Quoting Pekka J Enberg (penberg@xxxxxxxxxxxxxx): > Hi, > > On Wed, 19 Dec 2007, Serge E. Hallyn wrote: > > > I assume you mean S_REVOKE_LOCK and not ->i_mutex, right? > > > > No I did mean the i_mutex since you take the i_mutex when you set > > S_REVOKE_LOCK. So between that and the comment above do_lookup(), > > I assumed you were trying to lock out concurrent do_lookups() returning > > an inode whose revoke is starting at the same time. > > No, I only use ->i_mutex for synchronizing the write to ->i_flags. duh. > On Wed, 19 Dec 2007, Serge E. Hallyn wrote: > > > The caller is supposed to block open(2) with chmod(2)/chattr(2) so while > > > revoke is in progress, you can get references to the _revoked inode_, > > > which is fine (operations on it will fail with EBADFS). The > > > ->i_revoke_wait bits are there to make sure that while we revoke, you > > > can't get a _new reference_ to the inode until we're done. > > > > And a new reference means through iget(), so if revoke starts > > between the IS_REVOKE_LOCKED() check in do_lookup and its return, > > it's ok bc we'll get a reference later on? > > Yes, as soon as we unhash the dentries and the inode, do_lookup() will try > to find a new inode with iget() but we need to wait before writeback on > the revoked inode is finished. Ok, that makes sense. I'll let that sit for a short while and look again :) thanks, -serge > On Wed, 19 Dec 2007, Serge E. Hallyn wrote: > > I'm a little confused but i'll keep looking. > > I don't blame you. The patch is missing the following "minor detail" which > is needed to avoid fs corruption... > > Pekka > > Index: 2.6/fs/revoke.c > =================================================================== > --- 2.6.orig/fs/revoke.c 2007-12-16 19:57:40.000000000 +0200 > +++ 2.6/fs/revoke.c 2007-12-19 18:03:13.000000000 +0200 > @@ -426,6 +426,8 @@ int err = 0; > make_revoked_inode(inode); > remove_inode_hash(inode); > revoke_aliases(inode); > + > + err = write_inode_now(inode, 1); > failed: > revoke_unlock(inode); > wake_up(&inode->i_revoke_wait); - 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
