exfat: Return more than a single dirent at a time in exfat_read_dir().

* similar to what mmlr did in hrev45575 for bfs.
* DirectoryIterator could try to read past the end of the directory.
* replaced a dprintf with a TRACE() statement.

src/add-ons/kernel/file_systems/exfat/DirectoryIterator.cpp

@@ -47,9 +47,13 @@ status_t
 DirectoryIterator::GetNext(char* name, size_t* _nameLength, ino_t* _id,
 	EntryVisitor* visitor)
 {
+	if (fCluster == EXFAT_CLUSTER_END)
+		return B_ENTRY_NOT_FOUND;
 	if (fOffset == -2) {
-		*_nameLength = 3;
+		if (*_nameLength < 3)
-		strlcpy(name, "..", *_nameLength);
+			return B_BUFFER_OVERFLOW;
+		*_nameLength = 2;
+		strlcpy(name, "..", *_nameLength + 1);
 		if (fInode->ID() == 1)
 			*_id = fInode->ID();
 		else
@@ -58,19 +62,22 @@ DirectoryIterator::GetNext(char* name, size_t* _nameLength, ino_t* _id,
 		TRACE("DirectoryIterator::GetNext() found ..\n");
 		return B_OK;
 	} else if (fOffset == -1) {
-		*_nameLength = 2;
+		if (*_nameLength < 2)
-		strlcpy(name, ".", *_nameLength);
+			return B_BUFFER_OVERFLOW;
+		*_nameLength = 1;
+		strlcpy(name, ".", *_nameLength + 1);
 		*_id = fInode->ID();
 		fOffset = 0;
 		TRACE("DirectoryIterator::GetNext() found .\n");
 		return B_OK;
 	}
 
-	uchar unicodeName[EXFAT_FILENAME_MAX_LENGTH];
+	uchar unicodeName[EXFAT_FILENAME_MAX_LENGTH + 1];
 	size_t nameLength = EXFAT_FILENAME_MAX_LENGTH;
 	status_t status = _GetNext(unicodeName, &nameLength, _id, visitor);
 	if (status == B_OK && name != NULL) {
-		unicode_to_utf8(unicodeName, nameLength, (uint8 *)name , _nameLength);
+		status = unicode_to_utf8(unicodeName, nameLength, (uint8 *)name,
+			_nameLength);
 		TRACE("DirectoryIterator::GetNext() %ld %s, %" B_PRIdINO "\n", 
 			fInode->Cluster(), name, *_id);
 	}
@@ -96,7 +103,7 @@ DirectoryIterator::Lookup(const char* name, size_t nameLength, ino_t* _id)
 	Rewind();
 	fOffset = 0;
 
-	uchar currentName[EXFAT_FILENAME_MAX_LENGTH];
+	uchar currentName[EXFAT_FILENAME_MAX_LENGTH + 1];
 	size_t currentLength = EXFAT_FILENAME_MAX_LENGTH;
 	while (_GetNext((uchar*)currentName, &currentLength, _id) == B_OK) {
 		char utfName[EXFAT_FILENAME_MAX_LENGTH];
@@ -122,7 +129,7 @@ DirectoryIterator::LookupEntry(EntryVisitor* visitor)
 	fCluster = fInode->Cluster();
 	fOffset = fInode->Offset();
 
-	uchar unicodeName[EXFAT_FILENAME_MAX_LENGTH];
+	uchar unicodeName[EXFAT_FILENAME_MAX_LENGTH + 1];
 	size_t nameLength = EXFAT_FILENAME_MAX_LENGTH;
 	return _GetNext(unicodeName, &nameLength, NULL, visitor);
 }

src/add-ons/kernel/file_systems/exfat/Volume.cpp

@@ -218,7 +218,7 @@ LabelVisitor::LabelVisitor(Volume* volume)
 bool
 LabelVisitor::VisitLabel(struct exfat_entry* entry)
 {
-	dprintf("LabelVisitor::VisitLabel()\n");
+	TRACE("LabelVisitor::VisitLabel()\n");
 	char utfName[30];
 	size_t utfLength = 30;
 	unicode_to_utf8((const uchar*)entry->name_label.name,
@@ -418,6 +418,8 @@ Volume::LoadSuperBlock()
 status_t
 Volume::ClusterToBlock(cluster_t cluster, fsblock_t &block)
 {
+	if (cluster < 2)
+		return B_BAD_VALUE;
 	block = ((cluster - 2) << SuperBlock().BlocksPerClusterShift())
 		+ SuperBlock().FirstDataBlock();
 	TRACE("Volume::ClusterToBlock() cluster %lu %u %lu: %llu, %lu\n", cluster, 

src/add-ons/kernel/file_systems/exfat/encodings.cpp

@@ -106,6 +106,7 @@ _lendian_unicode_to_utf8(
 	int32 dstLimit = *dstLen;
 	int32 srcCount = 0;
 	int32 dstCount = 0;
+	status_t status = B_ERROR;
 
 	for (srcCount = 0; srcCount < srcLimit; srcCount += 2) {
 		uint16  *UNICODE = (uint16 *)&src[srcCount];
@@ -119,19 +120,22 @@ _lendian_unicode_to_utf8(
 		u_lendian_to_utf8(UTF8, UNICODE);
 
 		utf8Len = UTF8 - utf8;
-		if ((dstCount + utf8Len) > dstLimit)
+		if ((dstCount + utf8Len) > dstLimit) {
+			status = B_BUFFER_OVERFLOW;
 			break;
+		}
 
 		for (j = 0; j < utf8Len; j++)
 			dst[dstCount + j] = utf8[j];
 		dstCount += utf8Len;
+		status = B_OK;
 	}
 
 	*srcLen = srcCount;
 	*dstLen = dstCount;
 	dst[dstCount] = '\0';
 	
-	return ((dstCount > 0) ? B_NO_ERROR : B_ERROR);
+	return status;
 }
 
 // utf8 to LENDIAN unicode
@@ -146,6 +150,7 @@ _utf8_to_lendian_unicode(
 	int32 dstLimit = *dstLen - 1;
 	int32 srcCount = 0;
 	int32 dstCount = 0;
+	status_t status = B_ERROR;
 
 	while ((srcCount < srcLimit) && (dstCount < dstLimit)) {
 		uint16	unicode;
@@ -157,20 +162,25 @@ _utf8_to_lendian_unicode(
 			break;
 
 		utf8_to_u_hostendian(UTF8, UNICODE, err_flag);
-		if(err_flag == 1)
+		if (err_flag == 1)
 			return EINVAL;
 
 		unicode = B_HOST_TO_LENDIAN_INT16(unicode);
+		if ((dstCount + 1) > dstLimit) {
+			status = B_BUFFER_OVERFLOW;
+			break;
+		}
 		dst[dstCount++] = unicode & 0xFF;
 		dst[dstCount++] = unicode >> 8;
 
 		srcCount += UTF8 - ((uchar *)(src + srcCount));
+		status = B_OK;	
 	}
 
 	*srcLen = srcCount;
 	*dstLen = dstCount;
 
-	return ((dstCount > 0) ? B_NO_ERROR : B_ERROR);
+	return status;
 }
 
 

src/add-ons/kernel/file_systems/exfat/kernel_interface.cpp

@@ -179,7 +179,7 @@ static status_t
 exfat_get_vnode(fs_volume* _volume, ino_t id, fs_vnode* _node, int* _type,
 	uint32* _flags, bool reenter)
 {
-	TRACE("get_vnode %lu\n", id);
+	TRACE("get_vnode %" B_PRIdINO "\n", id);
 	Volume* volume = (Volume*)_volume->private_volume;
 
 	Inode* inode = new(std::nothrow) Inode(volume, id);
@@ -357,7 +357,7 @@ exfat_lookup(fs_volume* _volume, fs_vnode* _directory, const char* name,
 		return status;
 	}
 
-	TRACE("exfat_lookup: ID %d\n", *_vnodeID);
+	TRACE("exfat_lookup: ID %" B_PRIdINO "\n", *_vnodeID);
 	
 	return get_vnode(volume->FSVolume(), *_vnodeID, NULL);
 }
@@ -526,24 +526,40 @@ exfat_read_dir(fs_volume *_volume, fs_vnode *_node, void *_cookie,
 {
 	TRACE("exfat_read_dir\n");
 	DirectoryIterator* iterator = (DirectoryIterator*)_cookie;
-
-	size_t length = bufferSize;
-	ino_t id;
-	status_t status = iterator->GetNext(dirent->d_name, &length, &id);
-	if (status == B_ENTRY_NOT_FOUND) {
-		*_num = 0;
-		return B_OK;
-	} else if (status != B_OK)
-		return status;
-
 	Volume* volume = (Volume*)_volume->private_volume;
-	dirent->d_dev = volume->ID();
-	dirent->d_ino = id;
-	dirent->d_reclen = sizeof(struct dirent) + length;
-	*_num = 1;
 	
+	uint32 maxCount = *_num;
+	uint32 count = 0;
+
+	while (count < maxCount && bufferSize > sizeof(struct dirent)) {
+		ino_t id;
+		size_t length = bufferSize - sizeof(struct dirent) + 1;
+
+		status_t status = iterator->GetNext(dirent->d_name, &length, &id);
+		if (status == B_ENTRY_NOT_FOUND)
+			break;
+
+		if (status == B_BUFFER_OVERFLOW) {
+			// the remaining name buffer length was too small
+			if (count == 0)
+				return B_BUFFER_OVERFLOW;
+			break;
+		}
+
+		if (status != B_OK)
+			return status;
+
+		dirent->d_dev = volume->ID();
+		dirent->d_ino = id;
+		dirent->d_reclen = sizeof(struct dirent) + length;
+
+		bufferSize -= dirent->d_reclen;
+		dirent = (struct dirent*)((uint8*)dirent + dirent->d_reclen);
+		count++;
+	}
+
+	*_num = count;
 	TRACE("exfat_read_dir end\n");
-
 	return B_OK;
 }