---
fs/xfs/xfs_log.c | 38 ++++++++++++++------------
fs/xfs/xfs_log.h | 1 +
fs/xfs/xfs_log_cil.c | 61 ++++++++++++++++++++++++++++++++++++------
fs/xfs/xfs_log_priv.h | 5 ++++
fs/xfs/xfs_sysfs.c | 1 +
fs/xfs/xfs_trace.c | 1 +
fs/xfs/xfs_trans.c | 2 +-
fs/xfs/xfs_trans_ail.c | 11 +++++---
8 files changed, 91 insertions(+), 29 deletions(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index aa37f4319052..c53644d19dd3 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -50,11 +50,6 @@ xlog_state_get_iclog_space(
int *continued_write,
int *logoffsetp);
STATIC void
-xlog_state_switch_iclogs(
- struct xlog *log,
- struct xlog_in_core *iclog,
- int eventual_size);
-STATIC void
xlog_grant_push_ail(
struct xlog *log,
int need_bytes);
@@ -3104,7 +3099,7 @@ xfs_log_ticket_ungrant(
* This routine will mark the current iclog in the ring as WANT_SYNC and move
* the current iclog pointer to the next iclog in the ring.
*/
-STATIC void
+void
xlog_state_switch_iclogs(
struct xlog *log,
struct xlog_in_core *iclog,
@@ -3251,6 +3246,20 @@ xfs_log_force(
return -EIO;
}
+/*
+ * Force the log to a specific LSN.
+ *
+ * If an iclog with that lsn can be found:
+ * If it is in the DIRTY state, just return.
+ * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
+ * state and go to sleep or return.
+ * If it is in any other state, go to sleep or return.
+ *
+ * Synchronous forces are implemented with a wait queue. All callers trying
+ * to force a given lsn to disk must wait on the queue attached to the
+ * specific in-core log. When given in-core log finally completes its write
+ * to disk, that thread will wake up all threads waiting on the queue.
+ */
static int
xlog_force_lsn(
struct xlog *log,
@@ -3314,18 +3323,13 @@ xlog_force_lsn(
}
/*
- * Force the in-core log to disk for a specific LSN.
+ * Force the log to a specific checkpoint sequence.
*
- * Find in-core log with lsn.
- * If it is in the DIRTY state, just return.
- * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
- * state and go to sleep or return.
- * If it is in any other state, go to sleep or return.
- *
- * Synchronous forces are implemented with a wait queue. All callers trying
- * to force a given lsn to disk must wait on the queue attached to the
- * specific in-core log. When given in-core log finally completes its write
- * to disk, that thread will wake up all threads waiting on the queue.
+ * First force the CIL so that all the required changes have been flushed to the
+ * iclogs. If the CIL force completed it will return a commit LSN that indicates
+ * the iclog that needs to be flushed to stable storage. If the caller needs
+ * a synchronous log force, we will wait on the iclog with the LSN returned by
+ * xlog_cil_force_seq() to be completed.
*/
int
xfs_log_force_seq(
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 813b972e9788..1bd080ce3a95 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -104,6 +104,7 @@ struct xlog_ticket;
struct xfs_log_item;
struct xfs_item_ops;
struct xfs_trans;
+struct xlog;
int xfs_log_force(struct xfs_mount *mp, uint flags);
int xfs_log_force_seq(struct xfs_mount *mp, xfs_csn_t seq, uint flags,
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 3c2b1205944d..cb849e67b1c4 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -658,6 +658,7 @@ xlog_cil_push_work(
xfs_lsn_t push_seq;
struct bio bio;
DECLARE_COMPLETION_ONSTACK(bdev_flush);
+ bool push_commit_stable;
new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_NOFS);
new_ctx->ticket = xlog_cil_ticket_alloc(log);
@@ -668,6 +669,8 @@ xlog_cil_push_work(
spin_lock(&cil->xc_push_lock);
push_seq = cil->xc_push_seq;
ASSERT(push_seq <= ctx->sequence);
+ push_commit_stable = cil->xc_push_commit_stable;
+ cil->xc_push_commit_stable = false;
/*
* As we are about to switch to a new, empty CIL context, we no longer
@@ -910,8 +913,15 @@ xlog_cil_push_work(
* The commit iclog must be written to stable storage to guarantee
* journal IO vs metadata writeback IO is correctly ordered on stable
* storage.
+ *
+ * If the push caller needs the commit to be immediately stable and the
+ * commit_iclog is not yet marked as XLOG_STATE_WANT_SYNC to indicate it
+ * will be written when released, switch it's state to WANT_SYNC right
+ * now.
*/
commit_iclog->ic_flags |= XLOG_ICL_NEED_FUA;
+ if (push_commit_stable && commit_iclog->ic_state == XLOG_STATE_ACTIVE)
+ xlog_state_switch_iclogs(log, commit_iclog, 0);
xlog_state_release_iclog(log, commit_iclog);
spin_unlock(&log->l_icloglock);
return;
@@ -996,13 +1006,26 @@ xlog_cil_push_background(
/*
* xlog_cil_push_now() is used to trigger an immediate CIL push to the sequence
* number that is passed. When it returns, the work will be queued for
- * @push_seq, but it won't be completed. The caller is expected to do any
- * waiting for push_seq to complete if it is required.
+ * @push_seq, but it won't be completed.
+ *
+ * If the caller is performing a synchronous force, we will flush the workqueue
+ * to get previously queued work moving to minimise the wait time they will
+ * undergo waiting for all outstanding pushes to complete. The caller is
+ * expected to do the required waiting for push_seq to complete.
+ *
+ * If the caller is performing an async push, we need to ensure that the
+ * checkpoint is fully flushed out of the iclogs when we finish the push. If we
+ * don't do this, then the commit record may remain sitting in memory in an
+ * ACTIVE iclog. This then requires another full log force to push to disk,
+ * which defeats the purpose of having an async, non-blocking CIL force
+ * mechanism. Hence in this case we need to pass a flag to the push work to
+ * indicate it needs to flush the commit record itself.
*/
static void
xlog_cil_push_now(
struct xlog *log,
- xfs_lsn_t push_seq)
+ xfs_lsn_t push_seq,
+ bool async)
{
struct xfs_cil *cil = log->l_cilp;
@@ -1012,7 +1035,8 @@ xlog_cil_push_now(
ASSERT(push_seq && push_seq <= cil->xc_current_sequence);
/* start on any pending background push to minimise wait time on it */
- flush_work(&cil->xc_push_work);
+ if (!async)
+ flush_work(&cil->xc_push_work);
/*
* If the CIL is empty or we've already pushed the sequence then
@@ -1025,6 +1049,7 @@ xlog_cil_push_now(
}
cil->xc_push_seq = push_seq;
+ cil->xc_push_commit_stable = async;
queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work);
spin_unlock(&cil->xc_push_lock);
}
@@ -1109,12 +1134,27 @@ xlog_cil_commit(
xlog_cil_push_background(log);
}
+/*
+ * Flush the CIL to stable storage but don't wait for it to complete. This
+ * requires the CIL push to ensure the commit record for the push hits the disk,
+ * but otherwise is no different to a push done from a log force.
+ */
+void
+xlog_cil_flush(
+ struct xlog *log)
+{
+ xfs_csn_t seq = log->l_cilp->xc_current_sequence;
+
+ trace_xfs_log_force(log->l_mp, seq, _RET_IP_);
+ xlog_cil_push_now(log, seq, true);
+}
+
/*
* Conditionally push the CIL based on the sequence passed in.
*
- * We only need to push if we haven't already pushed the sequence
- * number given. Hence the only time we will trigger a push here is
- * if the push sequence is the same as the current context.
+ * We only need to push if we haven't already pushed the sequence number given.
+ * Hence the only time we will trigger a push here is if the push sequence is
+ * the same as the current context.
*
* We return the current commit lsn to allow the callers to determine if a
* iclog flush is necessary following this call.
@@ -1130,13 +1170,17 @@ xlog_cil_force_seq(
ASSERT(sequence <= cil->xc_current_sequence);
+ if (!sequence)
+ sequence = cil->xc_current_sequence;
+ trace_xfs_log_force(log->l_mp, sequence, _RET_IP_);
+
/*
* check to see if we need to force out the current context.
* xlog_cil_push() handles racing pushes for the same sequence,
* so no need to deal with it here.
*/
restart:
- xlog_cil_push_now(log, sequence);
+ xlog_cil_push_now(log, sequence, false);
/*
* See if we can find a previous sequence still committing.
@@ -1160,6 +1204,7 @@ xlog_cil_force_seq(
* It is still being pushed! Wait for the push to
* complete, then start again from the beginning.
*/
+ XFS_STATS_INC(log->l_mp, xs_log_force_sleep);
xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock);
goto restart;
}
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 2d7e7cbee8b7..a863ccb5ece6 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -273,6 +273,7 @@ struct xfs_cil {
spinlock_t xc_push_lock ____cacheline_aligned_in_smp;
xfs_csn_t xc_push_seq;
+ bool xc_push_commit_stable;
struct list_head xc_committing;
wait_queue_head_t xc_commit_wait;
xfs_csn_t xc_current_sequence;
@@ -487,9 +488,12 @@ int xlog_write(struct xlog *log, struct xfs_log_vec *log_vector,
struct xlog_in_core **commit_iclog, uint optype);
int xlog_commit_record(struct xlog *log, struct xlog_ticket *ticket,
struct xlog_in_core **iclog, xfs_lsn_t *lsn);
+
void xfs_log_ticket_ungrant(struct xlog *log, struct xlog_ticket *ticket);
void xfs_log_ticket_regrant(struct xlog *log, struct xlog_ticket *ticket);
+void xlog_state_switch_iclogs(struct xlog *log, struct xlog_in_core *iclog,
+ int eventual_size);
int xlog_state_release_iclog(struct xlog *log, struct xlog_in_core *iclog);
/*
@@ -560,6 +564,7 @@ void xlog_cil_commit(struct xlog *log, struct xfs_trans *tp,
/*
* CIL force routines
*/
+void xlog_cil_flush(struct xlog *log);
xfs_lsn_t xlog_cil_force_seq(struct xlog *log, xfs_csn_t sequence);
static inline void
diff --git a/fs/xfs/xfs_sysfs.c b/fs/xfs/xfs_sysfs.c
index f1bc88f4367c..18dc5eca6c04 100644
--- a/fs/xfs/xfs_sysfs.c
+++ b/fs/xfs/xfs_sysfs.c
@@ -10,6 +10,7 @@
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_sysfs.h"
+#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_mount.h"
diff --git a/fs/xfs/xfs_trace.c b/fs/xfs/xfs_trace.c
index 9b8d703dc9fd..d111a994b7b6 100644
--- a/fs/xfs/xfs_trace.c
+++ b/fs/xfs/xfs_trace.c
@@ -20,6 +20,7 @@
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_trans.h"
+#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_buf_item.h"
#include "xfs_quota.h"
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 87bffd12c20c..c214a69b573d 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -9,7 +9,6 @@
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
-#include "xfs_log_priv.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_extent_busy.h"
@@ -17,6 +16,7 @@
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_log.h"
+#include "xfs_log_priv.h"
#include "xfs_trace.h"
#include "xfs_error.h"
#include "xfs_defer.h"
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index dbb69b4bf3ed..69aac416e2ce 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -17,6 +17,7 @@
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_log.h"
+#include "xfs_log_priv.h"
#ifdef DEBUG
/*
@@ -429,8 +430,12 @@ xfsaild_push(
/*
* If we encountered pinned items or did not finish writing out all
- * buffers the last time we ran, force the log first and wait for it
- * before pushing again.
+ * buffers the last time we ran, force a background CIL push to get the
+ * items unpinned in the near future. We do not wait on the CIL push as
+ * that could stall us for seconds if there is enough background IO
+ * load. Stalling for that long when the tail of the log is pinned and
+ * needs flushing will hard stop the transaction subsystem when log
+ * space runs out.
*/
if (ailp->ail_log_flush && ailp->ail_last_pushed_lsn == 0 &&
(!list_empty_careful(&ailp->ail_buf_list) ||
@@ -438,7 +443,7 @@ xfsaild_push(
ailp->ail_log_flush = 0;
XFS_STATS_INC(mp, xs_push_ail_flush);
- xfs_log_force(mp, XFS_LOG_SYNC);
+ xlog_cil_flush(mp->m_log);
}
spin_lock(&ailp->ail_lock);
