On Fri, Aug 26, 2022 at 12:06:55PM -0700, Linus Torvalds wrote: > Because right now I think the main reason we cannot move the lock into > the filesystem is literally that we've made the lock cover not just > the filesystem part, but the "lookup and create dentry" part too. How about rename loop prevention? mount vs. rmdir? d_splice_alias() fun on tree reconnects? > But once you have that "DCACHE_PAR_LOOKUP" bit and the > d_alloc_parallel() logic to serialize a _particular_ dentry being > created (as opposed to serializing all the sleeping ops to that > directly), I really think we should strive to move the locking - that > no longer helps the VFS dcache layer - closer to the filesystem call > and eventually into it. See above.
