attr.c

EM85XX读NTFS修正代码包

					rl[i].len - rounded);
			if (error)
				return error; /* FIXME: Incomplete operation. */
			rl[i].len = rounded;
			newcount = count + rounded;
		}
		/* Free all other runs. */
		i++;
		error = ntfs_deallocate_clusters(ino->vol, rl + i,
				attr->d.r.len - i);
		if (error)
			return error; /* FIXME: Incomplete operation. */
		/*
		 * Free space for extra runs in memory if enough memory left
		 * to do so. FIXME: Only do it if it would free memory. (AIA)
		 */
		rl_size = ((i + 1) * sizeof(ntfs_runlist) + PAGE_SIZE - 1) &
				PAGE_MASK;
		if (rl_size < ((attr->d.r.len * sizeof(ntfs_runlist) +
				PAGE_SIZE - 1) & PAGE_MASK)) {
			rlt = ntfs_vmalloc(rl_size);
			if (rlt) {
				ntfs_memcpy(rlt, rl, i * sizeof(ntfs_runlist));
				ntfs_vfree(rl);
				attr->d.r.runlist = rl = rlt;
			}
		}
		rl[i].lcn = (ntfs_cluster_t)-1;
		rl[i].len = (ntfs_cluster_t)0;
		attr->d.r.len = i;
	} else {
		error = ntfs_extend_attr(ino, attr, newsize);
		if (error)
			return error; /* FIXME: Incomplete operation. */
		newcount = (newsize + ino->vol->cluster_size - 1) >>
				clustersizebits;
	}
	/* Fill in new sizes. */
	attr->allocated = (__s64)newcount << clustersizebits;
	attr->size = newsize;
	if (attr->initialized > newsize)
		attr->initialized = newsize;
	if (!newsize)
		error = ntfs_make_attr_resident(ino, attr);
	return error;
}

int ntfs_create_attr(ntfs_inode *ino, int anum, char *aname, void *data,
		int dsize, ntfs_attribute **rattr)
{
	void *name;
	int namelen;
	int found, i;
	int error;
	ntfs_attribute *attr;
	
	if (dsize > ino->vol->mft_record_size)
		/* FIXME: Non-resident attributes. */
		return -EOPNOTSUPP;
	if (aname) {
		namelen = strlen(aname);
		name = ntfs_malloc(2 * namelen);
		if (!name)
			return -ENOMEM;
		ntfs_ascii2uni(name, aname, namelen);
	} else {
		name = 0;
		namelen = 0;
	}
	error = ntfs_new_attr(ino, anum, name, namelen, data, dsize, &i,
			&found);
	if (error || found) {
		ntfs_free(name);
		return error ? error : -EEXIST;
	}
	*rattr = attr = ino->attrs + i;
	/* Allocate a new number.
	 * FIXME: Should this happen on inode writeback?
	 * FIXME: Extension records not supported. */
	error = ntfs_allocate_attr_number(ino, &i);
	if (error)
		return error;
	attr->attrno = i;
	if (attr->attrno + 1 != NTFS_GETU16(ino->attr + 0x28))
		ntfs_error("UH OH! attr->attrno (%i) != NTFS_GETU16(ino->attr "
				"+ 0x28) (%i)\n", attr->attrno,
				NTFS_GETU16(ino->attr + 0x28));
	attr->resident = 1;
	attr->flags = 0;
	attr->cengine = 0;
	attr->size = attr->allocated = attr->initialized = dsize;

	/* FIXME: INDEXED information should come from $AttrDef
	 * Currently, only file names are indexed. As of NTFS v3.0 (Win2k),
	 * this is no longer true. Different attributes can be indexed now. */
	if (anum == ino->vol->at_file_name)
		attr->indexed = 1;
	else
		attr->indexed = 0;
	attr->d.data = ntfs_malloc(dsize);
	if (!attr->d.data)
		return -ENOMEM;
	ntfs_memcpy(attr->d.data, data, dsize);
	return 0;
}

/*
 * Non-resident attributes are stored in runs (intervals of clusters).
 *
 * This function stores in the inode readable information about a non-resident
 * attribute.
 */
static int ntfs_process_runs(ntfs_inode *ino, ntfs_attribute* attr,
		unsigned char *data)
{
	int startvcn, endvcn;
	int vcn, cnum;
	ntfs_cluster_t cluster;
	int len, ctype;
	int er = 0;
	startvcn = NTFS_GETS64(data + 0x10);
	endvcn = NTFS_GETS64(data + 0x18);

	/* Check whether this chunk really belongs to the end. Problem with
	 * this: this functions can get called on the last extent first, before
	 * it is called on the other extents in sequence. This happens when the
	 * base mft record contains the last extent instead of the first one
	 * and the first extent is stored, like any intermediate extents in
	 * extension mft records. This would be difficult to allow the way the
	 * runlist is stored in memory. Thus we fix elsewhere by causing the
	 * attribute list attribute to be processed immediately when found. The
	 * extents will then be processed starting with the first one. */
	for (cnum = 0, vcn = 0; cnum < attr->d.r.len; cnum++)
		vcn += attr->d.r.runlist[cnum].len;
	if (vcn != startvcn) {
		ntfs_debug(DEBUG_FILE3, "ntfs_process_runs: ino = 0x%x, "
			"attr->type = 0x%x, startvcn = 0x%x, endvcn = 0x%x, "
			"vcn = 0x%x, cnum = 0x%x\n", ino->i_number, attr->type,
			startvcn, endvcn, vcn, cnum);
		if (vcn < startvcn) {
			ntfs_error("Problem with runlist in extended record\n");
			return -1;
		}
		/* Tried to insert an already inserted runlist. */
		return 0;
	}
	if (!endvcn) {
		if (!startvcn) {
			/* Allocated length. */
			endvcn = NTFS_GETS64(data + 0x28) - 1;
			endvcn >>= ino->vol->cluster_size_bits;
		} else {
			/* This is an extent. Allocated length is not defined!
			 * Extents must have an endvcn though so this is an
			 * error. */
			ntfs_error("Corrupt attribute extent. (endvcn is "
				"missing)\n");
			return -1;
		}
	}
	data = data + NTFS_GETU16(data + 0x20);
	cnum = attr->d.r.len;
	cluster = 0;
	for (vcn = startvcn; vcn <= endvcn; vcn += len)	{
		if (ntfs_decompress_run(&data, &len, &cluster, &ctype)) {
			ntfs_debug(DEBUG_FILE3, "ntfs_process_runs: "
				"ntfs_decompress_run failed. i_number = 0x%x\n",
				ino->i_number);
			return -1;
		}
		if (ctype)
			er = ntfs_insert_run(attr, cnum, -1, len);
		else
			er = ntfs_insert_run(attr, cnum, cluster, len);
		if (er)
			break;
		cnum++;
	}
	if (er)
		ntfs_error("ntfs_process_runs: ntfs_insert_run failed\n");
	ntfs_debug(DEBUG_FILE3, "ntfs_process_runs: startvcn = 0x%x, vcn = 0x%x"
				", endvcn = 0x%x, cnum = %i\n", startvcn, vcn,
				endvcn, cnum);
	return er;
}
  
/* Insert the attribute starting at attr in the inode ino. */
int ntfs_insert_attribute(ntfs_inode *ino, unsigned char *attrdata)
{
	int i, found;
	int type;
	short int *name;
	int namelen;
	void *data;
	ntfs_attribute *attr;
	int error;

	type = NTFS_GETU32(attrdata);
	namelen = NTFS_GETU8(attrdata + 9);
	ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: ino->i_number 0x%x, "
			"attr type 0x%x\n", ino->i_number, type);
	/* Read the attribute's name if it has one. */
	if (!namelen)
		name = 0;
	else {
		/* 1 Unicode character fits in 2 bytes. */
		name = ntfs_malloc(2 * namelen);
		if (!name)
			return -ENOMEM;
		ntfs_memcpy(name, attrdata + NTFS_GETU16(attrdata + 10),
			    2 * namelen);
	}
	/* If resident look for value, too. */
	if (NTFS_GETU8(attrdata + 8) == 0)
		error = ntfs_new_attr(ino, type, name, namelen,
				attrdata + NTFS_GETU16(attrdata + 0x14),
				NTFS_GETU16(attrdata + 0x10), &i, &found);
	else
		error = ntfs_new_attr(ino, type, name, namelen, NULL, 0, &i,
				&found);
	if (error) {
		ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: ntfs_new_attr "
				"failed.\n");
		if (name)
			ntfs_free(name);
		return error;
	}
	if (found) {
		/* It's already there, if not resident just process the runs. */
		if (!ino->attrs[i].resident) {
			ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute:"
						" processing runs 1.\n");
			/* FIXME: Check error code! (AIA) */
			ntfs_process_runs(ino, ino->attrs + i, attrdata);
		}
		return 0;
	}
	attr = ino->attrs + i;
	attr->resident = NTFS_GETU8(attrdata + 8) == 0;
	attr->flags = *(__u16*)(attrdata + 0xC);
	attr->attrno = NTFS_GETU16(attrdata + 0xE);
  
	if (attr->resident) {
		attr->size = NTFS_GETU16(attrdata + 0x10);
		data = attrdata + NTFS_GETU16(attrdata + 0x14);
		attr->d.data = (void*)ntfs_malloc(attr->size);
		if (!attr->d.data)
			return -ENOMEM;
		ntfs_memcpy(attr->d.data, data, attr->size);
		attr->indexed = NTFS_GETU8(attrdata + 0x16);
	} else {
		attr->allocated = NTFS_GETS64(attrdata + 0x28);
		attr->size = NTFS_GETS64(attrdata + 0x30);
		attr->initialized = NTFS_GETS64(attrdata + 0x38);
		attr->cengine = NTFS_GETU16(attrdata + 0x22);
		if (attr->flags & ATTR_IS_COMPRESSED)
			attr->compsize = NTFS_GETS64(attrdata + 0x40);
		ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: "
			"attr->allocated = 0x%Lx, attr->size = 0x%Lx, "
			"attr->initialized = 0x%Lx\n", attr->allocated,
			attr->size, attr->initialized);
		ino->attrs[i].d.r.runlist = 0;
		ino->attrs[i].d.r.len = 0;
		ntfs_debug(DEBUG_FILE3, "ntfs_insert_attribute: processing "
				"runs 2.\n");
		/* FIXME: Check error code! (AIA) */
		ntfs_process_runs(ino, attr, attrdata);
	}
	return 0;
}

int ntfs_read_zero(ntfs_io *dest, int size)
{
	int i;
	char *sparse = ntfs_calloc(512);
	if (!sparse)
		return -ENOMEM;
	i = 512;
	while (size) {
		if (i > size)
			i = size;
		dest->fn_put(dest, sparse, i);
		size -= i;
	}
	ntfs_free(sparse);
	return 0;
}

/* Process compressed attributes. */
int ntfs_read_compressed(ntfs_inode *ino, ntfs_attribute *attr, __s64 offset,
			 ntfs_io *dest)
{
	int error = 0;
	int clustersizebits;
	int s_vcn, rnum, vcn, got, l1;
	__s64 copied, len, chunk, offs1, l, chunk2;
	ntfs_cluster_t cluster, cl1;
	char *comp = 0, *comp1;
	char *decomp = 0;
	ntfs_io io;
	ntfs_runlist *rl;

	l = dest->size;
	clustersizebits = ino->vol->cluster_size_bits;
	/* Starting cluster of potential chunk. There are three situations:
	   a) In a large uncompressible or sparse chunk, s_vcn is in the middle
	      of a run.
	   b) s_vcn is right on a run border.
	   c) When several runs make a chunk, s_vcn is before the chunks. */
	s_vcn = offset >> clustersizebits;
	/* Round down to multiple of 16. */
	s_vcn &= ~15;
	rl = attr->d.r.runlist;
	for (rnum = vcn = 0; rnum < attr->d.r.len && vcn + rl->len <= s_vcn;
								rnum++, rl++)
		vcn += rl->len;
	if (rnum == attr->d.r.len) {
		/* Beyond end of file. */
		/* FIXME: Check allocated / initialized. */
		dest->size = 0;
		return 0;
	}
	io.do_read = 1;
	io.fn_put = ntfs_put;
	io.fn_get = 0;
	cluster = rl->lcn;
	len = rl->len;
	copied = 0;
	while (l) {
		chunk = 0;
		if (cluster == (ntfs_cluster_t)-1) {
			/* Sparse cluster. */
			__s64 ll;

			if ((len - (s_vcn - vcn)) & 15)
				ntfs_error("Unexpected sparse chunk size.");
			ll = ((__s64)(vcn + len) << clustersizebits) - offset;
			if (ll > l)
				ll = l;
			chunk = ll;
			error = ntfs_read_zero(dest, ll);
			if (error)
				goto out;
		} else if (dest->do_read) {
			if (!comp) {
				comp = ntfs_malloc(16 << clustersizebits);
				if (!comp) {
					error = -ENOMEM;
					goto out;
				}
			}
			got = 0;
			/* We might need to start in the middle of a run. */
			cl1 = cluster + s_vcn - vcn;
			comp1 = comp;
			do {
				int delta;

				io.param = comp1;
				delta = s_vcn - vcn;
				if (delta < 0)
					delta = 0;
				l1 = len - delta;
				if (l1 > 16 - got)
					l1 = 16 - got;
				io.size = (__s64)l1 << clustersizebits;
				error = ntfs_getput_clusters(ino->vol, cl1, 0,
					       		     &io);
				if (error)
					goto out;
				if (l1 + delta == len) {
					rnum++;
					rl++;
					vcn += len;
					cluster = cl1 = rl->lcn;
					len = rl->len;
				}
				got += l1;
				comp1 += (__s64)l1 << clustersizebits;
			} while (cluster != (ntfs_cluster_t)-1 && got < 16);
							/* Until empty run. */
			chunk = 16 << clustersizebits;
			if (cluster != (ntfs_cluster_t)-1 || got == 16)
				/* Uncompressible */
				comp1 = comp;
			else {
				if (!decomp) {
					decomp = ntfs_malloc(16 << 
							clustersizebits);
					if (!decomp) {
						error = -ENOMEM;
						goto out;
					}
				}
				/* Make sure there are null bytes after the
				 * last block. */
				*(ntfs_u32*)comp1 = 0;
				ntfs_decompress(decomp, comp, chunk);
				comp1 = decomp;
			}
			offs1 = offset - ((__s64)s_vcn << clustersizebits);
			chunk2 = (16 << clustersizebits) - offs1;
			if (chunk2 > l)
				chunk2 = l;
			if (chunk > chunk2)
				chunk = chunk2;
			dest->fn_put(dest, comp1 + offs1, chunk);
		}
		l -= chunk;
		copied += chunk;
		offset += chunk;
		s_vcn = (offset >> clustersizebits) & ~15;
		if (l && offset >= ((__s64)(vcn + len) << clustersizebits)) {
			rnum++;
			rl++;
			vcn += len;
			cluster = rl->lcn;
			len = rl->len;
		}
	}
out:
	if (comp)
		ntfs_free(comp);
	if (decomp)
		ntfs_free(decomp);
	dest->size = copied;
	return error;
}

int ntfs_write_compressed(ntfs_inode *ino, ntfs_attribute *attr, __s64 offset,
		ntfs_io *dest)
{
	return -EOPNOTSUPP;
}