Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7301AC6FD1D for ; Fri, 17 Mar 2023 09:10:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230274AbjCQJKO (ORCPT ); Fri, 17 Mar 2023 05:10:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231575AbjCQJJw (ORCPT ); Fri, 17 Mar 2023 05:09:52 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A73F6EB5 for ; Fri, 17 Mar 2023 02:09:34 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4PdJGx4J65z4f3jqx for ; Fri, 17 Mar 2023 17:09:29 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.170]) by APP4 (Coremail) with SMTP id gCh0CgAHcLNGLhRk8RgkFg--.44000S5; Fri, 17 Mar 2023 17:09:31 +0800 (CST) From: Zhang Yi To: linux-ext4@vger.kernel.org Cc: tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, yi.zhang@huawei.com, yi.zhang@huaweicloud.com, yukuai3@huawei.com Subject: [PATCH v4 1/2] jbd2: continue to record log between each mount Date: Fri, 17 Mar 2023 17:09:25 +0800 Message-Id: <20230317090926.4149399-2-yi.zhang@huaweicloud.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230317090926.4149399-1-yi.zhang@huaweicloud.com> References: <20230317090926.4149399-1-yi.zhang@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: gCh0CgAHcLNGLhRk8RgkFg--.44000S5 X-Coremail-Antispam: 1UD129KBjvJXoWxKF4rKryxAryUZrWDAF13Jwb_yoW3uFyxpF WkC3sxGrWkZr4UXF97JF4kJFWYqa40yFWUGryqk3Zaya15Kw1I93s7try3tFyDurnY9w10 vr18C34DGw1jka7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9m14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26r1I6r4UM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUXVWUAwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr 0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUkPEfUUUUU= X-CM-SenderInfo: d1lo6xhdqjqx5xdzvxpfor3voofrz/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Zhang Yi For a newly mounted file system, the journal committing thread always record new transactions from the start of the journal area, no matter whether the journal was clean or just has been recovered. So the logdump code in debugfs cannot dump continuous logs between each mount, it is disadvantageous to analysis corrupted file system image and locate the file system inconsistency bugs. If we get a corrupted file system in the running products and want to find out what has happened, besides lookup the system log, one effective way is to backtrack the journal log. But we may not always run e2fsck before each mount and the default fsck -a mode also cannot always checkout all inconsistencies, so it could left over some inconsistencies into the next mount until we detect it. Finally, transactions in the journal may probably discontinuous and some relatively new transactions has been covered, it becomes hard to analyse. If we could record transactions continuously between each mount, we could acquire more useful info from the journal. Like this: |Previous mount checkpointed/recovered logs|Current mount logs | |{------}{---}{--------} ... {------}| ... |{======}{========}...000000| And yes the journal area is limited and cannot record everything, the problematic transaction may also be covered even if we do this, but this is still useful for fuzzy tests and short-running products. This patch save the head blocknr in the superblock after flushing the journal or unmounting the file system, let the next mount could continue to record new transaction behind it. This change is backward compatible because the old kernel does not care about the head blocknr of the journal. It is also fine if we mount a clean old image without valid head blocknr, we fail back to set it to s_first just like before. Finally, for the case of mount an unclean file system, we could also get the journal head easily after scanning/replaying the journal, it will continue to record new transaction after the recovered transactions. Signed-off-by: Zhang Yi --- fs/jbd2/journal.c | 18 ++++++++++++++++-- fs/jbd2/recovery.c | 22 +++++++++++++++++----- include/linux/jbd2.h | 9 +++++++-- 3 files changed, 40 insertions(+), 9 deletions(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index e80c781731f8..c57ab466fc18 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1556,8 +1556,21 @@ static int journal_reset(journal_t *journal) journal->j_first = first; journal->j_last = last; - journal->j_head = journal->j_first; - journal->j_tail = journal->j_first; + if (journal->j_head != 0 && journal->j_flags & JBD2_CYCLE_RECORD) { + /* + * Disable the cycled recording mode if the journal head block + * number is not correct. + */ + if (journal->j_head < first || journal->j_head >= last) { + printk(KERN_WARNING "JBD2: Incorrect Journal head block %lu, " + "disable journal_cycle_record\n", + journal->j_head); + journal->j_head = journal->j_first; + } + } else { + journal->j_head = journal->j_first; + } + journal->j_tail = journal->j_head; journal->j_free = journal->j_last - journal->j_first; journal->j_tail_sequence = journal->j_transaction_sequence; @@ -1729,6 +1742,7 @@ static void jbd2_mark_journal_empty(journal_t *journal, blk_opf_t write_flags) sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); sb->s_start = cpu_to_be32(0); + sb->s_head = cpu_to_be32(journal->j_head); if (jbd2_has_feature_fast_commit(journal)) { /* * When journal is clean, no need to commit fast commit flag and diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index 8286a9ec122f..0184931d47f7 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -29,6 +29,7 @@ struct recovery_info { tid_t start_transaction; tid_t end_transaction; + unsigned long head_block; int nr_replays; int nr_revokes; @@ -301,11 +302,11 @@ int jbd2_journal_recover(journal_t *journal) * is always zero if, and only if, the journal was cleanly * unmounted. */ - if (!sb->s_start) { - jbd2_debug(1, "No recovery required, last transaction %d\n", - be32_to_cpu(sb->s_sequence)); + jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n", + be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head)); journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1; + journal->j_head = be32_to_cpu(sb->s_head); return 0; } @@ -324,6 +325,9 @@ int jbd2_journal_recover(journal_t *journal) /* Restart the log at the next transaction ID, thus invalidating * any existing commit records in the log. */ journal->j_transaction_sequence = ++info.end_transaction; + journal->j_head = info.head_block; + jbd2_debug(1, "JBD2: last transaction %d, head block %lu\n", + journal->j_transaction_sequence, journal->j_head); jbd2_journal_clear_revoke(journal); err2 = sync_blockdev(journal->j_fs_dev); @@ -364,6 +368,7 @@ int jbd2_journal_skip_recovery(journal_t *journal) if (err) { printk(KERN_ERR "JBD2: error %d scanning journal\n", err); ++journal->j_transaction_sequence; + journal->j_head = journal->j_first; } else { #ifdef CONFIG_JBD2_DEBUG int dropped = info.end_transaction - @@ -373,6 +378,7 @@ int jbd2_journal_skip_recovery(journal_t *journal) dropped, (dropped == 1) ? "" : "s"); #endif journal->j_transaction_sequence = ++info.end_transaction; + journal->j_head = info.head_block; } journal->j_tail = 0; @@ -462,7 +468,7 @@ static int do_one_pass(journal_t *journal, struct recovery_info *info, enum passtype pass) { unsigned int first_commit_ID, next_commit_ID; - unsigned long next_log_block; + unsigned long next_log_block, head_block; int err, success = 0; journal_superblock_t * sb; journal_header_t * tmp; @@ -485,6 +491,7 @@ static int do_one_pass(journal_t *journal, sb = journal->j_superblock; next_commit_ID = be32_to_cpu(sb->s_sequence); next_log_block = be32_to_cpu(sb->s_start); + head_block = next_log_block; first_commit_ID = next_commit_ID; if (pass == PASS_SCAN) @@ -809,6 +816,7 @@ static int do_one_pass(journal_t *journal, if (commit_time < last_trans_commit_time) goto ignore_crc_mismatch; info->end_transaction = next_commit_ID; + info->head_block = head_block; if (!jbd2_has_feature_async_commit(journal)) { journal->j_failed_commit = @@ -817,8 +825,10 @@ static int do_one_pass(journal_t *journal, break; } } - if (pass == PASS_SCAN) + if (pass == PASS_SCAN) { last_trans_commit_time = commit_time; + head_block = next_log_block; + } brelse(bh); next_commit_ID++; continue; @@ -868,6 +878,8 @@ static int do_one_pass(journal_t *journal, if (pass == PASS_SCAN) { if (!info->end_transaction) info->end_transaction = next_commit_ID; + if (!info->head_block) + info->head_block = head_block; } else { /* It's really bad news if different passes end up at * different places (but possible due to IO errors). */ diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 5962072a4b19..475f135260c9 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -265,8 +265,10 @@ typedef struct journal_superblock_s __u8 s_padding2[3]; /* 0x0054 */ __be32 s_num_fc_blks; /* Number of fast commit blocks */ -/* 0x0058 */ - __u32 s_padding[41]; + __be32 s_head; /* blocknr of head of log, only uptodate + * while the filesystem is clean */ +/* 0x005C */ + __u32 s_padding[40]; __be32 s_checksum; /* crc32c(superblock) */ /* 0x0100 */ @@ -1392,6 +1394,9 @@ JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit, FAST_COMMIT) #define JBD2_ABORT_ON_SYNCDATA_ERR 0x040 /* Abort the journal on file * data write error in ordered * mode */ +#define JBD2_CYCLE_RECORD 0x080 /* Journal cycled record log on + * clean and empty filesystem + * logging area */ #define JBD2_FAST_COMMIT_ONGOING 0x100 /* Fast commit is ongoing */ #define JBD2_FULL_COMMIT_ONGOING 0x200 /* Full commit is ongoing */ #define JBD2_JOURNAL_FLUSH_DISCARD 0x0001 -- 2.31.1