Here it is. The long awaited removal of the client_mutex from knfsd.
As many of us are aware, one of the major bottlenecks in NFSv4 serving
is the fact that all compounds are processed while holding a single,
global mutex.
This has an obvious detrimental effect on scalability. I've heard
anecdotal reports of 10x slowdowns with v4 serving vs. v3 on the same
machine, primarily due to it.
This patchset eliminates that mutex and (hopefully!) the bottleneck
that it imposes. The basic idea is to add refcounting to most of the
objects that compounds deal with to ensure that they are pinned while
in use. Spinlocks are used to protect things like the hashtables and
trees that track the objects.
Benny started this set quite some time ago, and Trond took up the
torch early this spring. He then handed it to me to clean up the
remaining bits about a month ago.
I'd like to see this considered for v3.17. Obviously, getting it into
linux-next ASAP would be a good thing once it passes review.
Some other highlights/notes:
- use of lockdep has been greatly increased. I found it was the only
way to ensure that I didn't create lock inversion problems and such.
- clients are now only looked up once per compund and are cached in
the cstate. This keeps us from having to keep searching for the
same client for each compound op.
- openowners and lockowners are now handled more sanely. References
to them are only held by the stateids that are associated with them,
and they are destroyed when the last reference to them is put. Also,
lockowners can now have more than one stateid (in accordance with
the spec)
- the fault injection code has been overhauled. It should look the same
to users, but it needed major work to deal with the new locking.
It's probably possible to consolidate some of that code as well --
it more cut-and-pastey than I'd like.
- I've added a file to document how all of the moving parts fit
together. It probably can use more fleshing out, but it's a start.
- the lease handling is now a bit more complex than I'd like. Lease
removal in particular is currently called under a spinlock, which
I think we'll need to eventually clean up. For now, this is ok
since the first thing that vfs_setlease does is lock the i_lock,
but I think we'll eventually need to do an i_lock pushdown in the
lease handling code, and ensure that vfs_setlease isn't called
under a spinlock.
As always, comments and review are welcome.
Benny Halevy (1):
nfsd4: use cl_lock to synchronize all stateid idr calls
Jeff Layton (40):
NFSd: Ensure that nfs4_file_get_access enforces share access modes
locks: add file_has_lease
NFSd: Protect the nfs4_file delegation fields using the fi_lock
NFSd: Allow lockowners to hold several stateids
NFSd: Ensure atomicity of stateid destruction and idr tree removal
NFSd: Cleanup the freeing of stateids
nfsd: do filp_close in sc_free callback for lock stateids
NFSd: Add locking to protect the state owner lists
nfsd: clean up races in lock stateid searching and creation
nfsd: clean up lockowner refcounting when finding them
nfsd: add an operation for unhashing a stateowner
nfsd: clean up nfs4_release_lockowner
nfsd: clean up refcounting for lockowners
nfsd: declare v4.1+ openowners confirmed on creation
nfsd: make openstateids hold references to their openowners
nfsd: don't allow CLOSE to proceed until refcount on stateid drops
lockdep: add lockdep_assert_not_held
nfsd: add locking to stateowner release
nfsd: optimize destroy_lockowner cl_lock thrashing
nfsd: reduce cl_lock trashing in release_openowner
NFSd: Protect session creation and client confirm using client_lock
nfsd: protect the close_lru list and oo_last_closed_stid with
client_lock
nfsd: ensure that clp->cl_revoked list is protected by clp->cl_lock
nfsd: move unhash_client_locked call into mark_client_expired_locked
nfsd: fix misleading comment
nfsd: don't destroy client if mark_client_expired_locked fails
nfsd: don't destroy clients that are busy
nfsd: abstract out the get and set routines into the fault injection
ops
nfsd: add a forget_clients "get" routine with proper locking
nfsd: add a forget_client set_clnt routine
nfsd: add nfsd_inject_forget_clients
nfsd: add a list_head arg to nfsd_foreach_client_lock
nfsd: add more granular locking to forget_locks fault injector
nfsd: add more granular locking to forget_openowners fault injector
nfsd: add more granular locking to *_delegations fault injectors
nfsd: remove old fault injection infrastructure
nfsd: remove nfs4_lock_state: nfs4_laundromat
nfsd: remove nfs4_lock_state: nfs4_state_shutdown_net
nfsd: remove the client_mutex and the nfs4_lock/unlock_state wrappers
nfsd: add file documenting new state object model
Trond Myklebust (63):
nfsd: Protect addition to the file_hashtbl
NFSd: Avoid taking state_lock while holding inode lock in
nfsd_break_one_deleg
NFSd: nfs4_preprocess_seqid_op should only set *stpp on success
NFSd: Add fine grained protection for the nfs4_file->fi_stateids list
NFSd: Add a mutex to protect the NFSv4.0 open owner replay cache
NFSd: Add locking to the nfs4_file->fi_fds[] array
NFSd: Lock owners are not per open stateid
NFSd: Clean up helper __release_lock_stateid
NFSd: NFSv4 lock-owners are not associated to a specific file
NFSd: Cleanup nfs4svc_encode_compoundres
NFSd: Don't get a session reference without a client reference
NFSd: Allow struct nfsd4_compound_state to cache the nfs4_client
NFSd: Move the delegation reference counter into the struct nfs4_stid
NFSd: Simplify stateid management
NFSd: Fix delegation revocation
NFSd: Add reference counting to the lock and open stateids
NFSd: clean up nfsd4_close_open_stateid
NFSd: Add a struct nfs4_file field to struct nfs4_stid
NFSd: Replace nfs4_ol_stateid->st_file with the st_stid.sc_file
NFSd: Ensure stateids remain unique until they are freed
NFSd: Convert delegation counter to an atomic_long_t type
NFSd: Slight cleanup of find_stateid()
NFSd: Add reference counting to find_stateid
NFSd: Add reference counting to lock stateids
NFSd: nfsd4_locku() must reference the lock stateid
NFSd: Ensure that nfs4_open_delegation() references the delegation
stateid
NFSd: nfsd4_process_open2() must reference the delegation stateid
NFSd: nfsd4_process_open2() must reference the open stateid
NFSd: Prepare nfsd4_close() for open stateid referencing
NFSd: nfsd4_open_confirm() must reference the open stateid
NFSd: Add reference counting to nfs4_preprocess_confirmed_seqid_op
NFSd: Migrate the stateid reference into nfs4_preprocess_seqid_op
NFSd: Migrate the stateid reference into nfs4_lookup_stateid()
NFSd: Migrate the stateid reference into nfs4_find_stateid_by_type()
NFSd: Add reference counting to state owners
NFSd: Keep a reference to the open stateid for the NFSv4.0 replay
cache
NFSd: Make lock stateid take a reference to the lockowner
NFSd: Protect adding/removing open state owners using client_lock
NFSd: Protect adding/removing lock owners using client_lock
NFSd: Cleanup - Let nfsd4_lookup_stateid() take a cstate argument
NFSd: Cache the client that was looked up in lookup_clientid()
NFSd: Convert nfsd4_process_open1() to work with lookup_clientid()
NFSd: Always use lookup_clientid() in nfsd4_process_open1
NFSd: Move the open owner hash table into struct nfs4_client
NFSd: Convert nfs4_check_open_reclaim() to work with lookup_clientid()
NFSd: Ensure struct nfs4_client is unhashed before we try to destroy
it
NFSd: Ensure that the laundromat unhashes the client before releasing
locks
NFSd: Don't require client_lock in free_client
NFSd: Move create_client() call outside the lock
NFSd: Protect unconfirmed client creation using client_lock
NFSd: Protect nfsd4_destroy_clientid using client_lock
NFSd: Ensure lookup_clientid() takes client_lock
NFSd: Add assertions to document the nfs4_client/session locking
NFSd: Remove nfs4_lock_state(): nfs4_preprocess_stateid_op()
NFSd: Remove nfs4_lock_state(): nfsd4_test_stateid/nfsd4_free_stateid
NFSd: Remove nfs4_lock_state(): nfsd4_release_lockowner
NFSd: Remove nfs4_lock_state(): nfsd4_lock/locku/lockt()
NFSd: Remove nfs4_lock_state(): nfsd4_open_downgrade + nfsd4_close
NFSd: Remove nfs4_lock_state(): nfsd4_delegreturn()
NFSd: Remove nfs4_lock_state(): nfsd4_open and nfsd4_open_confirm
NFSd: Remove nfs4_lock_state(): exchange_id, create/destroy_session()
NFSd: Remove nfs4_lock_state(): setclientid, setclientid_confirm,
renew
NFSd: Remove nfs4_lock_state(): reclaim_complete()
.../filesystems/nfs/nfsd4-state-objects.txt | 110 +
fs/locks.c | 26 +
fs/nfsd/fault_inject.c | 129 +-
fs/nfsd/netns.h | 5 -
fs/nfsd/nfs4callback.c | 18 +-
fs/nfsd/nfs4proc.c | 16 +-
fs/nfsd/nfs4state.c | 2569 ++++++++++++++------
fs/nfsd/nfs4xdr.c | 17 +-
fs/nfsd/state.h | 86 +-
fs/nfsd/xdr4.h | 8 +-
include/linux/fs.h | 6 +
include/linux/lockdep.h | 6 +
12 files changed, 2052 insertions(+), 944 deletions(-)
create mode 100644 Documentation/filesystems/nfs/nfsd4-state-objects.txt
--
1.9.3
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