From 5b849b5f96b47d82b5a432d8b91a8ad260e1de46 Mon Sep 17 00:00:00 2001 From: Harshad Shirwadkar Date: Thu, 15 Oct 2020 13:37:58 -0700 Subject: [PATCH] jbd2: fast commit recovery path This patch adds fast commit recovery support in JBD2. Signed-off-by: Harshad Shirwadkar Link: https://lore.kernel.org/r/20201015203802.3597742-7-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o --- fs/ext4/fast_commit.c | 15 ++++++++++++++ fs/jbd2/recovery.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++---- include/linux/jbd2.h | 20 ++++++++++++++++++ 3 files changed, 88 insertions(+), 4 deletions(-) diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c index 79e947c..888d9d21 100644 --- a/fs/ext4/fast_commit.c +++ b/fs/ext4/fast_commit.c @@ -1188,8 +1188,23 @@ static void ext4_fc_cleanup(journal_t *journal, int full) trace_ext4_fc_stats(sb); } +/* + * Main recovery path entry point. + */ +static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh, + enum passtype pass, int off, tid_t expected_tid) +{ + return 0; +} + void ext4_fc_init(struct super_block *sb, journal_t *journal) { + /* + * We set replay callback even if fast commit disabled because we may + * could still have fast commit blocks that need to be replayed even if + * fast commit has now been turned off. + */ + journal->j_fc_replay_callback = ext4_fc_replay; if (!test_opt2(sb, JOURNAL_FAST_COMMIT)) return; journal->j_fc_cleanup_callback = ext4_fc_cleanup; diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index fb134c7..eb26061 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -35,7 +35,6 @@ struct recovery_info int nr_revoke_hits; }; -enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY}; static int do_one_pass(journal_t *journal, struct recovery_info *info, enum passtype pass); static int scan_revoke_records(journal_t *, struct buffer_head *, @@ -225,10 +224,51 @@ static int count_tags(journal_t *journal, struct buffer_head *bh) /* Make sure we wrap around the log correctly! */ #define wrap(journal, var) \ do { \ - if (var >= (journal)->j_last) \ - var -= ((journal)->j_last - (journal)->j_first); \ + unsigned long _wrap_last = \ + jbd2_has_feature_fast_commit(journal) ? \ + (journal)->j_fc_last : (journal)->j_last; \ + \ + if (var >= _wrap_last) \ + var -= (_wrap_last - (journal)->j_first); \ } while (0) +static int fc_do_one_pass(journal_t *journal, + struct recovery_info *info, enum passtype pass) +{ + unsigned int expected_commit_id = info->end_transaction; + unsigned long next_fc_block; + struct buffer_head *bh; + int err = 0; + + next_fc_block = journal->j_fc_first; + if (!journal->j_fc_replay_callback) + return 0; + + while (next_fc_block <= journal->j_fc_last) { + jbd_debug(3, "Fast commit replay: next block %ld", + next_fc_block); + err = jread(&bh, journal, next_fc_block); + if (err) { + jbd_debug(3, "Fast commit replay: read error"); + break; + } + + jbd_debug(3, "Processing fast commit blk with seq %d"); + err = journal->j_fc_replay_callback(journal, bh, pass, + next_fc_block - journal->j_fc_first, + expected_commit_id); + next_fc_block++; + if (err < 0 || err == JBD2_FC_REPLAY_STOP) + break; + err = 0; + } + + if (err) + jbd_debug(3, "Fast commit replay failed, err = %d\n", err); + + return err; +} + /** * jbd2_journal_recover - recovers a on-disk journal * @journal: the journal to recover @@ -472,7 +512,9 @@ static int do_one_pass(journal_t *journal, break; jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n", - next_commit_ID, next_log_block, journal->j_last); + next_commit_ID, next_log_block, + jbd2_has_feature_fast_commit(journal) ? + journal->j_fc_last : journal->j_last); /* Skip over each chunk of the transaction looking * either the next descriptor block or the final commit @@ -834,6 +876,13 @@ static int do_one_pass(journal_t *journal, success = -EIO; } } + + if (jbd2_has_feature_fast_commit(journal) && pass != PASS_REVOKE) { + err = fc_do_one_pass(journal, info, pass); + if (err) + success = err; + } + if (block_error && success == 0) success = -EIO; return success; diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index a009d9b..fb3d71a 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -751,6 +751,11 @@ jbd2_time_diff(unsigned long start, unsigned long end) #define JBD2_NR_BATCH 64 +enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY}; + +#define JBD2_FC_REPLAY_STOP 0 +#define JBD2_FC_REPLAY_CONTINUE 1 + /** * struct journal_s - The journal_s type is the concrete type associated with * journal_t. @@ -1248,6 +1253,21 @@ struct journal_s */ void (*j_fc_cleanup_callback)(struct journal_s *journal, int); + /* + * @j_fc_replay_callback: + * + * File-system specific function that performs replay of a fast + * commit. JBD2 calls this function for each fast commit block found in + * the journal. This function should return JBD2_FC_REPLAY_CONTINUE + * to indicate that the block was processed correctly and more fast + * commit replay should continue. Return value of JBD2_FC_REPLAY_STOP + * indicates the end of replay (no more blocks remaining). A negative + * return value indicates error. + */ + int (*j_fc_replay_callback)(struct journal_s *journal, + struct buffer_head *bh, + enum passtype pass, int off, + tid_t expected_commit_id); }; #define jbd2_might_wait_for_commit(j) \ -- 2.7.4