diff options
| -rw-r--r-- | fs/jbd2/checkpoint.c | 195 |
1 files changed, 84 insertions, 111 deletions
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c index 7f34f4716165..f1507e5b7c9a 100644 --- a/fs/jbd2/checkpoint.c +++ b/fs/jbd2/checkpoint.c @@ -255,81 +255,6 @@ __flush_batch(journal_t *journal, int *batch_count) } /* - * Try to flush one buffer from the checkpoint list to disk. - * - * Return 1 if something happened which requires us to abort the current - * scan of the checkpoint list. Return <0 if the buffer has failed to - * be written out. - * - * Called with j_list_lock held and drops it if 1 is returned - */ -static int __process_buffer(journal_t *journal, struct journal_head *jh, - int *batch_count, transaction_t *transaction) -{ - struct buffer_head *bh = jh2bh(jh); - int ret = 0; - - if (buffer_locked(bh)) { - get_bh(bh); - spin_unlock(&journal->j_list_lock); - wait_on_buffer(bh); - /* the journal_head may have gone by now */ - BUFFER_TRACE(bh, "brelse"); - __brelse(bh); - ret = 1; - } else if (jh->b_transaction != NULL) { - transaction_t *t = jh->b_transaction; - tid_t tid = t->t_tid; - - transaction->t_chp_stats.cs_forced_to_close++; - spin_unlock(&journal->j_list_lock); - if (unlikely(journal->j_flags & JBD2_UNMOUNT)) - /* - * The journal thread is dead; so starting and - * waiting for a commit to finish will cause - * us to wait for a _very_ long time. - */ - printk(KERN_ERR "JBD2: %s: " - "Waiting for Godot: block %llu\n", - journal->j_devname, - (unsigned long long) bh->b_blocknr); - jbd2_log_start_commit(journal, tid); - jbd2_log_wait_commit(journal, tid); - ret = 1; - } else if (!buffer_dirty(bh)) { - ret = 1; - if (unlikely(buffer_write_io_error(bh))) - ret = -EIO; - get_bh(bh); - BUFFER_TRACE(bh, "remove from checkpoint"); - __jbd2_journal_remove_checkpoint(jh); - spin_unlock(&journal->j_list_lock); - __brelse(bh); - } else { - /* - * Important: we are about to write the buffer, and - * possibly block, while still holding the journal lock. - * We cannot afford to let the transaction logic start - * messing around with this buffer before we write it to - * disk, as that would break recoverability. - */ - BUFFER_TRACE(bh, "queue"); - get_bh(bh); - J_ASSERT_BH(bh, !buffer_jwrite(bh)); - journal->j_chkpt_bhs[*batch_count] = bh; - __buffer_relink_io(jh); - transaction->t_chp_stats.cs_written++; - (*batch_count)++; - if (*batch_count == JBD2_NR_BATCH) { - spin_unlock(&journal->j_list_lock); - __flush_batch(journal, batch_count); - ret = 1; - } - } - return ret; -} - -/* * Perform an actual checkpoint. We take the first transaction on the * list of transactions to be checkpointed and send all its buffers * to disk. We submit larger chunks of data at once. @@ -339,9 +264,11 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh, */ int jbd2_log_do_checkpoint(journal_t *journal) { - transaction_t *transaction; - tid_t this_tid; - int result; + struct journal_head *jh; + struct buffer_head *bh; + transaction_t *transaction; + tid_t this_tid; + int err, result, batch_count = 0; jbd_debug(1, "Start checkpoint\n"); @@ -374,46 +301,92 @@ restart: * done (maybe it's a new transaction, but it fell at the same * address). */ - if (journal->j_checkpoint_transactions == transaction && - transaction->t_tid == this_tid) { - int batch_count = 0; - struct journal_head *jh; - int retry = 0, err; - - while (!retry && transaction->t_checkpoint_list) { - jh = transaction->t_checkpoint_list; - retry = __process_buffer(journal, jh, &batch_count, - transaction); - if (retry < 0 && !result) - result = retry; - if (!retry && (need_resched() || - spin_needbreak(&journal->j_list_lock))) { - spin_unlock(&journal->j_list_lock); - retry = 1; - break; - } - } + if (journal->j_checkpoint_transactions != transaction || + transaction->t_tid != this_tid) + goto out; - if (batch_count) { - if (!retry) { - spin_unlock(&journal->j_list_lock); - retry = 1; - } - __flush_batch(journal, &batch_count); + /* checkpoint all of the transaction's buffers */ + while (transaction->t_checkpoint_list) { + jh = transaction->t_checkpoint_list; + bh = jh2bh(jh); + + if (buffer_locked(bh)) { + spin_unlock(&journal->j_list_lock); + get_bh(bh); + wait_on_buffer(bh); + /* the journal_head may have gone by now */ + BUFFER_TRACE(bh, "brelse"); + __brelse(bh); + goto retry; } + if (jh->b_transaction != NULL) { + transaction_t *t = jh->b_transaction; + tid_t tid = t->t_tid; - if (retry) { - spin_lock(&journal->j_list_lock); - goto restart; + transaction->t_chp_stats.cs_forced_to_close++; + spin_unlock(&journal->j_list_lock); + if (unlikely(journal->j_flags & JBD2_UNMOUNT)) + /* + * The journal thread is dead; so + * starting and waiting for a commit + * to finish will cause us to wait for + * a _very_ long time. + */ + printk(KERN_ERR + "JBD2: %s: Waiting for Godot: block %llu\n", + journal->j_devname, (unsigned long long) bh->b_blocknr); + + jbd2_log_start_commit(journal, tid); + jbd2_log_wait_commit(journal, tid); + goto retry; + } + if (!buffer_dirty(bh)) { + if (unlikely(buffer_write_io_error(bh)) && !result) + result = -EIO; + get_bh(bh); + BUFFER_TRACE(bh, "remove from checkpoint"); + __jbd2_journal_remove_checkpoint(jh); + spin_unlock(&journal->j_list_lock); + __brelse(bh); + goto retry; } /* - * Now we have cleaned up the first transaction's checkpoint - * list. Let's clean up the second one + * Important: we are about to write the buffer, and + * possibly block, while still holding the journal + * lock. We cannot afford to let the transaction + * logic start messing around with this buffer before + * we write it to disk, as that would break + * recoverability. */ - err = __wait_cp_io(journal, transaction); - if (!result) - result = err; + BUFFER_TRACE(bh, "queue"); + get_bh(bh); + J_ASSERT_BH(bh, !buffer_jwrite(bh)); + journal->j_chkpt_bhs[batch_count++] = bh; + __buffer_relink_io(jh); + transaction->t_chp_stats.cs_written++; + if ((batch_count == JBD2_NR_BATCH) || + need_resched() || + spin_needbreak(&journal->j_list_lock)) + goto unlock_and_flush; } + + if (batch_count) { + unlock_and_flush: + spin_unlock(&journal->j_list_lock); + retry: + if (batch_count) + __flush_batch(journal, &batch_count); + spin_lock(&journal->j_list_lock); + goto restart; + } + + /* + * Now we issued all of the transaction's buffers, let's deal + * with the buffers that are out for I/O. + */ + err = __wait_cp_io(journal, transaction); + if (!result) + result = err; out: spin_unlock(&journal->j_list_lock); if (result < 0) |