Added B_TRIM_DEVICE support to BFS.

* It currently ignores the offset/size, though, and always trims everything.
* Now only SCSI support is missing.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2012, Axel Dörfler, [email protected].
+ * Copyright 2001-2013, Axel Dörfler, [email protected].
  * This file may be used under the terms of the MIT License.
  */
 
@@ -1190,6 +1190,62 @@ BlockAllocator::_CheckGroup(int32 groupIndex) const
 #endif	// DEBUG_ALLOCATION_GROUPS
 
 
+status_t
+BlockAllocator::Trim(off_t offset, off_t size, off_t& trimmedSize)
+{
+	RecursiveLocker locker(fLock);
+
+	// TODO: take given offset and size into account!
+	int32 lastGroup = fNumGroups - 1;
+	uint32 firstBlock = 0;
+	uint32 firstBit = 0;
+	off_t currentBlock = 0;
+	uint32 blockShift = fVolume->BlockShift();
+
+	off_t firstFree = -1;
+	size_t freeLength = 0;
+	trimmedSize = 0;
+
+	AllocationBlock cached(fVolume);
+	for (int32 groupIndex = 0; groupIndex <= lastGroup; groupIndex++) {
+		AllocationGroup& group = fGroups[groupIndex];
+
+		for (uint32 block = firstBlock; block < group.NumBlocks(); block++) {
+			cached.SetTo(group, block);
+
+			for (uint32 i = firstBit; i < cached.NumBlockBits(); i++) {
+				if (cached.IsUsed(i)) {
+					// Block is in use
+					if (freeLength > 0) {
+						status_t status = _TrimNext(firstFree << blockShift,
+							freeLength << blockShift, trimmedSize);
+						if (status != B_OK)
+							return status;
+
+						freeLength = 0;
+					}
+				} else if (freeLength++ == 0) {
+					// Block is free, start new free range
+					firstFree = currentBlock;
+				}
+
+				currentBlock++;
+			}
+		}
+
+		firstBlock = 0;
+		firstBit = 0;
+	}
+
+	if (freeLength > 0) {
+		return _TrimNext(firstFree << blockShift, freeLength << blockShift,
+			trimmedSize);
+	}
+
+	return B_OK;
+}
+
+
 //	#pragma mark - Bitmap validity checking
 
 // TODO: implement new FS checking API
@@ -2124,6 +2180,26 @@ BlockAllocator::_AddInodeToIndex(Inode* inode)
 }
 
 
+status_t
+BlockAllocator::_TrimNext(off_t offset, off_t size, off_t& trimmedSize)
+{
+	PRINT(("_TrimNext(offset %lld, size %lld)\n", offset, size));
+
+	fs_trim_data trimData;
+	trimData.offset = offset;
+	trimData.size = size;
+	trimData.trimmed_size = 0;
+
+	if (ioctl(fVolume->Device(), B_TRIM_DEVICE, &trimData,
+			sizeof(fs_trim_data)) != 0) {
+		return errno;
+	}
+
+	trimmedSize += trimData.trimmed_size;
+	return B_OK;
+}
+
+
 //	#pragma mark - debugger commands
 
 

src/add-ons/kernel/file_systems/bfs/BlockAllocator.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2012, Axel Dörfler, [email protected].
+ * Copyright 2001-2013, Axel Dörfler, [email protected].
  * This file may be used under the terms of the MIT License.
  */
 #ifndef BLOCK_ALLOCATOR_H
@@ -46,6 +46,8 @@ public:
 								int32 group, uint16 start, uint16 numBlocks,
 								uint16 minimum, block_run& run);
 
+			status_t		Trim(off_t offset, off_t size, off_t& trimmedSize);
+
 			status_t		StartChecking(const check_control* control);
 			status_t		StopChecking(check_control* control);
 			status_t		CheckNextNode(check_control* control);
@@ -81,6 +83,8 @@ private:
 			void			_FreeIndices();
 			status_t		_AddInodeToIndex(Inode* inode);
 			status_t		_WriteBackCheckBitmap();
+			status_t		_TrimNext(off_t offset, off_t size,
+								off_t& trimmedSize);
 
 	static	status_t		_Initialize(BlockAllocator* self);
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2010, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2001-2013, Axel Dörfler, axeld@pinc-software.de.
  * This file may be used under the terms of the MIT License.
  */
 
@@ -623,6 +623,20 @@ bfs_ioctl(fs_volume* _volume, fs_vnode* _node, void* _cookie, uint32 cmd,
 	Volume* volume = (Volume*)_volume->private_volume;
 
 	switch (cmd) {
+		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);
+			if (status != B_OK)
+				return status;
+
+			return user_memcpy(buffer, &trimData, sizeof(fs_trim_data));
+		}
+
 		case BFS_IOCTL_VERSION:
 		{
 			uint32 version = 0x10000;