK | M_ZERO);
  
  	ds->node = node;
  	ds->offset = offset;
  	ds->udfmp = udfmp;
  	ds->fsize = fsize;
  
  	return (ds);
  }
  
  static struct fileid_desc *
  udf_getfid(struct udf_dirstream *ds)
  {
  	struct fileid_desc *fid;
  	int error, frag_size = 0, total_fid_size;
  
  	/* End of directory? */
  	if (ds->offset + ds->off >= ds->fsize) {
  		ds->error = 0;
  		return (NULL);
  	}
  
  	/* Grab the first extent of the directory */
  	if (ds->off == 0) {
  		ds->size = 0;
  		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
  		    &ds->bp, &ds->data);
  		if (error) {
  			ds->error = error;
  			if (ds->bp != NULL)
  				brelse(ds->bp);
  			return (NULL);
  		}
  	}
  
  	/*
  	 * Clean up from a previous fragmented FID.
  	 * XXX Is this the right place for this?
  	 */
  	if (ds->fid_fragment && ds->buf != NULL) {
  		ds->fid_fragment = 0;
  		free(ds->buf, M_UDFFID);
  	}
  
  	fid = (struct fileid_desc*)&ds->data[ds->off];
  
  	/*
  	 * Check to see if the fid is fragmented. The first test
  	 * ensures that we don't wander off the end of the buffer
  	 * looking for the l_iu and l_fi fields.
  	 */
  	if (ds->off + UDF_FID_SIZE > ds->size ||
  	    ds->off + le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
  
  		/* Copy what we have of the fid into a buffer */
  		frag_size = ds->size - ds->off;
  		if (frag_size >= ds->udfmp->bsize) {
  			printf("udf: invalid FID fragment\n");
  			ds->error = EINVAL;
  			return (NULL);
  		}
  
  		/*
  		 * File ID descriptors can only be at most one
  		 * logical sector in size.
  		 */
  		ds->buf = malloc(ds->udfmp->bsize, M_UDFFID,
  		     M_WAITOK | M_ZERO);
  		bcopy(fid, ds->buf, frag_size);
  
  		/* Reduce all of the casting magic */
  		fid = (struct fileid_desc*)ds->buf;
  
  		if (ds->bp != NULL)
  			brelse(ds->bp);
  
  		/* Fetch the next allocation */
  		ds->offset += ds->size;
  		ds->size = 0;
  		error = udf_readatoffset(ds->node, &ds->size, ds->offset,
  		    &ds->bp, &ds->data);
  		if (error) {
  			ds->error = error;
  			return (NULL);
  		}
  
  		/*
  		 * If the fragment was so small that we didn't get
  		 * the l_iu and l_fi fields, copy those in.
  		 */
  		if (frag_size < UDF_FID_SIZE)
  			bcopy(ds->data, &ds->buf[frag_size],
  			    UDF_FID_SIZE - frag_size);
  
  		/*
  		 * Now that we have enough of the fid to work with,
  		 * copy in the rest of the fid from the new
  		 * allocation.
  		 */
  		total_fid_size = UDF_FID_SIZE + le16toh(fid->l_iu) + fid->l_fi;
  		if (total_fid_size > ds->udfmp->bsize) {
  			printf("udf: invalid FID\n");
  			ds->error = EIO;
  			return (NULL);
  		}
  		bcopy(ds->data, &ds->buf[frag_size],
  		    total_fid_size - frag_size);
  
  		ds->fid_fragment = 1;
  	} else {
  		total_fid_size = le16toh(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;
  	}
  
  	/*
  	 * Update the offset. Align on a 4 byte boundary because the
  	 * UDF spec says so.
  	 */
  	ds->this_off = ds->offset + ds->off;
  	if (!ds->fid_fragment) {
  		ds->off += (total_fid_size + 3) & ~0x03;
  	} else {
  		ds->off = (total_fid_size - frag_size + 3) & ~0x03;
  	}
  
  	return (fid);
  }
  
  static void
  udf_closedir(struct udf_dirstream *ds)
  {
  
  	if (ds->bp != NULL)
  		brelse(ds->bp);
  
  	if (ds->fid_fragment && ds->buf != NULL)
  		free(ds->buf, M_UDFFID);
  
  	uma_zfree(udf_zone_ds, ds);
  }
  
  static int
  udf_readdir(struct vop_readdir_args *a)
  {
  	struct vnode *vp;
  	struct uio *uio;
  	struct dirent dir;
  	struct udf_node *node;
  	struct udf_mnt *udfmp;
  	struct fileid_desc *fid;
  	struct udf_uiodir uiodir;
  	struct udf_dirstream *ds;
  	u_long *cookies = NULL;
  	int ncookies;
  	int error = 0;
  
  	vp = a->a_vp;
  	uio = a->a_uio;
  	node = VTON(vp);
  	udfmp = node->udfmp;
  	uiodir.eofflag = 1;
  
  	if (a->a_ncookies != NULL) {
  		/*
  		 * Guess how many entries are needed.  If we run out, this
  		 * function will be called again and thing will pick up were
  		 * it left off.
  		 */
  		ncookies = uio->uio_resid / 8;
  		cookies = malloc(sizeof(u_long) * ncookies,
  		    M_TEMP, M_WAITOK);
  		if (cookies == NULL)
  			return (ENOMEM);
  		uiodir.ncookies = ncookies;
  		uiodir.cookies = cookies;
  		uiodir.acookies = 0;
  	} else {
  		uiodir.cookies = NULL;
  	}
  
  	/*
  	 * Iterate through the file id descriptors.  Give the parent dir
  	 * entry special attention.
  	 */
  	ds = udf_opendir(node, uio->uio_offset, le64toh(node->fentry->inf_len),
  	    node->udfmp);
  
  	while ((fid = udf_getfid(ds)) != NULL) {
  
  		/* XXX Should we return an error on a bad fid? */
  		if (udf_checktag(&fid->tag, TAGID_FID)) {
  			printf("Invalid FID tag\n");
  			hexdump(fid, UDF_FID_SIZE, NULL, 0);
  			error = EIO;
  			break;
  		}
  
  		/* Is this a deleted file? */
  		if (fid->file_char & UDF_FILE_CHAR_DEL)
  			continue;
  
  		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
  			/* Do up the '.' and '..' entries.  Dummy values are
  			 * used for the cookies since the offset here is
  			 * usually zero, and NFS doesn't like that value
  			 */
  			dir.d_fileno = node->hash_id;
  			dir.d_type = DT_DIR;
  			dir.d_name[0] = '.';
  			dir.d_name[1] = '\0';
  			dir.d_namlen = 1;
  			dir.d_reclen = GENERIC_DIRSIZ(&dir);
  			uiodir.dirent = &dir;
  			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 1);
  			if (error)
  				break;
  
  			dir.d_fileno = udf_getid(&fid->icb);
  			dir.d_type = DT_DIR;
  			dir.d_name[0] = '.';
  			dir.d_name[1] = '.';
  			dir.d_name[2] = '\0';
  			dir.d_namlen = 2;
  			dir.d_reclen = GENERIC_DIRSIZ(&dir);
  			uiodir.dirent = &dir;
  			error = udf_uiodir(&uiodir, dir.d_reclen, uio, 2);
  		} else {
  			dir.d_namlen = udf_transname(&fid->data[fid->l_iu],
  			    &dir.d_name[0], fid->l_fi, udfmp);
  			dir.d_fileno = udf_getid(&fid->icb);
  			dir.d_type = (fid->file_char & UDF_FILE_CHAR_DIR) ?
  			    DT_DIR : DT_UNKNOWN;
  			dir.d_reclen = GENERIC_DIRSIZ(&dir);
  			uiodir.dirent = &dir;
  			error = udf_uiodir(&uiodir, dir.d_reclen, uio,
  			    ds->this_off);
  		}
  		if (error)
  			break;
  		uio->uio_offset = ds->offset + ds->off;
  	}
  
  	/* tell the calling layer whether we need to be called again */
  	*a->a_eofflag = uiodir.eofflag;
  
  	if (error < 0)
  		error = 0;
  	if (!error)
  		error = ds->error;
  
  	udf_closedir(ds);
  
  	if (a->a_ncookies != NULL) {
  		if (error)
  			free(cookies, M_TEMP);
  		else {
  			*a->a_ncookies = uiodir.acookies;
  			*a->a_cookies = cookies;
  		}
  	}
  
  	return (error);
  }
  
  static int
  udf_readlink(struct vop_readlink_args *ap)
  {
  	struct path_component *pc, *end;
  	struct vnode *vp;
  	struct uio uio;
  	struct iovec iov[1];
  	struct udf_node *node;
  	void *buf;
  	char *cp;
  	int error, len, root;
  
  	/*
  	 * A symbolic link in UDF is a list of variable-length path
  	 * component structures.  We build a pathname in the caller's
  	 * uio by traversing this list.
  	 */
  	vp = ap->a_vp;
  	node = VTON(vp);
  	len = le64toh(node->fentry->inf_len);
  	buf = malloc(len, M_DEVBUF, M_WAITOK);
  	iov[0].iov_len = len;
  	iov[0].iov_base = buf;
  	uio.uio_iov = iov;
  	uio.uio_iovcnt = 1;
  	uio.uio_offset = 0;
  	uio.uio_resid = iov[0].iov_len;
  	uio.uio_segflg = UIO_SYSSPACE;
  	uio.uio_rw = UIO_READ;
  	uio.uio_td = curthread;
  	error = VOP_READ(vp, &uio, 0, ap->a_cred);
  	if (error)
  		goto error;
  
  	pc = buf;
  	end = (void *)((char *)buf + len);
  	root = 0;
  	while (pc < end) {
  		switch (pc->type) {
  		case UDF_PATH_ROOT:
  			/* Only allow this at the beginning of a path. */
  			if ((void *)pc != buf) {
  				error = EINVAL;
  				goto error;
  			}
  			cp = "/";
  			len = 1;
  			root = 1;
  			break;
  		case UDF_PATH_DOT:
  			cp = ".";
  			len = 1;
  			break;
  		case UDF_PATH_DOTDOT:
  			cp = "..";
  			len = 2;
  			break;
  		case UDF_PATH_PATH:
  			if (pc->length == 0) {
  				error = EINVAL;
  				goto error;
  			}
  			/*
  			 * XXX: We only support CS8 which appears to map
  			 * to ASCII directly.
  			 */
  			switch (pc->identifier[0]) {
  			case 8:
  				cp = pc->identifier + 1;
  				len = pc->length - 1;
  				break;
  			default:
  				error = EOPNOTSUPP;
  				goto error;
  			}
  			break;
  		default:
  			error = EINVAL;
  			goto error;
  		}
  
  		/*
  		 * If this is not the first component, insert a path
  		 * separator.
  		 */
  		if (pc != buf) {
  			/* If we started with root we already have a "/". */
  			if (root)
  				goto skipslash;
  			root = 0;
  			if (ap->a_uio->uio_resid < 1) {
  				error = ENAMETOOLONG;
  				goto error;
  			}
  			error = uiomove("/", 1, ap->a_uio);
  			if (error)
  				break;
  		}
  	skipslash:
  
  		/* Append string at 'cp' of length 'len' to our path. */
  		if (len > ap->a_uio->uio_resid) {
  			error = ENAMETOOLONG;
  			goto error;
  		}
  		error = uiomove(cp, len, ap->a_uio);
  		if (error)
  			break;
  
  		/* Advance to next component. */
  		pc = (void *)((char *)pc + 4 + pc->length);
  	}
  error:
  	free(buf, M_DEVBUF);
  	return (error);
  }
  
  static int
  udf_strategy(struct vop_strategy_args *a)
  {
  	struct buf *bp;
  	struct vnode *vp;
  	struct udf_node *node;
  	struct bufobj *bo;
  	off_t offset;
  	uint32_t maxsize;
  	daddr_t sector;
  	int error;
  
  	bp = a->a_bp;
  	vp = a->a_vp;
  	node = VTON(vp);
  
  	if (bp->b_blkno == bp->b_lblkno) {
  		offset = lblktosize(node->udfmp, bp->b_lblkno);
  		error = udf_bmap_internal(node, offset, &sector, &maxsize);
  		if (error) {
  			clrbuf(bp);
  			bp->b_blkno = -1;
  			bufdone(bp);
  			return (0);
  		}
  		/* bmap gives sector numbers, bio works with device blocks */
  		bp->b_blkno = sector << (node->udfmp->bshift - DEV_BSHIFT);
  	}
  	bo = node->udfmp->im_bo;
  	bp->b_iooffset = dbtob(bp->b_blkno);
  	BO_STRATEGY(bo, bp);
  	return (0);
  }
  
  static int
  udf_bmap(struct vop_bmap_args *a)
  {
  	struct udf_node *node;
  	uint32_t max_size;
  	daddr_t lsector;
  	int nblk;
  	int error;
  
  	node = VTON(a->a_vp);
  
  	if (a->a_bop != NULL)
  		*a->a_bop = &node->udfmp->im_devvp->v_bufobj;
  	if (a->a_bnp == NULL)
  		return (0);
  	if (a->a_runb)
  		*a->a_runb = 0;
  
  	/*
  	 * UDF_INVALID_BMAP means data embedded into fentry, this is an internal
  	 * error that should not be propagated to calling code.
  	 * Most obvious mapping for this error is EOPNOTSUPP as we can not truly
  	 * translate block numbers in this case.
  	 * Incidentally, this return code will make vnode pager to use VOP_READ
  	 * to get data for mmap-ed pages and udf_read knows how to do the right
  	 * thing for this kind of files.
  	 */
  	error = udf_bmap_internal(node, a->a_bn << node->udfmp->bshift,
  	    &lsector, &max_size);
  	if (error == UDF_INVALID_BMAP)
  		return (EOPNOTSUPP);
  	if (error)
  		return (error);
  
  	/* Translate logical to physical sector number */
  	*a->a_bnp = lsector << (node->udfmp->bshift - DEV_BSHIFT);
  
  	/*
  	 * Determine maximum number of readahead blocks following the
  	 * requested block.
  	 */
  	if (a->a_runp) {
  		nblk = (max_size >> node->udfmp->bshift) - 1;
  		if (nblk <= 0)
  			*a->a_runp = 0;
  		else if (nblk >= (MAXBSIZE >> node->udfmp->bshift))
  			*a->a_runp = (MAXBSIZE >> node->udfmp->bshift) - 1;
  		else
  			*a->a_runp = nblk;
  	}
  
  	if (a->a_runb) {
  		*a->a_runb = 0;
  	}
  
  	return (0);
  }
  
  /*
   * The all powerful VOP_LOOKUP().
   */
  static int
  udf_lookup(struct vop_cachedlookup_args *a)
  {
  	struct vnode *dvp;
  	struct vnode *tdp = NULL;
  	struct vnode **vpp = a->a_vpp;
  	struct udf_node *node;
  	struct udf_mnt *udfmp;
  	struct fileid_desc *fid = NULL;
  	struct udf_dirstream *ds;
  	u_long nameiop;
  	u_long flags;
  	char *nameptr;
  	long namelen;
  	ino_t id = 0;
  	int offset, error = 0;
  	int fsize, lkflags, ltype, numdirpasses;
  
  	dvp = a->a_dvp;
  	node = VTON(dvp);
  	udfmp = node->udfmp;
  	nameiop = a->a_cnp->cn_nameiop;
  	flags = a->a_cnp->cn_flags;
  	lkflags = a->a_cnp->cn_lkflags;
  	nameptr = a->a_cnp->cn_nameptr;
  	namelen = a->a_cnp->cn_namelen;
  	fsize = le64toh(node->fentry->inf_len);
  
  	/*
  	 * If this is a LOOKUP and we've already partially searched through
  	 * the directory, pick up where we left off and flag that the
  	 * directory may need to be searched twice.  For a full description,
  	 * see /sys/fs/cd9660/cd9660_lookup.c:cd9660_lookup()
  	 */
  	if (nameiop != LOOKUP || node->diroff == 0 || node->diroff > fsize) {
  		offset = 0;
  		numdirpasses = 1;
  	} else {
  		offset = node->diroff;
  		numdirpasses = 2;
  		nchstats.ncs_2passes++;
  	}
  
  lookloop:
  	ds = udf_opendir(node, offset, fsize, udfmp);
  
  	while ((fid = udf_getfid(ds)) != NULL) {
  
  		/* XXX Should we return an error on a bad fid? */
  		if (udf_checktag(&fid->tag, TAGID_FID)) {
  			printf("udf_lookup: Invalid tag\n");
  			error = EIO;
  			break;
  		}
  
  		/* Is this a deleted file? */
  		if (fid->file_char & UDF_FILE_CHAR_DEL)
  			continue;
  
  		if ((fid->l_fi == 0) && (fid->file_char & UDF_FILE_CHAR_PAR)) {
  			if (flags & ISDOTDOT) {
  				id = udf_getid(&fid->icb);
  				break;
  			}
  		} else {
  			if (!(udf_cmpname(&fid->data[fid->l_iu],
  			    nameptr, fid->l_fi, namelen, udfmp))) {
  				id = udf_getid(&fid->icb);
  				break;
  			}
  		}
  	}
  
  	if (!error)
  		error = ds->error;
  
  	/* XXX Bail out here? */
  	if (error) {
  		udf_closedir(ds);
  		return (error);
  	}
  
  	/* Did we have a match? */
  	if (id) {
  		/*
  		 * Remember where this entry was if it's the final
  		 * component.
  		 */
  		if ((flags & ISLASTCN) && nameiop == LOOKUP)
  			node->diroff = ds->offset + ds->off;
  		if (numdirpasses == 2)
  			nchstats.ncs_pass2++;
  		udf_closedir(ds);
  
  		if (flags & ISDOTDOT) {
  			error = vn_vget_ino(dvp, id, lkflags, &tdp);
  		} else if (node->hash_id == id) {
  			VREF(dvp);	/* we want ourself, ie "." */
  			/*
  			 * When we lookup "." we still can be asked to lock it
  			 * differently.
  			 */
  			ltype = lkflags & LK_TYPE_MASK;
  			if (ltype != VOP_ISLOCKED(dvp)) {
  				if (ltype == LK_EXCLUSIVE)
  					vn_lock(dvp, LK_UPGRADE | LK_RETRY);
  				else /* if (ltype == LK_SHARED) */
  					vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);
  			}
  			tdp = dvp;
  		} else
  			error = udf_vget(udfmp->im_mountp, id, lkflags, &tdp);
  		if (!error) {
  			*vpp = tdp;
  			/* Put this entry in the cache */
  			if (flags & MAKEENTRY)
  				cache_enter(dvp, *vpp, a->a_cnp);
  		}
  	} else {
  		/* Name wasn't found on this pass.  Do another pass? */
  		if (numdirpasses == 2) {
  			numdirpasses--;
  			offset = 0;
  			udf_closedir(ds);
  			goto lookloop;
  		}
  		udf_closedir(ds);
  
  		/* Enter name into cache as non-existant */
  		if (flags & MAKEENTRY)
  			cache_enter(dvp, *vpp, a->a_cnp);
  
  		if ((flags & ISLASTCN) &&
  		    (nameiop == CREATE || nameiop == RENAME)) {
  			error = EROFS;
  		} else {
  			error = ENOENT;
  		}
  	}
  
  	return (error);
  }
  
  static int
  udf_reclaim(struct vop_reclaim_args *a)
  {
  	struct vnode *vp;
  	struct udf_node *unode;
  
  	vp = a->a_vp;
  	unode = VTON(vp);
  
  	/*
  	 * Destroy the vm object and flush associated pages.
  	 */
  	vnode_destroy_vobject(vp);
  
  	if (unode != NULL) {
  		vfs_hash_remove(vp);
  
  		if (unode->fentry != NULL)
  			free(unode->fentry, M_UDFFENTRY);
  		uma_zfree(udf_zone_node, unode);
  		vp->v_data = NULL;
  	}
  
  	return (0);
  }
  
  static int
  udf_vptofh(struct vop_vptofh_args *a)
  {
  	struct udf_node *node;
  	struct ifid *ifhp;
  
  	node = VTON(a->a_vp);
  	ifhp = (struct ifid *)a->a_fhp;
  	ifhp->ifid_len = sizeof(struct ifid);
  	ifhp->ifid_ino = node->hash_id;
  
  	return (0);
  }
  
  /*
   * Read the block and then set the data pointer to correspond with the
   * offset passed in.  Only read in at most 'size' bytes, and then set 'size'
   * to the number of bytes pointed to.  If 'size' is zero, try to read in a
   * whole extent.
   *
   * Note that *bp may be assigned error or not.
   *
   */
  static int
  udf_readatoffset(struct udf_node *node, int *size, off_t offset,
      struct buf **bp, uint8_t **data)
  {
  	struct udf_mnt *udfmp = node->udfmp;
  	struct vnode *vp = node->i_vnode;
  	struct file_entry *fentry;
  	struct buf *bp1;
  	uint32_t max_size;
  	daddr_t sector;
  	off_t off;
  	int adj_size;
  	int error;
  
  	/*
  	 * This call is made *not* only to detect UDF_INVALID_BMAP case,
  	 * max_size is used as an ad-hoc read-ahead hint for "normal" case.
  	 */
  	error = udf_bmap_internal(node, offset, &sector, &max_size);
  	if (error == UDF_INVALID_BMAP) {
  		/*
  		 * This error means that the file *data* is stored in the
  		 * allocation descriptor field of the file entry.
  		 */
  		fentry = node->fentry;
  		*data = &fentry->data[le32toh(fentry->l_ea)];
  		*size = le32toh(fentry->l_ad);
  		if (offset >= *size)
  			*size = 0;
  		else {
  			*data += offset;
  			*size -= offset;
  		}
  		return (0);
  	} else if (error != 0) {
  		return (error);
  	}
  
  	/* Adjust the size so that it is within range */
  	if (*size == 0 || *size > max_size)
  		*size = max_size;
  
  	/*
  	 * Because we will read starting at block boundary, we need to adjust
  	 * how much we need to read so that all promised data is in.
  	 * Also, we can't promise to read more than MAXBSIZE bytes starting
  	 * from block boundary, so adjust what we promise too.
  	 */
  	off = blkoff(udfmp, offset);
  	*size = min(*size, MAXBSIZE - off);
  	adj_size = (*size + off + udfmp->bmask) & ~udfmp->bmask;
  	*bp = NULL;
  	if ((error = bread(vp, lblkno(udfmp, offset), adj_size, NOCRED, bp))) {
  		printf("warning: udf_readlblks returned error %d\n", error);
  		/* note: *bp may be non-NULL */
  		return (error);
  	}
  
  	bp1 = *bp;
  	*data = (uint8_t *)&bp1->b_data[offset & udfmp->bmask];
  	return (0);
  }
  
  /*
   * Translate a file offset into a logical block and then into a physical
   * block.
   * max_size - maximum number of bytes that can be read starting from given
   * offset, rather than beginning of calculated sector number
   */
  static int
  udf_bmap_internal(struct udf_node *node, off_t offset, daddr_t *sector,
      uint32_t *max_size)
  {
  	struct udf_mnt *udfmp;
  	struct file_entry *fentry;
  	void *icb;
  	struct icb_tag *tag;
  	uint32_t icblen = 0;
  	daddr_t lsector;
  	int ad_offset, ad_num = 0;
  	int i, p_offset;
  
  	udfmp = node->udfmp;
  	fentry = node->fentry;
  	tag = &fentry->icbtag;
  
  	switch (le16toh(tag->strat_type)) {
  	case 4:
  		break;
  
  	case 4096:
  		printf("Cannot deal with strategy4096 yet!\n");
  		return (ENODEV);
  
  	default:
  		printf("Unknown strategy type %d\n", tag->strat_type);
  		return (ENODEV);
  	}
  
  	switch (le16toh(tag->flags) & 0x7) {
  	case 0:
  		/*
  		 * The allocation descriptor field is filled with short_ad's.
  		 * If the offset is beyond the current extent, look for the
  		 * next extent.
  		 */
  		do {
  			offset -= icblen;
  			ad_offset = sizeof(struct short_ad) * ad_num;
  			if (ad_offset > le32toh(fentry->l_ad)) {
  				printf("File offset out of bounds\n");
  				return (EINVAL);
  			}
  			icb = GETICB(short_ad, fentry,
  			    le32toh(fentry->l_ea) + ad_offset);
  			icblen = GETICBLEN(short_ad, icb);
  			ad_num++;
  		} while(offset >= icblen);
  
  		lsector = (offset  >> udfmp->bshift) +
  		    le32toh(((struct short_ad *)(icb))->pos);
  
  		*max_size = icblen - offset;
  
  		break;
  	case 1:
  		/*
  		 * The allocation descriptor field is filled with long_ad's
  		 * If the offset is beyond the current extent, look for the
  		 * next extent.
  		 */
  		do {
  			offset -= icblen;
  			ad_offset = sizeof(struct long_ad) * ad_num;
  			if (ad_offset > le32toh(fentry->l_ad)) {
  				printf("File offset out of bounds\n");
  				return (EINVAL);
  			}
  			icb = GETICB(long_ad, fentry,
  			    le32toh(fentry->l_ea) + ad_offset);
  			icblen = GETICBLEN(long_ad, icb);
  			ad_num++;
  		} while(offset >= icblen);
  
  		lsector = (offset >> udfmp->bshift) +
  		    le32toh(((struct long_ad *)(icb))->loc.lb_num);
  
  		*max_size = icblen - offset;
  
  		break;
  	case 3:
  		/*
  		 * This type means that the file *data* is stored in the
  		 * allocation descriptor field of the file entry.
  		 */
  		*max_size = 0;
  		*sector = node->hash_id + udfmp->part_start;
  
  		return (UDF_INVALID_BMAP);
  	case 2:
  		/* DirectCD does not use extended_ad's */
  	default:
  		printf("Unsupported allocation descriptor %d\n",
  		       tag->flags & 0x7);
  		return (ENODEV);
  	}
  
  	*sector = lsector + udfmp->part_start;
  
  	/*
  	 * Check the sparing table.  Each entry represents the beginning of
  	 * a packet.
  	 */
  	if (udfmp->s_table != NULL) {
  		for (i = 0; i< udfmp->s_table_entries; i++) {
  			p_offset =
  			    lsector - le32toh(udfmp->s_table->entries[i].org);
  			if ((p_offset < udfmp->p_sectors) && (p_offset >= 0)) {
  				*sector =
  				   le32toh(udfmp->s_table->entries[i].map) +
  				    p_offset;
  				break;
  			}
  		}
  	}
  
  	return (0);
  }
  