to prevent delegations from claiming all available slots in the attribute cache, nfs41_name_cache_insert() now returns ERROR_TOO_MANY_OPEN_FILES when the number of delegated entries reaches 50% of the cache capacity. see comment 'delegations and cache feedback' in name_cache.c for details
when nfs41_open() sees this error from nfs41_name_cache_insert(), it calls new function nfs41_client_delegation_return_lru() to return the least-recently-used delegation and, if successful, loops back to nfs41_name_cache_insert(). nfs41_client_delegation_return_lru() returns NFS4ERR_BADHANDLE if all delegations are currently in use (associated with an existing open), in which case nfs41_open() returns the newly-granted delegation
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
added 2011 year to the copyright line
added authors info to the license
added UofM license to libtirpc files that we modified
(but i probably missed some)
new flags for nfs41_lock_state: exclusive, delegated, and id
on lock, open_lock_delegate() attempts to register a delegated lock instead of sending a LOCK request to the server
on unlock, open_unlock_delegate() removes/frees delegated locks instead of sending a LOCKU request
on delegreturn, delegation_flush_locks() sends LOCK requests for all delegated locks before returning a delegation
on recovery, recover_locks() avoids lock state recovery for delegated locks
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
10.2.1. Delegation Recovery (re: client restart/lease expiration)
A server MAY support claim types of CLAIM_DELEGATE_PREV and CLAIM_DELEG_PREV_FH, and if it does, it MUST NOT remove delegations upon a CREATE_SESSION that confirm a client ID created by EXCHANGE_ID. Instead, the server MUST, for a period of time no less than that of the value of the lease_time attribute, maintain the client's delegations to allow time for the client to send CLAIM_DELEGATE_PREV and/or CLAIM_DELEG_PREV_FH requests. The server that supports CLAIM_DELEGATE_PREV and/or CLAIM_DELEG_PREV_FH MUST support the DELEGPURGE operation.
if there's a delegation to reclaim, recover_open_no_grace() now tries CLAIM_DELEGATE_PREV (supported by emc server, but not linux) before falling back to CLAIM_NULL
nfs41_client_delegation_recovery() sends DELEGPURGE to indicate that we're finished reclaiming delegations
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
while the server is required to grant us delegations we reclaim through CLAIM_PREVIOUS, it may set the flag recalled=TRUE if it's not ready to grant the delegation. the client is then responsible for flushing modified state to the server and returning the delegation
new function nfs41_client_delegation_recovery() cleans up after delegation recovery by a) returning any delegations flagged as recalled, and b) 'forgetting' any delegations that we failed to reclaim. this function is called under the client's state recovery lock, directly after open and delegation state is recovered
added 'try_recovery' argument to delegation_return(), allowing it to be called during client state recovery. split out the code that removes the delegation from the client and its opens into delegation_remove(), which is what nfs41_client_delegation_recovery() uses to 'forget' a delegation
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
delegation stateid arguments to DELEGRETURN and OPEN are now stateid_arg, for use with recover_stateid_delegation(). added a nfs41_delegation_state pointer to stateid_arg, for when a delegation stateid is used in the absence of nfs41_open_state (DELEGRETURN, SETATTR)
recovery during a call to nfs41_delegation_to_open() requires special attention; recover_stateid_delegation() has to handle the case where recover_open() already reclaimed the open stateid. it does this by returning BAD_STATEID instead of retrying the OPEN (which would generate yet another open stateid)
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
recover_client_state() flags all delegations as revoked before starting open state recovery. if recover_open() finds that its delegation is revoked, it attempts to recover it using CLAIM_PREVIOUS. if its delegation has already been reclaimed by another open, it can skip reclaiming the open stateid (provided it has no byte-range locks to reclaim). after all opens have been reclaimed, any delegations still marked 'revoked' are passed to recover_delegation(). recover_delegation() also uses CLAIM_PREVIOUS (or CLAIM_NULL outside of the grace period) to reclaim the delegation, but has to throw away the open stateid with CLOSE
added a try_recovery argument to nfs41_delegreturn() and nfs41_delegation_granted(), so it can be called by recover_open() if OPEN grants an unexpected open
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
nfs41_open() in open.c is no longer used for recovery, so made static and renamed to do_open(). renamed nfs41_rpc_open() back to nfs41_open()
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
prevent an OPEN with OPEN4_CREATE from breaking a write delegation by sending a SETATTR instead
moved static function remove_unsupported_attrs() from setattr.c to nfs41_superblock_supported_attrs() in nfs41_superblock.c, now used by both setattr.c and delegation.c
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
new function nfs41_delegation_return() for synchronous delegation return. uses a condition variable to wait if another thread is already returning the delegation
if nfs41_delegate_open() would conflict with a delegation, return it before sending the OPEN
return the delegation before sending LINK, RENAME, REMOVE, and SETATTR
all of this functionality is dependent on the preprocessor define DELEGATION_RETURN_ON_CONFLICT (on by default). if not defined, nfs41_delegation_return() is a noop
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
moved thread creation from callback_server.c to nfs41_delegation_recall() in delegation.c
nfs41_delegation_recall() first searches for the delegation, and returns NFS4ERR_BADHANDLE if not found. otherwise, it spawns a thread to handle the recall and returns NFS4_OK
delegation_return() calls nfs41_delegation_to_open() for each nfs41_open_state associated with the delegation
nfs41_delegation_to_open() sends OPEN with CLAIM_DELEGATE_CUR to reclaim an open stateid, and uses a condition variable in nfs41_open_state to prevent multiple threads from attempting reclaim
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
added delegation.c and .h
nfs41_client stores a list of nfs41_delegation_state
new function nfs41_delegate_open() to look for a compatible delegation before calling nfs41_open()
if nfs41_open() is granted a delegation, call nfs41_delegation_granted() to register it with the client
client calls nfs41_client_delegation_free() on unmount to free list of delegations
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
