I hereby relicense all my work on Sortix under the ISC license as below. All Sortix contributions by other people are already under this license, are not substantial enough to be copyrightable, or have been removed. All imported code from other projects is compatible with this license. All GPL licensed code from other projects had previously been removed. Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors. Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
278 lines
8.4 KiB
C++
278 lines
8.4 KiB
C++
/*
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* Copyright (c) 2013, 2014, 2015 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* filesystem.cpp
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* Filesystem.
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*/
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#include <sys/types.h>
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#include <assert.h>
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#include <errno.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <string.h>
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#include <time.h>
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#include "ext-constants.h"
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#include "ext-structs.h"
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#include "block.h"
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#include "blockgroup.h"
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#include "device.h"
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#include "filesystem.h"
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#include "inode.h"
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#include "util.h"
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Filesystem::Filesystem(Device* device, const char* mount_path)
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{
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uint64_t sb_offset = 1024;
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uint32_t sb_block_id = sb_offset / device->block_size;
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this->sb_block = device->GetBlock(sb_block_id);
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assert(sb_block); // TODO: This can fail.
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this->sb = (struct ext_superblock*)
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(sb_block->block_data + sb_offset % device->block_size);
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this->device = device;
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this->block_groups = NULL;
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this->mount_path = mount_path;
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this->block_size = device->block_size;
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this->inode_size = this->sb->s_inode_size;
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this->num_blocks = this->sb->s_blocks_count;
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this->num_groups = divup(this->sb->s_blocks_count, this->sb->s_blocks_per_group);
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this->num_inodes = this->sb->s_inodes_count;
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this->mru_inode = NULL;
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this->lru_inode = NULL;
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this->dirty_inode = NULL;
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for ( size_t i = 0; i < INODE_HASH_LENGTH; i++ )
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this->hash_inodes[i] = NULL;
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struct timespec now_realtime, now_monotonic;
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clock_gettime(CLOCK_REALTIME, &now_realtime);
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clock_gettime(CLOCK_MONOTONIC, &now_monotonic);
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this->mtime_realtime = now_realtime.tv_sec;
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this->mtime_monotonic = now_monotonic.tv_sec;
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this->dirty = false;
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if ( device->write )
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{
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BeginWrite();
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sb->s_mtime = mtime_realtime;
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sb->s_mnt_count++;
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sb->s_state = EXT2_ERROR_FS;
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// TODO: Remove this temporarily compatibility when this driver is moved
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// into the kernel and the the FUSE frontend is removed.
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#ifdef __GLIBC__
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strncpy(sb->s_last_mounted, mount_path, sizeof(sb->s_last_mounted));
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#else
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strlcpy(sb->s_last_mounted, mount_path, sizeof(sb->s_last_mounted));
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#endif
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FinishWrite();
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Sync();
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}
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}
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Filesystem::~Filesystem()
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{
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Sync();
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while ( mru_inode )
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delete mru_inode;
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for ( size_t i = 0; i < num_groups; i++ )
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delete block_groups[i];
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delete[] block_groups;
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if ( device->write )
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{
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BeginWrite();
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sb->s_state = EXT2_VALID_FS;
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FinishWrite();
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Sync();
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}
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sb_block->Unref();
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}
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void Filesystem::BeginWrite()
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{
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sb_block->BeginWrite();
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}
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void Filesystem::FinishWrite()
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{
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dirty = true;
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sb_block->FinishWrite();
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}
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void Filesystem::Sync()
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{
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while ( dirty_inode )
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dirty_inode->Sync();
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// TODO: This can be made faster by maintaining a linked list of dirty block
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// groups.
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for ( size_t i = 0; i < num_groups; i++ )
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if ( block_groups && block_groups[i] )
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block_groups[i]->Sync();
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if ( dirty )
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{
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// The correct real-time might not have been known when the filesystem
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// was mounted (perhaps during early system boot), so find out what time
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// it is now, how long ago we were mounted, and subtract to get the
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// correct mount time.
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struct timespec now_realtime, now_monotonic;
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clock_gettime(CLOCK_REALTIME, &now_realtime);
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clock_gettime(CLOCK_MONOTONIC, &now_monotonic);
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time_t since_boot = now_monotonic.tv_sec - mtime_monotonic;
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mtime_realtime = now_realtime.tv_sec - since_boot;
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sb->s_wtime = now_realtime.tv_sec;
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sb->s_mtime = mtime_realtime;
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sb_block->Sync();
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dirty = false;
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}
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device->Sync();
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}
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BlockGroup* Filesystem::GetBlockGroup(uint32_t group_id)
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{
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assert(group_id < num_groups);
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if ( block_groups[group_id] )
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return block_groups[group_id]->Refer(), block_groups[group_id];
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size_t group_size = sizeof(ext_blockgrpdesc);
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uint32_t first_block_id = sb->s_first_data_block + 1 /* superblock */;
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uint32_t block_id = first_block_id + (group_id * group_size) / block_size;
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uint32_t offset = (group_id * group_size) % block_size;
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Block* block = device->GetBlock(block_id);
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if ( !block )
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return (BlockGroup*) NULL;
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BlockGroup* group = new BlockGroup(this, group_id);
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if ( !group ) // TODO: Use operator new nothrow!
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return block->Unref(), (BlockGroup*) NULL;
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group->data_block = block;
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uint8_t* buf = group->data_block->block_data + offset;
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group->data = (struct ext_blockgrpdesc*) buf;
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return block_groups[group_id] = group;
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}
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Inode* Filesystem::GetInode(uint32_t inode_id)
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{
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if ( !inode_id || num_inodes <= inode_id )
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return errno = EBADF, (Inode*) NULL;
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if ( !inode_id )
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return errno = EBADF, (Inode*) NULL;
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size_t bin = inode_id % INODE_HASH_LENGTH;
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for ( Inode* iter = hash_inodes[bin]; iter; iter = iter->next_hashed )
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if ( iter->inode_id == inode_id )
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return iter->Refer(), iter;
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uint32_t group_id = (inode_id-1) / sb->s_inodes_per_group;
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uint32_t tabel_index = (inode_id-1) % sb->s_inodes_per_group;
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assert(group_id < num_groups);
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BlockGroup* group = GetBlockGroup(group_id);
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if ( !group )
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return (Inode*) NULL;
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uint32_t tabel_block = group->data->bg_inode_table;
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group->Unref();
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uint32_t block_id = tabel_block + (tabel_index * inode_size) / block_size;
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uint32_t offset = (tabel_index * inode_size) % block_size;
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Block* block = device->GetBlock(block_id);
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if ( !block )
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return (Inode*) NULL;
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Inode* inode = new Inode(this, inode_id);
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if ( !inode )
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return block->Unref(), (Inode*) NULL;
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inode->data_block = block;
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uint8_t* buf = inode->data_block->block_data + offset;
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inode->data = (struct ext_inode*) buf;
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inode->Prelink();
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return inode;
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}
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uint32_t Filesystem::AllocateBlock(BlockGroup* preferred)
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{
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if ( !device->write )
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return errno = EROFS, 0;
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if ( !sb->s_free_blocks_count )
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return errno = ENOSPC, 0;
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if ( preferred )
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if ( uint32_t block_id = preferred->AllocateBlock() )
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return block_id;
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// TODO: This can be made faster by maintaining a linked list of block
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// groups that definitely have free blocks.
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for ( uint32_t group_id = 0; group_id < num_groups; group_id++ )
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if ( uint32_t block_id = GetBlockGroup(group_id)->AllocateBlock() )
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return block_id;
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// TODO: This case should only be fit in the event of corruption. We should
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// rebuild all these values upon filesystem mount instead so we know
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// this can't happen. That also allows us to make the linked list
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// requested above.
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BeginWrite();
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sb->s_free_blocks_count = 0;
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FinishWrite();
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return errno = ENOSPC, 0;
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}
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uint32_t Filesystem::AllocateInode(BlockGroup* preferred)
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{
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if ( !device->write )
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return errno = EROFS, 0;
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if ( !sb->s_free_inodes_count )
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return errno = ENOSPC, 0;
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if ( preferred )
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if ( uint32_t inode_id = preferred->AllocateInode() )
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return inode_id;
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// TODO: This can be made faster by maintaining a linked list of block
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// groups that definitely have free inodes.
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for ( uint32_t group_id = 0; group_id < num_groups; group_id++ )
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if ( uint32_t inode_id = GetBlockGroup(group_id)->AllocateInode() )
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return inode_id;
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// TODO: This case should only be fit in the event of corruption. We should
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// rebuild all these values upon filesystem mount instead so we know
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// this can't happen. That also allows us to make the linked list
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// requested above.
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BeginWrite();
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sb->s_free_inodes_count = 0;
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FinishWrite();
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return errno = ENOSPC, 0;
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}
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void Filesystem::FreeBlock(uint32_t block_id)
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{
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assert(device->write);
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assert(block_id);
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assert(block_id < num_blocks);
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uint32_t group_id = (block_id - sb->s_first_data_block) / sb->s_blocks_per_group;
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assert(group_id < num_groups);
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BlockGroup* group = GetBlockGroup(group_id);
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if ( !group )
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return;
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group->FreeBlock(block_id);
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group->Unref();
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}
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void Filesystem::FreeInode(uint32_t inode_id)
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{
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assert(device->write);
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assert(inode_id);
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assert(inode_id < num_inodes);
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uint32_t group_id = (inode_id-1) / sb->s_inodes_per_group;
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assert(group_id < num_groups);
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BlockGroup* group = GetBlockGroup(group_id);
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if ( !group )
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return;
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group->FreeInode(inode_id);
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group->Unref();
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}
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