From 87c89c232c8f7b3820c33c3b9bc803e9358027da Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 11 Jul 2008 19:27:31 -0400 Subject: jbd2: Remove data=ordered mode support using jbd buffer heads Signed-off-by: Jan Kara --- fs/jbd2/transaction.c | 217 ++------------------------------------------------ 1 file changed, 6 insertions(+), 211 deletions(-) (limited to 'fs/jbd2/transaction.c') diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index 98b596d2370..4f7cadbb19f 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -942,183 +942,6 @@ out: return err; } -/** - * int jbd2_journal_dirty_data() - mark a buffer as containing dirty data which - * needs to be flushed before we can commit the - * current transaction. - * @handle: transaction - * @bh: bufferhead to mark - * - * The buffer is placed on the transaction's data list and is marked as - * belonging to the transaction. - * - * Returns error number or 0 on success. - * - * jbd2_journal_dirty_data() can be called via page_launder->ext3_writepage - * by kswapd. - */ -int jbd2_journal_dirty_data(handle_t *handle, struct buffer_head *bh) -{ - journal_t *journal = handle->h_transaction->t_journal; - int need_brelse = 0; - struct journal_head *jh; - - if (is_handle_aborted(handle)) - return 0; - - jh = jbd2_journal_add_journal_head(bh); - JBUFFER_TRACE(jh, "entry"); - - /* - * The buffer could *already* be dirty. Writeout can start - * at any time. - */ - jbd_debug(4, "jh: %p, tid:%d\n", jh, handle->h_transaction->t_tid); - - /* - * What if the buffer is already part of a running transaction? - * - * There are two cases: - * 1) It is part of the current running transaction. Refile it, - * just in case we have allocated it as metadata, deallocated - * it, then reallocated it as data. - * 2) It is part of the previous, still-committing transaction. - * If all we want to do is to guarantee that the buffer will be - * written to disk before this new transaction commits, then - * being sure that the *previous* transaction has this same - * property is sufficient for us! Just leave it on its old - * transaction. - * - * In case (2), the buffer must not already exist as metadata - * --- that would violate write ordering (a transaction is free - * to write its data at any point, even before the previous - * committing transaction has committed). The caller must - * never, ever allow this to happen: there's nothing we can do - * about it in this layer. - */ - jbd_lock_bh_state(bh); - spin_lock(&journal->j_list_lock); - - /* Now that we have bh_state locked, are we really still mapped? */ - if (!buffer_mapped(bh)) { - JBUFFER_TRACE(jh, "unmapped buffer, bailing out"); - goto no_journal; - } - - if (jh->b_transaction) { - JBUFFER_TRACE(jh, "has transaction"); - if (jh->b_transaction != handle->h_transaction) { - JBUFFER_TRACE(jh, "belongs to older transaction"); - J_ASSERT_JH(jh, jh->b_transaction == - journal->j_committing_transaction); - - /* @@@ IS THIS TRUE ? */ - /* - * Not any more. Scenario: someone does a write() - * in data=journal mode. The buffer's transaction has - * moved into commit. Then someone does another - * write() to the file. We do the frozen data copyout - * and set b_next_transaction to point to j_running_t. - * And while we're in that state, someone does a - * writepage() in an attempt to pageout the same area - * of the file via a shared mapping. At present that - * calls jbd2_journal_dirty_data(), and we get right here. - * It may be too late to journal the data. Simply - * falling through to the next test will suffice: the - * data will be dirty and wil be checkpointed. The - * ordering comments in the next comment block still - * apply. - */ - //J_ASSERT_JH(jh, jh->b_next_transaction == NULL); - - /* - * If we're journalling data, and this buffer was - * subject to a write(), it could be metadata, forget - * or shadow against the committing transaction. Now, - * someone has dirtied the same darn page via a mapping - * and it is being writepage()'d. - * We *could* just steal the page from commit, with some - * fancy locking there. Instead, we just skip it - - * don't tie the page's buffers to the new transaction - * at all. - * Implication: if we crash before the writepage() data - * is written into the filesystem, recovery will replay - * the write() data. - */ - if (jh->b_jlist != BJ_None && - jh->b_jlist != BJ_SyncData && - jh->b_jlist != BJ_Locked) { - JBUFFER_TRACE(jh, "Not stealing"); - goto no_journal; - } - - /* - * This buffer may be undergoing writeout in commit. We - * can't return from here and let the caller dirty it - * again because that can cause the write-out loop in - * commit to never terminate. - */ - if (buffer_dirty(bh)) { - get_bh(bh); - spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - need_brelse = 1; - sync_dirty_buffer(bh); - jbd_lock_bh_state(bh); - spin_lock(&journal->j_list_lock); - /* Since we dropped the lock... */ - if (!buffer_mapped(bh)) { - JBUFFER_TRACE(jh, "buffer got unmapped"); - goto no_journal; - } - /* The buffer may become locked again at any - time if it is redirtied */ - } - - /* journal_clean_data_list() may have got there first */ - if (jh->b_transaction != NULL) { - JBUFFER_TRACE(jh, "unfile from commit"); - __jbd2_journal_temp_unlink_buffer(jh); - /* It still points to the committing - * transaction; move it to this one so - * that the refile assert checks are - * happy. */ - jh->b_transaction = handle->h_transaction; - } - /* The buffer will be refiled below */ - - } - /* - * Special case --- the buffer might actually have been - * allocated and then immediately deallocated in the previous, - * committing transaction, so might still be left on that - * transaction's metadata lists. - */ - if (jh->b_jlist != BJ_SyncData && jh->b_jlist != BJ_Locked) { - JBUFFER_TRACE(jh, "not on correct data list: unfile"); - J_ASSERT_JH(jh, jh->b_jlist != BJ_Shadow); - __jbd2_journal_temp_unlink_buffer(jh); - jh->b_transaction = handle->h_transaction; - JBUFFER_TRACE(jh, "file as data"); - __jbd2_journal_file_buffer(jh, handle->h_transaction, - BJ_SyncData); - } - } else { - JBUFFER_TRACE(jh, "not on a transaction"); - __jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_SyncData); - } -no_journal: - spin_unlock(&journal->j_list_lock); - jbd_unlock_bh_state(bh); - if (need_brelse) { - BUFFER_TRACE(bh, "brelse"); - __brelse(bh); - } - JBUFFER_TRACE(jh, "exit"); - jbd2_journal_put_journal_head(jh); - return 0; -} - /** * int jbd2_journal_dirty_metadata() - mark a buffer as containing dirty metadata * @handle: transaction to add buffer to. @@ -1541,10 +1364,10 @@ __blist_del_buffer(struct journal_head **list, struct journal_head *jh) * Remove a buffer from the appropriate transaction list. * * Note that this function can *change* the value of - * bh->b_transaction->t_sync_datalist, t_buffers, t_forget, - * t_iobuf_list, t_shadow_list, t_log_list or t_reserved_list. If the caller - * is holding onto a copy of one of thee pointers, it could go bad. - * Generally the caller needs to re-read the pointer from the transaction_t. + * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list, + * t_log_list or t_reserved_list. If the caller is holding onto a copy of one + * of these pointers, it could go bad. Generally the caller needs to re-read + * the pointer from the transaction_t. * * Called under j_list_lock. The journal may not be locked. */ @@ -1566,9 +1389,6 @@ void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) switch (jh->b_jlist) { case BJ_None: return; - case BJ_SyncData: - list = &transaction->t_sync_datalist; - break; case BJ_Metadata: transaction->t_nr_buffers--; J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0); @@ -1589,9 +1409,6 @@ void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh) case BJ_Reserved: list = &transaction->t_reserved_list; break; - case BJ_Locked: - list = &transaction->t_locked_list; - break; } __blist_del_buffer(list, jh); @@ -1634,15 +1451,7 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh) goto out; spin_lock(&journal->j_list_lock); - if (jh->b_transaction != NULL && jh->b_cp_transaction == NULL) { - if (jh->b_jlist == BJ_SyncData || jh->b_jlist == BJ_Locked) { - /* A written-back ordered data buffer */ - JBUFFER_TRACE(jh, "release data"); - __jbd2_journal_unfile_buffer(jh); - jbd2_journal_remove_journal_head(bh); - __brelse(bh); - } - } else if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) { + if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) { /* written-back checkpointed metadata buffer */ if (jh->b_jlist == BJ_None) { JBUFFER_TRACE(jh, "remove from checkpoint list"); @@ -1878,6 +1687,7 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) if (!buffer_jbd(bh)) goto zap_buffer_unlocked; + /* OK, we have data buffer in journaled mode */ spin_lock(&journal->j_state_lock); jbd_lock_bh_state(bh); spin_lock(&journal->j_list_lock); @@ -1941,15 +1751,6 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh) } } else if (transaction == journal->j_committing_transaction) { JBUFFER_TRACE(jh, "on committing transaction"); - if (jh->b_jlist == BJ_Locked) { - /* - * The buffer is on the committing transaction's locked - * list. We have the buffer locked, so I/O has - * completed. So we can nail the buffer now. - */ - may_free = __dispose_buffer(jh, transaction); - goto zap_buffer; - } /* * If it is committing, we simply cannot touch it. We * can remove it's next_transaction pointer from the @@ -2082,9 +1883,6 @@ void __jbd2_journal_file_buffer(struct journal_head *jh, J_ASSERT_JH(jh, !jh->b_committed_data); J_ASSERT_JH(jh, !jh->b_frozen_data); return; - case BJ_SyncData: - list = &transaction->t_sync_datalist; - break; case BJ_Metadata: transaction->t_nr_buffers++; list = &transaction->t_buffers; @@ -2104,9 +1902,6 @@ void __jbd2_journal_file_buffer(struct journal_head *jh, case BJ_Reserved: list = &transaction->t_reserved_list; break; - case BJ_Locked: - list = &transaction->t_locked_list; - break; } __blist_add_buffer(list, jh); -- cgit v1.2.3