[pschweitzer] 71409: [NTOSKRNL] Cherry pick r71407 by Trevor Thompson: - Rewrote FsRtlGetNextBaseMcbEntry(), FsRtlLookupBaseMcbEntry(), and FsRtlNumberOfRunsInBaseMcb() using simpler logic. This fi...
Author: pschweitzer Date: Thu May 26 16:35:45 2016 New Revision: 71409
URL: http://svn.reactos.org/svn/reactos?rev=71409&view=rev Log: [NTOSKRNL] Cherry pick r71407 by Trevor Thompson: - Rewrote FsRtlGetNextBaseMcbEntry(), FsRtlLookupBaseMcbEntry(), and FsRtlNumberOfRunsInBaseMcb() using simpler logic.
This finally fixes broken MCB handling in ReactOS and allows FSDs relying on MCB to properly work in ReactOS!
CORE-11002 #resolve #comment Fixed in r71409
Modified: trunk/reactos/ntoskrnl/fsrtl/largemcb.c
Modified: trunk/reactos/ntoskrnl/fsrtl/largemcb.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/fsrtl/largemcb.c?r... ============================================================================== --- trunk/reactos/ntoskrnl/fsrtl/largemcb.c [iso-8859-1] (original) +++ trunk/reactos/ntoskrnl/fsrtl/largemcb.c [iso-8859-1] Thu May 26 16:35:45 2016 @@ -5,6 +5,7 @@ * PURPOSE: Large Mapped Control Block (MCB) support for File System Drivers * PROGRAMMERS: Aleksey Bragin aleksey@reactos.org * Jan Kratochvil project-captive@jankratochvil.net + * Trevor Thompson */
/* INCLUDES ******************************************************************/ @@ -42,11 +43,13 @@ 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) { @@ -321,103 +324,59 @@ BOOLEAN NTAPI FsRtlGetNextBaseMcbEntry(IN PBASE_MCB OpaqueMcb, - IN ULONG RunIndex, - OUT PLONGLONG Vbn, - OUT PLONGLONG Lbn, - OUT PLONGLONG SectorCount) + IN ULONG RunIndex, + OUT PLONGLONG Vbn, + OUT PLONGLONG Lbn, + OUT PLONGLONG SectorCount) { BOOLEAN Result = FALSE; 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; + + // 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) + // 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; + + Result = TRUE; + goto quit; } - 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; + + Result = TRUE; + goto quit; }
- 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); + 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 = 0xdeadbeef; + *Lbn = 0xdeadbeef; + *SectorCount = 0xdeadbeef;
quit: DPRINT("FsRtlGetNextBaseMcbEntry(%p, %d, %p, %p, %p) = %d (%I64d, %I64d, %I64d)\n", Mcb, RunIndex, Vbn, Lbn, SectorCount, Result, *Vbn, *Lbn, *SectorCount); @@ -538,117 +497,55 @@ }
/* - * @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) + 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; + ULONG i; + LONGLONG LastVbn = 0, LastLbn = 0, Count = 0; // the last values we've found during traversal
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) + 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; + + Result = TRUE; + goto quit; } - - 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'. */ + } + + if (Lbn) + *Lbn = -1; + if (StartingLbn) + *StartingLbn = -1;
quit: DPRINT("FsRtlLookupBaseMcbEntry(%p, %I64d, %p, %p, %p, %p, %p) = %d (%I64d, %I64d, %I64d, %I64d, %d)\n", @@ -848,28 +745,18 @@ 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; }
-
pschweitzer＠svn.reactos.org