reactos/drivers/filesystems/btrfs/cache.c

118 lines
3.3 KiB
C

/* Copyright (c) Mark Harmstone 2016-17
*
* This file is part of WinBtrfs.
*
* WinBtrfs is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public Licence as published by
* the Free Software Foundation, either version 3 of the Licence, or
* (at your option) any later version.
*
* WinBtrfs is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public Licence for more details.
*
* You should have received a copy of the GNU Lesser General Public Licence
* along with WinBtrfs. If not, see <http://www.gnu.org/licenses/>. */
#include "btrfs_drv.h"
CACHE_MANAGER_CALLBACKS* cache_callbacks;
#ifdef __REACTOS__
static BOOLEAN NTAPI acquire_for_lazy_write(PVOID Context, BOOLEAN Wait) {
#else
static BOOLEAN acquire_for_lazy_write(PVOID Context, BOOLEAN Wait) {
#endif
PFILE_OBJECT FileObject = Context;
fcb* fcb = FileObject->FsContext;
TRACE("(%p, %u)\n", Context, Wait);
if (!ExAcquireResourceSharedLite(&fcb->Vcb->tree_lock, Wait))
return FALSE;
if (!ExAcquireResourceExclusiveLite(fcb->Header.Resource, Wait)) {
ExReleaseResourceLite(&fcb->Vcb->tree_lock);
return FALSE;
}
fcb->lazy_writer_thread = KeGetCurrentThread();
IoSetTopLevelIrp((PIRP)FSRTL_CACHE_TOP_LEVEL_IRP);
return TRUE;
}
#ifdef __REACTOS__
static void NTAPI release_from_lazy_write(PVOID Context) {
#else
static void release_from_lazy_write(PVOID Context) {
#endif
PFILE_OBJECT FileObject = Context;
fcb* fcb = FileObject->FsContext;
TRACE("(%p)\n", Context);
fcb->lazy_writer_thread = NULL;
ExReleaseResourceLite(fcb->Header.Resource);
ExReleaseResourceLite(&fcb->Vcb->tree_lock);
if (IoGetTopLevelIrp() == (PIRP)FSRTL_CACHE_TOP_LEVEL_IRP)
IoSetTopLevelIrp(NULL);
}
#ifdef __REACTOS__
static BOOLEAN NTAPI acquire_for_read_ahead(PVOID Context, BOOLEAN Wait) {
#else
static BOOLEAN acquire_for_read_ahead(PVOID Context, BOOLEAN Wait) {
#endif
PFILE_OBJECT FileObject = Context;
fcb* fcb = FileObject->FsContext;
TRACE("(%p, %u)\n", Context, Wait);
if (!ExAcquireResourceSharedLite(fcb->Header.Resource, Wait))
return FALSE;
IoSetTopLevelIrp((PIRP)FSRTL_CACHE_TOP_LEVEL_IRP);
return TRUE;
}
#ifdef __REACTOS__
static void NTAPI release_from_read_ahead(PVOID Context) {
#else
static void release_from_read_ahead(PVOID Context) {
#endif
PFILE_OBJECT FileObject = Context;
fcb* fcb = FileObject->FsContext;
TRACE("(%p)\n", Context);
ExReleaseResourceLite(fcb->Header.Resource);
if (IoGetTopLevelIrp() == (PIRP)FSRTL_CACHE_TOP_LEVEL_IRP)
IoSetTopLevelIrp(NULL);
}
NTSTATUS init_cache() {
cache_callbacks = ExAllocatePoolWithTag(NonPagedPool, sizeof(CACHE_MANAGER_CALLBACKS), ALLOC_TAG);
if (!cache_callbacks) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
cache_callbacks->AcquireForLazyWrite = acquire_for_lazy_write;
cache_callbacks->ReleaseFromLazyWrite = release_from_lazy_write;
cache_callbacks->AcquireForReadAhead = acquire_for_read_ahead;
cache_callbacks->ReleaseFromReadAhead = release_from_read_ahead;
return STATUS_SUCCESS;
}
void free_cache() {
ExFreePool(cache_callbacks);
}