jbd2: Remove data=ordered mode support using jbd buffer heads

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 6 insertions, 211 deletions

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 98b596d23705..4f7cadbb19fa 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -943,183 +943,6 @@ out:
 }
 
 /**
- * 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.
  * @bh: buffer to mark
@@ -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);