Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
xfs: copy li_lsn before dropping AIL lock
XFS bug in log recover with quota (bugzilla id 855)

fs/xfs/xfs_log_recover.c

···
 					"XFS: NULL dquot in %s.", __func__);
 				goto next;
 			}
-			if (item->ri_buf[i].i_len < sizeof(xfs_dqblk_t)) {
+			if (item->ri_buf[i].i_len < sizeof(xfs_disk_dquot_t)) {
 				cmn_err(CE_ALERT,
 					"XFS: dquot too small (%d) in %s.",
 					item->ri_buf[i].i_len, __func__);
···
 			"XFS: NULL dquot in %s.", __func__);
 		return XFS_ERROR(EIO);
 	}
-	if (item->ri_buf[1].i_len < sizeof(xfs_dqblk_t)) {
+	if (item->ri_buf[1].i_len < sizeof(xfs_disk_dquot_t)) {
 		cmn_err(CE_ALERT,
 			"XFS: dquot too small (%d) in %s.",
 			item->ri_buf[1].i_len, __func__);

fs/xfs/xfs_trans_ail.c

···
 {
 	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(ailp->xa_mount, mlip->li_lsn);
+		xfs_log_move_tail(ailp->xa_mount, tail_lsn);
 	} else {
 		spin_unlock(&ailp->xa_lock);
 	}
···
 {
 	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(ailp->xa_mount,
-						(mlip ? mlip->li_lsn : 0));
+			xfs_log_move_tail(ailp->xa_mount, tail_lsn);
 		} else {
 			spin_unlock(&ailp->xa_lock);
 		}