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 no fast commit blocks.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@xxxxxxxxx>
---
fs/jbd2/journal.c | 12 +++++++++
fs/jbd2/recovery.c | 63 +++++++++++++++++++++++++++++++++++++++++---
include/linux/jbd2.h | 13 +++++++++
3 files changed, 84 insertions(+), 4 deletions(-)
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 14d549445418..e0684212384d 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1635,6 +1635,7 @@ 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);
@@ -1648,9 +1649,20 @@ 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);
+ if (had_fast_commit)
+ jbd2_set_feature_fast_commit(journal);
+
/* Log is no longer empty */
write_lock(&journal->j_state_lock);
journal->j_flags |= JBD2_FLUSHED;
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index a4967b27ffb6..c1f4c94ed375 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 *,
@@ -225,8 +224,12 @@ 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 +416,51 @@ 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 (journal->j_fc_replay_callback) {
+ err = journal->j_fc_replay_callback(
+ journal, bh, pass,
+ next_fc_block -
+ journal->j_first_fc);
+ 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 +518,7 @@ 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 +816,8 @@ 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 +849,11 @@ static int do_one_pass(journal_t *journal,
success = -EIO;
}
}
+
+
+ if (jbd2_has_feature_fast_commit(journal) && pass != PASS_REVOKE)
+ fc_do_one_pass(journal, info, pass);
+
if (block_error && success == 0)
success = -EIO;
return success;
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index c6a2b82de4cf..312103fc9581 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -762,6 +762,8 @@ jbd2_time_diff(unsigned long start, unsigned long end)
#define JBD2_NR_BATCH 64
+enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
+
/**
* struct journal_s - The journal_s type is the concrete type associated with
* journal_t.
@@ -1243,6 +1245,17 @@ struct journal_s
* after every commit operation.
*/
void (*j_fc_cleanup_callback)(struct journal_s *journal);
+
+ /*
+ * @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.
+ */
+ int (*j_fc_replay_callback)(struct journal_s *journal,
+ struct buffer_head *bh,
+ enum passtype pass, int off);
};
#define jbd2_might_wait_for_commit(j) \
--
2.23.0.444.g18eeb5a265-goog
