1 files changed, 68 insertions, 45 deletions

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 48435cf2aa16..b43f0e8f43f2 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -574,10 +574,10 @@ xlog_discard_busy_extents(
  */
 static void
 xlog_cil_committed(
-	struct xfs_cil_ctx	*ctx,
-	bool			abort)
+	struct xfs_cil_ctx	*ctx)
 {
 	struct xfs_mount	*mp = ctx->cil->xc_log->l_mp;
+	bool			abort = XLOG_FORCED_SHUTDOWN(ctx->cil->xc_log);
 
 	/*
 	 * If the I/O failed, we're aborting the commit and already shutdown.
@@ -613,37 +613,38 @@ xlog_cil_committed(
 
 void
 xlog_cil_process_committed(
-	struct list_head	*list,
-	bool			aborted)
+	struct list_head	*list)
 {
 	struct xfs_cil_ctx	*ctx;
 
 	while ((ctx = list_first_entry_or_null(list,
 			struct xfs_cil_ctx, iclog_entry))) {
 		list_del(&ctx->iclog_entry);
-		xlog_cil_committed(ctx, aborted);
+		xlog_cil_committed(ctx);
 	}
 }
 
 /*
- * Push the Committed Item List to the log. If @push_seq flag is zero, then it
- * is a background flush and so we can chose to ignore it. Otherwise, if the
- * current sequence is the same as @push_seq we need to do a flush. If
- * @push_seq is less than the current sequence, then it has already been
+ * Push the Committed Item List to the log.
+ *
+ * If the current sequence is the same as xc_push_seq we need to do a flush. If
+ * xc_push_seq is less than the current sequence, then it has already been
  * flushed and we don't need to do anything - the caller will wait for it to
  * complete if necessary.
  *
- * @push_seq is a value rather than a flag because that allows us to do an
- * unlocked check of the sequence number for a match. Hence we can allows log
- * forces to run racily and not issue pushes for the same sequence twice. If we
- * get a race between multiple pushes for the same sequence they will block on
- * the first one and then abort, hence avoiding needless pushes.
+ * xc_push_seq is checked unlocked against the sequence number for a match.
+ * Hence we can allow log forces to run racily and not issue pushes for the
+ * same sequence twice.  If we get a race between multiple pushes for the same
+ * sequence they will block on the first one and then abort, hence avoiding
+ * needless pushes.
  */
-STATIC int
-xlog_cil_push(
-	struct xlog		*log)
+static void
+xlog_cil_push_work(
+	struct work_struct	*work)
 {
-	struct xfs_cil		*cil = log->l_cilp;
+	struct xfs_cil		*cil =
+		container_of(work, struct xfs_cil, xc_push_work);
+	struct xlog		*log = cil->xc_log;
 	struct xfs_log_vec	*lv;
 	struct xfs_cil_ctx	*ctx;
 	struct xfs_cil_ctx	*new_ctx;
@@ -657,9 +658,6 @@ xlog_cil_push(
 	xfs_lsn_t		commit_lsn;
 	xfs_lsn_t		push_seq;
 
-	if (!cil)
-		return 0;
-
 	new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_NOFS);
 	new_ctx->ticket = xlog_cil_ticket_alloc(log);
 
@@ -671,6 +669,11 @@ xlog_cil_push(
 	ASSERT(push_seq <= ctx->sequence);
 
 	/*
+	 * Wake up any background push waiters now this context is being pushed.
+	 */
+	wake_up_all(&ctx->push_wait);
+
+	/*
 	 * Check if we've anything to push. If there is nothing, then we don't
 	 * move on to a new sequence number and so we have to be able to push
 	 * this sequence again later.
@@ -746,6 +749,7 @@ xlog_cil_push(
 	 */
 	INIT_LIST_HEAD(&new_ctx->committing);
 	INIT_LIST_HEAD(&new_ctx->busy_extents);
+	init_waitqueue_head(&new_ctx->push_wait);
 	new_ctx->sequence = ctx->sequence + 1;
 	new_ctx->cil = cil;
 	cil->xc_ctx = new_ctx;
@@ -803,7 +807,7 @@ xlog_cil_push(
 	lvhdr.lv_iovecp = &lhdr;
 	lvhdr.lv_next = ctx->lv_chain;
 
-	error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0);
+	error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0, true);
 	if (error)
 		goto out_abort_free_ticket;
 
@@ -841,10 +845,11 @@ restart:
 	}
 	spin_unlock(&cil->xc_push_lock);
 
-	/* xfs_log_done always frees the ticket on error. */
-	commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, false);
-	if (commit_lsn == -1)
-		goto out_abort;
+	error = xlog_commit_record(log, tic, &commit_iclog, &commit_lsn);
+	if (error)
+		goto out_abort_free_ticket;
+
+	xfs_log_ticket_ungrant(log, tic);
 
 	spin_lock(&commit_iclog->ic_callback_lock);
 	if (commit_iclog->ic_state == XLOG_STATE_IOERROR) {
@@ -867,28 +872,20 @@ restart:
 	spin_unlock(&cil->xc_push_lock);
 
 	/* release the hounds! */
-	return xfs_log_release_iclog(log->l_mp, commit_iclog);
+	xfs_log_release_iclog(commit_iclog);
+	return;
 
 out_skip:
 	up_write(&cil->xc_ctx_lock);
 	xfs_log_ticket_put(new_ctx->ticket);
 	kmem_free(new_ctx);
-	return 0;
+	return;
 
 out_abort_free_ticket:
-	xfs_log_ticket_put(tic);
+	xfs_log_ticket_ungrant(log, tic);
 out_abort:
-	xlog_cil_committed(ctx, true);
-	return -EIO;
-}
-
-static void
-xlog_cil_push_work(
-	struct work_struct	*work)
-{
-	struct xfs_cil		*cil = container_of(work, struct xfs_cil,
-							xc_push_work);
-	xlog_cil_push(cil->xc_log);
+	ASSERT(XLOG_FORCED_SHUTDOWN(log));
+	xlog_cil_committed(ctx);
 }
 
 /*
@@ -900,7 +897,7 @@ xlog_cil_push_work(
  */
 static void
 xlog_cil_push_background(
-	struct xlog	*log)
+	struct xlog	*log) __releases(cil->xc_ctx_lock)
 {
 	struct xfs_cil	*cil = log->l_cilp;
 
@@ -914,14 +911,36 @@ xlog_cil_push_background(
 	 * don't do a background push if we haven't used up all the
 	 * space available yet.
 	 */
-	if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log))
+	if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) {
+		up_read(&cil->xc_ctx_lock);
 		return;
+	}
 
 	spin_lock(&cil->xc_push_lock);
 	if (cil->xc_push_seq < cil->xc_current_sequence) {
 		cil->xc_push_seq = cil->xc_current_sequence;
 		queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work);
 	}
+
+	/*
+	 * Drop the context lock now, we can't hold that if we need to sleep
+	 * because we are over the blocking threshold. The push_lock is still
+	 * held, so blocking threshold sleep/wakeup is still correctly
+	 * serialised here.
+	 */
+	up_read(&cil->xc_ctx_lock);
+
+	/*
+	 * If we are well over the space limit, throttle the work that is being
+	 * done until the push work on this context has begun.
+	 */
+	if (cil->xc_ctx->space_used >= XLOG_CIL_BLOCKING_SPACE_LIMIT(log)) {
+		trace_xfs_log_cil_wait(log, cil->xc_ctx->ticket);
+		ASSERT(cil->xc_ctx->space_used < log->l_logsize);
+		xlog_wait(&cil->xc_ctx->push_wait, &cil->xc_push_lock);
+		return;
+	}
+
 	spin_unlock(&cil->xc_push_lock);
 
 }
@@ -1017,7 +1036,10 @@ xfs_log_commit_cil(
 	if (commit_lsn)
 		*commit_lsn = xc_commit_lsn;
 
-	xfs_log_done(mp, tp->t_ticket, NULL, regrant);
+	if (regrant && !XLOG_FORCED_SHUTDOWN(log))
+		xfs_log_ticket_regrant(log, tp->t_ticket);
+	else
+		xfs_log_ticket_ungrant(log, tp->t_ticket);
 	tp->t_ticket = NULL;
 	xfs_trans_unreserve_and_mod_sb(tp);
 
@@ -1038,9 +1060,9 @@ xfs_log_commit_cil(
 		if (lip->li_ops->iop_committing)
 			lip->li_ops->iop_committing(lip, xc_commit_lsn);
 	}
-	xlog_cil_push_background(log);
 
-	up_read(&cil->xc_ctx_lock);
+	/* xlog_cil_push_background() releases cil->xc_ctx_lock */
+	xlog_cil_push_background(log);
 }
 
 /*
@@ -1199,6 +1221,7 @@ xlog_cil_init(
 
 	INIT_LIST_HEAD(&ctx->committing);
 	INIT_LIST_HEAD(&ctx->busy_extents);
+	init_waitqueue_head(&ctx->push_wait);
 	ctx->sequence = 1;
 	ctx->cil = cil;
 	cil->xc_ctx = ctx;