Re: [PATCH] e2fsprogs: error checking in blkid/devname.c

[Theodore Tso <tytso@MIT.EDU>]

On Fri, Feb 22, 2008 at 09:02:56AM -0600, Eric Sandeen wrote:
> Theodore Tso wrote:
> > This looks good, but I assume that the bug was caused by some race
> > condition where if you try to call dm_task_get_info() while some other
> > process is creating or removing a snapshot, dm_task_get_info() is
> > returning some kind of EAGAIN, or some other "Try again; we're busy"
> > error, right?
> > 
> > If that is the case, can you try to find out what error is being
> > returned?  It may be the right thing to do is to check to see if we
> > are getting a "resource is locked; try again in a sec" error message,
> > and retry the dm_task_get_info(), instead of just returning a failure.
> 
> well, dm_task_get_info just returns either 0 or 1; unless there is some
> other contextual piece of information to use, I don't know if we can
> differentiate between error types.  I'll ask agk...

Maybe the right thing is to try 3 times before giving up, maybe with a
nanosleep in between, or some such?  Hopefully agk can give us some
hints about what's the right way to handle errors from all of the
dm_task* calls.

Thanks!!

						- Ted