* 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 it's work.
+ * 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.
*/
void
-xfs_trans_push_ail(
- xfs_mount_t *mp,
- xfs_lsn_t threshold_lsn)
+xfs_trans_ail_push(
+ struct xfs_ail *ailp,
+ xfs_lsn_t threshold_lsn)
{
- xfs_log_item_t *lip;
+ xfs_log_item_t *lip;
- lip = xfs_ail_min(mp->m_ail);
- if (lip && !XFS_FORCED_SHUTDOWN(mp)) {
- if (XFS_LSN_CMP(threshold_lsn, mp->m_ail->xa_target) > 0)
- xfsaild_wakeup(mp->m_ail, threshold_lsn);
+ 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);
}
}
/*
* Now that the traversal is complete, we need to remove the cursor
* from the list of traversing cursors. Avoid removing the embedded
- * push cursor, but use the fact it is alway present to make the
+ * push cursor, but use the fact it is always present to make the
* list deletion simple.
*/
void
list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0)
- break;
+ goto out;
}
lip = NULL;
out:
}
/*
- * Function that does the work of pushing on the AIL
+ * xfsaild_push does the work of pushing on the AIL. Returning a timeout of
+ * zero indicates that the caller should sleep until woken.
*/
long
xfsaild_push(
struct xfs_ail *ailp,
xfs_lsn_t *last_lsn)
{
- long tout = 1000; /* milliseconds */
+ long tout = 0;
xfs_lsn_t last_pushed_lsn = *last_lsn;
xfs_lsn_t target = ailp->xa_target;
xfs_lsn_t lsn;
*/
xfs_trans_ail_cursor_done(ailp, cur);
spin_unlock(&ailp->xa_lock);
- last_pushed_lsn = 0;
+ *last_lsn = 0;
return tout;
}
* prevents use from spinning when we can't do anything or there is
* lots of contention on the AIL lists.
*/
- tout = 10;
lsn = lip->li_lsn;
flush_log = stuck = count = 0;
while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) {
if (!count) {
/* We're past our target or empty, so idle */
- tout = 1000;
+ last_pushed_lsn = 0;
} else if (XFS_LSN_CMP(lsn, target) >= 0) {
/*
* We reached the target so wait a bit longer for I/O to
* complete and remove pushed items from the AIL before we
* start the next scan from the start of the AIL.
*/
- tout += 20;
+ tout = 50;
last_pushed_lsn = 0;
} else if ((stuck * 100) / count > 90) {
/*
* Backoff a bit more to allow some I/O to complete before
* continuing from where we were.
*/
- tout += 10;
+ tout = 20;
+ } else {
+ /* more to do, but wait a short while before continuing */
+ tout = 10;
}
*last_lsn = last_pushed_lsn;
return tout;
-} /* xfsaild_push */
+}
/*
*/
void
xfs_trans_unlocked_item(
- xfs_mount_t *mp,
+ struct xfs_ail *ailp,
xfs_log_item_t *lip)
{
xfs_log_item_t *min_lip;
* over some potentially valid data.
*/
if (!(lip->li_flags & XFS_LI_IN_AIL) ||
- XFS_FORCED_SHUTDOWN(mp)) {
+ XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
return;
}
* the call to xfs_log_move_tail() doesn't do anything if there's
* not enough free space to wake people up so we're safe calling it.
*/
- min_lip = xfs_ail_min(mp->m_ail);
+ min_lip = xfs_ail_min(ailp);
if (min_lip == lip)
- xfs_log_move_tail(mp, 1);
+ xfs_log_move_tail(ailp->xa_mount, 1);
} /* xfs_trans_unlocked_item */
* is dropped before returning.
*/
void
-xfs_trans_update_ail(
- xfs_mount_t *mp,
+xfs_trans_ail_update(
+ struct xfs_ail *ailp,
xfs_log_item_t *lip,
xfs_lsn_t lsn) __releases(ailp->xa_lock)
{
- struct xfs_ail *ailp = mp->m_ail;
xfs_log_item_t *dlip = NULL;
xfs_log_item_t *mlip; /* ptr to minimum lip */
+ xfs_lsn_t tail_lsn;
mlip = xfs_ail_min(ailp);
if (mlip == dlip) {
mlip = xfs_ail_min(ailp);
+ /*
+ * It is not safe to access mlip after the AIL lock is
+ * dropped, so we must get a copy of li_lsn before we do
+ * so. This is especially important on 32-bit platforms
+ * where accessing and updating 64-bit values like li_lsn
+ * is not atomic.
+ */
+ tail_lsn = mlip->li_lsn;
spin_unlock(&ailp->xa_lock);
- xfs_log_move_tail(mp, mlip->li_lsn);
+ xfs_log_move_tail(ailp->xa_mount, tail_lsn);
} else {
spin_unlock(&ailp->xa_lock);
}
* is dropped before returning.
*/
void
-xfs_trans_delete_ail(
- xfs_mount_t *mp,
+xfs_trans_ail_delete(
+ struct xfs_ail *ailp,
xfs_log_item_t *lip) __releases(ailp->xa_lock)
{
- struct xfs_ail *ailp = mp->m_ail;
xfs_log_item_t *dlip;
xfs_log_item_t *mlip;
+ xfs_lsn_t tail_lsn;
if (lip->li_flags & XFS_LI_IN_AIL) {
mlip = xfs_ail_min(ailp);
if (mlip == dlip) {
mlip = xfs_ail_min(ailp);
+ /*
+ * It is not safe to access mlip after the AIL lock
+ * is dropped, so we must get a copy of li_lsn
+ * before we do so. This is especially important
+ * on 32-bit platforms where accessing and updating
+ * 64-bit values like li_lsn is not atomic.
+ */
+ tail_lsn = mlip ? mlip->li_lsn : 0;
spin_unlock(&ailp->xa_lock);
- xfs_log_move_tail(mp, (mlip ? mlip->li_lsn : 0));
+ xfs_log_move_tail(ailp->xa_mount, tail_lsn);
} else {
spin_unlock(&ailp->xa_lock);
}
* If the file system is not being shutdown, we are in
* serious trouble if we get to this stage.
*/
+ struct xfs_mount *mp = ailp->xa_mount;
+
spin_unlock(&ailp->xa_lock);
if (!XFS_FORCED_SHUTDOWN(mp)) {
xfs_cmn_err(XFS_PTAG_AILDELETE, CE_ALERT, mp,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff