* mount: remember the entry of a directory removed while still referenced
A directory removed while a descriptor is open on it keeps its inode until
the kernel's final forget, but unlike a file it has no handle to live on
through: OpenDir hands out only a listing cursor. Keep the last-known entry
in memory, keyed by inode, from rmdir until that forget.
Claude-Session: https://claude.ai/code/session_01GYqLENjZzbV5hgt4L8cSAK
* mount: serve metadata ops on a removed open directory from its remembered entry
fchmod, futimens, and the f*xattr calls on a descriptor whose directory was
removed failed with ENOENT: maybeReadEntry resolved the inode to a path, and
rmdir had already dropped it. Fall back to the remembered entry the same way
an unlinked file falls back to its open handle. Mutations publish a changed
copy back rather than editing in place, so a concurrent reader never sees a
half-applied change, and the empty path keeps nlink 0 in every reply.
Claude-Session: https://claude.ai/code/session_01GYqLENjZzbV5hgt4L8cSAK
* mount: stash the entry the delete itself returned, not an earlier snapshot
A chmod landing between Rmdir's entry load and the delete RPC would be
resurrected pre-change: the remembered entry was the earlier local snapshot.
The filer serializes the delete against updates under the path lock and hands
the entry back in the delete event, so prefer that, keeping the local load
for the sticky-bit check and as fallback when no event comes back.
Claude-Session: https://claude.ai/code/session_01GYqLENjZzbV5hgt4L8cSAK
* mount: drop a remembered entry whose insert lost to the final forget
The forget's cleanup runs between RemovePath and the insert when the kernel
evicts the inode concurrently, finds nothing, and the entry would sit in the
map for the life of the mount. Re-check the inode after inserting and take
the entry back out; every interleaving now ends with the map empty.
Claude-Session: https://claude.ai/code/session_01GYqLENjZzbV5hgt4L8cSAK
* mount: insert the remembered entry under the inode table lock
The post-insert HasInode re-check could be fooled by inode number reuse: a
lookup landing between the forget and the check makes the number look alive
and the stale entry stays, keyed to someone else's inode. Do not check after
the fact — RemovePath now runs the retention callback inside its critical
section, where the forget that releases under the same lock cannot have run
and cannot be missed. Publishes need no such fence: their open descriptor
keeps the kernel from issuing the final forget in the first place.
Claude-Session: https://claude.ai/code/session_01GYqLENjZzbV5hgt4L8cSAK
Chris Lu
86a189ff80