Thanks good point. I was trying to imitate how a jbd2 commit I guess. There's no reason really to do this in atomic way. I'll fix this in next version. On Thu, Oct 17, 2019 at 6:56 PM Theodore Y. Ts'o <tytso@xxxxxxx> wrote: > > On Tue, Oct 01, 2019 at 12:41:01AM -0700, Harshad Shirwadkar wrote: > > + > > +Multiple fast commit blocks are a part of one sub-transaction. To > > +indicate the last block in a fast commit transaction, fc_flags field > > +in the last block in every subtransaction is marked with "LAST" (0x1) > > +flag. A subtransaction is valid only if all the following conditions > > +are met: > > + > > +1) SUBTID of all blocks is either equal to or greater than SUBTID of > > + the previous fast commit block. > > +2) For every sub-transaction, last block is marked with LAST flag. > > +3) There are no invalid blocks in between. > > I'm wondering why we need to support multiple inodes being modified in > a single transaction. As we currently have defined what can be done, > all updates to an inode should be free standing and not dependent on a > change to another inode, right? And today, one block only modifies > one inode. > > The only reason why we might want to define a sub-transaction as being > composed of multiple inodes, which must all be updated in an > all-or-nothing fashion, is the swap boot inode ioctl, and if that's > the only one, I wonder if it's worth the extra complexity. > > Am I missing anything? > > - Ted
