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reactos/drivers/filesystems/btrfs/read.c

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/* 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"
enum read_data_status {
ReadDataStatus_Pending,
ReadDataStatus_Success,
ReadDataStatus_Error,
ReadDataStatus_MissingDevice,
ReadDataStatus_Skip
};
struct read_data_context;
typedef struct {
struct read_data_context* context;
UINT16 stripenum;
BOOL rewrite;
PIRP Irp;
IO_STATUS_BLOCK iosb;
enum read_data_status status;
PMDL mdl;
UINT64 stripestart;
UINT64 stripeend;
} read_data_stripe;
typedef struct {
KEVENT Event;
NTSTATUS Status;
chunk* c;
UINT64 address;
UINT32 buflen;
LONG num_stripes, stripes_left;
UINT64 type;
UINT32 sector_size;
UINT16 firstoff, startoffstripe, sectors_per_stripe;
UINT32* csum;
BOOL tree;
read_data_stripe* stripes;
UINT8* va;
} read_data_context;
extern BOOL diskacc;
extern tPsUpdateDiskCounters fPsUpdateDiskCounters;
extern tCcCopyReadEx fCcCopyReadEx;
extern tFsRtlUpdateDiskCounters fFsRtlUpdateDiskCounters;
#define LINUX_PAGE_SIZE 4096
_Function_class_(IO_COMPLETION_ROUTINE)
#ifdef __REACTOS__
static NTSTATUS NTAPI read_data_completion(PDEVICE_OBJECT DeviceObject, PIRP Irp, PVOID conptr) {
#else
static NTSTATUS read_data_completion(PDEVICE_OBJECT DeviceObject, PIRP Irp, PVOID conptr) {
#endif
read_data_stripe* stripe = conptr;
read_data_context* context = (read_data_context*)stripe->context;
UNUSED(DeviceObject);
stripe->iosb = Irp->IoStatus;
if (NT_SUCCESS(Irp->IoStatus.Status))
stripe->status = ReadDataStatus_Success;
else
stripe->status = ReadDataStatus_Error;
if (InterlockedDecrement(&context->stripes_left) == 0)
KeSetEvent(&context->Event, 0, FALSE);
return STATUS_MORE_PROCESSING_REQUIRED;
}
NTSTATUS check_csum(device_extension* Vcb, UINT8* data, UINT32 sectors, UINT32* csum) {
NTSTATUS Status;
calc_job* cj;
UINT32* csum2;
// From experimenting, it seems that 40 sectors is roughly the crossover
// point where offloading the crc32 calculation becomes worth it.
if (sectors < 40 || KeQueryActiveProcessorCount(NULL) < 2) {
ULONG j;
for (j = 0; j < sectors; j++) {
UINT32 crc32 = ~calc_crc32c(0xffffffff, data + (j * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (crc32 != csum[j]) {
return STATUS_CRC_ERROR;
}
}
return STATUS_SUCCESS;
}
csum2 = ExAllocatePoolWithTag(PagedPool, sizeof(UINT32) * sectors, ALLOC_TAG);
if (!csum2) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
Status = add_calc_job(Vcb, data, sectors, csum2, &cj);
if (!NT_SUCCESS(Status)) {
ERR("add_calc_job returned %08x\n", Status);
ExFreePool(csum2);
return Status;
}
KeWaitForSingleObject(&cj->event, Executive, KernelMode, FALSE, NULL);
if (RtlCompareMemory(csum2, csum, sectors * sizeof(UINT32)) != sectors * sizeof(UINT32)) {
free_calc_job(cj);
ExFreePool(csum2);
return STATUS_CRC_ERROR;
}
free_calc_job(cj);
ExFreePool(csum2);
return STATUS_SUCCESS;
}
static NTSTATUS read_data_dup(device_extension* Vcb, UINT8* buf, UINT64 addr, read_data_context* context, CHUNK_ITEM* ci,
device** devices, UINT64 generation) {
ULONG i;
BOOL checksum_error = FALSE;
UINT16 j, stripe = 0;
NTSTATUS Status;
CHUNK_ITEM_STRIPE* cis = (CHUNK_ITEM_STRIPE*)&ci[1];
for (j = 0; j < ci->num_stripes; j++) {
if (context->stripes[j].status == ReadDataStatus_Error) {
WARN("stripe %u returned error %08x\n", j, context->stripes[j].iosb.Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
return context->stripes[j].iosb.Status;
} else if (context->stripes[j].status == ReadDataStatus_Success) {
stripe = j;
break;
}
}
if (context->stripes[stripe].status != ReadDataStatus_Success)
return STATUS_INTERNAL_ERROR;
if (context->tree) {
tree_header* th = (tree_header*)buf;
UINT32 crc32;
crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, context->buflen - sizeof(th->csum));
if (th->address != context->address || crc32 != *((UINT32*)th->csum)) {
checksum_error = TRUE;
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
} else if (generation != 0 && th->generation != generation) {
checksum_error = TRUE;
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_GENERATION_ERRORS);
}
} else if (context->csum) {
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
time1 = KeQueryPerformanceCounter(NULL);
#endif
Status = check_csum(Vcb, buf, (ULONG)context->stripes[stripe].Irp->IoStatus.Information / context->sector_size, context->csum);
if (Status == STATUS_CRC_ERROR) {
checksum_error = TRUE;
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
} else if (!NT_SUCCESS(Status)) {
ERR("check_csum returned %08x\n", Status);
return Status;
}
#ifdef DEBUG_STATS
time2 = KeQueryPerformanceCounter(NULL);
Vcb->stats.read_csum_time += time2.QuadPart - time1.QuadPart;
#endif
}
if (!checksum_error)
return STATUS_SUCCESS;
if (ci->num_stripes == 1)
return STATUS_CRC_ERROR;
if (context->tree) {
tree_header* t2;
BOOL recovered = FALSE;
t2 = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.node_size, ALLOC_TAG);
if (!t2) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
for (j = 0; j < ci->num_stripes; j++) {
if (j != stripe && devices[j] && devices[j]->devobj) {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + context->stripes[stripe].stripestart, Vcb->superblock.node_size, (UINT8*)t2, FALSE);
if (!NT_SUCCESS(Status)) {
WARN("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
} else {
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&t2->fs_uuid, Vcb->superblock.node_size - sizeof(t2->csum));
if (t2->address == addr && crc32 == *((UINT32*)t2->csum) && (generation == 0 || t2->generation == generation)) {
RtlCopyMemory(buf, t2, Vcb->superblock.node_size);
ERR("recovering from checksum error at %llx, device %llx\n", addr, devices[stripe]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && !devices[stripe]->readonly) { // write good data over bad
Status = write_data_phys(devices[stripe]->devobj, cis[stripe].offset + context->stripes[stripe].stripestart,
t2, Vcb->superblock.node_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
break;
} else if (t2->address != addr || crc32 != *((UINT32*)t2->csum))
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
else
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_GENERATION_ERRORS);
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr);
ExFreePool(t2);
return STATUS_CRC_ERROR;
}
ExFreePool(t2);
} else {
ULONG sectors = (ULONG)context->stripes[stripe].Irp->IoStatus.Information / Vcb->superblock.sector_size;
UINT8* sector;
sector = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.sector_size, ALLOC_TAG);
if (!sector) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
for (i = 0; i < sectors; i++) {
UINT32 crc32 = ~calc_crc32c(0xffffffff, buf + (i * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (context->csum[i] != crc32) {
BOOL recovered = FALSE;
for (j = 0; j < ci->num_stripes; j++) {
if (j != stripe && devices[j] && devices[j]->devobj) {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + context->stripes[stripe].stripestart + UInt32x32To64(i, Vcb->superblock.sector_size),
Vcb->superblock.sector_size, sector, FALSE);
if (!NT_SUCCESS(Status)) {
WARN("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
} else {
UINT32 crc32b = ~calc_crc32c(0xffffffff, sector, Vcb->superblock.sector_size);
if (crc32b == context->csum[i]) {
RtlCopyMemory(buf + (i * Vcb->superblock.sector_size), sector, Vcb->superblock.sector_size);
ERR("recovering from checksum error at %llx, device %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size), devices[stripe]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && !devices[stripe]->readonly) { // write good data over bad
Status = write_data_phys(devices[stripe]->devobj, cis[stripe].offset + context->stripes[stripe].stripestart + UInt32x32To64(i, Vcb->superblock.sector_size),
sector, Vcb->superblock.sector_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
break;
} else
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size));
ExFreePool(sector);
return STATUS_CRC_ERROR;
}
}
}
ExFreePool(sector);
}
return STATUS_SUCCESS;
}
static NTSTATUS read_data_raid0(device_extension* Vcb, UINT8* buf, UINT64 addr, UINT32 length, read_data_context* context,
CHUNK_ITEM* ci, device** devices, UINT64 generation, UINT64 offset) {
UINT64 i;
for (i = 0; i < ci->num_stripes; i++) {
if (context->stripes[i].status == ReadDataStatus_Error) {
WARN("stripe %llu returned error %08x\n", i, context->stripes[i].iosb.Status);
log_device_error(Vcb, devices[i], BTRFS_DEV_STAT_READ_ERRORS);
return context->stripes[i].iosb.Status;
}
}
if (context->tree) { // shouldn't happen, as trees shouldn't cross stripe boundaries
tree_header* th = (tree_header*)buf;
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (crc32 != *((UINT32*)th->csum) || addr != th->address || (generation != 0 && generation != th->generation)) {
UINT64 off;
UINT16 stripe;
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes, &off, &stripe);
ERR("unrecoverable checksum error at %llx, device %llx\n", addr, devices[stripe]->devitem.dev_id);
if (crc32 != *((UINT32*)th->csum)) {
WARN("crc32 was %08x, expected %08x\n", crc32, *((UINT32*)th->csum));
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
return STATUS_CRC_ERROR;
} else if (addr != th->address) {
WARN("address of tree was %llx, not %llx as expected\n", th->address, addr);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
return STATUS_CRC_ERROR;
} else if (generation != 0 && generation != th->generation) {
WARN("generation of tree was %llx, not %llx as expected\n", th->generation, generation);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_GENERATION_ERRORS);
return STATUS_CRC_ERROR;
}
}
} else if (context->csum) {
NTSTATUS Status;
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
time1 = KeQueryPerformanceCounter(NULL);
#endif
Status = check_csum(Vcb, buf, length / Vcb->superblock.sector_size, context->csum);
if (Status == STATUS_CRC_ERROR) {
for (i = 0; i < length / Vcb->superblock.sector_size; i++) {
UINT32 crc32 = ~calc_crc32c(0xffffffff, buf + (i * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (context->csum[i] != crc32) {
UINT64 off;
UINT16 stripe;
get_raid0_offset(addr - offset + UInt32x32To64(i, Vcb->superblock.sector_size), ci->stripe_length, ci->num_stripes, &off, &stripe);
ERR("unrecoverable checksum error at %llx, device %llx\n", addr, devices[stripe]->devitem.dev_id);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
return Status;
}
}
return Status;
} else if (!NT_SUCCESS(Status)) {
ERR("check_csum returned %08x\n", Status);
return Status;
}
#ifdef DEBUG_STATS
time2 = KeQueryPerformanceCounter(NULL);
Vcb->stats.read_csum_time += time2.QuadPart - time1.QuadPart;
#endif
}
return STATUS_SUCCESS;
}
static NTSTATUS read_data_raid10(device_extension* Vcb, UINT8* buf, UINT64 addr, UINT32 length, read_data_context* context,
CHUNK_ITEM* ci, device** devices, UINT64 generation, UINT64 offset) {
UINT64 i;
UINT16 j, stripe;
NTSTATUS Status;
BOOL checksum_error = FALSE;
CHUNK_ITEM_STRIPE* cis = (CHUNK_ITEM_STRIPE*)&ci[1];
for (j = 0; j < ci->num_stripes; j++) {
if (context->stripes[j].status == ReadDataStatus_Error) {
WARN("stripe %llu returned error %08x\n", j, context->stripes[j].iosb.Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
return context->stripes[j].iosb.Status;
} else if (context->stripes[j].status == ReadDataStatus_Success)
stripe = j;
}
if (context->tree) {
tree_header* th = (tree_header*)buf;
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (crc32 != *((UINT32*)th->csum)) {
WARN("crc32 was %08x, expected %08x\n", crc32, *((UINT32*)th->csum));
checksum_error = TRUE;
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
} else if (addr != th->address) {
WARN("address of tree was %llx, not %llx as expected\n", th->address, addr);
checksum_error = TRUE;
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
} else if (generation != 0 && generation != th->generation) {
WARN("generation of tree was %llx, not %llx as expected\n", th->generation, generation);
checksum_error = TRUE;
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_GENERATION_ERRORS);
}
} else if (context->csum) {
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
time1 = KeQueryPerformanceCounter(NULL);
#endif
Status = check_csum(Vcb, buf, length / Vcb->superblock.sector_size, context->csum);
if (Status == STATUS_CRC_ERROR)
checksum_error = TRUE;
else if (!NT_SUCCESS(Status)) {
ERR("check_csum returned %08x\n", Status);
return Status;
}
#ifdef DEBUG_STATS
time2 = KeQueryPerformanceCounter(NULL);
Vcb->stats.read_csum_time += time2.QuadPart - time1.QuadPart;
#endif
}
if (!checksum_error)
return STATUS_SUCCESS;
if (context->tree) {
tree_header* t2;
UINT64 off;
UINT16 badsubstripe = 0;
BOOL recovered = FALSE;
t2 = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.node_size, ALLOC_TAG);
if (!t2) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes / ci->sub_stripes, &off, &stripe);
stripe *= ci->sub_stripes;
for (j = 0; j < ci->sub_stripes; j++) {
if (context->stripes[stripe + j].status == ReadDataStatus_Success) {
badsubstripe = j;
break;
}
}
for (j = 0; j < ci->sub_stripes; j++) {
if (context->stripes[stripe + j].status != ReadDataStatus_Success && devices[stripe + j] && devices[stripe + j]->devobj) {
Status = sync_read_phys(devices[stripe + j]->devobj, cis[stripe + j].offset + off,
Vcb->superblock.node_size, (UINT8*)t2, FALSE);
if (!NT_SUCCESS(Status)) {
WARN("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe + j], BTRFS_DEV_STAT_READ_ERRORS);
} else {
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&t2->fs_uuid, Vcb->superblock.node_size - sizeof(t2->csum));
if (t2->address == addr && crc32 == *((UINT32*)t2->csum) && (generation == 0 || t2->generation == generation)) {
RtlCopyMemory(buf, t2, Vcb->superblock.node_size);
ERR("recovering from checksum error at %llx, device %llx\n", addr, devices[stripe + j]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && !devices[stripe + badsubstripe]->readonly && devices[stripe + badsubstripe]->devobj) { // write good data over bad
Status = write_data_phys(devices[stripe + badsubstripe]->devobj, cis[stripe + badsubstripe].offset + off,
t2, Vcb->superblock.node_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe + badsubstripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
break;
} else if (t2->address != addr || crc32 != *((UINT32*)t2->csum))
log_device_error(Vcb, devices[stripe + j], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
else
log_device_error(Vcb, devices[stripe + j], BTRFS_DEV_STAT_GENERATION_ERRORS);
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr);
ExFreePool(t2);
return STATUS_CRC_ERROR;
}
ExFreePool(t2);
} else {
ULONG sectors = length / Vcb->superblock.sector_size;
UINT8* sector;
sector = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.sector_size, ALLOC_TAG);
if (!sector) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
for (i = 0; i < sectors; i++) {
UINT32 crc32 = ~calc_crc32c(0xffffffff, buf + (i * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (context->csum[i] != crc32) {
UINT64 off;
UINT16 stripe2, badsubstripe = 0;
BOOL recovered = FALSE;
get_raid0_offset(addr - offset + UInt32x32To64(i, Vcb->superblock.sector_size), ci->stripe_length,
ci->num_stripes / ci->sub_stripes, &off, &stripe2);
stripe2 *= ci->sub_stripes;
for (j = 0; j < ci->sub_stripes; j++) {
if (context->stripes[stripe2 + j].status == ReadDataStatus_Success) {
badsubstripe = j;
break;
}
}
log_device_error(Vcb, devices[stripe2 + badsubstripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
for (j = 0; j < ci->sub_stripes; j++) {
if (context->stripes[stripe2 + j].status != ReadDataStatus_Success && devices[stripe2 + j] && devices[stripe2 + j]->devobj) {
Status = sync_read_phys(devices[stripe2 + j]->devobj, cis[stripe2 + j].offset + off,
Vcb->superblock.sector_size, sector, FALSE);
if (!NT_SUCCESS(Status)) {
WARN("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe2 + j], BTRFS_DEV_STAT_READ_ERRORS);
} else {
UINT32 crc32b = ~calc_crc32c(0xffffffff, sector, Vcb->superblock.sector_size);
if (crc32b == context->csum[i]) {
RtlCopyMemory(buf + (i * Vcb->superblock.sector_size), sector, Vcb->superblock.sector_size);
ERR("recovering from checksum error at %llx, device %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size), devices[stripe2 + j]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && !devices[stripe2 + badsubstripe]->readonly && devices[stripe2 + badsubstripe]->devobj) { // write good data over bad
Status = write_data_phys(devices[stripe2 + badsubstripe]->devobj, cis[stripe2 + badsubstripe].offset + off,
sector, Vcb->superblock.sector_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe2 + badsubstripe], BTRFS_DEV_STAT_READ_ERRORS);
}
}
break;
} else
log_device_error(Vcb, devices[stripe2 + j], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size));
ExFreePool(sector);
return STATUS_CRC_ERROR;
}
}
}
ExFreePool(sector);
}
return STATUS_SUCCESS;
}
static NTSTATUS read_data_raid5(device_extension* Vcb, UINT8* buf, UINT64 addr, UINT32 length, read_data_context* context, CHUNK_ITEM* ci,
device** devices, UINT64 offset, UINT64 generation, chunk* c, BOOL degraded) {
ULONG i;
NTSTATUS Status;
BOOL checksum_error = FALSE;
CHUNK_ITEM_STRIPE* cis = (CHUNK_ITEM_STRIPE*)&ci[1];
UINT16 j, stripe;
BOOL no_success = TRUE;
for (j = 0; j < ci->num_stripes; j++) {
if (context->stripes[j].status == ReadDataStatus_Error) {
WARN("stripe %u returned error %08x\n", j, context->stripes[j].iosb.Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
return context->stripes[j].iosb.Status;
} else if (context->stripes[j].status == ReadDataStatus_Success) {
stripe = j;
no_success = FALSE;
}
}
if (c) { // check partial stripes
LIST_ENTRY* le;
UINT64 ps_length = (ci->num_stripes - 1) * ci->stripe_length;
ExAcquireResourceSharedLite(&c->partial_stripes_lock, TRUE);
le = c->partial_stripes.Flink;
while (le != &c->partial_stripes) {
partial_stripe* ps = CONTAINING_RECORD(le, partial_stripe, list_entry);
if (ps->address + ps_length > addr && ps->address < addr + length) {
ULONG runlength, index;
runlength = RtlFindFirstRunClear(&ps->bmp, &index);
while (runlength != 0) {
UINT64 runstart = ps->address + (index * Vcb->superblock.sector_size);
UINT64 runend = runstart + (runlength * Vcb->superblock.sector_size);
UINT64 start = max(runstart, addr);
UINT64 end = min(runend, addr + length);
if (end > start)
RtlCopyMemory(buf + start - addr, &ps->data[start - ps->address], (ULONG)(end - start));
runlength = RtlFindNextForwardRunClear(&ps->bmp, index + runlength, &index);
}
} else if (ps->address >= addr + length)
break;
le = le->Flink;
}
ExReleaseResourceLite(&c->partial_stripes_lock);
}
if (context->tree) {
tree_header* th = (tree_header*)buf;
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (addr != th->address || crc32 != *((UINT32*)th->csum)) {
checksum_error = TRUE;
if (!no_success && !degraded)
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
} else if (generation != 0 && generation != th->generation) {
checksum_error = TRUE;
if (!no_success && !degraded)
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_GENERATION_ERRORS);
}
} else if (context->csum) {
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
time1 = KeQueryPerformanceCounter(NULL);
#endif
Status = check_csum(Vcb, buf, length / Vcb->superblock.sector_size, context->csum);
if (Status == STATUS_CRC_ERROR) {
if (!degraded)
WARN("checksum error\n");
checksum_error = TRUE;
} else if (!NT_SUCCESS(Status)) {
ERR("check_csum returned %08x\n", Status);
return Status;
}
#ifdef DEBUG_STATS
time2 = KeQueryPerformanceCounter(NULL);
Vcb->stats.read_csum_time += time2.QuadPart - time1.QuadPart;
#endif
} else if (degraded)
checksum_error = TRUE;
if (!checksum_error)
return STATUS_SUCCESS;
if (context->tree) {
UINT16 parity;
UINT64 off;
BOOL recovered = FALSE, first = TRUE, failed = FALSE;
UINT8* t2;
t2 = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.node_size * 2, ALLOC_TAG);
if (!t2) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes - 1, &off, &stripe);
parity = (((addr - offset) / ((ci->num_stripes - 1) * ci->stripe_length)) + ci->num_stripes - 1) % ci->num_stripes;
stripe = (parity + stripe + 1) % ci->num_stripes;
for (j = 0; j < ci->num_stripes; j++) {
if (j != stripe) {
if (devices[j] && devices[j]->devobj) {
if (first) {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + off, Vcb->superblock.node_size, t2, FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
failed = TRUE;
break;
}
first = FALSE;
} else {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + off, Vcb->superblock.node_size, t2 + Vcb->superblock.node_size, FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
failed = TRUE;
break;
}
do_xor(t2, t2 + Vcb->superblock.node_size, Vcb->superblock.node_size);
}
} else {
failed = TRUE;
break;
}
}
}
if (!failed) {
tree_header* t3 = (tree_header*)t2;
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&t3->fs_uuid, Vcb->superblock.node_size - sizeof(t3->csum));
if (t3->address == addr && crc32 == *((UINT32*)t3->csum) && (generation == 0 || t3->generation == generation)) {
RtlCopyMemory(buf, t2, Vcb->superblock.node_size);
if (!degraded)
ERR("recovering from checksum error at %llx, device %llx\n", addr, devices[stripe]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && devices[stripe] && !devices[stripe]->readonly && devices[stripe]->devobj) { // write good data over bad
Status = write_data_phys(devices[stripe]->devobj, cis[stripe].offset + off, t2, Vcb->superblock.node_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr);
ExFreePool(t2);
return STATUS_CRC_ERROR;
}
ExFreePool(t2);
} else {
ULONG sectors = length / Vcb->superblock.sector_size;
UINT8* sector;
sector = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.sector_size * 2, ALLOC_TAG);
if (!sector) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
for (i = 0; i < sectors; i++) {
UINT16 parity;
UINT64 off;
UINT32 crc32;
if (context->csum)
crc32 = ~calc_crc32c(0xffffffff, buf + (i * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
get_raid0_offset(addr - offset + UInt32x32To64(i, Vcb->superblock.sector_size), ci->stripe_length,
ci->num_stripes - 1, &off, &stripe);
parity = (((addr - offset + UInt32x32To64(i, Vcb->superblock.sector_size)) / ((ci->num_stripes - 1) * ci->stripe_length)) + ci->num_stripes - 1) % ci->num_stripes;
stripe = (parity + stripe + 1) % ci->num_stripes;
if (!devices[stripe] || !devices[stripe]->devobj || (context->csum && context->csum[i] != crc32)) {
BOOL recovered = FALSE, first = TRUE, failed = FALSE;
if (devices[stripe] && devices[stripe]->devobj)
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_READ_ERRORS);
for (j = 0; j < ci->num_stripes; j++) {
if (j != stripe) {
if (devices[j] && devices[j]->devobj) {
if (first) {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + off, Vcb->superblock.sector_size, sector, FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
failed = TRUE;
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
break;
}
first = FALSE;
} else {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + off, Vcb->superblock.sector_size, sector + Vcb->superblock.sector_size, FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
failed = TRUE;
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
break;
}
do_xor(sector, sector + Vcb->superblock.sector_size, Vcb->superblock.sector_size);
}
} else {
failed = TRUE;
break;
}
}
}
if (!failed) {
if (context->csum)
crc32 = ~calc_crc32c(0xffffffff, sector, Vcb->superblock.sector_size);
if (!context->csum || crc32 == context->csum[i]) {
RtlCopyMemory(buf + (i * Vcb->superblock.sector_size), sector, Vcb->superblock.sector_size);
if (!degraded)
ERR("recovering from checksum error at %llx, device %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size), devices[stripe]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && devices[stripe] && !devices[stripe]->readonly && devices[stripe]->devobj) { // write good data over bad
Status = write_data_phys(devices[stripe]->devobj, cis[stripe].offset + off,
sector, Vcb->superblock.sector_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size));
ExFreePool(sector);
return STATUS_CRC_ERROR;
}
}
}
ExFreePool(sector);
}
return STATUS_SUCCESS;
}
void raid6_recover2(UINT8* sectors, UINT16 num_stripes, ULONG sector_size, UINT16 missing1, UINT16 missing2, UINT8* out) {
if (missing1 == num_stripes - 2 || missing2 == num_stripes - 2) { // reconstruct from q and data
UINT16 missing = missing1 == (num_stripes - 2) ? missing2 : missing1;
UINT16 stripe;
stripe = num_stripes - 3;
if (stripe == missing)
RtlZeroMemory(out, sector_size);
else
RtlCopyMemory(out, sectors + (stripe * sector_size), sector_size);
do {
stripe--;
galois_double(out, sector_size);
if (stripe != missing)
do_xor(out, sectors + (stripe * sector_size), sector_size);
} while (stripe > 0);
do_xor(out, sectors + ((num_stripes - 1) * sector_size), sector_size);
if (missing != 0)
galois_divpower(out, (UINT8)missing, sector_size);
} else { // reconstruct from p and q
UINT16 x, y, stripe;
UINT8 gyx, gx, denom, a, b, *p, *q, *pxy, *qxy;
UINT32 j;
stripe = num_stripes - 3;
pxy = out + sector_size;
qxy = out;
if (stripe == missing1 || stripe == missing2) {
RtlZeroMemory(qxy, sector_size);
RtlZeroMemory(pxy, sector_size);
if (stripe == missing1)
x = stripe;
else
y = stripe;
} else {
RtlCopyMemory(qxy, sectors + (stripe * sector_size), sector_size);
RtlCopyMemory(pxy, sectors + (stripe * sector_size), sector_size);
}
do {
stripe--;
galois_double(qxy, sector_size);
if (stripe != missing1 && stripe != missing2) {
do_xor(qxy, sectors + (stripe * sector_size), sector_size);
do_xor(pxy, sectors + (stripe * sector_size), sector_size);
} else if (stripe == missing1)
x = stripe;
else if (stripe == missing2)
y = stripe;
} while (stripe > 0);
gyx = gpow2(y > x ? (y-x) : (255-x+y));
gx = gpow2(255-x);
denom = gdiv(1, gyx ^ 1);
a = gmul(gyx, denom);
b = gmul(gx, denom);
p = sectors + ((num_stripes - 2) * sector_size);
q = sectors + ((num_stripes - 1) * sector_size);
for (j = 0; j < sector_size; j++) {
*qxy = gmul(a, *p ^ *pxy) ^ gmul(b, *q ^ *qxy);
p++;
q++;
pxy++;
qxy++;
}
do_xor(out + sector_size, out, sector_size);
do_xor(out + sector_size, sectors + ((num_stripes - 2) * sector_size), sector_size);
}
}
static NTSTATUS read_data_raid6(device_extension* Vcb, UINT8* buf, UINT64 addr, UINT32 length, read_data_context* context, CHUNK_ITEM* ci,
device** devices, UINT64 offset, UINT64 generation, chunk* c, BOOL degraded) {
NTSTATUS Status;
ULONG i;
BOOL checksum_error = FALSE;
CHUNK_ITEM_STRIPE* cis = (CHUNK_ITEM_STRIPE*)&ci[1];
UINT16 stripe, j;
BOOL no_success = TRUE;
for (j = 0; j < ci->num_stripes; j++) {
if (context->stripes[j].status == ReadDataStatus_Error) {
WARN("stripe %u returned error %08x\n", j, context->stripes[j].iosb.Status);
if (devices[j])
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
return context->stripes[j].iosb.Status;
} else if (context->stripes[j].status == ReadDataStatus_Success) {
stripe = j;
no_success = FALSE;
}
}
if (c) { // check partial stripes
LIST_ENTRY* le;
UINT64 ps_length = (ci->num_stripes - 2) * ci->stripe_length;
ExAcquireResourceSharedLite(&c->partial_stripes_lock, TRUE);
le = c->partial_stripes.Flink;
while (le != &c->partial_stripes) {
partial_stripe* ps = CONTAINING_RECORD(le, partial_stripe, list_entry);
if (ps->address + ps_length > addr && ps->address < addr + length) {
ULONG runlength, index;
runlength = RtlFindFirstRunClear(&ps->bmp, &index);
while (runlength != 0) {
UINT64 runstart = ps->address + (index * Vcb->superblock.sector_size);
UINT64 runend = runstart + (runlength * Vcb->superblock.sector_size);
UINT64 start = max(runstart, addr);
UINT64 end = min(runend, addr + length);
if (end > start)
RtlCopyMemory(buf + start - addr, &ps->data[start - ps->address], (ULONG)(end - start));
runlength = RtlFindNextForwardRunClear(&ps->bmp, index + runlength, &index);
}
} else if (ps->address >= addr + length)
break;
le = le->Flink;
}
ExReleaseResourceLite(&c->partial_stripes_lock);
}
if (context->tree) {
tree_header* th = (tree_header*)buf;
UINT32 crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (addr != th->address || crc32 != *((UINT32*)th->csum)) {
checksum_error = TRUE;
if (!no_success && !degraded && devices[stripe])
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
} else if (generation != 0 && generation != th->generation) {
checksum_error = TRUE;
if (!no_success && !degraded && devices[stripe])
log_device_error(Vcb, devices[stripe], BTRFS_DEV_STAT_GENERATION_ERRORS);
}
} else if (context->csum) {
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
time1 = KeQueryPerformanceCounter(NULL);
#endif
Status = check_csum(Vcb, buf, length / Vcb->superblock.sector_size, context->csum);
if (Status == STATUS_CRC_ERROR) {
if (!degraded)
WARN("checksum error\n");
checksum_error = TRUE;
} else if (!NT_SUCCESS(Status)) {
ERR("check_csum returned %08x\n", Status);
return Status;
}
#ifdef DEBUG_STATS
time2 = KeQueryPerformanceCounter(NULL);
Vcb->stats.read_csum_time += time2.QuadPart - time1.QuadPart;
#endif
} else if (degraded)
checksum_error = TRUE;
if (!checksum_error)
return STATUS_SUCCESS;
if (context->tree) {
UINT8* sector;
UINT16 k, physstripe, parity1, parity2, error_stripe;
UINT64 off;
BOOL recovered = FALSE, failed = FALSE;
ULONG num_errors = 0;
sector = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.node_size * (ci->num_stripes + 2), ALLOC_TAG);
if (!sector) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes - 2, &off, &stripe);
parity1 = (((addr - offset) / ((ci->num_stripes - 2) * ci->stripe_length)) + ci->num_stripes - 2) % ci->num_stripes;
parity2 = (parity1 + 1) % ci->num_stripes;
physstripe = (parity2 + stripe + 1) % ci->num_stripes;
j = (parity2 + 1) % ci->num_stripes;
for (k = 0; k < ci->num_stripes - 1; k++) {
if (j != physstripe) {
if (devices[j] && devices[j]->devobj) {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + off, Vcb->superblock.node_size, sector + (k * Vcb->superblock.node_size), FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
num_errors++;
error_stripe = k;
if (num_errors > 1) {
failed = TRUE;
break;
}
}
} else {
num_errors++;
error_stripe = k;
if (num_errors > 1) {
failed = TRUE;
break;
}
}
}
j = (j + 1) % ci->num_stripes;
}
if (!failed) {
if (num_errors == 0) {
tree_header* th = (tree_header*)(sector + (stripe * Vcb->superblock.node_size));
UINT32 crc32;
RtlCopyMemory(sector + (stripe * Vcb->superblock.node_size), sector + ((ci->num_stripes - 2) * Vcb->superblock.node_size),
Vcb->superblock.node_size);
for (j = 0; j < ci->num_stripes - 2; j++) {
if (j != stripe)
do_xor(sector + (stripe * Vcb->superblock.node_size), sector + (j * Vcb->superblock.node_size), Vcb->superblock.node_size);
}
crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (th->address == addr && crc32 == *((UINT32*)th->csum) && (generation == 0 || th->generation == generation)) {
RtlCopyMemory(buf, sector + (stripe * Vcb->superblock.node_size), Vcb->superblock.node_size);
if (devices[physstripe] && devices[physstripe]->devobj)
ERR("recovering from checksum error at %llx, device %llx\n", addr, devices[physstripe]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && devices[physstripe] && devices[physstripe]->devobj && !devices[physstripe]->readonly) { // write good data over bad
Status = write_data_phys(devices[physstripe]->devobj, cis[physstripe].offset + off,
sector + (stripe * Vcb->superblock.node_size), Vcb->superblock.node_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[physstripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
}
}
if (!recovered) {
UINT32 crc32;
tree_header* th = (tree_header*)(sector + (ci->num_stripes * Vcb->superblock.node_size));
BOOL read_q = FALSE;
if (devices[parity2] && devices[parity2]->devobj) {
Status = sync_read_phys(devices[parity2]->devobj, cis[parity2].offset + off,
Vcb->superblock.node_size, sector + ((ci->num_stripes - 1) * Vcb->superblock.node_size), FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
} else
read_q = TRUE;
}
if (read_q) {
if (num_errors == 1) {
raid6_recover2(sector, ci->num_stripes, Vcb->superblock.node_size, stripe, error_stripe, sector + (ci->num_stripes * Vcb->superblock.node_size));
crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (th->address == addr && crc32 == *((UINT32*)th->csum) && (generation == 0 || th->generation == generation))
recovered = TRUE;
} else {
for (j = 0; j < ci->num_stripes - 1; j++) {
if (j != stripe) {
raid6_recover2(sector, ci->num_stripes, Vcb->superblock.node_size, stripe, j, sector + (ci->num_stripes * Vcb->superblock.node_size));
crc32 = ~calc_crc32c(0xffffffff, (UINT8*)&th->fs_uuid, Vcb->superblock.node_size - sizeof(th->csum));
if (th->address == addr && crc32 == *((UINT32*)th->csum) && (generation == 0 || th->generation == generation)) {
recovered = TRUE;
error_stripe = j;
break;
}
}
}
}
}
if (recovered) {
UINT16 error_stripe_phys = (parity2 + error_stripe + 1) % ci->num_stripes;
if (devices[physstripe] && devices[physstripe]->devobj)
ERR("recovering from checksum error at %llx, device %llx\n", addr, devices[physstripe]->devitem.dev_id);
RtlCopyMemory(buf, sector + (ci->num_stripes * Vcb->superblock.node_size), Vcb->superblock.node_size);
if (!Vcb->readonly && devices[physstripe] && devices[physstripe]->devobj && !devices[physstripe]->readonly) { // write good data over bad
Status = write_data_phys(devices[physstripe]->devobj, cis[physstripe].offset + off,
sector + (ci->num_stripes * Vcb->superblock.node_size), Vcb->superblock.node_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[physstripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
if (devices[error_stripe_phys] && devices[error_stripe_phys]->devobj) {
if (error_stripe == ci->num_stripes - 2) {
ERR("recovering from parity error at %llx, device %llx\n", addr, devices[error_stripe_phys]->devitem.dev_id);
log_device_error(Vcb, devices[error_stripe_phys], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
RtlZeroMemory(sector + ((ci->num_stripes - 2) * Vcb->superblock.node_size), Vcb->superblock.node_size);
for (j = 0; j < ci->num_stripes - 2; j++) {
if (j == stripe) {
do_xor(sector + ((ci->num_stripes - 2) * Vcb->superblock.node_size), sector + (ci->num_stripes * Vcb->superblock.node_size),
Vcb->superblock.node_size);
} else {
do_xor(sector + ((ci->num_stripes - 2) * Vcb->superblock.node_size), sector + (j * Vcb->superblock.node_size),
Vcb->superblock.node_size);
}
}
} else {
ERR("recovering from checksum error at %llx, device %llx\n", addr + ((error_stripe - stripe) * ci->stripe_length),
devices[error_stripe_phys]->devitem.dev_id);
log_device_error(Vcb, devices[error_stripe_phys], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
RtlCopyMemory(sector + (error_stripe * Vcb->superblock.node_size),
sector + ((ci->num_stripes + 1) * Vcb->superblock.node_size), Vcb->superblock.node_size);
}
}
if (!Vcb->readonly && devices[error_stripe_phys] && devices[error_stripe_phys]->devobj && !devices[error_stripe_phys]->readonly) { // write good data over bad
Status = write_data_phys(devices[error_stripe_phys]->devobj, cis[error_stripe_phys].offset + off,
sector + (error_stripe * Vcb->superblock.node_size), Vcb->superblock.node_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[error_stripe_phys], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr);
ExFreePool(sector);
return STATUS_CRC_ERROR;
}
ExFreePool(sector);
} else {
ULONG sectors = length / Vcb->superblock.sector_size;
UINT8* sector;
sector = ExAllocatePoolWithTag(NonPagedPool, Vcb->superblock.sector_size * (ci->num_stripes + 2), ALLOC_TAG);
if (!sector) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
for (i = 0; i < sectors; i++) {
UINT64 off;
UINT16 physstripe, parity1, parity2;
UINT32 crc32;
if (context->csum)
crc32 = ~calc_crc32c(0xffffffff, buf + (i * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
get_raid0_offset(addr - offset + UInt32x32To64(i, Vcb->superblock.sector_size), ci->stripe_length,
ci->num_stripes - 2, &off, &stripe);
parity1 = (((addr - offset + UInt32x32To64(i, Vcb->superblock.sector_size)) / ((ci->num_stripes - 2) * ci->stripe_length)) + ci->num_stripes - 2) % ci->num_stripes;
parity2 = (parity1 + 1) % ci->num_stripes;
physstripe = (parity2 + stripe + 1) % ci->num_stripes;
if (!devices[physstripe] || !devices[physstripe]->devobj || (context->csum && context->csum[i] != crc32)) {
UINT16 k, error_stripe;
BOOL recovered = FALSE, failed = FALSE;
ULONG num_errors = 0;
if (devices[physstripe] && devices[physstripe]->devobj)
log_device_error(Vcb, devices[physstripe], BTRFS_DEV_STAT_READ_ERRORS);
j = (parity2 + 1) % ci->num_stripes;
for (k = 0; k < ci->num_stripes - 1; k++) {
if (j != physstripe) {
if (devices[j] && devices[j]->devobj) {
Status = sync_read_phys(devices[j]->devobj, cis[j].offset + off, Vcb->superblock.sector_size, sector + (k * Vcb->superblock.sector_size), FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[j], BTRFS_DEV_STAT_READ_ERRORS);
num_errors++;
error_stripe = k;
if (num_errors > 1) {
failed = TRUE;
break;
}
}
} else {
num_errors++;
error_stripe = k;
if (num_errors > 1) {
failed = TRUE;
break;
}
}
}
j = (j + 1) % ci->num_stripes;
}
if (!failed) {
if (num_errors == 0) {
RtlCopyMemory(sector + (stripe * Vcb->superblock.sector_size), sector + ((ci->num_stripes - 2) * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
for (j = 0; j < ci->num_stripes - 2; j++) {
if (j != stripe)
do_xor(sector + (stripe * Vcb->superblock.sector_size), sector + (j * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
}
if (context->csum)
crc32 = ~calc_crc32c(0xffffffff, sector + (stripe * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (!context->csum || crc32 == context->csum[i]) {
RtlCopyMemory(buf + (i * Vcb->superblock.sector_size), sector + (stripe * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (devices[physstripe] && devices[physstripe]->devobj)
ERR("recovering from checksum error at %llx, device %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size),
devices[physstripe]->devitem.dev_id);
recovered = TRUE;
if (!Vcb->readonly && devices[physstripe] && devices[physstripe]->devobj && !devices[physstripe]->readonly) { // write good data over bad
Status = write_data_phys(devices[physstripe]->devobj, cis[physstripe].offset + off,
sector + (stripe * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[physstripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
}
}
if (!recovered) {
BOOL read_q = FALSE;
if (devices[parity2] && devices[parity2]->devobj) {
Status = sync_read_phys(devices[parity2]->devobj, cis[parity2].offset + off,
Vcb->superblock.sector_size, sector + ((ci->num_stripes - 1) * Vcb->superblock.sector_size), FALSE);
if (!NT_SUCCESS(Status)) {
ERR("sync_read_phys returned %08x\n", Status);
log_device_error(Vcb, devices[parity2], BTRFS_DEV_STAT_READ_ERRORS);
} else
read_q = TRUE;
}
if (read_q) {
if (num_errors == 1) {
raid6_recover2(sector, ci->num_stripes, Vcb->superblock.sector_size, stripe, error_stripe, sector + (ci->num_stripes * Vcb->superblock.sector_size));
if (!devices[physstripe] || !devices[physstripe]->devobj)
recovered = TRUE;
else {
crc32 = ~calc_crc32c(0xffffffff, sector + (ci->num_stripes * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (crc32 == context->csum[i])
recovered = TRUE;
}
} else {
for (j = 0; j < ci->num_stripes - 1; j++) {
if (j != stripe) {
raid6_recover2(sector, ci->num_stripes, Vcb->superblock.sector_size, stripe, j, sector + (ci->num_stripes * Vcb->superblock.sector_size));
crc32 = ~calc_crc32c(0xffffffff, sector + (ci->num_stripes * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (crc32 == context->csum[i]) {
recovered = TRUE;
error_stripe = j;
break;
}
}
}
}
}
if (recovered) {
UINT16 error_stripe_phys = (parity2 + error_stripe + 1) % ci->num_stripes;
if (devices[physstripe] && devices[physstripe]->devobj)
ERR("recovering from checksum error at %llx, device %llx\n",
addr + UInt32x32To64(i, Vcb->superblock.sector_size), devices[physstripe]->devitem.dev_id);
RtlCopyMemory(buf + (i * Vcb->superblock.sector_size), sector + (ci->num_stripes * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (!Vcb->readonly && devices[physstripe] && devices[physstripe]->devobj && !devices[physstripe]->readonly) { // write good data over bad
Status = write_data_phys(devices[physstripe]->devobj, cis[physstripe].offset + off,
sector + (ci->num_stripes * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[physstripe], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
if (devices[error_stripe_phys] && devices[error_stripe_phys]->devobj) {
if (error_stripe == ci->num_stripes - 2) {
ERR("recovering from parity error at %llx, device %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size),
devices[error_stripe_phys]->devitem.dev_id);
log_device_error(Vcb, devices[error_stripe_phys], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
RtlZeroMemory(sector + ((ci->num_stripes - 2) * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
for (j = 0; j < ci->num_stripes - 2; j++) {
if (j == stripe) {
do_xor(sector + ((ci->num_stripes - 2) * Vcb->superblock.sector_size), sector + (ci->num_stripes * Vcb->superblock.sector_size),
Vcb->superblock.sector_size);
} else {
do_xor(sector + ((ci->num_stripes - 2) * Vcb->superblock.sector_size), sector + (j * Vcb->superblock.sector_size),
Vcb->superblock.sector_size);
}
}
} else {
ERR("recovering from checksum error at %llx, device %llx\n",
addr + UInt32x32To64(i, Vcb->superblock.sector_size) + ((error_stripe - stripe) * ci->stripe_length),
devices[error_stripe_phys]->devitem.dev_id);
log_device_error(Vcb, devices[error_stripe_phys], BTRFS_DEV_STAT_CORRUPTION_ERRORS);
RtlCopyMemory(sector + (error_stripe * Vcb->superblock.sector_size),
sector + ((ci->num_stripes + 1) * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
}
}
if (!Vcb->readonly && devices[error_stripe_phys] && devices[error_stripe_phys]->devobj && !devices[error_stripe_phys]->readonly) { // write good data over bad
Status = write_data_phys(devices[error_stripe_phys]->devobj, cis[error_stripe_phys].offset + off,
sector + (error_stripe * Vcb->superblock.sector_size), Vcb->superblock.sector_size);
if (!NT_SUCCESS(Status)) {
WARN("write_data_phys returned %08x\n", Status);
log_device_error(Vcb, devices[error_stripe_phys], BTRFS_DEV_STAT_WRITE_ERRORS);
}
}
}
}
}
if (!recovered) {
ERR("unrecoverable checksum error at %llx\n", addr + UInt32x32To64(i, Vcb->superblock.sector_size));
ExFreePool(sector);
return STATUS_CRC_ERROR;
}
}
}
ExFreePool(sector);
}
return STATUS_SUCCESS;
}
NTSTATUS read_data(_In_ device_extension* Vcb, _In_ UINT64 addr, _In_ UINT32 length, _In_reads_bytes_opt_(length*sizeof(UINT32)/Vcb->superblock.sector_size) UINT32* csum,
_In_ BOOL is_tree, _Out_writes_bytes_(length) UINT8* buf, _In_opt_ chunk* c, _Out_opt_ chunk** pc, _In_opt_ PIRP Irp, _In_ UINT64 generation, _In_ BOOL file_read,
_In_ ULONG priority) {
CHUNK_ITEM* ci;
CHUNK_ITEM_STRIPE* cis;
read_data_context context;
UINT64 type, offset, total_reading = 0;
NTSTATUS Status;
device** devices = NULL;
UINT16 i, startoffstripe, allowed_missing, missing_devices = 0;
UINT8* dummypage = NULL;
PMDL dummy_mdl = NULL;
BOOL need_to_wait;
UINT64 lockaddr, locklen;
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
#endif
if (Vcb->log_to_phys_loaded) {
if (!c) {
c = get_chunk_from_address(Vcb, addr);
if (!c) {
ERR("get_chunk_from_address failed\n");
return STATUS_INTERNAL_ERROR;
}
}
ci = c->chunk_item;
offset = c->offset;
devices = c->devices;
if (pc)
*pc = c;
} else {
LIST_ENTRY* le = Vcb->sys_chunks.Flink;
ci = NULL;
c = NULL;
while (le != &Vcb->sys_chunks) {
sys_chunk* sc = CONTAINING_RECORD(le, sys_chunk, list_entry);
if (sc->key.obj_id == 0x100 && sc->key.obj_type == TYPE_CHUNK_ITEM && sc->key.offset <= addr) {
CHUNK_ITEM* chunk_item = sc->data;
if ((addr - sc->key.offset) < chunk_item->size && chunk_item->num_stripes > 0) {
ci = chunk_item;
offset = sc->key.offset;
cis = (CHUNK_ITEM_STRIPE*)&chunk_item[1];
devices = ExAllocatePoolWithTag(PagedPool, sizeof(device*) * ci->num_stripes, ALLOC_TAG);
if (!devices) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
for (i = 0; i < ci->num_stripes; i++) {
devices[i] = find_device_from_uuid(Vcb, &cis[i].dev_uuid);
}
break;
}
}
le = le->Flink;
}
if (!ci) {
ERR("could not find chunk for %llx in bootstrap\n", addr);
return STATUS_INTERNAL_ERROR;
}
if (pc)
*pc = NULL;
}
if (ci->type & BLOCK_FLAG_DUPLICATE) {
type = BLOCK_FLAG_DUPLICATE;
allowed_missing = ci->num_stripes - 1;
} else if (ci->type & BLOCK_FLAG_RAID0) {
type = BLOCK_FLAG_RAID0;
allowed_missing = 0;
} else if (ci->type & BLOCK_FLAG_RAID1) {
type = BLOCK_FLAG_DUPLICATE;
allowed_missing = 1;
} else if (ci->type & BLOCK_FLAG_RAID10) {
type = BLOCK_FLAG_RAID10;
allowed_missing = 1;
} else if (ci->type & BLOCK_FLAG_RAID5) {
type = BLOCK_FLAG_RAID5;
allowed_missing = 1;
} else if (ci->type & BLOCK_FLAG_RAID6) {
type = BLOCK_FLAG_RAID6;
allowed_missing = 2;
} else { // SINGLE
type = BLOCK_FLAG_DUPLICATE;
allowed_missing = 0;
}
cis = (CHUNK_ITEM_STRIPE*)&ci[1];
RtlZeroMemory(&context, sizeof(read_data_context));
KeInitializeEvent(&context.Event, NotificationEvent, FALSE);
context.stripes = ExAllocatePoolWithTag(NonPagedPool, sizeof(read_data_stripe) * ci->num_stripes, ALLOC_TAG);
if (!context.stripes) {
ERR("out of memory\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
if (c && (type == BLOCK_FLAG_RAID5 || type == BLOCK_FLAG_RAID6)) {
get_raid56_lock_range(c, addr, length, &lockaddr, &locklen);
chunk_lock_range(Vcb, c, lockaddr, locklen);
}
RtlZeroMemory(context.stripes, sizeof(read_data_stripe) * ci->num_stripes);
context.buflen = length;
context.num_stripes = ci->num_stripes;
context.stripes_left = context.num_stripes;
context.sector_size = Vcb->superblock.sector_size;
context.csum = csum;
context.tree = is_tree;
context.type = type;
if (type == BLOCK_FLAG_RAID0) {
UINT64 startoff, endoff;
UINT16 endoffstripe, stripe;
UINT32 *stripeoff, pos;
PMDL master_mdl;
PFN_NUMBER* pfns;
// FIXME - test this still works if page size isn't the same as sector size
// This relies on the fact that MDLs are followed in memory by the page file numbers,
// so with a bit of jiggery-pokery you can trick your disks into deinterlacing your RAID0
// data for you without doing a memcpy yourself.
// MDLs are officially opaque, so this might very well break in future versions of Windows.
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes, &startoff, &startoffstripe);
get_raid0_offset(addr + length - offset - 1, ci->stripe_length, ci->num_stripes, &endoff, &endoffstripe);
if (file_read) {
// Unfortunately we can't avoid doing at least one memcpy, as Windows can give us an MDL
// with duplicated dummy PFNs, which confuse check_csum. Ah well.
// See https://msdn.microsoft.com/en-us/library/windows/hardware/Dn614012.aspx if you're interested.
context.va = ExAllocatePoolWithTag(NonPagedPool, length, ALLOC_TAG);
if (!context.va) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
} else
context.va = buf;
master_mdl = IoAllocateMdl(context.va, length, FALSE, FALSE, NULL);
if (!master_mdl) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
Status = STATUS_SUCCESS;
_SEH2_TRY {
MmProbeAndLockPages(master_mdl, KernelMode, IoWriteAccess);
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (!NT_SUCCESS(Status)) {
ERR("MmProbeAndLockPages threw exception %08x\n", Status);
IoFreeMdl(master_mdl);
goto exit;
}
pfns = (PFN_NUMBER*)(master_mdl + 1);
for (i = 0; i < ci->num_stripes; i++) {
if (startoffstripe > i)
context.stripes[i].stripestart = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
else if (startoffstripe == i)
context.stripes[i].stripestart = startoff;
else
context.stripes[i].stripestart = startoff - (startoff % ci->stripe_length);
if (endoffstripe > i)
context.stripes[i].stripeend = endoff - (endoff % ci->stripe_length) + ci->stripe_length;
else if (endoffstripe == i)
context.stripes[i].stripeend = endoff + 1;
else
context.stripes[i].stripeend = endoff - (endoff % ci->stripe_length);
if (context.stripes[i].stripestart != context.stripes[i].stripeend) {
context.stripes[i].mdl = IoAllocateMdl(context.va, (ULONG)(context.stripes[i].stripeend - context.stripes[i].stripestart), FALSE, FALSE, NULL);
if (!context.stripes[i].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
}
}
stripeoff = ExAllocatePoolWithTag(NonPagedPool, sizeof(UINT32) * ci->num_stripes, ALLOC_TAG);
if (!stripeoff) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
RtlZeroMemory(stripeoff, sizeof(UINT32) * ci->num_stripes);
pos = 0;
stripe = startoffstripe;
while (pos < length) {
PFN_NUMBER* stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
if (pos == 0) {
UINT32 readlen = (UINT32)min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart, ci->stripe_length - (context.stripes[stripe].stripestart % ci->stripe_length));
RtlCopyMemory(stripe_pfns, pfns, readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] += readlen;
pos += readlen;
} else if (length - pos < ci->stripe_length) {
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], (length - pos) * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
pos = length;
} else {
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], (ULONG)(ci->stripe_length * sizeof(PFN_NUMBER) >> PAGE_SHIFT));
stripeoff[stripe] += (UINT32)ci->stripe_length;
pos += (UINT32)ci->stripe_length;
}
stripe = (stripe + 1) % ci->num_stripes;
}
MmUnlockPages(master_mdl);
IoFreeMdl(master_mdl);
ExFreePool(stripeoff);
} else if (type == BLOCK_FLAG_RAID10) {
UINT64 startoff, endoff;
UINT16 endoffstripe, j, stripe;
ULONG orig_ls;
PMDL master_mdl;
PFN_NUMBER* pfns;
UINT32* stripeoff, pos;
read_data_stripe** stripes;
if (c)
orig_ls = c->last_stripe;
else
orig_ls = 0;
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes / ci->sub_stripes, &startoff, &startoffstripe);
get_raid0_offset(addr + length - offset - 1, ci->stripe_length, ci->num_stripes / ci->sub_stripes, &endoff, &endoffstripe);
if ((ci->num_stripes % ci->sub_stripes) != 0) {
ERR("chunk %llx: num_stripes %x was not a multiple of sub_stripes %x!\n", offset, ci->num_stripes, ci->sub_stripes);
Status = STATUS_INTERNAL_ERROR;
goto exit;
}
if (file_read) {
context.va = ExAllocatePoolWithTag(NonPagedPool, length, ALLOC_TAG);
if (!context.va) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
} else
context.va = buf;
context.firstoff = (UINT16)((startoff % ci->stripe_length) / Vcb->superblock.sector_size);
context.startoffstripe = startoffstripe;
context.sectors_per_stripe = (UINT16)(ci->stripe_length / Vcb->superblock.sector_size);
startoffstripe *= ci->sub_stripes;
endoffstripe *= ci->sub_stripes;
if (c)
c->last_stripe = (orig_ls + 1) % ci->sub_stripes;
master_mdl = IoAllocateMdl(context.va, length, FALSE, FALSE, NULL);
if (!master_mdl) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
Status = STATUS_SUCCESS;
_SEH2_TRY {
MmProbeAndLockPages(master_mdl, KernelMode, IoWriteAccess);
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (!NT_SUCCESS(Status)) {
ERR("MmProbeAndLockPages threw exception %08x\n", Status);
IoFreeMdl(master_mdl);
goto exit;
}
pfns = (PFN_NUMBER*)(master_mdl + 1);
stripes = ExAllocatePoolWithTag(NonPagedPool, sizeof(read_data_stripe*) * ci->num_stripes / ci->sub_stripes, ALLOC_TAG);
if (!stripes) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
RtlZeroMemory(stripes, sizeof(read_data_stripe*) * ci->num_stripes / ci->sub_stripes);
for (i = 0; i < ci->num_stripes; i += ci->sub_stripes) {
UINT64 sstart, send;
BOOL stripeset = FALSE;
if (startoffstripe > i)
sstart = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
else if (startoffstripe == i)
sstart = startoff;
else
sstart = startoff - (startoff % ci->stripe_length);
if (endoffstripe > i)
send = endoff - (endoff % ci->stripe_length) + ci->stripe_length;
else if (endoffstripe == i)
send = endoff + 1;
else
send = endoff - (endoff % ci->stripe_length);
for (j = 0; j < ci->sub_stripes; j++) {
if (j == orig_ls && devices[i+j] && devices[i+j]->devobj) {
context.stripes[i+j].stripestart = sstart;
context.stripes[i+j].stripeend = send;
stripes[i / ci->sub_stripes] = &context.stripes[i+j];
if (sstart != send) {
context.stripes[i+j].mdl = IoAllocateMdl(context.va, (ULONG)(send - sstart), FALSE, FALSE, NULL);
if (!context.stripes[i+j].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
}
stripeset = TRUE;
} else
context.stripes[i+j].status = ReadDataStatus_Skip;
}
if (!stripeset) {
for (j = 0; j < ci->sub_stripes; j++) {
if (devices[i+j] && devices[i+j]->devobj) {
context.stripes[i+j].stripestart = sstart;
context.stripes[i+j].stripeend = send;
context.stripes[i+j].status = ReadDataStatus_Pending;
stripes[i / ci->sub_stripes] = &context.stripes[i+j];
if (sstart != send) {
context.stripes[i+j].mdl = IoAllocateMdl(context.va, (ULONG)(send - sstart), FALSE, FALSE, NULL);
if (!context.stripes[i+j].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
}
stripeset = TRUE;
break;
}
}
if (!stripeset) {
ERR("could not find stripe to read\n");
Status = STATUS_DEVICE_NOT_READY;
goto exit;
}
}
}
stripeoff = ExAllocatePoolWithTag(NonPagedPool, sizeof(UINT32) * ci->num_stripes / ci->sub_stripes, ALLOC_TAG);
if (!stripeoff) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
RtlZeroMemory(stripeoff, sizeof(UINT32) * ci->num_stripes / ci->sub_stripes);
pos = 0;
stripe = startoffstripe / ci->sub_stripes;
while (pos < length) {
PFN_NUMBER* stripe_pfns = (PFN_NUMBER*)(stripes[stripe]->mdl + 1);
if (pos == 0) {
UINT32 readlen = (UINT32)min(stripes[stripe]->stripeend - stripes[stripe]->stripestart,
ci->stripe_length - (stripes[stripe]->stripestart % ci->stripe_length));
RtlCopyMemory(stripe_pfns, pfns, readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] += readlen;
pos += readlen;
} else if (length - pos < ci->stripe_length) {
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], (length - pos) * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
pos = length;
} else {
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], (ULONG)(ci->stripe_length * sizeof(PFN_NUMBER) >> PAGE_SHIFT));
stripeoff[stripe] += (ULONG)ci->stripe_length;
pos += (ULONG)ci->stripe_length;
}
stripe = (stripe + 1) % (ci->num_stripes / ci->sub_stripes);
}
MmUnlockPages(master_mdl);
IoFreeMdl(master_mdl);
ExFreePool(stripeoff);
ExFreePool(stripes);
} else if (type == BLOCK_FLAG_DUPLICATE) {
UINT64 orig_ls;
if (c)
orig_ls = i = c->last_stripe;
else
orig_ls = i = 0;
while (!devices[i] || !devices[i]->devobj) {
i = (i + 1) % ci->num_stripes;
if (i == orig_ls) {
ERR("no devices available to service request\n");
Status = STATUS_DEVICE_NOT_READY;
goto exit;
}
}
if (c)
c->last_stripe = (i + 1) % ci->num_stripes;
context.stripes[i].stripestart = addr - offset;
context.stripes[i].stripeend = context.stripes[i].stripestart + length;
if (file_read) {
context.va = ExAllocatePoolWithTag(NonPagedPool, length, ALLOC_TAG);
if (!context.va) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
context.stripes[i].mdl = IoAllocateMdl(context.va, length, FALSE, FALSE, NULL);
if (!context.stripes[i].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
MmBuildMdlForNonPagedPool(context.stripes[i].mdl);
} else {
context.stripes[i].mdl = IoAllocateMdl(buf, length, FALSE, FALSE, NULL);
if (!context.stripes[i].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
Status = STATUS_SUCCESS;
_SEH2_TRY {
MmProbeAndLockPages(context.stripes[i].mdl, KernelMode, IoWriteAccess);
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (!NT_SUCCESS(Status)) {
ERR("MmProbeAndLockPages threw exception %08x\n", Status);
goto exit;
}
}
} else if (type == BLOCK_FLAG_RAID5) {
UINT64 startoff, endoff;
UINT16 endoffstripe, parity;
UINT32 *stripeoff, pos;
PMDL master_mdl;
PFN_NUMBER *pfns, dummy;
BOOL need_dummy = FALSE;
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes - 1, &startoff, &startoffstripe);
get_raid0_offset(addr + length - offset - 1, ci->stripe_length, ci->num_stripes - 1, &endoff, &endoffstripe);
if (file_read) {
context.va = ExAllocatePoolWithTag(NonPagedPool, length, ALLOC_TAG);
if (!context.va) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
} else
context.va = buf;
master_mdl = IoAllocateMdl(context.va, length, FALSE, FALSE, NULL);
if (!master_mdl) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
Status = STATUS_SUCCESS;
_SEH2_TRY {
MmProbeAndLockPages(master_mdl, KernelMode, IoWriteAccess);
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (!NT_SUCCESS(Status)) {
ERR("MmProbeAndLockPages threw exception %08x\n", Status);
IoFreeMdl(master_mdl);
goto exit;
}
pfns = (PFN_NUMBER*)(master_mdl + 1);
pos = 0;
while (pos < length) {
parity = (((addr - offset + pos) / ((ci->num_stripes - 1) * ci->stripe_length)) + ci->num_stripes - 1) % ci->num_stripes;
if (pos == 0) {
UINT16 stripe = (parity + startoffstripe + 1) % ci->num_stripes;
ULONG skip, readlen;
i = startoffstripe;
while (stripe != parity) {
if (i == startoffstripe) {
readlen = min(length, (ULONG)(ci->stripe_length - (startoff % ci->stripe_length)));
context.stripes[stripe].stripestart = startoff;
context.stripes[stripe].stripeend = startoff + readlen;
pos += readlen;
if (pos == length)
break;
} else {
readlen = min(length - pos, (ULONG)ci->stripe_length);
context.stripes[stripe].stripestart = startoff - (startoff % ci->stripe_length);
context.stripes[stripe].stripeend = context.stripes[stripe].stripestart + readlen;
pos += readlen;
if (pos == length)
break;
}
i++;
stripe = (stripe + 1) % ci->num_stripes;
}
if (pos == length)
break;
for (i = 0; i < startoffstripe; i++) {
UINT16 stripe2 = (parity + i + 1) % ci->num_stripes;
context.stripes[stripe2].stripestart = context.stripes[stripe2].stripeend = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
}
context.stripes[parity].stripestart = context.stripes[parity].stripeend = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
if (length - pos > ci->num_stripes * (ci->num_stripes - 1) * ci->stripe_length) {
skip = (ULONG)(((length - pos) / (ci->num_stripes * (ci->num_stripes - 1) * ci->stripe_length)) - 1);
for (i = 0; i < ci->num_stripes; i++) {
context.stripes[i].stripeend += skip * ci->num_stripes * ci->stripe_length;
}
pos += (UINT32)(skip * (ci->num_stripes - 1) * ci->num_stripes * ci->stripe_length);
need_dummy = TRUE;
}
} else if (length - pos >= ci->stripe_length * (ci->num_stripes - 1)) {
for (i = 0; i < ci->num_stripes; i++) {
context.stripes[i].stripeend += ci->stripe_length;
}
pos += (UINT32)(ci->stripe_length * (ci->num_stripes - 1));
need_dummy = TRUE;
} else {
UINT16 stripe = (parity + 1) % ci->num_stripes;
i = 0;
while (stripe != parity) {
if (endoffstripe == i) {
context.stripes[stripe].stripeend = endoff + 1;
break;
} else if (endoffstripe > i)
context.stripes[stripe].stripeend = endoff - (endoff % ci->stripe_length) + ci->stripe_length;
i++;
stripe = (stripe + 1) % ci->num_stripes;
}
break;
}
}
for (i = 0; i < ci->num_stripes; i++) {
if (context.stripes[i].stripestart != context.stripes[i].stripeend) {
context.stripes[i].mdl = IoAllocateMdl(context.va, (ULONG)(context.stripes[i].stripeend - context.stripes[i].stripestart),
FALSE, FALSE, NULL);
if (!context.stripes[i].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
}
}
if (need_dummy) {
dummypage = ExAllocatePoolWithTag(NonPagedPool, PAGE_SIZE, ALLOC_TAG);
if (!dummypage) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
dummy_mdl = IoAllocateMdl(dummypage, PAGE_SIZE, FALSE, FALSE, NULL);
if (!dummy_mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
ExFreePool(dummypage);
goto exit;
}
MmBuildMdlForNonPagedPool(dummy_mdl);
dummy = *(PFN_NUMBER*)(dummy_mdl + 1);
}
stripeoff = ExAllocatePoolWithTag(NonPagedPool, sizeof(UINT32) * ci->num_stripes, ALLOC_TAG);
if (!stripeoff) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
RtlZeroMemory(stripeoff, sizeof(UINT32) * ci->num_stripes);
pos = 0;
while (pos < length) {
PFN_NUMBER* stripe_pfns;
parity = (((addr - offset + pos) / ((ci->num_stripes - 1) * ci->stripe_length)) + ci->num_stripes - 1) % ci->num_stripes;
if (pos == 0) {
UINT16 stripe = (parity + startoffstripe + 1) % ci->num_stripes;
UINT32 readlen = min(length - pos, (UINT32)min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart,
ci->stripe_length - (context.stripes[stripe].stripestart % ci->stripe_length)));
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
RtlCopyMemory(stripe_pfns, pfns, readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] = readlen;
pos += readlen;
stripe = (stripe + 1) % ci->num_stripes;
while (stripe != parity) {
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
readlen = min(length - pos, (UINT32)min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart, ci->stripe_length));
if (readlen == 0)
break;
RtlCopyMemory(stripe_pfns, &pfns[pos >> PAGE_SHIFT], readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] = readlen;
pos += readlen;
stripe = (stripe + 1) % ci->num_stripes;
}
} else if (length - pos >= ci->stripe_length * (ci->num_stripes - 1)) {
UINT16 stripe = (parity + 1) % ci->num_stripes;
ULONG k;
while (stripe != parity) {
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], (ULONG)(ci->stripe_length * sizeof(PFN_NUMBER) >> PAGE_SHIFT));
stripeoff[stripe] += (UINT32)ci->stripe_length;
pos += (UINT32)ci->stripe_length;
stripe = (stripe + 1) % ci->num_stripes;
}
stripe_pfns = (PFN_NUMBER*)(context.stripes[parity].mdl + 1);
for (k = 0; k < ci->stripe_length >> PAGE_SHIFT; k++) {
stripe_pfns[stripeoff[parity] >> PAGE_SHIFT] = dummy;
stripeoff[parity] += PAGE_SIZE;
}
} else {
UINT16 stripe = (parity + 1) % ci->num_stripes;
UINT32 readlen;
while (pos < length) {
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
readlen = min(length - pos, (ULONG)min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart, ci->stripe_length));
if (readlen == 0)
break;
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] += readlen;
pos += readlen;
stripe = (stripe + 1) % ci->num_stripes;
}
}
}
MmUnlockPages(master_mdl);
IoFreeMdl(master_mdl);
ExFreePool(stripeoff);
} else if (type == BLOCK_FLAG_RAID6) {
UINT64 startoff, endoff;
UINT16 endoffstripe, parity1;
UINT32 *stripeoff, pos;
PMDL master_mdl;
PFN_NUMBER *pfns, dummy;
BOOL need_dummy = FALSE;
get_raid0_offset(addr - offset, ci->stripe_length, ci->num_stripes - 2, &startoff, &startoffstripe);
get_raid0_offset(addr + length - offset - 1, ci->stripe_length, ci->num_stripes - 2, &endoff, &endoffstripe);
if (file_read) {
context.va = ExAllocatePoolWithTag(NonPagedPool, length, ALLOC_TAG);
if (!context.va) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
} else
context.va = buf;
master_mdl = IoAllocateMdl(context.va, length, FALSE, FALSE, NULL);
if (!master_mdl) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
Status = STATUS_SUCCESS;
_SEH2_TRY {
MmProbeAndLockPages(master_mdl, KernelMode, IoWriteAccess);
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (!NT_SUCCESS(Status)) {
ERR("MmProbeAndLockPages threw exception %08x\n", Status);
IoFreeMdl(master_mdl);
goto exit;
}
pfns = (PFN_NUMBER*)(master_mdl + 1);
pos = 0;
while (pos < length) {
parity1 = (((addr - offset + pos) / ((ci->num_stripes - 2) * ci->stripe_length)) + ci->num_stripes - 2) % ci->num_stripes;
if (pos == 0) {
UINT16 stripe = (parity1 + startoffstripe + 2) % ci->num_stripes, parity2;
ULONG skip, readlen;
i = startoffstripe;
while (stripe != parity1) {
if (i == startoffstripe) {
readlen = (ULONG)min(length, ci->stripe_length - (startoff % ci->stripe_length));
context.stripes[stripe].stripestart = startoff;
context.stripes[stripe].stripeend = startoff + readlen;
pos += readlen;
if (pos == length)
break;
} else {
readlen = min(length - pos, (ULONG)ci->stripe_length);
context.stripes[stripe].stripestart = startoff - (startoff % ci->stripe_length);
context.stripes[stripe].stripeend = context.stripes[stripe].stripestart + readlen;
pos += readlen;
if (pos == length)
break;
}
i++;
stripe = (stripe + 1) % ci->num_stripes;
}
if (pos == length)
break;
for (i = 0; i < startoffstripe; i++) {
UINT16 stripe2 = (parity1 + i + 2) % ci->num_stripes;
context.stripes[stripe2].stripestart = context.stripes[stripe2].stripeend = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
}
context.stripes[parity1].stripestart = context.stripes[parity1].stripeend = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
parity2 = (parity1 + 1) % ci->num_stripes;
context.stripes[parity2].stripestart = context.stripes[parity2].stripeend = startoff - (startoff % ci->stripe_length) + ci->stripe_length;
if (length - pos > ci->num_stripes * (ci->num_stripes - 2) * ci->stripe_length) {
skip = (ULONG)(((length - pos) / (ci->num_stripes * (ci->num_stripes - 2) * ci->stripe_length)) - 1);
for (i = 0; i < ci->num_stripes; i++) {
context.stripes[i].stripeend += skip * ci->num_stripes * ci->stripe_length;
}
pos += (UINT32)(skip * (ci->num_stripes - 2) * ci->num_stripes * ci->stripe_length);
need_dummy = TRUE;
}
} else if (length - pos >= ci->stripe_length * (ci->num_stripes - 2)) {
for (i = 0; i < ci->num_stripes; i++) {
context.stripes[i].stripeend += ci->stripe_length;
}
pos += (UINT32)(ci->stripe_length * (ci->num_stripes - 2));
need_dummy = TRUE;
} else {
UINT16 stripe = (parity1 + 2) % ci->num_stripes;
i = 0;
while (stripe != parity1) {
if (endoffstripe == i) {
context.stripes[stripe].stripeend = endoff + 1;
break;
} else if (endoffstripe > i)
context.stripes[stripe].stripeend = endoff - (endoff % ci->stripe_length) + ci->stripe_length;
i++;
stripe = (stripe + 1) % ci->num_stripes;
}
break;
}
}
for (i = 0; i < ci->num_stripes; i++) {
if (context.stripes[i].stripestart != context.stripes[i].stripeend) {
context.stripes[i].mdl = IoAllocateMdl(context.va, (ULONG)(context.stripes[i].stripeend - context.stripes[i].stripestart), FALSE, FALSE, NULL);
if (!context.stripes[i].mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
}
}
if (need_dummy) {
dummypage = ExAllocatePoolWithTag(NonPagedPool, PAGE_SIZE, ALLOC_TAG);
if (!dummypage) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
dummy_mdl = IoAllocateMdl(dummypage, PAGE_SIZE, FALSE, FALSE, NULL);
if (!dummy_mdl) {
ERR("IoAllocateMdl failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
ExFreePool(dummypage);
goto exit;
}
MmBuildMdlForNonPagedPool(dummy_mdl);
dummy = *(PFN_NUMBER*)(dummy_mdl + 1);
}
stripeoff = ExAllocatePoolWithTag(NonPagedPool, sizeof(UINT32) * ci->num_stripes, ALLOC_TAG);
if (!stripeoff) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
RtlZeroMemory(stripeoff, sizeof(UINT32) * ci->num_stripes);
pos = 0;
while (pos < length) {
PFN_NUMBER* stripe_pfns;
parity1 = (((addr - offset + pos) / ((ci->num_stripes - 2) * ci->stripe_length)) + ci->num_stripes - 2) % ci->num_stripes;
if (pos == 0) {
UINT16 stripe = (parity1 + startoffstripe + 2) % ci->num_stripes;
UINT32 readlen = min(length - pos, (UINT32)min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart,
ci->stripe_length - (context.stripes[stripe].stripestart % ci->stripe_length)));
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
RtlCopyMemory(stripe_pfns, pfns, readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] = readlen;
pos += readlen;
stripe = (stripe + 1) % ci->num_stripes;
while (stripe != parity1) {
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
readlen = (UINT32)min(length - pos, min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart, ci->stripe_length));
if (readlen == 0)
break;
RtlCopyMemory(stripe_pfns, &pfns[pos >> PAGE_SHIFT], readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] = readlen;
pos += readlen;
stripe = (stripe + 1) % ci->num_stripes;
}
} else if (length - pos >= ci->stripe_length * (ci->num_stripes - 2)) {
UINT16 stripe = (parity1 + 2) % ci->num_stripes;
UINT16 parity2 = (parity1 + 1) % ci->num_stripes;
ULONG k;
while (stripe != parity1) {
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], (ULONG)(ci->stripe_length * sizeof(PFN_NUMBER) >> PAGE_SHIFT));
stripeoff[stripe] += (UINT32)ci->stripe_length;
pos += (UINT32)ci->stripe_length;
stripe = (stripe + 1) % ci->num_stripes;
}
stripe_pfns = (PFN_NUMBER*)(context.stripes[parity1].mdl + 1);
for (k = 0; k < ci->stripe_length >> PAGE_SHIFT; k++) {
stripe_pfns[stripeoff[parity1] >> PAGE_SHIFT] = dummy;
stripeoff[parity1] += PAGE_SIZE;
}
stripe_pfns = (PFN_NUMBER*)(context.stripes[parity2].mdl + 1);
for (k = 0; k < ci->stripe_length >> PAGE_SHIFT; k++) {
stripe_pfns[stripeoff[parity2] >> PAGE_SHIFT] = dummy;
stripeoff[parity2] += PAGE_SIZE;
}
} else {
UINT16 stripe = (parity1 + 2) % ci->num_stripes;
UINT32 readlen;
while (pos < length) {
stripe_pfns = (PFN_NUMBER*)(context.stripes[stripe].mdl + 1);
readlen = (UINT32)min(length - pos, min(context.stripes[stripe].stripeend - context.stripes[stripe].stripestart, ci->stripe_length));
if (readlen == 0)
break;
RtlCopyMemory(&stripe_pfns[stripeoff[stripe] >> PAGE_SHIFT], &pfns[pos >> PAGE_SHIFT], readlen * sizeof(PFN_NUMBER) >> PAGE_SHIFT);
stripeoff[stripe] += readlen;
pos += readlen;
stripe = (stripe + 1) % ci->num_stripes;
}
}
}
MmUnlockPages(master_mdl);
IoFreeMdl(master_mdl);
ExFreePool(stripeoff);
}
context.address = addr;
for (i = 0; i < ci->num_stripes; i++) {
if (!devices[i] || !devices[i]->devobj || context.stripes[i].stripestart == context.stripes[i].stripeend) {
context.stripes[i].status = ReadDataStatus_MissingDevice;
context.stripes_left--;
if (!devices[i] || !devices[i]->devobj)
missing_devices++;
}
}
if (missing_devices > allowed_missing) {
ERR("not enough devices to service request (%u missing)\n", missing_devices);
Status = STATUS_UNEXPECTED_IO_ERROR;
goto exit;
}
for (i = 0; i < ci->num_stripes; i++) {
PIO_STACK_LOCATION IrpSp;
if (devices[i] && devices[i]->devobj && context.stripes[i].stripestart != context.stripes[i].stripeend && context.stripes[i].status != ReadDataStatus_Skip) {
context.stripes[i].context = (struct read_data_context*)&context;
if (type == BLOCK_FLAG_RAID10) {
context.stripes[i].stripenum = i / ci->sub_stripes;
}
if (!Irp) {
context.stripes[i].Irp = IoAllocateIrp(devices[i]->devobj->StackSize, FALSE);
if (!context.stripes[i].Irp) {
ERR("IoAllocateIrp failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
} else {
context.stripes[i].Irp = IoMakeAssociatedIrp(Irp, devices[i]->devobj->StackSize);
if (!context.stripes[i].Irp) {
ERR("IoMakeAssociatedIrp failed\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
}
IrpSp = IoGetNextIrpStackLocation(context.stripes[i].Irp);
IrpSp->MajorFunction = IRP_MJ_READ;
if (devices[i]->devobj->Flags & DO_BUFFERED_IO) {
context.stripes[i].Irp->AssociatedIrp.SystemBuffer = ExAllocatePoolWithTag(NonPagedPool, (ULONG)(context.stripes[i].stripeend - context.stripes[i].stripestart), ALLOC_TAG);
if (!context.stripes[i].Irp->AssociatedIrp.SystemBuffer) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
context.stripes[i].Irp->Flags |= IRP_BUFFERED_IO | IRP_DEALLOCATE_BUFFER | IRP_INPUT_OPERATION;
context.stripes[i].Irp->UserBuffer = MmGetSystemAddressForMdlSafe(context.stripes[i].mdl, priority);
} else if (devices[i]->devobj->Flags & DO_DIRECT_IO)
context.stripes[i].Irp->MdlAddress = context.stripes[i].mdl;
else
context.stripes[i].Irp->UserBuffer = MmGetSystemAddressForMdlSafe(context.stripes[i].mdl, priority);
IrpSp->Parameters.Read.Length = (ULONG)(context.stripes[i].stripeend - context.stripes[i].stripestart);
IrpSp->Parameters.Read.ByteOffset.QuadPart = context.stripes[i].stripestart + cis[i].offset;
total_reading += IrpSp->Parameters.Read.Length;
context.stripes[i].Irp->UserIosb = &context.stripes[i].iosb;
IoSetCompletionRoutine(context.stripes[i].Irp, read_data_completion, &context.stripes[i], TRUE, TRUE, TRUE);
context.stripes[i].status = ReadDataStatus_Pending;
}
}
#ifdef DEBUG_STATS
if (!is_tree)
time1 = KeQueryPerformanceCounter(NULL);
#endif
need_to_wait = FALSE;
for (i = 0; i < ci->num_stripes; i++) {
if (context.stripes[i].status != ReadDataStatus_MissingDevice && context.stripes[i].status != ReadDataStatus_Skip) {
IoCallDriver(devices[i]->devobj, context.stripes[i].Irp);
need_to_wait = TRUE;
}
}
if (need_to_wait)
KeWaitForSingleObject(&context.Event, Executive, KernelMode, FALSE, NULL);
#ifdef DEBUG_STATS
if (!is_tree) {
time2 = KeQueryPerformanceCounter(NULL);
Vcb->stats.read_disk_time += time2.QuadPart - time1.QuadPart;
}
#endif
if (diskacc)
fFsRtlUpdateDiskCounters(total_reading, 0);
// check if any of the devices return a "user-induced" error
for (i = 0; i < ci->num_stripes; i++) {
if (context.stripes[i].status == ReadDataStatus_Error && IoIsErrorUserInduced(context.stripes[i].iosb.Status)) {
Status = context.stripes[i].iosb.Status;
goto exit;
}
}
if (type == BLOCK_FLAG_RAID0) {
Status = read_data_raid0(Vcb, file_read ? context.va : buf, addr, length, &context, ci, devices, generation, offset);
if (!NT_SUCCESS(Status)) {
ERR("read_data_raid0 returned %08x\n", Status);
if (file_read)
ExFreePool(context.va);
goto exit;
}
if (file_read) {
RtlCopyMemory(buf, context.va, length);
ExFreePool(context.va);
}
} else if (type == BLOCK_FLAG_RAID10) {
Status = read_data_raid10(Vcb, file_read ? context.va : buf, addr, length, &context, ci, devices, generation, offset);
if (!NT_SUCCESS(Status)) {
ERR("read_data_raid10 returned %08x\n", Status);
if (file_read)
ExFreePool(context.va);
goto exit;
}
if (file_read) {
RtlCopyMemory(buf, context.va, length);
ExFreePool(context.va);
}
} else if (type == BLOCK_FLAG_DUPLICATE) {
Status = read_data_dup(Vcb, file_read ? context.va : buf, addr, &context, ci, devices, generation);
if (!NT_SUCCESS(Status)) {
ERR("read_data_dup returned %08x\n", Status);
if (file_read)
ExFreePool(context.va);
goto exit;
}
if (file_read) {
RtlCopyMemory(buf, context.va, length);
ExFreePool(context.va);
}
} else if (type == BLOCK_FLAG_RAID5) {
Status = read_data_raid5(Vcb, file_read ? context.va : buf, addr, length, &context, ci, devices, offset, generation, c, missing_devices > 0 ? TRUE : FALSE);
if (!NT_SUCCESS(Status)) {
ERR("read_data_raid5 returned %08x\n", Status);
if (file_read)
ExFreePool(context.va);
goto exit;
}
if (file_read) {
RtlCopyMemory(buf, context.va, length);
ExFreePool(context.va);
}
} else if (type == BLOCK_FLAG_RAID6) {
Status = read_data_raid6(Vcb, file_read ? context.va : buf, addr, length, &context, ci, devices, offset, generation, c, missing_devices > 0 ? TRUE : FALSE);
if (!NT_SUCCESS(Status)) {
ERR("read_data_raid6 returned %08x\n", Status);
if (file_read)
ExFreePool(context.va);
goto exit;
}
if (file_read) {
RtlCopyMemory(buf, context.va, length);
ExFreePool(context.va);
}
}
exit:
if (c && (type == BLOCK_FLAG_RAID5 || type == BLOCK_FLAG_RAID6))
chunk_unlock_range(Vcb, c, lockaddr, locklen);
if (dummy_mdl)
IoFreeMdl(dummy_mdl);
if (dummypage)
ExFreePool(dummypage);
for (i = 0; i < ci->num_stripes; i++) {
if (context.stripes[i].mdl) {
if (context.stripes[i].mdl->MdlFlags & MDL_PAGES_LOCKED)
MmUnlockPages(context.stripes[i].mdl);
IoFreeMdl(context.stripes[i].mdl);
}
if (context.stripes[i].Irp)
IoFreeIrp(context.stripes[i].Irp);
}
ExFreePool(context.stripes);
if (!Vcb->log_to_phys_loaded)
ExFreePool(devices);
return Status;
}
NTSTATUS read_stream(fcb* fcb, UINT8* data, UINT64 start, ULONG length, ULONG* pbr) {
ULONG readlen;
TRACE("(%p, %p, %llx, %llx, %p)\n", fcb, data, start, length, pbr);
if (pbr) *pbr = 0;
if (start >= fcb->adsdata.Length) {
TRACE("tried to read beyond end of stream\n");
return STATUS_END_OF_FILE;
}
if (length == 0) {
WARN("tried to read zero bytes\n");
return STATUS_SUCCESS;
}
if (start + length < fcb->adsdata.Length)
readlen = length;
else
readlen = fcb->adsdata.Length - (ULONG)start;
if (readlen > 0)
RtlCopyMemory(data + start, fcb->adsdata.Buffer, readlen);
if (pbr) *pbr = readlen;
return STATUS_SUCCESS;
}
NTSTATUS read_file(fcb* fcb, UINT8* data, UINT64 start, UINT64 length, ULONG* pbr, PIRP Irp) {
NTSTATUS Status;
EXTENT_DATA* ed;
UINT32 bytes_read = 0;
UINT64 last_end;
LIST_ENTRY* le;
#ifdef DEBUG_STATS
LARGE_INTEGER time1, time2;
#endif
TRACE("(%p, %p, %llx, %llx, %p)\n", fcb, data, start, length, pbr);
if (pbr)
*pbr = 0;
if (start >= fcb->inode_item.st_size) {
WARN("Tried to read beyond end of file\n");
Status = STATUS_END_OF_FILE;
goto exit;
}
#ifdef DEBUG_STATS
time1 = KeQueryPerformanceCounter(NULL);
#endif
le = fcb->extents.Flink;
last_end = start;
while (le != &fcb->extents) {
UINT64 len;
extent* ext = CONTAINING_RECORD(le, extent, list_entry);
EXTENT_DATA2* ed2;
if (!ext->ignore) {
ed = &ext->extent_data;
ed2 = (ed->type == EXTENT_TYPE_REGULAR || ed->type == EXTENT_TYPE_PREALLOC) ? (EXTENT_DATA2*)ed->data : NULL;
len = ed2 ? ed2->num_bytes : ed->decoded_size;
if (ext->offset + len <= start) {
last_end = ext->offset + len;
goto nextitem;
}
if (ext->offset > last_end && ext->offset > start + bytes_read) {
UINT32 read = (UINT32)min(length, ext->offset - max(start, last_end));
RtlZeroMemory(data + bytes_read, read);
bytes_read += read;
length -= read;
}
if (length == 0 || ext->offset > start + bytes_read + length)
break;
if (ed->encryption != BTRFS_ENCRYPTION_NONE) {
WARN("Encryption not supported\n");
Status = STATUS_NOT_IMPLEMENTED;
goto exit;
}
if (ed->encoding != BTRFS_ENCODING_NONE) {
WARN("Other encodings not supported\n");
Status = STATUS_NOT_IMPLEMENTED;
goto exit;
}
switch (ed->type) {
case EXTENT_TYPE_INLINE:
{
UINT64 off = start + bytes_read - ext->offset;
UINT32 read;
if (ed->compression == BTRFS_COMPRESSION_NONE) {
read = (UINT32)min(min(len, ext->datalen) - off, length);
RtlCopyMemory(data + bytes_read, &ed->data[off], read);
} else if (ed->compression == BTRFS_COMPRESSION_ZLIB || ed->compression == BTRFS_COMPRESSION_LZO) {
UINT8* decomp;
BOOL decomp_alloc;
UINT16 inlen = ext->datalen - (UINT16)offsetof(EXTENT_DATA, data[0]);
if (ed->decoded_size == 0 || ed->decoded_size > 0xffffffff) {
ERR("ed->decoded_size was invalid (%llx)\n", ed->decoded_size);
Status = STATUS_INTERNAL_ERROR;
goto exit;
}
read = (UINT32)min(ed->decoded_size - off, length);
if (off > 0) {
decomp = ExAllocatePoolWithTag(NonPagedPool, (UINT32)ed->decoded_size, ALLOC_TAG);
if (!decomp) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
decomp_alloc = TRUE;
} else {
decomp = data + bytes_read;
decomp_alloc = FALSE;
}
if (ed->compression == BTRFS_COMPRESSION_ZLIB) {
Status = zlib_decompress(ed->data, inlen, decomp, (UINT32)(read + off));
if (!NT_SUCCESS(Status)) {
ERR("zlib_decompress returned %08x\n", Status);
if (decomp_alloc) ExFreePool(decomp);
goto exit;
}
} else if (ed->compression == BTRFS_COMPRESSION_LZO) {
if (inlen < sizeof(UINT32)) {
ERR("extent data was truncated\n");
Status = STATUS_INTERNAL_ERROR;
if (decomp_alloc) ExFreePool(decomp);
goto exit;
} else
inlen -= sizeof(UINT32);
Status = lzo_decompress(ed->data + sizeof(UINT32), inlen, decomp, (UINT32)(read + off), sizeof(UINT32));
if (!NT_SUCCESS(Status)) {
ERR("lzo_decompress returned %08x\n", Status);
if (decomp_alloc) ExFreePool(decomp);
goto exit;
}
}
if (decomp_alloc) {
RtlCopyMemory(data + bytes_read, decomp + off, read);
ExFreePool(decomp);
}
} else {
ERR("unhandled compression type %x\n", ed->compression);
Status = STATUS_NOT_IMPLEMENTED;
goto exit;
}
bytes_read += read;
length -= read;
break;
}
case EXTENT_TYPE_REGULAR:
{
UINT64 off = start + bytes_read - ext->offset;
UINT32 to_read, read;
UINT8* buf;
BOOL mdl = (Irp && Irp->MdlAddress) ? TRUE : FALSE;
BOOL buf_free;
UINT32 bumpoff = 0, *csum;
UINT64 addr;
chunk* c;
read = (UINT32)(len - off);
if (read > length) read = (UINT32)length;
if (ed->compression == BTRFS_COMPRESSION_NONE) {
addr = ed2->address + ed2->offset + off;
to_read = (UINT32)sector_align(read, fcb->Vcb->superblock.sector_size);
if (addr % fcb->Vcb->superblock.sector_size > 0) {
bumpoff = addr % fcb->Vcb->superblock.sector_size;
addr -= bumpoff;
to_read = (UINT32)sector_align(read + bumpoff, fcb->Vcb->superblock.sector_size);
}
} else {
addr = ed2->address;
to_read = (UINT32)sector_align(ed2->size, fcb->Vcb->superblock.sector_size);
}
if (ed->compression == BTRFS_COMPRESSION_NONE && start % fcb->Vcb->superblock.sector_size == 0 &&
length % fcb->Vcb->superblock.sector_size == 0) {
buf = data + bytes_read;
buf_free = FALSE;
} else {
buf = ExAllocatePoolWithTag(PagedPool, to_read, ALLOC_TAG);
buf_free = TRUE;
if (!buf) {
ERR("out of memory\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
mdl = FALSE;
}
c = get_chunk_from_address(fcb->Vcb, addr);
if (!c) {
ERR("get_chunk_from_address(%llx) failed\n", addr);
if (buf_free)
ExFreePool(buf);
goto exit;
}
if (ext->csum) {
if (ed->compression == BTRFS_COMPRESSION_NONE)
csum = &ext->csum[off / fcb->Vcb->superblock.sector_size];
else
csum = ext->csum;
} else
csum = NULL;
Status = read_data(fcb->Vcb, addr, to_read, csum, FALSE, buf, c, NULL, Irp, 0, mdl,
fcb && fcb->Header.Flags2 & FSRTL_FLAG2_IS_PAGING_FILE ? HighPagePriority : NormalPagePriority);
if (!NT_SUCCESS(Status)) {
ERR("read_data returned %08x\n", Status);
if (buf_free)
ExFreePool(buf);
goto exit;
}
if (ed->compression == BTRFS_COMPRESSION_NONE) {
if (buf_free)
RtlCopyMemory(data + bytes_read, buf + bumpoff, read);
} else {
UINT8 *decomp = NULL, *buf2;
ULONG outlen, inlen, off2;
UINT32 inpageoff = 0;
off2 = (ULONG)(ed2->offset + off);
buf2 = buf;
inlen = (ULONG)ed2->size;
if (ed->compression == BTRFS_COMPRESSION_LZO) {
ULONG inoff = sizeof(UINT32);
inlen -= sizeof(UINT32);
// If reading a few sectors in, skip to the interesting bit
while (off2 > LINUX_PAGE_SIZE) {
UINT32 partlen;
if (inlen < sizeof(UINT32))
break;
partlen = *(UINT32*)(buf2 + inoff);
if (partlen < inlen) {
off2 -= LINUX_PAGE_SIZE;
inoff += partlen + sizeof(UINT32);
inlen -= partlen + sizeof(UINT32);
if (LINUX_PAGE_SIZE - (inoff % LINUX_PAGE_SIZE) < sizeof(UINT32))
inoff = ((inoff / LINUX_PAGE_SIZE) + 1) * LINUX_PAGE_SIZE;
} else
break;
}
buf2 = &buf2[inoff];
inpageoff = inoff % LINUX_PAGE_SIZE;
}
if (off2 != 0) {
outlen = off2 + min(read, (UINT32)(ed2->num_bytes - off));
decomp = ExAllocatePoolWithTag(PagedPool, outlen, ALLOC_TAG);
if (!decomp) {
ERR("out of memory\n");
ExFreePool(buf);
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
} else
outlen = min(read, (UINT32)(ed2->num_bytes - off));
if (ed->compression == BTRFS_COMPRESSION_ZLIB) {
Status = zlib_decompress(buf2, inlen, decomp ? decomp : (data + bytes_read), outlen);
if (!NT_SUCCESS(Status)) {
ERR("zlib_decompress returned %08x\n", Status);
ExFreePool(buf);
if (decomp)
ExFreePool(decomp);
goto exit;
}
} else if (ed->compression == BTRFS_COMPRESSION_LZO) {
Status = lzo_decompress(buf2, inlen, decomp ? decomp : (data + bytes_read), outlen, inpageoff);
if (!NT_SUCCESS(Status)) {
ERR("lzo_decompress returned %08x\n", Status);
ExFreePool(buf);
if (decomp)
ExFreePool(decomp);
goto exit;
}
} else {
ERR("unsupported compression type %x\n", ed->compression);
Status = STATUS_NOT_SUPPORTED;
ExFreePool(buf);
if (decomp)
ExFreePool(decomp);
goto exit;
}
if (decomp) {
RtlCopyMemory(data + bytes_read, decomp + off2, (size_t)min(read, ed2->num_bytes - off));
ExFreePool(decomp);
}
}
if (buf_free)
ExFreePool(buf);
bytes_read += read;
length -= read;
break;
}
case EXTENT_TYPE_PREALLOC:
{
UINT64 off = start + bytes_read - ext->offset;
UINT32 read = (UINT32)(len - off);
if (read > length) read = (UINT32)length;
RtlZeroMemory(data + bytes_read, read);
bytes_read += read;
length -= read;
break;
}
default:
WARN("Unsupported extent data type %u\n", ed->type);
Status = STATUS_NOT_IMPLEMENTED;
goto exit;
}
last_end = ext->offset + len;
if (length == 0)
break;
}
nextitem:
le = le->Flink;
}
if (length > 0 && start + bytes_read < fcb->inode_item.st_size) {
UINT32 read = (UINT32)min(fcb->inode_item.st_size - start - bytes_read, length);
RtlZeroMemory(data + bytes_read, read);
bytes_read += read;
length -= read;
}
Status = STATUS_SUCCESS;
if (pbr)
*pbr = bytes_read;
#ifdef DEBUG_STATS
time2 = KeQueryPerformanceCounter(NULL);
fcb->Vcb->stats.num_reads++;
fcb->Vcb->stats.data_read += bytes_read;
fcb->Vcb->stats.read_total_time += time2.QuadPart - time1.QuadPart;
#endif
exit:
return Status;
}
NTSTATUS do_read(PIRP Irp, BOOLEAN wait, ULONG* bytes_read) {
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
PFILE_OBJECT FileObject = IrpSp->FileObject;
fcb* fcb = FileObject->FsContext;
UINT8* data = NULL;
ULONG length = IrpSp->Parameters.Read.Length, addon = 0;
UINT64 start = IrpSp->Parameters.Read.ByteOffset.QuadPart;
*bytes_read = 0;
if (!fcb || !fcb->Vcb || !fcb->subvol)
return STATUS_INTERNAL_ERROR;
TRACE("file = %S (fcb = %p)\n", file_desc(FileObject), fcb);
TRACE("offset = %llx, length = %x\n", start, length);
TRACE("paging_io = %s, no cache = %s\n", Irp->Flags & IRP_PAGING_IO ? "TRUE" : "FALSE", Irp->Flags & IRP_NOCACHE ? "TRUE" : "FALSE");
if (!fcb->ads && fcb->type == BTRFS_TYPE_DIRECTORY)
return STATUS_INVALID_DEVICE_REQUEST;
if (!(Irp->Flags & IRP_PAGING_IO) && !FsRtlCheckLockForReadAccess(&fcb->lock, Irp)) {
WARN("tried to read locked region\n");
return STATUS_FILE_LOCK_CONFLICT;
}
if (length == 0) {
TRACE("tried to read zero bytes\n");
return STATUS_SUCCESS;
}
if (start >= (UINT64)fcb->Header.FileSize.QuadPart) {
TRACE("tried to read with offset after file end (%llx >= %llx)\n", start, fcb->Header.FileSize.QuadPart);
return STATUS_END_OF_FILE;
}
TRACE("FileObject %p fcb %p FileSize = %llx st_size = %llx (%p)\n", FileObject, fcb, fcb->Header.FileSize.QuadPart, fcb->inode_item.st_size, &fcb->inode_item.st_size);
if (Irp->Flags & IRP_NOCACHE || !(IrpSp->MinorFunction & IRP_MN_MDL)) {
data = map_user_buffer(Irp, fcb->Header.Flags2 & FSRTL_FLAG2_IS_PAGING_FILE ? HighPagePriority : NormalPagePriority);
if (Irp->MdlAddress && !data) {
ERR("MmGetSystemAddressForMdlSafe returned NULL\n");
return STATUS_INSUFFICIENT_RESOURCES;
}
if (start >= (UINT64)fcb->Header.ValidDataLength.QuadPart) {
length = (ULONG)min(length, min(start + length, (UINT64)fcb->Header.FileSize.QuadPart) - fcb->Header.ValidDataLength.QuadPart);
RtlZeroMemory(data, length);
Irp->IoStatus.Information = *bytes_read = length;
return STATUS_SUCCESS;
}
if (length + start > (UINT64)fcb->Header.ValidDataLength.QuadPart) {
addon = (ULONG)(min(start + length, (UINT64)fcb->Header.FileSize.QuadPart) - fcb->Header.ValidDataLength.QuadPart);
RtlZeroMemory(data + (fcb->Header.ValidDataLength.QuadPart - start), addon);
length = (ULONG)(fcb->Header.ValidDataLength.QuadPart - start);
}
}
if (!(Irp->Flags & IRP_NOCACHE)) {
NTSTATUS Status = STATUS_SUCCESS;
_SEH2_TRY {
if (!FileObject->PrivateCacheMap) {
CC_FILE_SIZES ccfs;
ccfs.AllocationSize = fcb->Header.AllocationSize;
ccfs.FileSize = fcb->Header.FileSize;
ccfs.ValidDataLength = fcb->Header.ValidDataLength;
init_file_cache(FileObject, &ccfs);
}
if (IrpSp->MinorFunction & IRP_MN_MDL) {
CcMdlRead(FileObject,&IrpSp->Parameters.Read.ByteOffset, length, &Irp->MdlAddress, &Irp->IoStatus);
} else {
if (fCcCopyReadEx) {
TRACE("CcCopyReadEx(%p, %llx, %x, %u, %p, %p, %p, %p)\n", FileObject, IrpSp->Parameters.Read.ByteOffset.QuadPart,
length, wait, data, &Irp->IoStatus, Irp->Tail.Overlay.Thread);
TRACE("sizes = %llx, %llx, %llx\n", fcb->Header.AllocationSize, fcb->Header.FileSize, fcb->Header.ValidDataLength);
if (!fCcCopyReadEx(FileObject, &IrpSp->Parameters.Read.ByteOffset, length, wait, data, &Irp->IoStatus, Irp->Tail.Overlay.Thread)) {
TRACE("CcCopyReadEx could not wait\n");
IoMarkIrpPending(Irp);
return STATUS_PENDING;
}
TRACE("CcCopyReadEx finished\n");
} else {
TRACE("CcCopyRead(%p, %llx, %x, %u, %p, %p)\n", FileObject, IrpSp->Parameters.Read.ByteOffset.QuadPart, length, wait, data, &Irp->IoStatus);
TRACE("sizes = %llx, %llx, %llx\n", fcb->Header.AllocationSize, fcb->Header.FileSize, fcb->Header.ValidDataLength);
if (!CcCopyRead(FileObject, &IrpSp->Parameters.Read.ByteOffset, length, wait, data, &Irp->IoStatus)) {
TRACE("CcCopyRead could not wait\n");
IoMarkIrpPending(Irp);
return STATUS_PENDING;
}
TRACE("CcCopyRead finished\n");
}
}
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (NT_SUCCESS(Status)) {
Status = Irp->IoStatus.Status;
Irp->IoStatus.Information += addon;
*bytes_read = (ULONG)Irp->IoStatus.Information;
} else
ERR("EXCEPTION - %08x\n", Status);
return Status;
} else {
NTSTATUS Status;
if (!wait) {
IoMarkIrpPending(Irp);
return STATUS_PENDING;
}
if (!(Irp->Flags & IRP_PAGING_IO) && FileObject->SectionObjectPointer->DataSectionObject) {
IO_STATUS_BLOCK iosb;
CcFlushCache(FileObject->SectionObjectPointer, &IrpSp->Parameters.Read.ByteOffset, length, &iosb);
if (!NT_SUCCESS(iosb.Status)) {
ERR("CcFlushCache returned %08x\n", iosb.Status);
return iosb.Status;
}
}
if (fcb->ads)
Status = read_stream(fcb, data, start, length, bytes_read);
else
Status = read_file(fcb, data, start, length, bytes_read, Irp);
*bytes_read += addon;
TRACE("read %u bytes\n", *bytes_read);
Irp->IoStatus.Information = *bytes_read;
if (diskacc && Status != STATUS_PENDING) {
PETHREAD thread = NULL;
if (Irp->Tail.Overlay.Thread && !IoIsSystemThread(Irp->Tail.Overlay.Thread))
thread = Irp->Tail.Overlay.Thread;
else if (!IoIsSystemThread(PsGetCurrentThread()))
thread = PsGetCurrentThread();
else if (IoIsSystemThread(PsGetCurrentThread()) && IoGetTopLevelIrp() == Irp)
thread = PsGetCurrentThread();
if (thread)
fPsUpdateDiskCounters(PsGetThreadProcess(thread), *bytes_read, 0, 1, 0, 0);
}
return Status;
}
}
_Dispatch_type_(IRP_MJ_READ)
_Function_class_(DRIVER_DISPATCH)
NTSTATUS drv_read(PDEVICE_OBJECT DeviceObject, PIRP Irp) {
device_extension* Vcb = DeviceObject->DeviceExtension;
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
PFILE_OBJECT FileObject = IrpSp->FileObject;
ULONG bytes_read = 0;
NTSTATUS Status;
BOOL top_level;
fcb* fcb;
ccb* ccb;
BOOLEAN fcb_lock = FALSE, wait;
FsRtlEnterFileSystem();
top_level = is_top_level(Irp);
TRACE("read\n");
if (Vcb && Vcb->type == VCB_TYPE_VOLUME) {
Status = vol_read(DeviceObject, Irp);
goto exit2;
} else if (!Vcb || Vcb->type != VCB_TYPE_FS) {
Status = STATUS_INVALID_PARAMETER;
goto end;
}
Irp->IoStatus.Information = 0;
if (IrpSp->MinorFunction & IRP_MN_COMPLETE) {
CcMdlReadComplete(IrpSp->FileObject, Irp->MdlAddress);
Irp->MdlAddress = NULL;
Status = STATUS_SUCCESS;
goto exit;
}
fcb = FileObject->FsContext;
if (!fcb) {
ERR("fcb was NULL\n");
Status = STATUS_INVALID_PARAMETER;
goto exit;
}
ccb = FileObject->FsContext2;
if (!ccb) {
ERR("ccb was NULL\n");
Status = STATUS_INVALID_PARAMETER;
goto exit;
}
if (Irp->RequestorMode == UserMode && !(ccb->access & FILE_READ_DATA)) {
WARN("insufficient privileges\n");
Status = STATUS_ACCESS_DENIED;
goto exit;
}
if (fcb == Vcb->volume_fcb) {
TRACE("reading volume FCB\n");
IoSkipCurrentIrpStackLocation(Irp);
Status = IoCallDriver(Vcb->Vpb->RealDevice, Irp);
goto exit2;
}
wait = IoIsOperationSynchronous(Irp);
// Don't offload jobs when doing paging IO - otherwise this can lead to
// deadlocks in CcCopyRead.
if (Irp->Flags & IRP_PAGING_IO)
wait = TRUE;
if (!ExIsResourceAcquiredSharedLite(fcb->Header.Resource)) {
if (!ExAcquireResourceSharedLite(fcb->Header.Resource, wait)) {
Status = STATUS_PENDING;
IoMarkIrpPending(Irp);
goto exit;
}
fcb_lock = TRUE;
}
Status = do_read(Irp, wait, &bytes_read);
if (fcb_lock)
ExReleaseResourceLite(fcb->Header.Resource);
exit:
if (FileObject->Flags & FO_SYNCHRONOUS_IO && !(Irp->Flags & IRP_PAGING_IO))
FileObject->CurrentByteOffset.QuadPart = IrpSp->Parameters.Read.ByteOffset.QuadPart + (NT_SUCCESS(Status) ? bytes_read : 0);
end:
Irp->IoStatus.Status = Status;
TRACE("Irp->IoStatus.Status = %08x\n", Irp->IoStatus.Status);
TRACE("Irp->IoStatus.Information = %lu\n", Irp->IoStatus.Information);
TRACE("returning %08x\n", Status);
if (Status != STATUS_PENDING)
IoCompleteRequest(Irp, IO_NO_INCREMENT);
else {
if (!add_thread_job(Vcb, Irp))
do_read_job(Irp);
}
exit2:
if (top_level)
IoSetTopLevelIrp(NULL);
FsRtlExitFileSystem();
return Status;
}
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