> On Jul 8, 2022, at 4:27 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > On Fri, 2022-07-08 at 14:23 -0400, Chuck Lever wrote: >> This series overhauls the NFSD filecache, a cache of server-side >> "struct file" objects recently used by NFS clients. The purposes of >> this overhaul are an immediate improvement in cache scalability in >> the number of open files, and preparation for further improvements. >> >> There are three categories of patches in this series: >> >> 1. Add observability of cache operation so we can see what we're >> doing as changes are made to the code. >> >> 2. Improve the scalability of filecache garbage collection, >> addressing several bugs along the way. >> >> 3. Improve the scalability of the filecache hash table by converting >> it to use rhashtable. >> >> These patches are available in the for-next branch of: >> >> https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git >> >> Changes since v2: >> - Fix a cred use-after-free crasher >> - Fix a Smatch error reported by Dan Carpenter >> - Replace dereferences of nfsd_file::nf_inode >> - Further clean-ups and white-space adjustments >> >> Changes since RFC: >> - Fixed several crashers >> - Adjusted some of the new observability >> - Tests with generic/531 now pass >> - Fixed bugzilla 387 too, maybe >> - Plenty of clean-ups >> >> --- >> >> Chuck Lever (32): >> NFSD: Demote a WARN to a pr_warn() >> NFSD: Report filecache LRU size >> NFSD: Report count of calls to nfsd_file_acquire() >> NFSD: Report count of freed filecache items >> NFSD: Report average age of filecache items >> NFSD: Add nfsd_file_lru_dispose_list() helper >> NFSD: Refactor nfsd_file_gc() >> NFSD: Refactor nfsd_file_lru_scan() >> NFSD: Report the number of items evicted by the LRU walk >> NFSD: Record number of flush calls >> NFSD: Zero counters when the filecache is re-initialized >> NFSD: Hook up the filecache stat file >> NFSD: WARN when freeing an item still linked via nf_lru >> NFSD: Trace filecache LRU activity >> NFSD: Leave open files out of the filecache LRU >> NFSD: Fix the filecache LRU shrinker >> NFSD: Never call nfsd_file_gc() in foreground paths >> NFSD: No longer record nf_hashval in the trace log >> NFSD: Remove lockdep assertion from unhash_and_release_locked() >> NFSD: nfsd_file_unhash can compute hashval from nf->nf_inode >> NFSD: Refactor __nfsd_file_close_inode() >> NFSD: nfsd_file_hash_remove can compute hashval >> NFSD: Remove nfsd_file::nf_hashval >> NFSD: Replace the "init once" mechanism >> NFSD: Set up an rhashtable for the filecache >> NFSD: Convert the filecache to use rhashtable >> NFSD: Clean up unused code after rhashtable conversion >> NFSD: Separate tracepoints for acquire and create >> NFSD: Move nfsd_file_trace_alloc() tracepoint >> NFSD: Update the nfsd_file_fsnotify_handle_event() tracepoint >> NFSD: NFSv4 CLOSE should release an nfsd_file immediately >> NFSD: Ensure nf_inode is never dereferenced >> >> >> fs/nfsd/filecache.c | 727 ++++++++++++++++++++++++-------------- >> fs/nfsd/filecache.h | 7 +- >> fs/nfsd/nfs4proc.c | 6 +- >> fs/nfsd/nfs4state.c | 7 +- >> fs/nfsd/nfsctl.c | 10 + >> fs/nfsd/trace.h | 300 +++++++++++++--- >> include/trace/events/fs.h | 37 ++ >> 7 files changed, 774 insertions(+), 320 deletions(-) >> >> -- >> Chuck Lever >> > > Nice work, Chuck! > > You can add this to all but #15 (where I still have a question about > whether adding it to the LRU on every put is the right thing to do). Thanks for your review! #15 emulates what other list_lru consumers appear to do, but I'd like to hear from Trond and/or Dave who advocated for that approach. > Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> -- Chuck Lever
