1 files changed, 105 insertions, 189 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index a2ed72f..f8b3be8 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -22,6 +22,8 @@
 #include <linux/pagemap.h>
 #include <linux/jiffies.h>
 #include <linux/crc32.h>
+#include <linux/writeback.h>
+#include <linux/backing-dev.h>
 
 /*
  * Default IO end handler for temporary BJ_IO buffer_heads.
@@ -37,8 +39,8 @@ static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
 }
 
 /*
- * When an ext3-ordered file is truncated, it is possible that many pages are
- * not sucessfully freed, because they are attached to a committing transaction.
+ * When an ext4 file is truncated, it is possible that some pages are not
+ * successfully freed, because they are attached to a committing transaction.
  * After the transaction commits, these pages are left on the LRU, with no
  * ->mapping, and with attached buffers.  These pages are trivially reclaimable
  * by the VM, but their apparent absence upsets the VM accounting, and it makes
@@ -80,21 +82,6 @@ nope:
 }
 
 /*
- * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
- * held.  For ranking reasons we must trylock.  If we lose, schedule away and
- * return 0.  j_list_lock is dropped in this case.
- */
-static int inverted_lock(journal_t *journal, struct buffer_head *bh)
-{
-	if (!jbd_trylock_bh_state(bh)) {
-		spin_unlock(&journal->j_list_lock);
-		schedule();
-		return 0;
-	}
-	return 1;
-}
-
-/*
  * Done it all: now submit the commit record.  We should have
  * cleaned up our previous buffers by now, so if we are in abort
  * mode we can now just skip the rest of the journal write
@@ -112,6 +99,7 @@ static int journal_submit_commit_record(journal_t *journal,
 	struct buffer_head *bh;
 	int ret;
 	int barrier_done = 0;
+	struct timespec now = current_kernel_time();
 
 	if (is_journal_aborted(journal))
 		return 0;
@@ -126,6 +114,8 @@ static int journal_submit_commit_record(journal_t *journal,
 	tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
 	tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
 	tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
+	tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
+	tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
 
 	if (JBD2_HAS_COMPAT_FEATURE(journal,
 				    JBD2_FEATURE_COMPAT_CHECKSUM)) {
@@ -197,159 +187,104 @@ static int journal_wait_on_commit_record(struct buffer_head *bh)
 }
 
 /*
- * Wait for all submitted IO to complete.
+ * write the filemap data using writepage() address_space_operations.
+ * We don't do block allocation here even for delalloc. We don't
+ * use writepages() because with dealyed allocation we may be doing
+ * block allocation in writepages().
  */
-static int journal_wait_on_locked_list(journal_t *journal,
-				       transaction_t *commit_transaction)
+static int journal_submit_inode_data_buffers(struct address_space *mapping)
 {
-	int ret = 0;
-	struct journal_head *jh;
-
-	while (commit_transaction->t_locked_list) {
-		struct buffer_head *bh;
-
-		jh = commit_transaction->t_locked_list->b_tprev;
-		bh = jh2bh(jh);
-		get_bh(bh);
-		if (buffer_locked(bh)) {
-			spin_unlock(&journal->j_list_lock);
-			wait_on_buffer(bh);
-			if (unlikely(!buffer_uptodate(bh)))
-				ret = -EIO;
-			spin_lock(&journal->j_list_lock);
-		}
-		if (!inverted_lock(journal, bh)) {
-			put_bh(bh);
-			spin_lock(&journal->j_list_lock);
-			continue;
-		}
-		if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
-			__jbd2_journal_unfile_buffer(jh);
-			jbd_unlock_bh_state(bh);
-			jbd2_journal_remove_journal_head(bh);
-			put_bh(bh);
-		} else {
-			jbd_unlock_bh_state(bh);
-		}
-		put_bh(bh);
-		cond_resched_lock(&journal->j_list_lock);
-	}
+	int ret;
+	struct writeback_control wbc = {
+		.sync_mode =  WB_SYNC_ALL,
+		.nr_to_write = mapping->nrpages * 2,
+		.range_start = 0,
+		.range_end = i_size_read(mapping->host),
+		.for_writepages = 1,
+	};
+
+	ret = generic_writepages(mapping, &wbc);
 	return ret;
-  }
+}
 
-static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
+/*
+ * Submit all the data buffers of inode associated with the transaction to
+ * disk.
+ *
+ * We are in a committing transaction. Therefore no new inode can be added to
+ * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
+ * operate on from being released while we write out pages.
+ */
+static int journal_submit_data_buffers(journal_t *journal,
+		transaction_t *commit_transaction)
 {
-	int i;
+	struct jbd2_inode *jinode;
+	int err, ret = 0;
+	struct address_space *mapping;
 
-	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, wbuf[i]);
+	spin_lock(&journal->j_list_lock);
+	list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
+		mapping = jinode->i_vfs_inode->i_mapping;
+		jinode->i_flags |= JI_COMMIT_RUNNING;
+		spin_unlock(&journal->j_list_lock);
+		/*
+		 * submit the inode data buffers. We use writepage
+		 * instead of writepages. Because writepages can do
+		 * block allocation  with delalloc. We need to write
+		 * only allocated blocks here.
+		 */
+		err = journal_submit_inode_data_buffers(mapping);
+		if (!ret)
+			ret = err;
+		spin_lock(&journal->j_list_lock);
+		J_ASSERT(jinode->i_transaction == commit_transaction);
+		jinode->i_flags &= ~JI_COMMIT_RUNNING;
+		wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
 	}
+	spin_unlock(&journal->j_list_lock);
+	return ret;
 }
 
 /*
- *  Submit all the data buffers to disk
+ * Wait for data submitted for writeout, refile inodes to proper
+ * transaction if needed.
+ *
  */
-static void journal_submit_data_buffers(journal_t *journal,
-				transaction_t *commit_transaction)
+static int journal_finish_inode_data_buffers(journal_t *journal,
+		transaction_t *commit_transaction)
 {
-	struct journal_head *jh;
-	struct buffer_head *bh;
-	int locked;
-	int bufs = 0;
-	struct buffer_head **wbuf = journal->j_wbuf;
+	struct jbd2_inode *jinode, *next_i;
+	int err, ret = 0;
 
-	/*
-	 * Whenever we unlock the journal and sleep, things can get added
-	 * onto ->t_sync_datalist, so we have to keep looping back to
-	 * write_out_data until we *know* that the list is empty.
-	 *
-	 * Cleanup any flushed data buffers from the data list.  Even in
-	 * abort mode, we want to flush this out as soon as possible.
-	 */
-write_out_data:
-	cond_resched();
+	/* For locking, see the comment in journal_submit_data_buffers() */
 	spin_lock(&journal->j_list_lock);
+	list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
+		jinode->i_flags |= JI_COMMIT_RUNNING;
+		spin_unlock(&journal->j_list_lock);
+		err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
+		if (!ret)
+			ret = err;
+		spin_lock(&journal->j_list_lock);
+		jinode->i_flags &= ~JI_COMMIT_RUNNING;
+		wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
+	}
 
-	while (commit_transaction->t_sync_datalist) {
-		jh = commit_transaction->t_sync_datalist;
-		bh = jh2bh(jh);
-		locked = 0;
-
-		/* Get reference just to make sure buffer does not disappear
-		 * when we are forced to drop various locks */
-		get_bh(bh);
-		/* If the buffer is dirty, we need to submit IO and hence
-		 * we need the buffer lock. We try to lock the buffer without
-		 * blocking. If we fail, we need to drop j_list_lock and do
-		 * blocking lock_buffer().
-		 */
-		if (buffer_dirty(bh)) {
-			if (test_set_buffer_locked(bh)) {
-				BUFFER_TRACE(bh, "needs blocking lock");
-				spin_unlock(&journal->j_list_lock);
-				/* Write out all data to prevent deadlocks */
-				journal_do_submit_data(wbuf, bufs);
-				bufs = 0;
-				lock_buffer(bh);
-				spin_lock(&journal->j_list_lock);
-			}
-			locked = 1;
-		}
-		/* We have to get bh_state lock. Again out of order, sigh. */
-		if (!inverted_lock(journal, bh)) {
-			jbd_lock_bh_state(bh);
-			spin_lock(&journal->j_list_lock);
-		}
-		/* Someone already cleaned up the buffer? */
-		if (!buffer_jbd(bh)
-			|| jh->b_transaction != commit_transaction
-			|| jh->b_jlist != BJ_SyncData) {
-			jbd_unlock_bh_state(bh);
-			if (locked)
-				unlock_buffer(bh);
-			BUFFER_TRACE(bh, "already cleaned up");
-			put_bh(bh);
-			continue;
-		}
-		if (locked && test_clear_buffer_dirty(bh)) {
-			BUFFER_TRACE(bh, "needs writeout, adding to array");
-			wbuf[bufs++] = bh;
-			__jbd2_journal_file_buffer(jh, commit_transaction,
-						BJ_Locked);
-			jbd_unlock_bh_state(bh);
-			if (bufs == journal->j_wbufsize) {
-				spin_unlock(&journal->j_list_lock);
-				journal_do_submit_data(wbuf, bufs);
-				bufs = 0;
-				goto write_out_data;
-			}
-		} else if (!locked && buffer_locked(bh)) {
-			__jbd2_journal_file_buffer(jh, commit_transaction,
-						BJ_Locked);
-			jbd_unlock_bh_state(bh);
-			put_bh(bh);
+	/* Now refile inode to proper lists */
+	list_for_each_entry_safe(jinode, next_i,
+				 &commit_transaction->t_inode_list, i_list) {
+		list_del(&jinode->i_list);
+		if (jinode->i_next_transaction) {
+			jinode->i_transaction = jinode->i_next_transaction;
+			jinode->i_next_transaction = NULL;
+			list_add(&jinode->i_list,
+				&jinode->i_transaction->t_inode_list);
 		} else {
-			BUFFER_TRACE(bh, "writeout complete: unfile");
-			__jbd2_journal_unfile_buffer(jh);
-			jbd_unlock_bh_state(bh);
-			if (locked)
-				unlock_buffer(bh);
-			jbd2_journal_remove_journal_head(bh);
-			/* Once for our safety reference, once for
-			 * jbd2_journal_remove_journal_head() */
-			put_bh(bh);
-			put_bh(bh);
-		}
-
-		if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
-			spin_unlock(&journal->j_list_lock);
-			goto write_out_data;
+			jinode->i_transaction = NULL;
 		}
 	}
 	spin_unlock(&journal->j_list_lock);
-	journal_do_submit_data(wbuf, bufs);
+
+	return ret;
 }
 
 static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
@@ -524,21 +459,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	 * Now start flushing things to disk, in the order they appear
 	 * on the transaction lists.  Data blocks go first.
 	 */
-	err = 0;
-	journal_submit_data_buffers(journal, commit_transaction);
-
-	/*
-	 * Wait for all previously submitted IO to complete if commit
-	 * record is to be written synchronously.
-	 */
-	spin_lock(&journal->j_list_lock);
-	if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
-		JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
-		err = journal_wait_on_locked_list(journal,
-						commit_transaction);
-
-	spin_unlock(&journal->j_list_lock);
-
+	err = journal_submit_data_buffers(journal, commit_transaction);
 	if (err)
 		jbd2_journal_abort(journal, err);
 
@@ -547,16 +468,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	jbd_debug(3, "JBD: commit phase 2\n");
 
 	/*
-	 * If we found any dirty or locked buffers, then we should have
-	 * looped back up to the write_out_data label.  If there weren't
-	 * any then journal_clean_data_list should have wiped the list
-	 * clean by now, so check that it is in fact empty.
-	 */
-	J_ASSERT (commit_transaction->t_sync_datalist == NULL);
-
-	jbd_debug (3, "JBD: commit phase 3\n");
-
-	/*
 	 * Way to go: we have now written out all of the data for a
 	 * transaction!  Now comes the tricky part: we need to write out
 	 * metadata.  Loop over the transaction's entire buffer list:
@@ -574,6 +485,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	J_ASSERT(commit_transaction->t_nr_buffers <=
 		 commit_transaction->t_outstanding_credits);
 
+	err = 0;
 	descriptor = NULL;
 	bufs = 0;
 	while (commit_transaction->t_buffers) {
@@ -748,15 +660,19 @@ start_journal_io:
 						 &cbh, crc32_sum);
 		if (err)
 			__jbd2_journal_abort_hard(journal);
-
-		spin_lock(&journal->j_list_lock);
-		err = journal_wait_on_locked_list(journal,
-						commit_transaction);
-		spin_unlock(&journal->j_list_lock);
-		if (err)
-			__jbd2_journal_abort_hard(journal);
 	}
 
+	/*
+	 * This is the right place to wait for data buffers both for ASYNC
+	 * and !ASYNC commit. If commit is ASYNC, we need to wait only after
+	 * the commit block went to disk (which happens above). If commit is
+	 * SYNC, we need to wait for data buffers before we start writing
+	 * commit block, which happens below in such setting.
+	 */
+	err = journal_finish_inode_data_buffers(journal, commit_transaction);
+	if (err)
+		jbd2_journal_abort(journal, err);
+
 	/* Lo and behold: we have just managed to send a transaction to
            the log.  Before we can commit it, wait for the IO so far to
            complete.  Control buffers being written are on the
@@ -768,7 +684,7 @@ start_journal_io:
 	   so we incur less scheduling load.
 	*/
 
-	jbd_debug(3, "JBD: commit phase 4\n");
+	jbd_debug(3, "JBD: commit phase 3\n");
 
 	/*
 	 * akpm: these are BJ_IO, and j_list_lock is not needed.
@@ -827,7 +743,7 @@ wait_for_iobuf:
 
 	J_ASSERT (commit_transaction->t_shadow_list == NULL);
 
-	jbd_debug(3, "JBD: commit phase 5\n");
+	jbd_debug(3, "JBD: commit phase 4\n");
 
 	/* Here we wait for the revoke record and descriptor record buffers */
  wait_for_ctlbuf:
@@ -854,7 +770,7 @@ wait_for_iobuf:
 		/* AKPM: bforget here */
 	}
 
-	jbd_debug(3, "JBD: commit phase 6\n");
+	jbd_debug(3, "JBD: commit phase 5\n");
 
 	if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
 		JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
@@ -874,9 +790,9 @@ wait_for_iobuf:
            transaction can be removed from any checkpoint list it was on
            before. */
 
-	jbd_debug(3, "JBD: commit phase 7\n");
+	jbd_debug(3, "JBD: commit phase 6\n");
 
-	J_ASSERT(commit_transaction->t_sync_datalist == NULL);
+	J_ASSERT(list_empty(&commit_transaction->t_inode_list));
 	J_ASSERT(commit_transaction->t_buffers == NULL);
 	J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
 	J_ASSERT(commit_transaction->t_iobuf_list == NULL);
@@ -997,7 +913,7 @@ restart_loop:
 
 	/* Done with this transaction! */
 
-	jbd_debug(3, "JBD: commit phase 8\n");
+	jbd_debug(3, "JBD: commit phase 7\n");
 
 	J_ASSERT(commit_transaction->t_state == T_COMMIT);