On Fri, Jan 30, 2015 at 09:44:03AM +0800, Qu Wenruo wrote: > This shouldn't happen. If someone is ro, the whole fs should be ro, right? Wrong. Individual vfsmounts over an r/w superblock might very well be r/o. As for that trylock... What for? It invites transient failures for no good reason. Removal of sysfs entry will block while write(2) to that sucker is in progress, so btrfs shutdown will block at that point in ctree_close(). It won't go away under you. Now, you might want to move those sysfs entry removals to the very beginning of btrfs_kill_super(), but that's a different story - you need only to make sure that they are removed not later than the destruction of the data structures they need (IOW, the current location might very well be OK - I hadn't checked the details). As for "it won't go r/o under us" - sb_want_write() will do that just fine. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
