During page migrations UBIFS gets confused. We triggered this by using CMA on two different targets. It turned out that fallback_migrate_page() is not suitable for UBIFS as it does not copy the PagePrivate flag. Non-trivial block based filesystems do not notice since they can use buffer_migrate_page(). UBIFS is using this flag among with PageChecked to account free space. One possible solution is implementing a ->migratepage() function in UBIFS which does more or less the same as fallback_migrate_page() but also copies PagePrivate. I'm not at all sure whether this is the way to go. IMHO either page migration should not happen if ->migratepage() is not implement or fallback_migrate_page() has to work for all filesystems. Comments? Flames? :-) Thanks, //richard [PATCH 1/2] mm: Export migrate_page_move_mapping and [PATCH 2/2] UBIFS: Implement ->migratepage() -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>