From patchwork Thu Jun 20 14:26:11 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Beno=C3=AEt_Canet?= X-Patchwork-Id: 252955 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id AE7602C00A0 for ; Fri, 21 Jun 2013 00:33:29 +1000 (EST) Received: from localhost ([::1]:53736 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UpfrU-0003b7-Pk for incoming@patchwork.ozlabs.org; Thu, 20 Jun 2013 10:29:20 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59482) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UpfoF-0005HR-RS for qemu-devel@nongnu.org; Thu, 20 Jun 2013 10:26:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Upfo7-0000Qk-O0 for qemu-devel@nongnu.org; Thu, 20 Jun 2013 10:25:59 -0400 Received: from nodalink.pck.nerim.net ([62.212.105.220]:37536 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Upfo6-0000QS-Jb for qemu-devel@nongnu.org; Thu, 20 Jun 2013 10:25:51 -0400 Received: by paradis.irqsave.net (Postfix, from userid 1002) id D7F6287466D; Thu, 20 Jun 2013 16:25:49 +0200 (CEST) Received: from localhost.localdomain (unknown [192.168.77.1]) by paradis.irqsave.net (Postfix) with ESMTP id 41D5687466E; Thu, 20 Jun 2013 16:25:00 +0200 (CEST) From: =?UTF-8?q?Beno=C3=AEt=20Canet?= To: qemu-devel@nongnu.org Date: Thu, 20 Jun 2013 16:26:11 +0200 Message-Id: <1371738392-9594-4-git-send-email-benoit@irqsave.net> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1371738392-9594-1-git-send-email-benoit@irqsave.net> References: <1371738392-9594-1-git-send-email-benoit@irqsave.net> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 62.212.105.220 Cc: kwolf@redhat.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= , stefanha@redhat.com Subject: [Qemu-devel] =?utf-8?q?=5BRFC_V8_03/24=5D_qcow2=3A_Add_journal=2E?= X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This commit add the code required to manage one or more journals in a qcow2 file. The primary user of this journal will be the qcow2-log-store.c. The journal is asynchronous and will require it's users to issue flushs in order to make sure that entries had reached stable storage. Signed-off-by: Benoit Canet --- block/Makefile.objs | 1 + block/qcow2-journal.c | 587 +++++++++++++++++++++++++++++++++++++++++++++++++ block/qcow2.h | 29 +++ 3 files changed, 617 insertions(+) create mode 100644 block/qcow2-journal.c diff --git a/block/Makefile.objs b/block/Makefile.objs index 5f0358a..ee894b5 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -1,5 +1,6 @@ block-obj-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat.o block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o +block-obj-y += qcow2-journal.o block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o block-obj-y += qed-check.o block-obj-y += vhdx.o diff --git a/block/qcow2-journal.c b/block/qcow2-journal.c new file mode 100644 index 0000000..693de37 --- /dev/null +++ b/block/qcow2-journal.c @@ -0,0 +1,587 @@ +/* + * QCOW2 journal + * + * Copyright (C) Nodalink, SARL. 2013 + * + * Author: + * Benoît Canet + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu-common.h" +#include "block/block_int.h" +#include "block/qcow2.h" + +/* This function reset the state of a journal + * + * @journal: the journal to initialize + * @sector: the on disk sector where the journal start + * @size: the size of the journal + */ +static void qcow2_journal_reset(QCowJournal *journal, + uint64_t sector, + uint64_t size) +{ + journal->sector = sector; + journal->size = size; + journal->index = 0; + /* clear write buffer */ + memset(journal->write_buf, QCOW_LOG_NONE, JOURNAL_CLUSTER_SIZE * 2); + journal->offset_in_buf = 0; + journal->flushed = true; + /* clear read cache */ + memset(journal->read_cache, QCOW_LOG_NONE, JOURNAL_CLUSTER_SIZE * 2); + /* so we will load the cache at first hit */ + journal->read_index = -1; + /* journal need to be resumed */ + journal->started = false; +} + +/* This function set the journal to the correct state after having replaying it + * + * @journal: the journal to resume + * @offset: the offset inside the journal + * @ret: 0 on success, -errno on error + */ +int qcow2_journal_resume(BlockDriverState *bs, + QCowJournal *journal, + uint64_t offset) +{ + uint64_t disk_offset; + + /* flush read cache */ + journal->read_index = -1; + + /* mark the journal as resumed */ + journal->started = true; + + /* reset state */ + journal->index = offset / JOURNAL_CLUSTER_SIZE; + journal->offset_in_buf = offset % JOURNAL_CLUSTER_SIZE; + + /* compute on disk offset of the current cluster */ + disk_offset = journal->sector * BDRV_SECTOR_SIZE + + journal->index * JOURNAL_CLUSTER_SIZE; + + /* read the current cluster in buffer */ + return bdrv_pread(bs->file, + disk_offset, + journal->write_buf, + JOURNAL_CLUSTER_SIZE); + +} + +uint64_t qcow2_journal_round_to_erase_blocks(uint64_t size) +{ + return ((size / SSD_ERASE_BLOCK_SIZE) + 1) * SSD_ERASE_BLOCK_SIZE; +} + +/* This function reset a journal content to none + * + * To be called at the end of the incarnate/freeze coroutine + * + * @journal: the QCowJournal to reset + * @in_coroutine: true if called from a coroutine + * @ret: 0 on success, -errno on error + */ +static int qcow2_journal_set_to_none(BlockDriverState *bs, + QCowJournal *journal, + bool in_coroutine) +{ + int ret = 0; + uint8_t *buf; + uint64_t i, offset; + + /* prepare buffer to erase journal */ + buf = qemu_blockalign(bs, SSD_ERASE_BLOCK_SIZE); + memset(buf, QCOW_LOG_NONE, SSD_ERASE_BLOCK_SIZE); + + /* do the erasing */ + for (i = 0; i < (journal->size / SSD_ERASE_BLOCK_SIZE); i++) { + offset = journal->sector * BDRV_SECTOR_SIZE + + i * SSD_ERASE_BLOCK_SIZE; + /* function will be called from the incarnate coroutine -> + * don't write on disk when vm is paused + */ + if (in_coroutine) { + co_sleep_ns(vm_clock, 1); + } + ret = bdrv_pwrite(bs->file, + offset, + buf, + SSD_ERASE_BLOCK_SIZE); + + if (ret < 0) { + qemu_vfree(buf); + return ret; + } + } + + qemu_vfree(buf); + return 0; +} + +/* This function is used to recycle a QCowJournal + * + * It reset it's state and buffer while keeping back the allocated on disk + * space. + * Then it clear the two first clusters. + * + * @journal: the journal to recycle + * @ret: 0 on success, -errno on error + */ +int qcow2_journal_recycle(BlockDriverState *bs, QCowJournal *journal) +{ + qcow2_journal_reset(journal, + journal->sector, + journal->size); + /* mark the journal as started */ + journal->started = true; + /* writes 0xFF so QCOW_LOG_NONE terminate the journal */ + return qcow2_journal_set_to_none(bs, journal, true); +} + +/* This function is used to allocate a journal's buffers + * + * Set sector and size to zero so the journal will be treated as unallocated + * + * @journal: the journal to initialize + */ +void qcow2_journal_init(BlockDriverState *bs, + QCowJournal *journal) +{ + journal->sector = 0; + journal->size = 0; + /* allocate extra cluster because sometime we will read an end entry + * which spill on the second cluster + */ + journal->write_buf = qemu_blockalign(bs, JOURNAL_CLUSTER_SIZE * 2); + /* allocate extra read_cache cluster to avoid read casting overflow */ + journal->read_cache = qemu_blockalign(bs, JOURNAL_CLUSTER_SIZE * 2); +} + +/* This function cleanup a journal + * + * @journal: the journal to cleanup + */ +void qcow2_journal_cleanup(QCowJournal *journal) +{ + qemu_vfree(journal->write_buf); + qemu_vfree(journal->read_cache); +} + +/* This function tell if a journal on disk space has been allocated + * + * @journal: the journal to test + * @ret: true if allocated else false + */ +bool qcow2_journal_is_allocated(QCowJournal *journal) +{ + return journal->sector; +} + +/* This function is used to allocate the on disk space of a journal + * + * @size: the on disk size of the journal + * @ret: 0 on success, -errno on error + */ +int qcow2_journal_disk_allocate(BlockDriverState *bs, + QCowJournal *journal, + uint64_t size) +{ + BDRVQcowState *s = bs->opaque; + int64_t offset; + int ret = 0; + + /* allocate journal disk space */ + offset = qcow2_alloc_clusters(bs, size); + + if (offset < 0) { + return offset; + } + + ret = qcow2_cache_flush(bs, s->refcount_block_cache); + + if (ret < 0) { + goto deallocate_exit; + } + + qcow2_journal_reset(journal, offset / BDRV_SECTOR_SIZE, size); + + ret = qcow2_journal_set_to_none(bs, journal, false); + + if (ret < 0) { + goto deallocate_exit; + } + + /* success */ + return 0; + +deallocate_exit: + qcow2_free_clusters(bs, offset, size); + return ret; +} + + +/* This function deallocate a journal disk space + * + * @journal: the journal to deallocate + */ +void qcow2_journal_disk_deallocate(BlockDriverState *bs, + QCowJournal *journal) +{ + qcow2_free_clusters(bs, + journal->sector * BDRV_SECTOR_SIZE, + journal->size); +} + +/* Add a QCOW_LOG_END entry pointing to the next cluster of the journal + * + * Note: the caller code must be sure the end entry will be written in the last + * 256 bytes of the current cluster + * + * @journal: the journal to operate on + */ +static void qcow2_journal_add_end_entry(QCowJournal *journal) +{ + QCowJournalEntry entry; + + memset(&entry, QCOW_LOG_NONE, sizeof(entry)); + entry.size = JOURNAL_CLUSTER_SIZE - journal->offset_in_buf; + entry.type = QCOW_LOG_END; + memcpy(journal->write_buf + journal->offset_in_buf, &entry, entry.size); +} + +/* Reset the journal write buffer increments counters + * + * @journal: the journal to operate on + */ +static void qcow2_journal_reset_buffer_and_inc(QCowJournal *journal) +{ + memset(journal->write_buf, QCOW_LOG_NONE, JOURNAL_CLUSTER_SIZE); + journal->offset_in_buf = 0; + journal->index++; +} + +/* This function write a journal buffer to disk + * + * note: caller code must be sure that there is at max only 256 bytes of free + * space in the buffer when deciding to end writting in this cluster + * note: this function will never return -1 (full) when end_cluster == false + * This is used to flush the current cluster. + * + * @journal: the journal to flush the buffer to disk + * @end_cluster: true if we must prepare to write in a new cluster + * @ret: 0 on success, -errno on error, -1 if journal is full + */ +static int qcow2_journal_write_buffer(BlockDriverState *bs, + QCowJournal *journal, + bool end_cluster) +{ + int ret = 0; + uint64_t offset, total_bytes; + + /* We will add a QCOW_LOG_END entry at the end of the buffer + * before writing it to disk. + * This entry will have the size required for a walk in the journal to jump + * to the next cluster. + */ + if (end_cluster) { + qcow2_journal_add_end_entry(journal); + } + + /* check if the journal is full and we are creating a new cluster */ + total_bytes = (journal->index + 1) * JOURNAL_CLUSTER_SIZE; + if (end_cluster && total_bytes >= journal->size) { + return -1; + } + + /* We write the journal buffer to disk */ + offset = journal->sector * BDRV_SECTOR_SIZE + + journal->index * JOURNAL_CLUSTER_SIZE; + ret = bdrv_pwrite(bs->file, + offset, + journal->write_buf, + JOURNAL_CLUSTER_SIZE); + + if (ret < 0) { + return ret; + } + + /* prepare the journal state to buffer a new serie of entry */ + if (end_cluster) { + qcow2_journal_reset_buffer_and_inc(journal); + } + + journal->flushed = true; + + return 0; +} + +/* This function is used to append an entry to a journal + * + * Note: Appending an entry to the journal is an asynchronous process. + * The journal must be flushed at some point to ensure that data have + * reached stable storage. + * + * @journal: the journal to append the entry to + * @entry: the journal entry to write + * @ret: offset of the entry in the journal, -errno on error, -1 if full + */ +int64_t qcow2_journal_append(BlockDriverState *bs, QCowJournal *journal, + QCowJournalEntry *entry) +{ + int ret = 0; + uint64_t entry_offset; + + assert(entry->size <= 254); + + /* check if there is room left for this entry and end entry + * regular entry size are at max 254 bytes + * QCOW_LOG_END entry takes 2 bytes and can skip 256 bytes + */ + if ((journal->offset_in_buf + entry->size + QCOW_LOG_END_SIZE) >= + JOURNAL_CLUSTER_SIZE) { + /* if not we must flush the buffer and create a new one */ + ret = qcow2_journal_write_buffer(bs, journal, true); + } + + /* error or journal full */ + if (ret < 0) { + return ret; + } + + entry_offset = journal->index * JOURNAL_CLUSTER_SIZE + + journal->offset_in_buf; + + /* write entry to the journal buffer */ + memcpy(journal->write_buf + journal->offset_in_buf, entry, entry->size); + journal->offset_in_buf += entry->size; + journal->flushed = false; + + return entry_offset; +} + +/* This function is used to read a journal entry from disk given it's offset + * + * @journal: the journal to read the entry from + * @offset: the offset of the entry in the journal + * @entry: the journal entry to read the data into + * @ret: size of the entry on success, -errno on error + */ +static int qcow2_journal_read_from_disk(BlockDriverState *bs, + QCowJournal *journal, + uint64_t offset, + QCowJournalEntry *entry) +{ + + int ret = 0; + uint64_t index; + + + index = offset / JOURNAL_CLUSTER_SIZE; + + /* If this cluster is not cached read it. + * Cache will help if we iterate, otherwise for dedup access it will be + * totally random. + */ + if (index != journal->read_index) { + uint64_t read_offset = journal->sector * BDRV_SECTOR_SIZE + + index * JOURNAL_CLUSTER_SIZE; + ret = bdrv_pread(bs->file, + read_offset, + journal->read_cache, + JOURNAL_CLUSTER_SIZE); + + if (ret < 0) { + return ret; + } + + journal->read_index = index; + } + + /* The maximum size of an entry is 254 bytes and the journal + * read_cache has an extra cluster to avoid read overflow + */ + memcpy(entry, + journal->read_cache + offset % JOURNAL_CLUSTER_SIZE, + sizeof(QCowJournalEntry)); + + return entry->size; +} + +/* This function tell if a journal entry is in the write buffer */ +static bool qcow2_journal_is_offset_in_buf(QCowJournal *journal, + uint64_t offset) +{ + return journal->index == offset / JOURNAL_CLUSTER_SIZE; +} + +/* This function read a journal entry from the write buffer */ +static int qcow2_journal_read_from_buf(QCowJournal *journal, + uint64_t offset, + QCowJournalEntry *entry) +{ + memcpy(entry, + journal->write_buf + offset % JOURNAL_CLUSTER_SIZE, + sizeof(QCowJournalEntry)); + return entry->size; +} + +/* This function is used to read a journal entry given it's offset + * + * As this function return the size of the entry just read it can be used as + * an iterator to walk in the journal. + * + * @journal: the journal to read the entry from + * @offset: the offset of the entry in the journal + * @entry: the journal entry to read the data into + * @ret: size of the entry on success, -errno on error + */ +int qcow2_journal_read(BlockDriverState *bs, QCowJournal *journal, + uint64_t offset, QCowJournalEntry *entry) +{ + if (offset >= journal->size) { + return -EFBIG; + } + + if (journal->started && + qcow2_journal_is_offset_in_buf(journal, offset)) { + return qcow2_journal_read_from_buf(journal, offset, entry); + } + + return qcow2_journal_read_from_disk(bs, journal, offset, entry); +} + +/* This function is used to flush the current journal page to disk + * + * Note: it does not issue a bdrv_flush it's up to the caller to do so. + * Note: qcow2_journal_write_buffer will never return -1 (full) when it receive + * end_cluster == false) + * + * @journal: the journal to flush + * @ret: 0 on success, -errno on error + */ +int qcow2_journal_flush(BlockDriverState *bs, QCowJournal *journal) +{ + if (journal->flushed) { + return 0; + } + + /* write the current cluster while not ending it */ + return qcow2_journal_write_buffer(bs, journal, false); +} + +/* This function flush and stop a journal + * + * @journal: the journal to stop + * @ret: 0 on success, -errno on error + */ +int qcow2_journal_stop(BlockDriverState *bs, QCowJournal *journal) +{ + int ret = 0; + + ret = qcow2_journal_flush(bs, journal); + + if (ret < 0) { + return ret; + } + + journal->started = false; + + return 0; +} + +/* This function convert a hash info to to a journal entry + * + * @entry: the already allocated destination journal entry + * @hash_info: the QCowHashInfo to take data from + */ +void qcow2_journal_entry_from_hash_info(QCowJournalEntry *entry, + QCowHashInfo *hash_info) +{ + entry->size = 2 + sizeof(QCowHashInfo); + entry->type = QCOW_LOG_HASH; + memcpy(&entry->u.hash_info, hash_info, sizeof(QCowHashInfo)); + entry->u.hash_info.physical_sect = cpu_to_be64(hash_info->physical_sect); + entry->u.hash_info.first_logical_sect = + cpu_to_be64(hash_info->first_logical_sect); +} + +/* This function convert a journal entry to a hash info + * + * @entry: the already allocated QCowHashInfo + * @hash_info: the QCowJournalEntry to take data from + * @ret: O on success, -1 on invalid entry + */ +int qcow2_hash_info_from_journal_entry(QCowHashInfo *hash_info, + QCowJournalEntry *entry) +{ + if (entry->type != QCOW_LOG_HASH) { + return -EINVAL; + } + + if (entry->size != (2 + sizeof(QCowHashInfo))) { + return -EINVAL; + } + + memcpy(hash_info, &entry->u.hash_info, sizeof(QCowHashInfo)); + hash_info->physical_sect = be64_to_cpu(hash_info->physical_sect); + hash_info->first_logical_sect = be64_to_cpu(hash_info->first_logical_sect); + + return 0; +} + +/* This function compute the size of a journal when dumped */ +size_t qcow2_journal_dump_size(void) +{ + return sizeof(uint64_t) * 2; +} + +/* This function dump the required journal information in a buffer + * + * @buf: the buffer to do the dump into + * @journal: the journal to dump + * @ret: the size of the dump + */ +size_t qcow2_journal_dump(uint8_t *buf, QCowJournal *journal) +{ + uint64_t *buf64 = (uint64_t *) buf; + + buf64[0] = cpu_to_be64(journal->sector); + buf64[1] = cpu_to_be64(journal->size); + + return qcow2_journal_dump_size(); +} + +/* This function parse a journal dump + * + * + * @journal: the journal to parse the dump into + * @buf: the buffer to read the journal info from + */ +void qcow2_journal_parse(QCowJournal *journal, uint8_t *buf) +{ + uint64_t *buf64 = (uint64_t *) buf; + + return qcow2_journal_reset(journal, + be64_to_cpu(buf64[0]), /* sector */ + be64_to_cpu(buf64[1])); /* size */ +} diff --git a/block/qcow2.h b/block/qcow2.h index 953edfe..adde631 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -606,4 +606,33 @@ int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, void **table); int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); +/* qcow2-journal.c functions */ +int qcow2_journal_resume(BlockDriverState *bs, + QCowJournal *journal, + uint64_t offset); +uint64_t qcow2_journal_round_to_erase_blocks(uint64_t size); +int qcow2_journal_recycle(BlockDriverState *bs, QCowJournal *journal); +void qcow2_journal_init(BlockDriverState *bs, + QCowJournal *journal); +void qcow2_journal_cleanup(QCowJournal *journal); +bool qcow2_journal_is_allocated(QCowJournal *journal); +int qcow2_journal_disk_allocate(BlockDriverState *bs, + QCowJournal *journal, + uint64_t size); +void qcow2_journal_disk_deallocate(BlockDriverState *bs, + QCowJournal *journal); +int64_t qcow2_journal_append(BlockDriverState *bs, QCowJournal *journal, + QCowJournalEntry *entry); +int qcow2_journal_read(BlockDriverState *bs, QCowJournal *journal, + uint64_t offset, QCowJournalEntry *entry); +int qcow2_journal_flush(BlockDriverState *bs, QCowJournal *journal); +int qcow2_journal_stop(BlockDriverState *bs, QCowJournal *journal); +void qcow2_journal_entry_from_hash_info(QCowJournalEntry *entry, + QCowHashInfo *hash_info); +int qcow2_hash_info_from_journal_entry(QCowHashInfo *hash_info, + QCowJournalEntry *entry); +size_t qcow2_journal_dump_size(void); +size_t qcow2_journal_dump(uint8_t *buf, QCowJournal *journal); +void qcow2_journal_parse(QCowJournal *journal, uint8_t *buf); + #endif