On Mon, Jul 11, 2016 at 03:06:03PM +0800, Kaho Ng wrote: > Just wonders why we prefer failing the request of refilling freelist > with XFS_WANT_CORRUPTED_RETURN(mp, i == 1) in some rare case, rather > than returning NULLAGBLOCK and allowing the loop in > xfs_alloc_ag_vextent_size() to try xfs_alloc_ag_vextent_small()... Have a look at where xfs_alloc_ag_vextent_small() gets the blocks it returns to the caller if the btree cursor doesn't point to a btree record we can use. i.e. you can't refill the free list from xfs_alloc_ag_vextent_small() because it allocates blocks from ... > In > such corner case there will always be a lot of small extents at the > front of the by-count tree, and any truncation changes to the first > entry in the tree will not result in tree splits and triggering > assertion failure. If there are records we can use, then we'll allocate them from the btree. Failure to allocate from the btree indicates something is inconsistent, there's a bug in the code or we've got corruption occuring. A corruption shutdown is the only safe course of action when we find something confusing like this - if we guess wrong them we'll only make the bad state/corruption worse. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
