OSErr BlockDeallocate (
SVCB *vcb, // Which volume to deallocate space on
UInt32 firstBlock, // First block in range to deallocate
UInt32 numBlocks) // Number of contiguous blocks to deallocate
{
OSErr err;
//
// If no blocks to deallocate, then exit early
//
if (numBlocks == 0) {
err = noErr;
goto Exit;
}
//
// Call internal routine to free the sequence of blocks
//
err = BlockMarkFree(vcb, firstBlock, numBlocks);
if (err)
goto Exit;
//
// Update the volume's free block count, and mark the VCB as dirty.
//
vcb->vcbFreeBlocks += numBlocks;
MarkVCBDirty(vcb);
Exit:
return err;
}
OSErr
FlushCatalog(ExtendedVCB *volume)
{
FCB * fcb;
OSErr result;
fcb = GetFileControlBlock(volume->catalogRefNum);
result = BTFlushPath(fcb);
if (result == noErr)
{
//--- check if catalog's fcb is dirty...
if ( 0 /*fcb->fcbFlags & fcbModifiedMask*/ )
{
HFS_MOUNT_LOCK(volume, TRUE);
MarkVCBDirty(volume); // Mark the VCB dirty
volume->vcbLsMod = GetTimeUTC(); // update last modified date
HFS_MOUNT_UNLOCK(volume, TRUE);
// result = FlushVolumeControlBlock(volume);
}
}
return result;
}
__private_extern__
OSErr BlockDeallocate (
ExtendedVCB *vcb, // Which volume to deallocate space on
u_int32_t firstBlock, // First block in range to deallocate
u_int32_t numBlocks) // Number of contiguous blocks to deallocate
{
OSErr err;
//
// If no blocks to deallocate, then exit early
//
if (numBlocks == 0) {
err = noErr;
goto Exit;
}
//
// Call internal routine to free the sequence of blocks
//
err = BlockMarkFree(vcb, firstBlock, numBlocks);
if (err)
goto Exit;
//
// Update the volume's free block count, and mark the VCB as dirty.
//
HFS_MOUNT_LOCK(vcb, TRUE);
vcb->freeBlocks += numBlocks;
if (vcb->nextAllocation == (firstBlock + numBlocks))
HFS_UPDATE_NEXT_ALLOCATION(vcb, (vcb->nextAllocation - numBlocks));
MarkVCBDirty(vcb);
HFS_MOUNT_UNLOCK(vcb, TRUE);
hfs_generate_volume_notifications(VCBTOHFS(vcb));
Exit:
return err;
}
__private_extern__
OSErr BlockAllocate (
ExtendedVCB *vcb, /* which volume to allocate space on */
u_int32_t startingBlock, /* preferred starting block, or 0 for no preference */
u_int32_t minBlocks, /* desired number of blocks to allocate */
u_int32_t maxBlocks, /* maximum number of blocks to allocate */
Boolean forceContiguous, /* non-zero to force contiguous allocation and to force */
/* minBlocks bytes to actually be allocated */
Boolean useMetaZone,
u_int32_t *actualStartBlock, /* actual first block of allocation */
u_int32_t *actualNumBlocks) /* number of blocks actually allocated; if forceContiguous */
/* was zero, then this may represent fewer than minBlocks */
{
u_int32_t freeBlocks;
OSErr err;
Boolean updateAllocPtr = false; // true if nextAllocation needs to be updated
//
// Initialize outputs in case we get an error
//
*actualStartBlock = 0;
*actualNumBlocks = 0;
freeBlocks = hfs_freeblks(VCBTOHFS(vcb), 0);
//
// If the disk is already full, don't bother.
//
if (freeBlocks == 0) {
err = dskFulErr;
goto Exit;
}
if (forceContiguous && freeBlocks < minBlocks) {
err = dskFulErr;
goto Exit;
}
/*
* Clip if necessary so we don't over-subscribe the free blocks.
*/
if (minBlocks > freeBlocks) {
minBlocks = freeBlocks;
}
if (maxBlocks > freeBlocks) {
maxBlocks = freeBlocks;
}
//
// If caller didn't specify a starting block number, then use the volume's
// next block to allocate from.
//
if (startingBlock == 0) {
HFS_MOUNT_LOCK(vcb, TRUE);
startingBlock = vcb->nextAllocation;
HFS_MOUNT_UNLOCK(vcb, TRUE);
updateAllocPtr = true;
}
if (startingBlock >= vcb->allocLimit) {
startingBlock = 0; /* overflow so start at beginning */
}
//
// If the request must be contiguous, then find a sequence of free blocks
// that is long enough. Otherwise, find the first free block.
//
if (forceContiguous) {
err = BlockAllocateContig(vcb, startingBlock, minBlocks, maxBlocks,
useMetaZone, actualStartBlock, actualNumBlocks);
/*
* If we allocated from a new position then
* also update the roving allocator.
*/
if ((err == noErr) &&
(*actualStartBlock > startingBlock) &&
((*actualStartBlock < VCBTOHFS(vcb)->hfs_metazone_start) ||
(*actualStartBlock > VCBTOHFS(vcb)->hfs_metazone_end))) {
HFS_MOUNT_LOCK(vcb, TRUE);
HFS_UPDATE_NEXT_ALLOCATION(vcb, *actualStartBlock);
HFS_MOUNT_UNLOCK(vcb, TRUE);
}
} else {
/*
* Scan the bitmap once, gather the N largest free extents, then
* allocate from these largest extents. Repeat as needed until
* we get all the space we needed. We could probably build up
* that list when the higher level caller tried (and failed) a
* contiguous allocation first.
*/
err = BlockAllocateKnown(vcb, maxBlocks, actualStartBlock, actualNumBlocks);
if (err == dskFulErr)
err = BlockAllocateAny(vcb, startingBlock, vcb->allocLimit,
maxBlocks, useMetaZone, actualStartBlock,
actualNumBlocks);
if (err == dskFulErr)
err = BlockAllocateAny(vcb, 1, startingBlock, maxBlocks,
useMetaZone, actualStartBlock,
actualNumBlocks);
}
Exit:
// if we actually allocated something then go update the
// various bits of state that we maintain regardless of
// whether there was an error (i.e. partial allocations
// still need to update things like the free block count).
//
if (*actualNumBlocks != 0) {
//
// If we used the volume's roving allocation pointer, then we need to update it.
// Adding in the length of the current allocation might reduce the next allocate
// call by avoiding a re-scan of the already allocated space. However, the clump
// just allocated can quite conceivably end up being truncated or released when
// the file is closed or its EOF changed. Leaving the allocation pointer at the
// start of the last allocation will avoid unnecessary fragmentation in this case.
//
HFS_MOUNT_LOCK(vcb, TRUE);
if (updateAllocPtr &&
((*actualStartBlock < VCBTOHFS(vcb)->hfs_metazone_start) ||
(*actualStartBlock > VCBTOHFS(vcb)->hfs_metazone_end))) {
HFS_UPDATE_NEXT_ALLOCATION(vcb, *actualStartBlock);
}
//
// Update the number of free blocks on the volume
//
vcb->freeBlocks -= *actualNumBlocks;
MarkVCBDirty(vcb);
HFS_MOUNT_UNLOCK(vcb, TRUE);
hfs_generate_volume_notifications(VCBTOHFS(vcb));
}
return err;
}
OSErr BlockAllocate (
SVCB *vcb, /* which volume to allocate space on */
UInt32 startingBlock, /* preferred starting block, or 0 for no preference */
UInt32 blocksRequested, /* desired number of BYTES to allocate */
UInt32 blocksMaximum, /* maximum number of bytes to allocate */
Boolean forceContiguous, /* non-zero to force contiguous allocation and to force */
/* bytesRequested bytes to actually be allocated */
UInt32 *actualStartBlock, /* actual first block of allocation */
UInt32 *actualNumBlocks) /* number of blocks actually allocated; if forceContiguous */
/* was zero, then this may represent fewer than bytesRequested */
/* bytes */
{
OSErr err;
Boolean updateAllocPtr = false; // true if nextAllocation needs to be updated
//
// Initialize outputs in case we get an error
//
*actualStartBlock = 0;
*actualNumBlocks = 0;
//
// If the disk is already full, don't bother.
//
if (vcb->vcbFreeBlocks == 0) {
err = dskFulErr;
goto Exit;
}
if (forceContiguous && vcb->vcbFreeBlocks < blocksRequested) {
err = dskFulErr;
goto Exit;
}
//
// If caller didn't specify a starting block number, then use the volume's
// next block to allocate from.
//
if (startingBlock == 0) {
startingBlock = vcb->vcbNextAllocation;
updateAllocPtr = true;
}
//
// If the request must be contiguous, then find a sequence of free blocks
// that is long enough. Otherwise, find the first free block.
//
if (forceContiguous)
err = BlockAllocateContig(vcb, startingBlock, blocksRequested, blocksMaximum, actualStartBlock, actualNumBlocks);
else {
// We'll try to allocate contiguous space first. If that fails, we'll fall back to finding whatever tiny
// extents we can find. It would be nice if we kept track of the largest N free extents so that falling
// back grabbed a small number of large extents.
err = BlockAllocateContig(vcb, startingBlock, blocksRequested, blocksMaximum, actualStartBlock, actualNumBlocks);
if (err == dskFulErr)
err = BlockAllocateAny(vcb, startingBlock, vcb->vcbTotalBlocks, blocksMaximum, actualStartBlock, actualNumBlocks);
if (err == dskFulErr)
err = BlockAllocateAny(vcb, 0, startingBlock, blocksMaximum, actualStartBlock, actualNumBlocks);
}
if (err == noErr) {
//
// If we used the volume's roving allocation pointer, then we need to update it.
// Adding in the length of the current allocation might reduce the next allocate
// call by avoiding a re-scan of the already allocated space. However, the clump
// just allocated can quite conceivably end up being truncated or released when
// the file is closed or its EOF changed. Leaving the allocation pointer at the
// start of the last allocation will avoid unnecessary fragmentation in this case.
//
if (updateAllocPtr)
vcb->vcbNextAllocation = *actualStartBlock;
//
// Update the number of free blocks on the volume
//
vcb->vcbFreeBlocks -= *actualNumBlocks;
MarkVCBDirty(vcb);
}
Exit:
return err;
}
