diff options
Diffstat (limited to 'fs/jbd/commit.c')
| -rw-r--r-- | fs/jbd/commit.c | 97 |
1 files changed, 79 insertions, 18 deletions
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index 8799207df058..bb217dcb41af 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -86,7 +86,12 @@ nope: static void release_data_buffer(struct buffer_head *bh) { if (buffer_freed(bh)) { + WARN_ON_ONCE(buffer_dirty(bh)); clear_buffer_freed(bh); + clear_buffer_mapped(bh); + clear_buffer_new(bh); + clear_buffer_req(bh); + bh->b_bdev = NULL; release_buffer_page(bh); } else put_bh(bh); @@ -157,8 +162,17 @@ static void journal_do_submit_data(struct buffer_head **wbuf, int bufs, for (i = 0; i < bufs; i++) { wbuf[i]->b_end_io = end_buffer_write_sync; - /* We use-up our safety reference in submit_bh() */ - submit_bh(write_op, wbuf[i]); + /* + * Here we write back pagecache data that may be mmaped. Since + * we cannot afford to clean the page and set PageWriteback + * here due to lock ordering (page lock ranks above transaction + * start), the data can change while IO is in flight. Tell the + * block layer it should bounce the bio pages if stable data + * during write is required. + * + * We use up our safety reference in submit_bh(). + */ + _submit_bh(write_op, wbuf[i], 1 << BIO_SNAP_STABLE); } } @@ -298,6 +312,7 @@ void journal_commit_transaction(journal_t *journal) int tag_flag; int i; struct blk_plug plug; + int write_op = WRITE; /* * First job: lock down the current transaction and wait for @@ -307,7 +322,16 @@ void journal_commit_transaction(journal_t *journal) /* Do we need to erase the effects of a prior journal_flush? */ if (journal->j_flags & JFS_FLUSHED) { jbd_debug(3, "super block updated\n"); - journal_update_superblock(journal, 1); + mutex_lock(&journal->j_checkpoint_mutex); + /* + * We hold j_checkpoint_mutex so tail cannot change under us. + * We don't need any special data guarantees for writing sb + * since journal is empty and it is ok for write to be + * flushed only with transaction commit. + */ + journal_update_sb_log_tail(journal, journal->j_tail_sequence, + journal->j_tail, WRITE_SYNC); + mutex_unlock(&journal->j_checkpoint_mutex); } else { jbd_debug(3, "superblock not updated\n"); } @@ -316,13 +340,13 @@ void journal_commit_transaction(journal_t *journal) J_ASSERT(journal->j_committing_transaction == NULL); commit_transaction = journal->j_running_transaction; - J_ASSERT(commit_transaction->t_state == T_RUNNING); trace_jbd_start_commit(journal, commit_transaction); jbd_debug(1, "JBD: starting commit of transaction %d\n", commit_transaction->t_tid); spin_lock(&journal->j_state_lock); + J_ASSERT(commit_transaction->t_state == T_RUNNING); commit_transaction->t_state = T_LOCKED; trace_jbd_commit_locking(journal, commit_transaction); @@ -392,6 +416,12 @@ void journal_commit_transaction(journal_t *journal) jbd_debug (3, "JBD: commit phase 1\n"); /* + * Clear revoked flag to reflect there is no revoked buffers + * in the next transaction which is going to be started. + */ + journal_clear_buffer_revoked_flags(journal); + + /* * Switch to a new revoke table. */ journal_switch_revoke_table(journal); @@ -407,13 +437,16 @@ void journal_commit_transaction(journal_t *journal) jbd_debug (3, "JBD: commit phase 2\n"); + if (tid_geq(journal->j_commit_waited, commit_transaction->t_tid)) + write_op = WRITE_SYNC; + /* * Now start flushing things to disk, in the order they appear * on the transaction lists. Data blocks go first. */ blk_start_plug(&plug); err = journal_submit_data_buffers(journal, commit_transaction, - WRITE_SYNC); + write_op); blk_finish_plug(&plug); /* @@ -472,7 +505,7 @@ void journal_commit_transaction(journal_t *journal) blk_start_plug(&plug); - journal_write_revoke_records(journal, commit_transaction, WRITE_SYNC); + journal_write_revoke_records(journal, commit_transaction, write_op); /* * If we found any dirty or locked buffers, then we should have @@ -643,7 +676,17 @@ start_journal_io: clear_buffer_dirty(bh); set_buffer_uptodate(bh); bh->b_end_io = journal_end_buffer_io_sync; - submit_bh(WRITE_SYNC, bh); + /* + * In data=journal mode, here we can end up + * writing pagecache data that might be + * mmapped. Since we can't afford to clean the + * page and set PageWriteback (see the comment + * near the other use of _submit_bh()), the + * data can change while the write is in + * flight. Tell the block layer to bounce the + * bio pages if stable pages are required. + */ + _submit_bh(write_op, bh, 1 << BIO_SNAP_STABLE); } cond_resched(); @@ -847,17 +890,35 @@ restart_loop: * there's no point in keeping a checkpoint record for * it. */ - /* A buffer which has been freed while still being - * journaled by a previous transaction may end up still - * being dirty here, but we want to avoid writing back - * that buffer in the future after the "add to orphan" - * operation been committed, That's not only a performance - * gain, it also stops aliasing problems if the buffer is - * left behind for writeback and gets reallocated for another - * use in a different page. */ - if (buffer_freed(bh) && !jh->b_next_transaction) { - clear_buffer_freed(bh); - clear_buffer_jbddirty(bh); + /* + * A buffer which has been freed while still being journaled by + * a previous transaction. + */ + if (buffer_freed(bh)) { + /* + * If the running transaction is the one containing + * "add to orphan" operation (b_next_transaction != + * NULL), we have to wait for that transaction to + * commit before we can really get rid of the buffer. + * So just clear b_modified to not confuse transaction + * credit accounting and refile the buffer to + * BJ_Forget of the running transaction. If the just + * committed transaction contains "add to orphan" + * operation, we can completely invalidate the buffer + * now. We are rather throughout in that since the + * buffer may be still accessible when blocksize < + * pagesize and it is attached to the last partial + * page. + */ + jh->b_modified = 0; + if (!jh->b_next_transaction) { + clear_buffer_freed(bh); + clear_buffer_jbddirty(bh); + clear_buffer_mapped(bh); + clear_buffer_new(bh); + clear_buffer_req(bh); + bh->b_bdev = NULL; + } } if (buffer_jbddirty(bh)) { |