On Wed 04-01-12 13:47:46, Christoph Hellwig wrote: > On Wed, Jan 04, 2012 at 07:00:33PM +0100, Jan Kara wrote: > > On Wed 04-01-12 13:50:20, Dave Chinner wrote: > > > On Wed, Jan 04, 2012 at 02:17:54AM +0000, Al Viro wrote: > > > > I'm still not > > > > sure about ->statfs(), BTW - any input on that would be welcome. Can > > > > it end up blocked on a frozen fs until said fs is thawed? > > > > > > I don't see why this should ever happen - ->statfs has to work on > > > read-only filesystems so shoul dnot be modifying state, and hence > > > should never need to care about the frozen state of the superblock. > > Well, I'm also not aware of a filesystem where ->statfs would wait on > > frozen filesystem. Just note that e.g. for stat(2) frozen filesystem and > > RO filesystem *are* different because of atime updates. So stat(2) can > > block on frozen fs because of atime update while on RO filesystem it is > > just fine. > > Neither of those should cause atime updates. Sorry, I'm not sure why I thought stat(2) would touch atime. But still my claim is correct in the sence that operations that do touch atime (follow_link, readdir, ...) behave differently on frozen filesystem and on read-only filesystem. So rDave's argument that read-only access to frozen filesystem is OK is not correct in general. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
