From 9f356e5a4f12008fa0df8b6385fc0ab830416e72 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 5 Nov 2019 17:44:24 +0100 Subject: jbd2: Account descriptor blocks into t_outstanding_credits Currently, journal descriptor blocks were not accounted in transaction->t_outstanding_credits and we were just leaving some slack space in the journal for them (in jbd2_log_space_left() and jbd2_space_needed()). This is making proper accounting (and reservation we want to add) of descriptor blocks difficult so switch to accounting descriptor blocks in transaction->t_outstanding_credits and just reserve the same amount of credits in t_outstanding credits for journal descriptor blocks when creating transaction. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191105164437.32602-18-jack@suse.cz Signed-off-by: Theodore Ts'o --- fs/jbd2/commit.c | 6 ++++-- fs/jbd2/journal.c | 1 + fs/jbd2/transaction.c | 20 ++++++++++++-------- include/linux/jbd2.h | 22 +++++++--------------- 4 files changed, 24 insertions(+), 25 deletions(-) diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index b67e2d0cff88..9047f8e269d0 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -560,8 +560,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) stats.run.rs_logging = jiffies; stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing, stats.run.rs_logging); - stats.run.rs_blocks = - atomic_read(&commit_transaction->t_outstanding_credits); + stats.run.rs_blocks = commit_transaction->t_nr_buffers; stats.run.rs_blocks_logged = 0; J_ASSERT(commit_transaction->t_nr_buffers <= @@ -889,6 +888,9 @@ start_journal_io: if (err) jbd2_journal_abort(journal, err); + WARN_ON_ONCE( + atomic_read(&commit_transaction->t_outstanding_credits) < 0); + /* * Now disk caches for filesystem device are flushed so we are safe to * erase checkpointed transactions from the log by updating journal diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index cc11097f1176..22b14b3ca197 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -840,6 +840,7 @@ jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type) bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); if (!bh) return NULL; + atomic_dec(&transaction->t_outstanding_credits); lock_buffer(bh); memset(bh->b_data, 0, journal->j_blocksize); header = (journal_header_t *)bh->b_data; diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index b30df011beaa..ed7cf9e62584 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -62,6 +62,17 @@ void jbd2_journal_free_transaction(transaction_t *transaction) kmem_cache_free(transaction_cache, transaction); } +/* + * We reserve t_outstanding_credits >> JBD2_CONTROL_BLOCKS_SHIFT for + * transaction descriptor blocks. + */ +#define JBD2_CONTROL_BLOCKS_SHIFT 5 + +static int jbd2_descriptor_blocks_per_trans(journal_t *journal) +{ + return journal->j_max_transaction_buffers >> JBD2_CONTROL_BLOCKS_SHIFT; +} + /* * jbd2_get_transaction: obtain a new transaction_t object. * @@ -88,6 +99,7 @@ static void jbd2_get_transaction(journal_t *journal, spin_lock_init(&transaction->t_handle_lock); atomic_set(&transaction->t_updates, 0); atomic_set(&transaction->t_outstanding_credits, + jbd2_descriptor_blocks_per_trans(journal) + atomic_read(&journal->j_reserved_credits)); atomic_set(&transaction->t_handle_count, 0); INIT_LIST_HEAD(&transaction->t_inode_list); @@ -634,14 +646,6 @@ int jbd2_journal_extend(handle_t *handle, int nblocks) goto unlock; } - if (wanted + (wanted >> JBD2_CONTROL_BLOCKS_SHIFT) > - jbd2_log_space_left(journal)) { - jbd_debug(3, "denied handle %p %d blocks: " - "insufficient log space\n", handle, nblocks); - atomic_sub(nblocks, &transaction->t_outstanding_credits); - goto unlock; - } - trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev, transaction->t_tid, handle->h_type, handle->h_line_no, diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 727ff91d7f3e..bef4f74b1ea0 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -681,8 +681,10 @@ struct transaction_s atomic_t t_updates; /* - * Number of buffers reserved for use by all handles in this transaction - * handle but not yet modified. [none] + * Number of blocks reserved for this transaction in the journal. + * This is including all credits reserved when starting transaction + * handles as well as all journal descriptor blocks needed for this + * transaction. [none] */ atomic_t t_outstanding_credits; @@ -1560,20 +1562,13 @@ static inline int jbd2_journal_has_csum_v2or3(journal_t *journal) return journal->j_chksum_driver != NULL; } -/* - * We reserve t_outstanding_credits >> JBD2_CONTROL_BLOCKS_SHIFT for - * transaction control blocks. - */ -#define JBD2_CONTROL_BLOCKS_SHIFT 5 - /* * Return the minimum number of blocks which must be free in the journal * before a new transaction may be started. Must be called under j_state_lock. */ static inline int jbd2_space_needed(journal_t *journal) { - int nblocks = journal->j_max_transaction_buffers; - return nblocks + (nblocks >> JBD2_CONTROL_BLOCKS_SHIFT); + return journal->j_max_transaction_buffers; } /* @@ -1585,11 +1580,8 @@ static inline unsigned long jbd2_log_space_left(journal_t *journal) long free = journal->j_free - 32; if (journal->j_committing_transaction) { - unsigned long committing = atomic_read(&journal-> - j_committing_transaction->t_outstanding_credits); - - /* Transaction + control blocks */ - free -= committing + (committing >> JBD2_CONTROL_BLOCKS_SHIFT); + free -= atomic_read(&journal-> + j_committing_transaction->t_outstanding_credits); } return max_t(long, free, 0); } -- cgit v1.2.3