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Diffstat (limited to 'fs/xfs/xfs_trans_ail.c')
-rw-r--r--fs/xfs/xfs_trans_ail.c421
1 files changed, 231 insertions, 190 deletions
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 12aff9584e2..acdb92f14d5 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -28,74 +28,138 @@
#include "xfs_trans_priv.h"
#include "xfs_error.h"
-STATIC void xfs_ail_splice(struct xfs_ail *, struct list_head *, xfs_lsn_t);
-STATIC void xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *);
-STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *);
-STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *);
+struct workqueue_struct *xfs_ail_wq; /* AIL workqueue */
#ifdef DEBUG
-STATIC void xfs_ail_check(struct xfs_ail *, xfs_log_item_t *);
-#else
+/*
+ * Check that the list is sorted as it should be.
+ */
+STATIC void
+xfs_ail_check(
+ struct xfs_ail *ailp,
+ xfs_log_item_t *lip)
+{
+ xfs_log_item_t *prev_lip;
+
+ if (list_empty(&ailp->xa_ail))
+ return;
+
+ /*
+ * Check the next and previous entries are valid.
+ */
+ ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
+ prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
+ if (&prev_lip->li_ail != &ailp->xa_ail)
+ ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
+
+ prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
+ if (&prev_lip->li_ail != &ailp->xa_ail)
+ ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
+
+
+#ifdef XFS_TRANS_DEBUG
+ /*
+ * Walk the list checking lsn ordering, and that every entry has the
+ * XFS_LI_IN_AIL flag set. This is really expensive, so only do it
+ * when specifically debugging the transaction subsystem.
+ */
+ prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
+ list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
+ if (&prev_lip->li_ail != &ailp->xa_ail)
+ ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
+ ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
+ prev_lip = lip;
+ }
+#endif /* XFS_TRANS_DEBUG */
+}
+#else /* !DEBUG */
#define xfs_ail_check(a,l)
#endif /* DEBUG */
+/*
+ * Return a pointer to the first item in the AIL. If the AIL is empty, then
+ * return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_min(
+ struct xfs_ail *ailp)
+{
+ if (list_empty(&ailp->xa_ail))
+ return NULL;
+
+ return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
+}
+
+ /*
+ * Return a pointer to the last item in the AIL. If the AIL is empty, then
+ * return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_max(
+ struct xfs_ail *ailp)
+{
+ if (list_empty(&ailp->xa_ail))
+ return NULL;
+
+ return list_entry(ailp->xa_ail.prev, xfs_log_item_t, li_ail);
+}
+
+/*
+ * Return a pointer to the item which follows the given item in the AIL. If
+ * the given item is the last item in the list, then return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_next(
+ struct xfs_ail *ailp,
+ xfs_log_item_t *lip)
+{
+ if (lip->li_ail.next == &ailp->xa_ail)
+ return NULL;
+
+ return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
+}
/*
- * This is called by the log manager code to determine the LSN
- * of the tail of the log. This is exactly the LSN of the first
- * item in the AIL. If the AIL is empty, then this function
- * returns 0.
+ * This is called by the log manager code to determine the LSN of the tail of
+ * the log. This is exactly the LSN of the first item in the AIL. If the AIL
+ * is empty, then this function returns 0.
*
- * We need the AIL lock in order to get a coherent read of the
- * lsn of the last item in the AIL.
+ * We need the AIL lock in order to get a coherent read of the lsn of the last
+ * item in the AIL.
*/
xfs_lsn_t
-xfs_trans_ail_tail(
+xfs_ail_min_lsn(
struct xfs_ail *ailp)
{
- xfs_lsn_t lsn;
+ xfs_lsn_t lsn = 0;
xfs_log_item_t *lip;
spin_lock(&ailp->xa_lock);
lip = xfs_ail_min(ailp);
- if (lip == NULL) {
- lsn = (xfs_lsn_t)0;
- } else {
+ if (lip)
lsn = lip->li_lsn;
- }
spin_unlock(&ailp->xa_lock);
return lsn;
}
/*
- * xfs_trans_push_ail
- *
- * This routine is called to move the tail of the AIL forward. It does this by
- * trying to flush items in the AIL whose lsns are below the given
- * threshold_lsn.
- *
- * the push is run asynchronously in a separate thread, so we return the tail
- * of the log right now instead of the tail after the push. This means we will
- * either continue right away, or we will sleep waiting on the async thread to
- * do its work.
- *
- * We do this unlocked - we only need to know whether there is anything in the
- * AIL at the time we are called. We don't need to access the contents of
- * any of the objects, so the lock is not needed.
+ * Return the maximum lsn held in the AIL, or zero if the AIL is empty.
*/
-void
-xfs_trans_ail_push(
- struct xfs_ail *ailp,
- xfs_lsn_t threshold_lsn)
+static xfs_lsn_t
+xfs_ail_max_lsn(
+ struct xfs_ail *ailp)
{
- xfs_log_item_t *lip;
+ xfs_lsn_t lsn = 0;
+ xfs_log_item_t *lip;
- lip = xfs_ail_min(ailp);
- if (lip && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
- if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0)
- xfsaild_wakeup(ailp, threshold_lsn);
- }
+ spin_lock(&ailp->xa_lock);
+ lip = xfs_ail_max(ailp);
+ if (lip)
+ lsn = lip->li_lsn;
+ spin_unlock(&ailp->xa_lock);
+
+ return lsn;
}
/*
@@ -236,16 +300,57 @@ out:
}
/*
- * xfsaild_push does the work of pushing on the AIL. Returning a timeout of
- * zero indicates that the caller should sleep until woken.
+ * splice the log item list into the AIL at the given LSN.
*/
-long
-xfsaild_push(
- struct xfs_ail *ailp,
- xfs_lsn_t *last_lsn)
+static void
+xfs_ail_splice(
+ struct xfs_ail *ailp,
+ struct list_head *list,
+ xfs_lsn_t lsn)
{
- long tout = 0;
- xfs_lsn_t last_pushed_lsn = *last_lsn;
+ xfs_log_item_t *next_lip;
+
+ /* If the list is empty, just insert the item. */
+ if (list_empty(&ailp->xa_ail)) {
+ list_splice(list, &ailp->xa_ail);
+ return;
+ }
+
+ list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
+ if (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0)
+ break;
+ }
+
+ ASSERT(&next_lip->li_ail == &ailp->xa_ail ||
+ XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0);
+
+ list_splice_init(list, &next_lip->li_ail);
+}
+
+/*
+ * Delete the given item from the AIL. Return a pointer to the item.
+ */
+static void
+xfs_ail_delete(
+ struct xfs_ail *ailp,
+ xfs_log_item_t *lip)
+{
+ xfs_ail_check(ailp, lip);
+ list_del(&lip->li_ail);
+ xfs_trans_ail_cursor_clear(ailp, lip);
+}
+
+/*
+ * xfs_ail_worker does the work of pushing on the AIL. It will requeue itself
+ * to run at a later time if there is more work to do to complete the push.
+ */
+STATIC void
+xfs_ail_worker(
+ struct work_struct *work)
+{
+ struct xfs_ail *ailp = container_of(to_delayed_work(work),
+ struct xfs_ail, xa_work);
+ long tout;
xfs_lsn_t target = ailp->xa_target;
xfs_lsn_t lsn;
xfs_log_item_t *lip;
@@ -256,15 +361,15 @@ xfsaild_push(
spin_lock(&ailp->xa_lock);
xfs_trans_ail_cursor_init(ailp, cur);
- lip = xfs_trans_ail_cursor_first(ailp, cur, *last_lsn);
+ lip = xfs_trans_ail_cursor_first(ailp, cur, ailp->xa_last_pushed_lsn);
if (!lip || XFS_FORCED_SHUTDOWN(mp)) {
/*
* AIL is empty or our push has reached the end.
*/
xfs_trans_ail_cursor_done(ailp, cur);
spin_unlock(&ailp->xa_lock);
- *last_lsn = 0;
- return tout;
+ ailp->xa_last_pushed_lsn = 0;
+ return;
}
XFS_STATS_INC(xs_push_ail);
@@ -301,13 +406,13 @@ xfsaild_push(
case XFS_ITEM_SUCCESS:
XFS_STATS_INC(xs_push_ail_success);
IOP_PUSH(lip);
- last_pushed_lsn = lsn;
+ ailp->xa_last_pushed_lsn = lsn;
break;
case XFS_ITEM_PUSHBUF:
XFS_STATS_INC(xs_push_ail_pushbuf);
IOP_PUSHBUF(lip);
- last_pushed_lsn = lsn;
+ ailp->xa_last_pushed_lsn = lsn;
push_xfsbufd = 1;
break;
@@ -319,7 +424,7 @@ xfsaild_push(
case XFS_ITEM_LOCKED:
XFS_STATS_INC(xs_push_ail_locked);
- last_pushed_lsn = lsn;
+ ailp->xa_last_pushed_lsn = lsn;
stuck++;
break;
@@ -374,9 +479,23 @@ xfsaild_push(
wake_up_process(mp->m_ddev_targp->bt_task);
}
+ /* assume we have more work to do in a short while */
+ tout = 10;
if (!count) {
/* We're past our target or empty, so idle */
- last_pushed_lsn = 0;
+ ailp->xa_last_pushed_lsn = 0;
+
+ /*
+ * Check for an updated push target before clearing the
+ * XFS_AIL_PUSHING_BIT. If the target changed, we've got more
+ * work to do. Wait a bit longer before starting that work.
+ */
+ smp_rmb();
+ if (ailp->xa_target == target) {
+ clear_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags);
+ return;
+ }
+ tout = 50;
} else if (XFS_LSN_CMP(lsn, target) >= 0) {
/*
* We reached the target so wait a bit longer for I/O to
@@ -384,7 +503,7 @@ xfsaild_push(
* start the next scan from the start of the AIL.
*/
tout = 50;
- last_pushed_lsn = 0;
+ ailp->xa_last_pushed_lsn = 0;
} else if ((stuck * 100) / count > 90) {
/*
* Either there is a lot of contention on the AIL or we
@@ -396,14 +515,61 @@ xfsaild_push(
* continuing from where we were.
*/
tout = 20;
- } else {
- /* more to do, but wait a short while before continuing */
- tout = 10;
}
- *last_lsn = last_pushed_lsn;
- return tout;
+
+ /* There is more to do, requeue us. */
+ queue_delayed_work(xfs_syncd_wq, &ailp->xa_work,
+ msecs_to_jiffies(tout));
+}
+
+/*
+ * This routine is called to move the tail of the AIL forward. It does this by
+ * trying to flush items in the AIL whose lsns are below the given
+ * threshold_lsn.
+ *
+ * The push is run asynchronously in a workqueue, which means the caller needs
+ * to handle waiting on the async flush for space to become available.
+ * We don't want to interrupt any push that is in progress, hence we only queue
+ * work if we set the pushing bit approriately.
+ *
+ * We do this unlocked - we only need to know whether there is anything in the
+ * AIL at the time we are called. We don't need to access the contents of
+ * any of the objects, so the lock is not needed.
+ */
+void
+xfs_ail_push(
+ struct xfs_ail *ailp,
+ xfs_lsn_t threshold_lsn)
+{
+ xfs_log_item_t *lip;
+
+ lip = xfs_ail_min(ailp);
+ if (!lip || XFS_FORCED_SHUTDOWN(ailp->xa_mount) ||
+ XFS_LSN_CMP(threshold_lsn, ailp->xa_target) <= 0)
+ return;
+
+ /*
+ * Ensure that the new target is noticed in push code before it clears
+ * the XFS_AIL_PUSHING_BIT.
+ */
+ smp_wmb();
+ ailp->xa_target = threshold_lsn;
+ if (!test_and_set_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags))
+ queue_delayed_work(xfs_syncd_wq, &ailp->xa_work, 0);
}
+/*
+ * Push out all items in the AIL immediately
+ */
+void
+xfs_ail_push_all(
+ struct xfs_ail *ailp)
+{
+ xfs_lsn_t threshold_lsn = xfs_ail_max_lsn(ailp);
+
+ if (threshold_lsn)
+ xfs_ail_push(ailp, threshold_lsn);
+}
/*
* This is to be called when an item is unlocked that may have
@@ -615,7 +781,6 @@ xfs_trans_ail_init(
xfs_mount_t *mp)
{
struct xfs_ail *ailp;
- int error;
ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL);
if (!ailp)
@@ -624,15 +789,9 @@ xfs_trans_ail_init(
ailp->xa_mount = mp;
INIT_LIST_HEAD(&ailp->xa_ail);
spin_lock_init(&ailp->xa_lock);
- error = xfsaild_start(ailp);
- if (error)
- goto out_free_ailp;
+ INIT_DELAYED_WORK(&ailp->xa_work, xfs_ail_worker);
mp->m_ail = ailp;
return 0;
-
-out_free_ailp:
- kmem_free(ailp);
- return error;
}
void
@@ -641,124 +800,6 @@ xfs_trans_ail_destroy(
{
struct xfs_ail *ailp = mp->m_ail;
- xfsaild_stop(ailp);
+ cancel_delayed_work_sync(&ailp->xa_work);
kmem_free(ailp);
}
-
-/*
- * splice the log item list into the AIL at the given LSN.
- */
-STATIC void
-xfs_ail_splice(
- struct xfs_ail *ailp,
- struct list_head *list,
- xfs_lsn_t lsn)
-{
- xfs_log_item_t *next_lip;
-
- /*
- * If the list is empty, just insert the item.
- */
- if (list_empty(&ailp->xa_ail)) {
- list_splice(list, &ailp->xa_ail);
- return;
- }
-
- list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
- if (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0)
- break;
- }
-
- ASSERT((&next_lip->li_ail == &ailp->xa_ail) ||
- (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0));
-
- list_splice_init(list, &next_lip->li_ail);
- return;
-}
-
-/*
- * Delete the given item from the AIL. Return a pointer to the item.
- */
-STATIC void
-xfs_ail_delete(
- struct xfs_ail *ailp,
- xfs_log_item_t *lip)
-{
- xfs_ail_check(ailp, lip);
- list_del(&lip->li_ail);
- xfs_trans_ail_cursor_clear(ailp, lip);
-}
-
-/*
- * Return a pointer to the first item in the AIL.
- * If the AIL is empty, then return NULL.
- */
-STATIC xfs_log_item_t *
-xfs_ail_min(
- struct xfs_ail *ailp)
-{
- if (list_empty(&ailp->xa_ail))
- return NULL;
-
- return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
-}
-
-/*
- * Return a pointer to the item which follows
- * the given item in the AIL. If the given item
- * is the last item in the list, then return NULL.
- */
-STATIC xfs_log_item_t *
-xfs_ail_next(
- struct xfs_ail *ailp,
- xfs_log_item_t *lip)
-{
- if (lip->li_ail.next == &ailp->xa_ail)
- return NULL;
-
- return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
-}
-
-#ifdef DEBUG
-/*
- * Check that the list is sorted as it should be.
- */
-STATIC void
-xfs_ail_check(
- struct xfs_ail *ailp,
- xfs_log_item_t *lip)
-{
- xfs_log_item_t *prev_lip;
-
- if (list_empty(&ailp->xa_ail))
- return;
-
- /*
- * Check the next and previous entries are valid.
- */
- ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
- prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
- if (&prev_lip->li_ail != &ailp->xa_ail)
- ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
-
- prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
- if (&prev_lip->li_ail != &ailp->xa_ail)
- ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
-
-
-#ifdef XFS_TRANS_DEBUG
- /*
- * Walk the list checking lsn ordering, and that every entry has the
- * XFS_LI_IN_AIL flag set. This is really expensive, so only do it
- * when specifically debugging the transaction subsystem.
- */
- prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
- list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
- if (&prev_lip->li_ail != &ailp->xa_ail)
- ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
- ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
- prev_lip = lip;
- }
-#endif /* XFS_TRANS_DEBUG */
-}
-#endif /* DEBUG */