diff options
Diffstat (limited to 'fs/jbd2/transaction.c')
-rw-r--r-- | fs/jbd2/transaction.c | 74 |
1 files changed, 59 insertions, 15 deletions
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index f3d06174b051..6b8338ec2464 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -204,6 +204,20 @@ static int add_transaction_credits(journal_t *journal, int blocks, * attach this handle to a new transaction. */ atomic_sub(total, &t->t_outstanding_credits); + + /* + * Is the number of reserved credits in the current transaction too + * big to fit this handle? Wait until reserved credits are freed. + */ + if (atomic_read(&journal->j_reserved_credits) + total > + journal->j_max_transaction_buffers) { + read_unlock(&journal->j_state_lock); + wait_event(journal->j_wait_reserved, + atomic_read(&journal->j_reserved_credits) + total <= + journal->j_max_transaction_buffers); + return 1; + } + wait_transaction_locked(journal); return 1; } @@ -262,20 +276,24 @@ static int start_this_handle(journal_t *journal, handle_t *handle, int rsv_blocks = 0; unsigned long ts = jiffies; + if (handle->h_rsv_handle) + rsv_blocks = handle->h_rsv_handle->h_buffer_credits; + /* - * 1/2 of transaction can be reserved so we can practically handle - * only 1/2 of maximum transaction size per operation + * Limit the number of reserved credits to 1/2 of maximum transaction + * size and limit the number of total credits to not exceed maximum + * transaction size per operation. */ - if (WARN_ON(blocks > journal->j_max_transaction_buffers / 2)) { - printk(KERN_ERR "JBD2: %s wants too many credits (%d > %d)\n", - current->comm, blocks, - journal->j_max_transaction_buffers / 2); + if ((rsv_blocks > journal->j_max_transaction_buffers / 2) || + (rsv_blocks + blocks > journal->j_max_transaction_buffers)) { + printk(KERN_ERR "JBD2: %s wants too many credits " + "credits:%d rsv_credits:%d max:%d\n", + current->comm, blocks, rsv_blocks, + journal->j_max_transaction_buffers); + WARN_ON(1); return -ENOSPC; } - if (handle->h_rsv_handle) - rsv_blocks = handle->h_rsv_handle->h_buffer_credits; - alloc_transaction: if (!journal->j_running_transaction) { /* @@ -1280,8 +1298,6 @@ void jbd2_buffer_abort_trigger(struct journal_head *jh, triggers->t_abort(triggers, jh2bh(jh)); } - - /** * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata * @handle: transaction to add buffer to. @@ -1314,12 +1330,41 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) if (is_handle_aborted(handle)) return -EROFS; - journal = transaction->t_journal; - jh = jbd2_journal_grab_journal_head(bh); - if (!jh) { + if (!buffer_jbd(bh)) { ret = -EUCLEAN; goto out; } + /* + * We don't grab jh reference here since the buffer must be part + * of the running transaction. + */ + jh = bh2jh(bh); + /* + * This and the following assertions are unreliable since we may see jh + * in inconsistent state unless we grab bh_state lock. But this is + * crucial to catch bugs so let's do a reliable check until the + * lockless handling is fully proven. + */ + if (jh->b_transaction != transaction && + jh->b_next_transaction != transaction) { + jbd_lock_bh_state(bh); + J_ASSERT_JH(jh, jh->b_transaction == transaction || + jh->b_next_transaction == transaction); + jbd_unlock_bh_state(bh); + } + if (jh->b_modified == 1) { + /* If it's in our transaction it must be in BJ_Metadata list. */ + if (jh->b_transaction == transaction && + jh->b_jlist != BJ_Metadata) { + jbd_lock_bh_state(bh); + J_ASSERT_JH(jh, jh->b_transaction != transaction || + jh->b_jlist == BJ_Metadata); + jbd_unlock_bh_state(bh); + } + goto out; + } + + journal = transaction->t_journal; jbd_debug(5, "journal_head %p\n", jh); JBUFFER_TRACE(jh, "entry"); @@ -1410,7 +1455,6 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) spin_unlock(&journal->j_list_lock); out_unlock_bh: jbd_unlock_bh_state(bh); - jbd2_journal_put_journal_head(jh); out: JBUFFER_TRACE(jh, "exit"); return ret; |