[v2,06/12] jbd2: fast-commit recovery path changes
diff mbox series

Message ID 20190809034552.148629-7-harshadshirwadkar@gmail.com
State New
Headers show
Series
  • ext4: add support fast commit
Related show

Commit Message

Harshad Shirwadkar Aug. 9, 2019, 3:45 a.m. UTC
This patch adds fast-commit recovery path changes for JBD2. If we find
a fast commit block that is valid in our recovery phase call file
system specific routine to handle that block.

We also clear the fast commit flag in jbd2_mark_journal_empty() which
is called after successful recovery as well successful
checkpointing. This allows JBD2 journal to be compatible with older
versions when there are not fast commit blocks.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

---

Changelog:

V2: Fixed checkpatch error.
---
 fs/jbd2/journal.c  | 12 ++++++++++
 fs/jbd2/recovery.c | 59 +++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 68 insertions(+), 3 deletions(-)

Comments

Andreas Dilger Aug. 9, 2019, 8:57 p.m. UTC | #1
> On Aug 8, 2019, at 9:45 PM, Harshad Shirwadkar <harshadshirwadkar@gmail.com> wrote:
> 
> This patch adds fast-commit recovery path changes for JBD2. If we find
> a fast commit block that is valid in our recovery phase call file
> system specific routine to handle that block.
> 
> We also clear the fast commit flag in jbd2_mark_journal_empty() which
> is called after successful recovery as well successful

... as well as after successful ...

> checkpointing. This allows JBD2 journal to be compatible with older
> versions when there are not fast commit blocks.
> 
> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

Reviewed-by: Andreas Dilger <adilger@dilger.ca>

> 
> ---
> 
> Changelog:
> 
> V2: Fixed checkpatch error.
> ---
> fs/jbd2/journal.c  | 12 ++++++++++
> fs/jbd2/recovery.c | 59 +++++++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 68 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index 1e15804b2c3c..ae4584a60cc3 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -1604,6 +1604,7 @@ int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
> static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
> {
> 	journal_superblock_t *sb = journal->j_superblock;
> +	bool had_fast_commit = false;
> 
> 	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
> 	lock_buffer(journal->j_sb_buffer);
> @@ -1617,6 +1618,14 @@ static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
> 
> 	sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
> 	sb->s_start    = cpu_to_be32(0);
> +	if (jbd2_has_feature_fast_commit(journal)) {
> +		/*
> +		 * When journal is clean, no need to commit fast commit flag and
> +		 * make file system incompatible with older kernels.
> +		 */
> +		jbd2_clear_feature_fast_commit(journal);
> +		had_fast_commit = true;
> +	}
> 
> 	jbd2_write_superblock(journal, write_op);
> 
> @@ -1624,6 +1633,9 @@ static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
> 	write_lock(&journal->j_state_lock);
> 	journal->j_flags |= JBD2_FLUSHED;
> 	write_unlock(&journal->j_state_lock);
> +
> +	if (had_fast_commit)
> +		jbd2_set_feature_fast_commit(journal);
> }
> 
> 
> diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
> index a4967b27ffb6..3a6cd1497504 100644
> --- a/fs/jbd2/recovery.c
> +++ b/fs/jbd2/recovery.c
> @@ -225,8 +225,12 @@ 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_last_fc : (journal)->j_last;	\
> +									\
> +	if (var >= _wrap_last)						\
> +		var -= (_wrap_last - (journal)->j_first);		\
> } while (0)
> 
> /**
> @@ -413,6 +417,49 @@ static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
> 		return tag->t_checksum == cpu_to_be16(csum32);
> }
> 
> +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;
> +	unsigned int seq;
> +	journal_header_t *jhdr;
> +	int err = 0;
> +
> +	next_fc_block = journal->j_first_fc;
> +
> +	while (next_fc_block != journal->j_last_fc) {
> +		jbd_debug(3, "Fast commit replay: next block %lld",
> +			  next_fc_block);
> +		err = jread(&bh, journal, next_fc_block);
> +		if (err)
> +			break;
> +
> +		jhdr = (journal_header_t *)bh->b_data;
> +		seq = be32_to_cpu(jhdr->h_sequence);
> +		if (be32_to_cpu(jhdr->h_magic) != JBD2_MAGIC_NUMBER ||
> +		    seq != expected_commit_id) {
> +			break;
> +		}
> +		jbd_debug(3, "Processing fast commit blk with seq %d",
> +			  seq);
> +		if (pass == PASS_REPLAY &&
> +		    journal->j_fc_replay_callback) {
> +			err = journal->j_fc_replay_callback(journal,
> +							    bh);
> +			if (err)
> +				break;
> +		}
> +		next_fc_block++;
> +	}
> +
> +	if (err)
> +		jbd_debug(3, "Fast commit replay failed, err = %d\n", err);
> +
> +	return err;
> +}
> +
> static int do_one_pass(journal_t *journal,
> 			struct recovery_info *info, enum passtype pass)
> {
> @@ -470,7 +517,7 @@ 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, journal->j_last_fc);
> 
> 		/* Skip over each chunk of the transaction looking
> 		 * either the next descriptor block or the final commit
> @@ -768,6 +815,8 @@ static int do_one_pass(journal_t *journal,
> 			if (err)
> 				goto failed;
> 			continue;
> +		case JBD2_FC_BLOCK:
> +			continue;
> 
> 		default:
> 			jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
> @@ -799,6 +848,10 @@ static int do_one_pass(journal_t *journal,
> 				success = -EIO;
> 		}
> 	}
> +
> +	if (jbd2_has_feature_fast_commit(journal) && pass == PASS_REPLAY)
> +		fc_do_one_pass(journal, info, pass);
> +
> 	if (block_error && success == 0)
> 		success = -EIO;
> 	return success;
> --
> 2.23.0.rc1.153.gdeed80330f-goog
> 


Cheers, Andreas

Patch
diff mbox series

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 1e15804b2c3c..ae4584a60cc3 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1604,6 +1604,7 @@  int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
 static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
 {
 	journal_superblock_t *sb = journal->j_superblock;
+	bool had_fast_commit = false;
 
 	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
 	lock_buffer(journal->j_sb_buffer);
@@ -1617,6 +1618,14 @@  static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
 
 	sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
 	sb->s_start    = cpu_to_be32(0);
+	if (jbd2_has_feature_fast_commit(journal)) {
+		/*
+		 * When journal is clean, no need to commit fast commit flag and
+		 * make file system incompatible with older kernels.
+		 */
+		jbd2_clear_feature_fast_commit(journal);
+		had_fast_commit = true;
+	}
 
 	jbd2_write_superblock(journal, write_op);
 
@@ -1624,6 +1633,9 @@  static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
 	write_lock(&journal->j_state_lock);
 	journal->j_flags |= JBD2_FLUSHED;
 	write_unlock(&journal->j_state_lock);
+
+	if (had_fast_commit)
+		jbd2_set_feature_fast_commit(journal);
 }
 
 
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index a4967b27ffb6..3a6cd1497504 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -225,8 +225,12 @@  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_last_fc : (journal)->j_last;	\
+									\
+	if (var >= _wrap_last)						\
+		var -= (_wrap_last - (journal)->j_first);		\
 } while (0)
 
 /**
@@ -413,6 +417,49 @@  static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
 		return tag->t_checksum == cpu_to_be16(csum32);
 }
 
+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;
+	unsigned int seq;
+	journal_header_t *jhdr;
+	int err = 0;
+
+	next_fc_block = journal->j_first_fc;
+
+	while (next_fc_block != journal->j_last_fc) {
+		jbd_debug(3, "Fast commit replay: next block %lld",
+			  next_fc_block);
+		err = jread(&bh, journal, next_fc_block);
+		if (err)
+			break;
+
+		jhdr = (journal_header_t *)bh->b_data;
+		seq = be32_to_cpu(jhdr->h_sequence);
+		if (be32_to_cpu(jhdr->h_magic) != JBD2_MAGIC_NUMBER ||
+		    seq != expected_commit_id) {
+			break;
+		}
+		jbd_debug(3, "Processing fast commit blk with seq %d",
+			  seq);
+		if (pass == PASS_REPLAY &&
+		    journal->j_fc_replay_callback) {
+			err = journal->j_fc_replay_callback(journal,
+							    bh);
+			if (err)
+				break;
+		}
+		next_fc_block++;
+	}
+
+	if (err)
+		jbd_debug(3, "Fast commit replay failed, err = %d\n", err);
+
+	return err;
+}
+
 static int do_one_pass(journal_t *journal,
 			struct recovery_info *info, enum passtype pass)
 {
@@ -470,7 +517,7 @@  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, journal->j_last_fc);
 
 		/* Skip over each chunk of the transaction looking
 		 * either the next descriptor block or the final commit
@@ -768,6 +815,8 @@  static int do_one_pass(journal_t *journal,
 			if (err)
 				goto failed;
 			continue;
+		case JBD2_FC_BLOCK:
+			continue;
 
 		default:
 			jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
@@ -799,6 +848,10 @@  static int do_one_pass(journal_t *journal,
 				success = -EIO;
 		}
 	}
+
+	if (jbd2_has_feature_fast_commit(journal) && pass == PASS_REPLAY)
+		fc_do_one_pass(journal, info, pass);
+
 	if (block_error && success == 0)
 		success = -EIO;
 	return success;