trim: Target SCSI UNMAP command instead of WRITE SAME.

* The UNMAP command is theoretically much faster, as it can get many block
  ranges instead of just a single range.
* Furthermore, the ATA TRIM command resembles it much better.
* Therefore, fs_trim_data now gets an array of ranges, and we use SCSI UNMAP
  to trim.
* Updated BFS code to collect array ranges to fully support the new
  fs_trim_data possibilities.

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

@@ -20,8 +20,10 @@
 // TODO: temporary solution as long as there is no public I/O requests API
 #ifndef BFS_SHELL
 #	include <io_requests.h>
+#	include <util/fs_trim_support.h>
 #endif
 
+
 #define BFS_IO_SIZE	65536
 
 
@@ -623,19 +625,32 @@ bfs_ioctl(fs_volume* _volume, fs_vnode* _node, void* _cookie, uint32 cmd,
 	Volume* volume = (Volume*)_volume->private_volume;
 
 	switch (cmd) {
+#ifndef BFS_SHELL
 		case B_TRIM_DEVICE:
 		{
-			fs_trim_data trimData;
-			if (user_memcpy(&trimData, buffer, sizeof(fs_trim_data)) != B_OK)
-				return B_BAD_ADDRESS;
-
-			status_t status = volume->Allocator().Trim(trimData.offset,
-				trimData.size, trimData.trimmed_size);
+			fs_trim_data* trimData;
+			status_t status = copy_trim_data_from_user(buffer, bufferLength,
+				trimData);
 			if (status != B_OK)
 				return status;
 
-			return user_memcpy(buffer, &trimData, sizeof(fs_trim_data));
+			MemoryDeleter deleter(trimData);
+			trimData->trimmed_size = 0;
+
+			for (uint32 i = 0; i < trimData->range_count; i++) {
+				uint64 trimmedSize = 0;
+				status_t status = volume->Allocator().Trim(
+					trimData->ranges[i].offset, trimData->ranges[i].size,
+					trimmedSize);
+				if (status != B_OK)
+					return status;
+
+				trimData->trimmed_size += trimmedSize;
+			}
+
+			return copy_trim_data_to_user(buffer, trimData);
 		}
+#endif
 
 		case BFS_IOCTL_VERSION:
 		{