[tthompson] 71407: [FsRtl] -Rewrote FsRtlGetNextBaseMcbEntry(), FsRtlLookupBaseMcbEntry(), and FsRtlNumberOfRunsInBaseMcb() using simpler logic. -Commented-out StaticRunBelow0, since it's no longer...
26 May
2016
26 May
'16
12:27 p.m.
Author: tthompson
Date: Thu May 26 12:27:16 2016
New Revision: 71407
URL: http://svn.reactos.org/svn/reactos?rev=71407&view=rev
Log:
[FsRtl]
-Rewrote FsRtlGetNextBaseMcbEntry(), FsRtlLookupBaseMcbEntry(), and
FsRtlNumberOfRunsInBaseMcb() using simpler logic.
-Commented-out StaticRunBelow0, since it's no longer used.
These changes enable kmtest_ FsRtlMcb to run without failure.
Modified:
branches/GSoC_2016/NTFS/ntoskrnl/fsrtl/largemcb.c
Modified: branches/GSoC_2016/NTFS/ntoskrnl/fsrtl/largemcb.c
URL:
http://svn.reactos.org/svn/reactos/branches/GSoC_2016/NTFS/ntoskrnl/fsrtl/l…
==============================================================================
--- branches/GSoC_2016/NTFS/ntoskrnl/fsrtl/largemcb.c [iso-8859-1] (original)
+++ branches/GSoC_2016/NTFS/ntoskrnl/fsrtl/largemcb.c [iso-8859-1] Thu May 26 12:27:16
2016
@@ -42,11 +42,13 @@
PLARGE_MCB_MAPPING Mapping;
} BASE_MCB_INTERNAL, *PBASE_MCB_INTERNAL;
+/*
static LARGE_MCB_MAPPING_ENTRY StaticRunBelow0 = {
- {{-1}}, /* ignored */
+ {{-1}}, // ignored
{{0}},
- {{-1}}, /* ignored */
+ {{-1}}, // ignored
};
+*/
static PVOID NTAPI McbMappingAllocate(PRTL_GENERIC_TABLE Table, CLONG Bytes)
{
@@ -321,107 +323,60 @@
BOOLEAN
NTAPI
FsRtlGetNextBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
- IN ULONG RunIndex,
- OUT PLONGLONG Vbn,
- OUT PLONGLONG Lbn,
- OUT PLONGLONG SectorCount)
-{
- BOOLEAN Result = FALSE;
+ IN ULONG RunIndex,
+ OUT PLONGLONG Vbn,
+ OUT PLONGLONG Lbn,
+ OUT PLONGLONG SectorCount)
+{
PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
- ULONG RunIndexRemaining;
- PLARGE_MCB_MAPPING_ENTRY Run, RunFound = NULL, RunFoundLower = NULL, RunFoundHigher =
NULL;
- BOOLEAN First = TRUE;
-
- DPRINT("FsRtlGetNextBaseMcbEntry(%p, %d, %p, %p, %p)\n", OpaqueMcb,
RunIndex, Vbn, Lbn, SectorCount);
-
- RunIndexRemaining = RunIndex;
-
- /* Traverse the tree */
+ PLARGE_MCB_MAPPING_ENTRY Run = NULL;
+ ULONG CurrentIndex = 0;
+ ULONGLONG LastVbn = 0;
+ ULONGLONG LastSectorCount = 0;
+ ULONG TableElementsConsumed = 0;
+
+ // Traverse the tree
for (Run =
(PLARGE_MCB_MAPPING_ENTRY)RtlEnumerateGenericTable(&Mcb->Mapping->Table, TRUE);
- Run;
+ Run;
Run =
(PLARGE_MCB_MAPPING_ENTRY)RtlEnumerateGenericTable(&Mcb->Mapping->Table,
FALSE))
{
- if (First)
+ TableElementsConsumed++; // we consume one element in the table everytime we call
RtlEnumeratGenericTable
+
+ // is the current index a hole?
+ if (Run->RunStartVbn.QuadPart > (LastVbn + LastSectorCount))
{
- /* Take care when we must emulate missing 'hole' run at start of our
run list. */
- if (Run->RunStartVbn.QuadPart > 0)
+ // Is this the index we're looking for?
+ if (RunIndex == CurrentIndex)
{
- if (RunIndexRemaining == 0)
- {
- RunFoundLower = &StaticRunBelow0;
- RunFoundHigher = Run;
-
- /* stop the traversal */
- break;
- }
- /* If someone wants RunIndex #1 we are already on it. */
- RunIndexRemaining--;
+ *Vbn = LastVbn + LastSectorCount;
+ *Lbn = -1;
+ *SectorCount = Run->RunStartVbn.QuadPart - *Vbn;
+
+ return TRUE;
}
- First = FALSE;
+
+ CurrentIndex++;
}
- if (RunIndexRemaining > 0)
+ if (RunIndex == CurrentIndex)
{
- /* FIXME: performance: non-linear direct seek to the requested RunIndex */
- RunIndexRemaining--;
- if (RunIndexRemaining == 0)
- RunFoundLower = Run;
- else
- RunIndexRemaining--;
-
- /* continue the traversal */
- continue;
+ *Vbn = Run->RunStartVbn.QuadPart;
+ *Lbn = Run->StartingLbn.QuadPart;
+ *SectorCount = Run->RunEndVbn.QuadPart - Run->RunStartVbn.QuadPart;
+
+ return TRUE;
}
- if (RunFoundLower)
- RunFoundHigher = Run;
- else
- RunFound = Run;
-
- /* stop the traversal */
- break;
- }
-
- if (RunFound) DPRINT("RunFound(%lu %lu %lu)\n",
RunFound->RunStartVbn.LowPart, RunFound->RunEndVbn.LowPart,
RunFound->StartingLbn.LowPart);
- if (RunFoundLower) DPRINT("RunFoundLower(%lu %lu %lu)\n",
RunFoundLower->RunStartVbn.LowPart, RunFoundLower->RunEndVbn.LowPart,
RunFoundLower->StartingLbn.LowPart);
- if (RunFoundHigher) DPRINT("RunFoundHigher(%lu %lu %lu)\n",
RunFoundHigher->RunStartVbn.LowPart, RunFoundHigher->RunEndVbn.LowPart,
RunFoundHigher->StartingLbn.LowPart);
-
- if (RunFound)
- {
- ASSERT(RunFoundLower == NULL);
- ASSERT(RunFoundHigher == NULL);
-
- if (Vbn)
- *Vbn = RunFound->RunStartVbn.QuadPart;
- if (Lbn)
- *Lbn = RunFound->StartingLbn.QuadPart;
- if (SectorCount)
- *SectorCount = RunFound->RunEndVbn.QuadPart -
RunFound->RunStartVbn.QuadPart;
-
- Result = TRUE;
- goto quit;
- }
-
- if (RunFoundLower && RunFoundHigher)
- {
- //ASSERT(RunFoundHigher != NULL);
-
- if (Vbn)
- *Vbn = RunFoundLower->RunEndVbn.QuadPart;
- if (Lbn)
- *Lbn = -1;
- if (SectorCount)
- *SectorCount = RunFoundHigher->RunStartVbn.QuadPart -
RunFoundLower->RunEndVbn.QuadPart;
-
- Result = TRUE;
- goto quit;
- }
-
- ASSERT(RunFoundHigher == NULL);
-
-quit:
- DPRINT("FsRtlGetNextBaseMcbEntry(%p, %d, %p, %p, %p) = %d (%I64d, %I64d,
%I64d)\n", Mcb, RunIndex, Vbn, Lbn, SectorCount, Result, *Vbn, *Lbn, *SectorCount);
- return Result;
+ CurrentIndex++;
+ LastVbn = Run->RunStartVbn.QuadPart;
+ LastSectorCount = Run->RunEndVbn.QuadPart - Run->RunStartVbn.QuadPart;
+ }
+
+ // these values are meaningless when returning false (but setting them can be helpful
for debugging purposes)
+ *Vbn = -7777;
+ *Lbn = -7777;
+ *SectorCount = -7777;
+ return FALSE;
}
/*
@@ -538,125 +493,53 @@
}
/*
- * @unimplemented
+ * @implemented
*/
BOOLEAN
NTAPI
FsRtlLookupBaseMcbEntry(IN PBASE_MCB OpaqueMcb,
- IN LONGLONG Vbn,
- OUT PLONGLONG Lbn OPTIONAL,
- OUT PLONGLONG SectorCountFromLbn OPTIONAL,
- OUT PLONGLONG StartingLbn OPTIONAL,
- OUT PLONGLONG SectorCountFromStartingLbn OPTIONAL,
- OUT PULONG Index OPTIONAL)
-{
- BOOLEAN Result = FALSE;
- PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
-
- ULONG RunIndex = 0;
- PLARGE_MCB_MAPPING_ENTRY Run, RunFound = NULL, RunFoundLower = NULL, RunFoundHigher =
NULL;
- BOOLEAN First = TRUE;
-
- DPRINT("FsRtlLookupBaseMcbEntry(%p, %I64d, %p, %p, %p, %p, %p)\n",
OpaqueMcb, Vbn, Lbn, SectorCountFromLbn, StartingLbn, SectorCountFromStartingLbn, Index);
-
- /* Traverse the tree */
- for (Run =
(PLARGE_MCB_MAPPING_ENTRY)RtlEnumerateGenericTable(&Mcb->Mapping->Table, TRUE);
- Run;
- Run =
(PLARGE_MCB_MAPPING_ENTRY)RtlEnumerateGenericTable(&Mcb->Mapping->Table,
FALSE))
- {
- if (First)
+ IN LONGLONG Vbn,
+ OUT PLONGLONG Lbn OPTIONAL,
+ OUT PLONGLONG SectorCountFromLbn OPTIONAL,
+ OUT PLONGLONG StartingLbn OPTIONAL,
+ OUT PLONGLONG SectorCountFromStartingLbn OPTIONAL,
+ OUT PULONG Index OPTIONAL)
+{
+ ULONG i;
+ LONGLONG LastVbn = 0, LastLbn = 0, Count = 0; // the last values we've found
during traversal
+
+ for (i = 0; FsRtlGetNextBaseMcbEntry(OpaqueMcb, i, &LastVbn, &LastLbn,
&Count); i++)
+ {
+ // have we reached the target mapping?
+ if (Vbn < LastVbn + Count)
{
- /* Take care when we must emulate missing 'hole' run at start of our
run list. */
- if (Run->RunStartVbn.QuadPart > 0)
+ if (Lbn)
{
- RunIndex++;
- RunFoundLower = &StaticRunBelow0;
+ if (LastLbn == -1)
+ *Lbn = -1;
+ else
+ *Lbn = LastLbn + (Vbn - LastVbn);
}
- First = FALSE;
+
+ if (SectorCountFromLbn)
+ *SectorCountFromLbn = LastVbn + Count - Vbn;
+ if (StartingLbn)
+ *StartingLbn = LastLbn;
+ if (SectorCountFromStartingLbn)
+ *SectorCountFromStartingLbn = LastVbn + Count - LastVbn;
+ if (Index)
+ *Index = i;
+
+ return TRUE;
}
-
- if (Run->RunStartVbn.QuadPart <= Vbn && Vbn <
Run->RunEndVbn.QuadPart)
- {
- RunFound = Run;
- RunFoundLower = NULL;
- /* stop the traversal; hit */
- break;
- }
-
- if (Run->RunEndVbn.QuadPart <= Vbn)
- {
- RunFoundLower = Run;
- if (Run->StartingLbn.QuadPart > 0)
- {
- RunIndex += 2;
- }
- /* continue the traversal; not yet crossed by the run */
- continue;
- }
-
- if (Vbn < Run->RunStartVbn.QuadPart)
- {
- RunFoundHigher = Run;
- RunIndex++;
- /* stop the traversal; the run skipped us */
- break;
- }
-
- ASSERT(FALSE);
- /* stop the traversal */
- break;
- }
-
- if (RunFound)
- {
- ASSERT(RunFoundLower == NULL);
- ASSERT(RunFoundHigher == NULL);
-
- if (Lbn)
- *Lbn = RunFound->StartingLbn.QuadPart + (Vbn -
RunFound->RunStartVbn.QuadPart);
-
- if (SectorCountFromLbn) /* FIXME: 'after' means including current
'Lbn' or without it? */
- *SectorCountFromLbn = RunFound->RunEndVbn.QuadPart - Vbn;
- if (StartingLbn)
- *StartingLbn = RunFound->StartingLbn.QuadPart;
- if (SectorCountFromStartingLbn)
- *SectorCountFromStartingLbn = RunFound->RunEndVbn.QuadPart -
RunFound->RunStartVbn.QuadPart;
- if (Index)
- *Index = RunIndex;
-
- Result = TRUE;
- goto quit;
- }
-
- if (RunFoundHigher)
- {
- /* search for hole */
- ASSERT(RunFoundLower != NULL);
-
- if (Lbn)
- *Lbn = ~0ull;
- if (SectorCountFromLbn) /* FIXME: 'after' means including current
'Lbn' or without it? */
- *SectorCountFromLbn = RunFoundHigher->RunStartVbn.QuadPart - Vbn;
- if (StartingLbn)
- *StartingLbn = ~0ull;
- if (SectorCountFromStartingLbn)
- *SectorCountFromStartingLbn = RunFoundHigher->RunStartVbn.QuadPart -
RunFoundLower->RunEndVbn.QuadPart;
- if (Index)
- *Index = RunIndex - 2;
-
- Result = TRUE;
- goto quit;
- }
-
- /* We may have some 'RunFoundLower'. */
-
-quit:
- DPRINT("FsRtlLookupBaseMcbEntry(%p, %I64d, %p, %p, %p, %p, %p) = %d (%I64d,
%I64d, %I64d, %I64d, %d)\n",
- OpaqueMcb, Vbn, Lbn, SectorCountFromLbn, StartingLbn,
SectorCountFromStartingLbn, Index, Result,
- (Lbn ? *Lbn : (ULONGLONG)-1), (SectorCountFromLbn ? *SectorCountFromLbn :
(ULONGLONG)-1), (StartingLbn ? *StartingLbn : (ULONGLONG)-1),
- (SectorCountFromStartingLbn ? *SectorCountFromStartingLbn : (ULONGLONG)-1),
(Index ? *Index : (ULONG)-1));
-
- return Result;
+ }
+
+ if (Lbn)
+ *Lbn = -1;
+ if (StartingLbn)
+ *StartingLbn = -1;
+
+ return FALSE;
}
/*
@@ -848,28 +731,18 @@
NTAPI
FsRtlNumberOfRunsInBaseMcb(IN PBASE_MCB OpaqueMcb)
{
- PBASE_MCB_INTERNAL Mcb = (PBASE_MCB_INTERNAL)OpaqueMcb;
- LONGLONG LbnAtVbn0 = -1;
ULONG NumberOfRuns = 0;
+ LONGLONG Vbn, Lbn, Count;
+ int i;
DPRINT("FsRtlNumberOfRunsInBaseMcb(%p)\n", OpaqueMcb);
- if (Mcb->PairCount == 0) goto quit;
-
- FsRtlLookupBaseMcbEntry(OpaqueMcb,
- 0, /* Vbn */
- &LbnAtVbn0, /* Lbn */
- NULL, NULL, NULL, NULL); /* 4 output arguments - not interested in them */
-
-
- /* Return the count */
- //return Mcb->PairCount;
- /* Return the number of 'real' and 'hole' runs.
- * If we do not have sector 0 as 'real' emulate a 'hole' there.
- */
- NumberOfRuns = Mcb->PairCount * 2 - (LbnAtVbn0 != -1 ? 1 : 0); /* include holes as
runs */
-
-quit:
+ // Count how many Mcb entries there are
+ for (i = 0; FsRtlGetNextBaseMcbEntry(OpaqueMcb, i, &Vbn, &Lbn, &Count);
i++)
+ {
+ NumberOfRuns++;
+ }
+
DPRINT("FsRtlNumberOfRunsInBaseMcb(%p) = %d\n", OpaqueMcb, NumberOfRuns);
return NumberOfRuns;
}
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