Ceph

Right now our chained xattr implementation hard-codes a limit of 2K for each individual xattr. This is smaller than the filesystems generally support (just checking Wikipedia, extN and btrfs allows an xattr to be a full block, although extN also caps total xattr data at that size; xfs allows 64KB xattrs with unlimited totals) and increasing that value to what the FS supports will probably increase performance by requiring reads of fewer disk blocks to retrieve large xattrs.