* flushed to disk. It is responsible for removing the inode item
* from the AIL if it has not been re-logged, and unlocking the inode's
* flush lock.
+ *
+ * To reduce AIL lock traffic as much as possible, we scan the buffer log item
+ * list for other inodes that will run this function. We remove them from the
+ * buffer list so we can process all the inode IO completions in one AIL lock
+ * traversal.
*/
void
xfs_iflush_done(
struct xfs_buf *bp,
struct xfs_log_item *lip)
{
- struct xfs_inode_log_item *iip = INODE_ITEM(lip);
- xfs_inode_t *ip = iip->ili_inode;
+ struct xfs_inode_log_item *iip;
+ struct xfs_log_item *blip;
+ struct xfs_log_item *next;
+ struct xfs_log_item *prev;
struct xfs_ail *ailp = lip->li_ailp;
+ int need_ail = 0;
+
+ /*
+ * Scan the buffer IO completions for other inodes being completed and
+ * attach them to the current inode log item.
+ */
+ blip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
+ prev = NULL;
+ while (blip != NULL) {
+ if (lip->li_cb != xfs_iflush_done) {
+ prev = blip;
+ blip = blip->li_bio_list;
+ continue;
+ }
+
+ /* remove from list */
+ next = blip->li_bio_list;
+ if (!prev) {
+ XFS_BUF_SET_FSPRIVATE(bp, next);
+ } else {
+ prev->li_bio_list = next;
+ }
+
+ /* add to current list */
+ blip->li_bio_list = lip->li_bio_list;
+ lip->li_bio_list = blip;
+
+ /*
+ * while we have the item, do the unlocked check for needing
+ * the AIL lock.
+ */
+ iip = INODE_ITEM(blip);
+ if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn)
+ need_ail++;
+
+ blip = next;
+ }
+
+ /* make sure we capture the state of the initial inode. */
+ iip = INODE_ITEM(lip);
+ if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn)
+ need_ail++;
/*
* We only want to pull the item from the AIL if it is
* the lock since it's cheaper, and then we recheck while
* holding the lock before removing the inode from the AIL.
*/
- if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) {
+ if (need_ail) {
+ struct xfs_log_item *log_items[need_ail];
+ int i = 0;
spin_lock(&ailp->xa_lock);
- if (lip->li_lsn == iip->ili_flush_lsn) {
- /* xfs_trans_ail_delete() drops the AIL lock. */
- xfs_trans_ail_delete(ailp, lip);
- } else {
- spin_unlock(&ailp->xa_lock);
+ for (blip = lip; blip; blip = blip->li_bio_list) {
+ iip = INODE_ITEM(blip);
+ if (iip->ili_logged &&
+ blip->li_lsn == iip->ili_flush_lsn) {
+ log_items[i++] = blip;
+ }
+ ASSERT(i <= need_ail);
}
+ /* xfs_trans_ail_delete_bulk() drops the AIL lock. */
+ xfs_trans_ail_delete_bulk(ailp, log_items, i);
}
- iip->ili_logged = 0;
/*
- * Clear the ili_last_fields bits now that we know that the
- * data corresponding to them is safely on disk.
+ * clean up and unlock the flush lock now we are done. We can clear the
+ * ili_last_fields bits now that we know that the data corresponding to
+ * them is safely on disk.
*/
- iip->ili_last_fields = 0;
+ for (blip = lip; blip; blip = next) {
+ next = blip->li_bio_list;
+ blip->li_bio_list = NULL;
- /*
- * Release the inode's flush lock since we're done with it.
- */
- xfs_ifunlock(ip);
+ iip = INODE_ITEM(blip);
+ iip->ili_logged = 0;
+ iip->ili_last_fields = 0;
+ xfs_ifunlock(iip->ili_inode);
+ }
}
/*
}
}
+/*
+ * xfs_trans_ail_delete_bulk - remove multiple log items from the AIL
+ *
+ * @xfs_trans_ail_delete_bulk takes an array of log items that all need to
+ * removed from the AIL. The caller is already holding the AIL lock, and done
+ * all the checks necessary to ensure the items passed in via @log_items are
+ * ready for deletion. This includes checking that the items are in the AIL.
+ *
+ * For each log item to be removed, unlink it from the AIL, clear the IN_AIL
+ * flag from the item and reset the item's lsn to 0. If we remove the first
+ * item in the AIL, update the log tail to match the new minimum LSN in the
+ * AIL.
+ *
+ * This function will not drop the AIL lock until all items are removed from
+ * the AIL to minimise the amount of lock traffic on the AIL. This does not
+ * greatly increase the AIL hold time, but does significantly reduce the amount
+ * of traffic on the lock, especially during IO completion.
+ *
+ * This function must be called with the AIL lock held. The lock is dropped
+ * before returning.
+ */
+void
+xfs_trans_ail_delete_bulk(
+ struct xfs_ail *ailp,
+ struct xfs_log_item **log_items,
+ int nr_items) __releases(ailp->xa_lock)
+{
+ xfs_log_item_t *mlip;
+ xfs_lsn_t tail_lsn;
+ int mlip_changed = 0;
+ int i;
+
+ mlip = xfs_ail_min(ailp);
+
+ for (i = 0; i < nr_items; i++) {
+ struct xfs_log_item *lip = log_items[i];
+ if (!(lip->li_flags & XFS_LI_IN_AIL)) {
+ 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,
+ "%s: attempting to delete a log item that is not in the AIL",
+ __func__);
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+ }
+ return;
+ }
+
+ xfs_ail_delete(ailp, lip);
+ lip->li_flags &= ~XFS_LI_IN_AIL;
+ lip->li_lsn = 0;
+ if (mlip == lip)
+ mlip_changed = 1;
+ }
+
+ if (!mlip_changed) {
+ spin_unlock(&ailp->xa_lock);
+ return;
+ }
+
+ /*
+ * 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. It is possible we've emptied the
+ * AIL here, so if that is the case, pass an LSN of 0 to the tail move.
+ */
+ mlip = xfs_ail_min(ailp);
+ tail_lsn = mlip ? mlip->li_lsn : 0;
+ spin_unlock(&ailp->xa_lock);
+ xfs_log_move_tail(ailp->xa_mount, tail_lsn);
+}
/*
projects / users / willy / pagecache.git / commitdiff