• Christoph Hellwig's avatar
    xfs: use per-AG reservations for the finobt · 76d771b4
    Christoph Hellwig authored
    Currently we try to rely on the global reserved block pool for block
    allocations for the free inode btree, but I have customer reports
    (fairly complex workload, need to find an easier reproducer) where that
    is not enough as the AG where we free an inode that requires a new
    finobt block is entirely full.  This causes us to cancel a dirty
    transaction and thus a file system shutdown.
    
    I think the right way to guard against this is to treat the finot the same
    way as the refcount btree and have a per-AG reservations for the possible
    worst case size of it, and the patch below implements that.
    
    Note that this could increase mount times with large finobt trees.  In
    an ideal world we would have added a field for the number of finobt
    fields to the AGI, similar to what we did for the refcount blocks.
    We should do add it next time we rev the AGI or AGF format by adding
    new fields.
    Signed-off-by: 's avatarChristoph Hellwig <hch@lst.de>
    Reviewed-by: 's avatarDarrick J. Wong <darrick.wong@oracle.com>
    Signed-off-by: 's avatarDarrick J. Wong <darrick.wong@oracle.com>
    76d771b4