exclusive locks are no longer held over LAYOUTGET, LAYOUTRETURN, or GETDEVICEINFO rpcs. this prevents a deadlock when CB_LAYOUTRECALL needs an exclusive lock while another operation is on the wire
introduced a 'pending' condition variable to protect access to state->layout while the layout's lock is not held
updated file_layout_recall() to compare the stateid sequence numbers to determine if the server has processed an outstanding LAYOUTGET or LAYOUTRETURN, where we're required to reply with NFS4ERR_DELAY
LAYOUTGET, LAYOUTRETURN, and GETDEVICEINFO can now be sent with try_recovery=TRUE because they no longer hold an exclusive lock. this makes it possible for recover_client_state() to recall all of the client's layouts without deadlocking
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
LAYOUTGET xdr now supports decoding of multiple layout segments, which are returned in a list with pnfs_layoutget_res_ok
LAYOUTRETURN no longer operates on an existing pnfs_file_layout. it now takes a copy of the layout stateid, and returns the new stateid with pnfs_layoutreturn_res
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
send CREATE_SESSION with compound_encode_send_decode() instead of nfs41_send_compound() for its NFS4ERR_DELAY and NFS4ERR_STALE_CLIENTID handling
added 'try_recovery' argument to nfs41_create_session(), which is passed on to compound_encode_send_decode(). nfs41_session_renew() uses try_recovery=FALSE, because it handles the NFS4ERR_STALE_CLIENTID error on its own. nfs41_session_create() uses try_recovery=TRUE to make use of the NFS4ERR_STALE_CLIENTID error handling. modified the NFS4ERR_STALE_CLIENTID block to call nfs41_client_renew() and retry the operation (i.e. CREATE_SESSION), instead of falling through to session recovery
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
12.7.4. Recovery from Metadata Server Restart
"The client MUST stop using layouts and delete the device ID to device address mappings it previously received from the metadata server."
during client state recovery, call pnfs_file_layout_recall() to revoke all layouts and devices held by the client
LAYOUTGET, LAYOUTRETURN, and GETDEVICEINFO are all sent under their respective locks, and pnfs_file_layout_recall() requires a lock on each layout and device it operates on, so this would cause a deadlock if one of those operations triggered the recovery. to avoid this, LAYOUTGET, LAYOUTRETURN, and GETDEVICEINFO are all sent with try_recovery=FALSE. this behavior is preferable for recovery, because errors in the pnfs path cause us to fall back to the metadata server
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
if we see NFS4ERR_NO_GRACE from recovery operations, it means we lost our state due to a lease expiration rather than a server reboot. in this case, it's possible that conflicting locks were granted to other clients, so we have to try normal OPEN/LOCK operations to recover our state. because they're sent during recovery, nfs41_open() and nfs41_lock() take a new 'bool_t try_recovery' argument so we can avoid recursion
if these operations fail due to conflicting locks, we have no choice but to return errors to the application. using a stateid that was revoked due to lease expiration results in NFS4ERR_EXPIRED, and we map this error to ERROR_FILE_INVALID: The volume for a file has been externally altered so that the opened file is no longer valid.
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
nfs41_open_state maintains a list of outstanding byte-range locks by calling open_lock_add() and open_lock_remove() in lock.c
during client state recovery, after reclaiming each OPEN stateid, send LOCK requests with reclaim=TRUE for each lock it owns, and update the open's lock stateid with the result
added 'bool_t reclaim' argument to nfs41_lock(); when set, compound_encode_send_decode() is called with try_recovery=FALSE to avoid recursive recovery
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
avoid the recursive case where state recovery operations (OPEN for reclaim and RECLAIM_COMPLETE) return BADSESSION, which kicks off another round of recovery
added a 'bool_t try_recovery' argument to compound_encode_send_decode() in place of its unused 'bufsize_in' and 'bufsize_out'. when try_recovery=FALSE, return BADSESSION/STALE_CLIENTID errors instead of attempting recovery. nfs41_open_reclaim(), nfs41_reclaim_complete(), and nfs41_destroy_session() now pass try_recovery=FALSE
during state recovery, we can now check the return values of nfs41_open_reclaim() and nfs41_reclaim_complete() for BADSESSION, and use a goto to restart session recovery
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
operations that require a stateid now take stateid_arg for recovery information. these operations include close, setattr, lock/unlock, layoutget, and read/write (including pnfs)
nfs41_open_stateid_arg() locks nfs41_open_state and copies its stateid into a stateid_arg
nfs41_lock_stateid_arg() locks nfs41_open_state.last_lock and copies its stateid into a stateid_arg; if there is no lock state, it falls back to nfs41_open_stateid_arg()
pnfs_read/write() now take nfs41_open_state so they can generate stateid_args
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
added optional symlink argument to nfs41_create(), used when type is NF4LNK
changed createttype4.u.lnk.linkdata from char[] to const char* and updated encoding in nfs41_xdr.c
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
/* we shouldn't ever see this, but a buggy server could
* send us into an infinite loop. return NFS4ERR_IO */
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
the link part of basic test7 was failing because LINK's target was still cached as a negative entry, leading to the error "can't stat newfile.0 after link". the solution is to replace the negative entry with the real fh and attributes of the target file
so instead of doing RESTOREFH+GETATTR on the source file and calling nfs41_attr_cache_update(), nfs41_link() uses LOOKUP+GETATTR+GETFH to get attributes for the target file and passes them to nfs41_name_cache_insert() along with dst_dir's changeinfo. because the source and target file will have the same fileid attribute, nfs41_name_cache_insert() will update the attributes of both at the same time. added the target file as an optional return parameter
Signed-off-by: Casey Bodley <cbodley@umich.edu>
