2022-01-18 02:23:12

by Ritesh Harjani

[permalink] [raw]
Subject: [PATCHv2 5/5] jbd2: Refactor wait logic for transaction updates into a common function

No functionality change as such in this patch. This only refactors the
common piece of code which waits for t_updates to finish into a common
function named as jbd2_journal_wait_updates(journal_t *)

Signed-off-by: Ritesh Harjani <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
---
fs/jbd2/commit.c | 19 +++-------------
fs/jbd2/transaction.c | 53 ++++++++++++++++++++++++++-----------------
include/linux/jbd2.h | 4 +++-
3 files changed, 38 insertions(+), 38 deletions(-)

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 3cc4ab2ba7f4..428364f107be 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -484,22 +484,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
stats.run.rs_locked);

- spin_lock(&commit_transaction->t_handle_lock);
- while (atomic_read(&commit_transaction->t_updates)) {
- DEFINE_WAIT(wait);
+ // waits for any t_updates to finish
+ jbd2_journal_wait_updates(journal);

- prepare_to_wait(&journal->j_wait_updates, &wait,
- TASK_UNINTERRUPTIBLE);
- if (atomic_read(&commit_transaction->t_updates)) {
- spin_unlock(&commit_transaction->t_handle_lock);
- write_unlock(&journal->j_state_lock);
- schedule();
- write_lock(&journal->j_state_lock);
- spin_lock(&commit_transaction->t_handle_lock);
- }
- finish_wait(&journal->j_wait_updates, &wait);
- }
- spin_unlock(&commit_transaction->t_handle_lock);
commit_transaction->t_state = T_SWITCH;
write_unlock(&journal->j_state_lock);

@@ -817,7 +804,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
commit_transaction->t_state = T_COMMIT_DFLUSH;
write_unlock(&journal->j_state_lock);

- /*
+ /*
* If the journal is not located on the file system device,
* then we must flush the file system device before we issue
* the commit record
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 6a3caedd2285..8e2f8275a253 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -449,7 +449,7 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
}

/* OK, account for the buffers that this operation expects to
- * use and add the handle to the running transaction.
+ * use and add the handle to the running transaction.
*/
update_t_max_wait(transaction, ts);
handle->h_transaction = transaction;
@@ -836,6 +836,35 @@ int jbd2_journal_restart(handle_t *handle, int nblocks)
}
EXPORT_SYMBOL(jbd2_journal_restart);

+/*
+ * Waits for any outstanding t_updates to finish.
+ * This is called with write j_state_lock held.
+ */
+void jbd2_journal_wait_updates(journal_t *journal)
+{
+ transaction_t *commit_transaction = journal->j_running_transaction;
+
+ if (!commit_transaction)
+ return;
+
+ spin_lock(&commit_transaction->t_handle_lock);
+ while (atomic_read(&commit_transaction->t_updates)) {
+ DEFINE_WAIT(wait);
+
+ prepare_to_wait(&journal->j_wait_updates, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&commit_transaction->t_updates)) {
+ spin_unlock(&commit_transaction->t_handle_lock);
+ write_unlock(&journal->j_state_lock);
+ schedule();
+ write_lock(&journal->j_state_lock);
+ spin_lock(&commit_transaction->t_handle_lock);
+ }
+ finish_wait(&journal->j_wait_updates, &wait);
+ }
+ spin_unlock(&commit_transaction->t_handle_lock);
+}
+
/**
* jbd2_journal_lock_updates () - establish a transaction barrier.
* @journal: Journal to establish a barrier on.
@@ -863,27 +892,9 @@ void jbd2_journal_lock_updates(journal_t *journal)
write_lock(&journal->j_state_lock);
}

- /* Wait until there are no running updates */
- while (1) {
- transaction_t *transaction = journal->j_running_transaction;
-
- if (!transaction)
- break;
+ /* Wait until there are no running t_updates */
+ jbd2_journal_wait_updates(journal);

- spin_lock(&transaction->t_handle_lock);
- prepare_to_wait(&journal->j_wait_updates, &wait,
- TASK_UNINTERRUPTIBLE);
- if (!atomic_read(&transaction->t_updates)) {
- spin_unlock(&transaction->t_handle_lock);
- finish_wait(&journal->j_wait_updates, &wait);
- break;
- }
- spin_unlock(&transaction->t_handle_lock);
- write_unlock(&journal->j_state_lock);
- schedule();
- finish_wait(&journal->j_wait_updates, &wait);
- write_lock(&journal->j_state_lock);
- }
write_unlock(&journal->j_state_lock);

/*
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index f76598265896..575c3057a98a 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -594,7 +594,7 @@ struct transaction_s
*/
unsigned long t_log_start;

- /*
+ /*
* Number of buffers on the t_buffers list [j_list_lock, no locks
* needed for jbd2 thread]
*/
@@ -1538,6 +1538,8 @@ extern int jbd2_journal_flush(journal_t *journal, unsigned int flags);
extern void jbd2_journal_lock_updates (journal_t *);
extern void jbd2_journal_unlock_updates (journal_t *);

+void jbd2_journal_wait_updates(journal_t *);
+
extern journal_t * jbd2_journal_init_dev(struct block_device *bdev,
struct block_device *fs_dev,
unsigned long long start, int len, int bsize);
--
2.31.1