| // Copyright 2018 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "fvm-host/format.h" |
| #include "fvm-host/fvm-info.h" |
| |
| zx_status_t FvmInfo::Reset(size_t disk_size, size_t slice_size) { |
| valid_ = false; |
| |
| if (slice_size == 0) { |
| fprintf(stderr, "Invalid slice size\n"); |
| return ZX_ERR_INVALID_ARGS; |
| } |
| |
| // Even if disk size is 0, this will default to at least FVM_BLOCK_SIZE |
| metadata_size_ = fvm::MetadataSize(disk_size, slice_size); |
| metadata_.reset(new uint8_t[metadata_size_ * 2]); |
| |
| // Clear entire primary copy of metadata |
| memset(metadata_.get(), 0, metadata_size_); |
| |
| // Superblock |
| fvm::fvm_t* sb = SuperBlock(); |
| sb->magic = FVM_MAGIC; |
| sb->version = FVM_VERSION; |
| sb->pslice_count = fvm::UsableSlicesCount(disk_size, slice_size); |
| sb->slice_size = slice_size; |
| sb->fvm_partition_size = disk_size; |
| sb->vpartition_table_size = fvm::kVPartTableLength; |
| sb->allocation_table_size = fvm::AllocTableLength(disk_size, slice_size); |
| sb->generation = 0; |
| |
| if (sb->pslice_count == 0) { |
| fprintf(stderr, "No space available for slices\n"); |
| return ZX_ERR_NO_SPACE; |
| } |
| |
| valid_ = true; |
| dirty_ = true; |
| |
| xprintf("fvm_init: Success\n"); |
| xprintf("fvm_init: Slice Count: %" PRIu64 ", size: %" PRIu64 "\n", sb->pslice_count, |
| sb->slice_size); |
| xprintf("fvm_init: Vpart offset: %zu, length: %zu\n", |
| fvm::kVPartTableOffset, fvm::kVPartTableLength); |
| xprintf("fvm_init: Atable offset: %zu, length: %zu\n", |
| fvm::kAllocTableOffset, fvm::AllocTableLength(disk_size_, slice_size_)); |
| xprintf("fvm_init: Backup meta starts at: %zu\n", |
| fvm::BackupStart(disk_size_, slice_size_)); |
| xprintf("fvm_init: Slices start at %zu, there are %zu of them\n", |
| fvm::SlicesStart(disk_size_, slice_size_), |
| fvm::UsableSlicesCount(disk_size_, slice_size_)); |
| |
| return ZX_OK; |
| } |
| |
| zx_status_t FvmInfo::Load(const fbl::unique_fd& fd, uint64_t disk_offset, uint64_t disk_size) { |
| valid_ = false; |
| |
| if (disk_size == 0) { |
| return ZX_OK; |
| } |
| |
| // For now just reset this to the fvm header size - we can grow it to the full metadata size |
| // later. |
| metadata_.reset(new uint8_t[sizeof(fvm::fvm_t)]); |
| |
| // If Container already exists, read metadata from disk. |
| // Read superblock first so we can determine if container has a different slice size. |
| ssize_t result = pread(fd.get(), metadata_.get(), sizeof(fvm::fvm_t), disk_offset); |
| if (result != static_cast<ssize_t>(sizeof(fvm::fvm_t))) { |
| fprintf(stderr, "Superblock read failed: expected %ld, actual %ld\n", |
| sizeof(fvm::fvm_t), result); |
| return ZX_ERR_IO; |
| } |
| |
| // If the image is obviously not an FVM header, bail out early. |
| // Otherwise, we go through the effort of ensuring the header is |
| // valid before using it. |
| if (SuperBlock()->magic != FVM_MAGIC) { |
| return ZX_OK; |
| } |
| |
| if (DiskSize() != disk_size) { |
| fprintf(stderr, "Disk size does not match expected"); |
| return ZX_ERR_BAD_STATE; |
| } |
| |
| // Recalculate metadata size. |
| size_t old_slice_size = SuperBlock()->slice_size; |
| size_t old_metadata_size = fvm::MetadataSize(disk_size, old_slice_size); |
| fbl::unique_ptr<uint8_t[]> old_metadata = |
| fbl::make_unique<uint8_t[]>(old_metadata_size * 2); |
| |
| // Read remainder of metadata. |
| result = pread(fd.get(), old_metadata.get(), old_metadata_size * 2, disk_offset); |
| if (result != static_cast<ssize_t>(old_metadata_size * 2)) { |
| fprintf(stderr, "Metadata read failed: expected %ld, actual %ld\n", |
| old_metadata_size * 2, result); |
| return ZX_ERR_IO; |
| } |
| |
| metadata_size_ = old_metadata_size; |
| metadata_.reset(old_metadata.release()); |
| |
| if (Validate() == ZX_OK) { |
| valid_ = true; |
| } |
| |
| return ZX_OK; |
| } |
| |
| zx_status_t FvmInfo::Validate() const { |
| const void* primary = nullptr; |
| const void* backup = reinterpret_cast<void*>( |
| reinterpret_cast<uintptr_t>(metadata_.get()) + metadata_size_); |
| zx_status_t status = fvm_validate_header(metadata_.get(), backup, metadata_size_, &primary); |
| |
| if (status != ZX_OK) { |
| fprintf(stderr, "Header validation failed with status %d\n", status); |
| return status; |
| } |
| |
| if (primary != metadata_.get()) { |
| fprintf(stderr, "Can only update FVM with valid primary as first copy\n"); |
| return ZX_ERR_NOT_SUPPORTED; |
| } |
| |
| return ZX_OK; |
| } |
| |
| zx_status_t FvmInfo::Write(const fbl::unique_fd& fd, size_t disk_offset, size_t disk_size) { |
| fvm::fvm_t* sb = SuperBlock(); |
| if (disk_size != sb->fvm_partition_size) { |
| // If disk size has changed, update and attempt to grow metadata. |
| sb->pslice_count = fvm::UsableSlicesCount(disk_size, SliceSize()); |
| sb->fvm_partition_size = disk_size; |
| sb->allocation_table_size = fvm::AllocTableLength(disk_size, SliceSize()); |
| |
| size_t new_metadata_size = fvm::MetadataSize(disk_size, SliceSize()); |
| zx_status_t status = Grow(new_metadata_size); |
| if (status != ZX_OK) { |
| return status; |
| } |
| } |
| |
| fvm_update_hash(metadata_.get(), metadata_size_); |
| |
| if (Validate() != ZX_OK) { |
| fprintf(stderr, "Metadata is invalid"); |
| return ZX_ERR_BAD_STATE; |
| } |
| |
| if (lseek(fd.get(), disk_offset, SEEK_SET) < 0) { |
| fprintf(stderr, "Error seeking disk\n"); |
| return ZX_ERR_IO; |
| } |
| |
| if (write(fd.get(), metadata_.get(), metadata_size_) != static_cast<ssize_t>(metadata_size_)) { |
| fprintf(stderr, "Error writing metadata to disk\n"); |
| return ZX_ERR_IO; |
| } |
| |
| if (write(fd.get(), metadata_.get(), metadata_size_) != static_cast<ssize_t>(metadata_size_)) { |
| fprintf(stderr, "Error writing metadata to disk\n"); |
| return ZX_ERR_IO; |
| } |
| |
| return ZX_OK; |
| } |
| |
| void FvmInfo::CheckValid() const { |
| if (!valid_) { |
| fprintf(stderr, "Error: FVM is invalid\n"); |
| exit(-1); |
| } |
| } |
| |
| zx_status_t FvmInfo::Grow(size_t new_size) { |
| if (new_size <= metadata_size_) { |
| return ZX_OK; |
| } |
| |
| xprintf("Growing metadata from %zu to %zu\n", metadata_size_, new_size); |
| fbl::unique_ptr<uint8_t[]> new_metadata(new uint8_t[new_size * 2]); |
| |
| memcpy(new_metadata.get(), metadata_.get(), metadata_size_); |
| memset(new_metadata.get() + metadata_size_, 0, new_size - metadata_size_); |
| |
| metadata_.reset(new_metadata.release()); |
| metadata_size_ = new_size; |
| return ZX_OK; |
| } |
| |
| zx_status_t FvmInfo::GrowForSlices(size_t slice_count) { |
| size_t required_size = fvm::kAllocTableOffset + (pslice_hint_ + slice_count) |
| * sizeof(fvm::slice_entry_t); |
| return Grow(required_size); |
| } |
| |
| zx_status_t FvmInfo::AllocatePartition(const fvm::partition_descriptor_t* partition, uint8_t* guid, |
| uint32_t* vpart_index) { |
| CheckValid(); |
| for (unsigned index = vpart_hint_; index < FVM_MAX_ENTRIES; index++) { |
| zx_status_t status; |
| fvm::vpart_entry_t* vpart = nullptr; |
| if ((status = GetPartition(index, &vpart)) != ZX_OK) { |
| fprintf(stderr, "Failed to retrieve partition %u\n", index); |
| return status; |
| } |
| |
| // Make sure this vpartition has not already been allocated |
| if (vpart->slices == 0) { |
| vpart->init(partition->type, guid, 0, reinterpret_cast<const char*>(partition->name), |
| partition->flags); |
| vpart_hint_ = index + 1; |
| dirty_ = true; |
| *vpart_index = index; |
| return ZX_OK; |
| } |
| } |
| |
| fprintf(stderr, "Unable to find any free partitions\n"); |
| return ZX_ERR_INTERNAL; |
| } |
| |
| zx_status_t FvmInfo::AllocateSlice(uint32_t vpart, uint32_t vslice, uint32_t* pslice) { |
| CheckValid(); |
| fvm::fvm_t* sb = SuperBlock(); |
| |
| for (uint32_t index = pslice_hint_; index <= sb->pslice_count; index++) { |
| zx_status_t status; |
| fvm::slice_entry_t* slice = nullptr; |
| if ((status = GetSlice(index, &slice)) != ZX_OK) { |
| fprintf(stderr, "Failed to retrieve slice %u\n", index); |
| return status; |
| } |
| |
| if (slice->Vpart() != FVM_SLICE_ENTRY_FREE) { |
| continue; |
| } |
| |
| pslice_hint_ = index + 1; |
| |
| fvm::vpart_entry_t* partition; |
| if ((status = GetPartition(vpart, &partition)) != ZX_OK) { |
| return status; |
| } |
| |
| slice->SetVpart(vpart); |
| slice->SetVslice(vslice); |
| partition->slices++; |
| |
| dirty_ = true; |
| *pslice = index; |
| return ZX_OK; |
| } |
| |
| fprintf(stderr, "Unable to find any free slices\n"); |
| return ZX_ERR_INTERNAL; |
| } |
| |
| zx_status_t FvmInfo::GetPartition(size_t index, fvm::vpart_entry_t** out) const { |
| CheckValid(); |
| |
| if (index < 1 || index > FVM_MAX_ENTRIES) { |
| return ZX_ERR_OUT_OF_RANGE; |
| } |
| |
| uintptr_t metadata_start = reinterpret_cast<uintptr_t>(metadata_.get()); |
| uintptr_t offset = static_cast<uintptr_t>(fvm::kVPartTableOffset + |
| index * sizeof(fvm::vpart_entry_t)); |
| *out = reinterpret_cast<fvm::vpart_entry_t*>(metadata_start + offset); |
| return ZX_OK; |
| } |
| |
| zx_status_t FvmInfo::GetSlice(size_t index, fvm::slice_entry_t** out) const { |
| CheckValid(); |
| |
| if (index < 1 || index > SuperBlock()->pslice_count) { |
| return ZX_ERR_OUT_OF_RANGE; |
| } |
| |
| uintptr_t metadata_start = reinterpret_cast<uintptr_t>(metadata_.get()); |
| uintptr_t offset = static_cast<uintptr_t>(fvm::kAllocTableOffset + |
| index * sizeof(fvm::slice_entry_t)); |
| *out = reinterpret_cast<fvm::slice_entry_t*>(metadata_start + offset); |
| return ZX_OK; |
| } |
| |
| fvm::fvm_t* FvmInfo::SuperBlock() const { |
| return static_cast<fvm::fvm_t*>((void*)metadata_.get()); |
| } |