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2020-02-04NFSv4.0: nfs4_do_fsinfo() should not do implicit lease renewalsRobert Milkowski1-3/+1
Currently, each time nfs4_do_fsinfo() is called it will do an implicit NFS4 lease renewal, which is not compliant with the NFS4 specification. This can result in a lease being expired by an NFS server. Commit 83ca7f5ab31f ("NFS: Avoid PUTROOTFH when managing leases") introduced implicit client lease renewal in nfs4_do_fsinfo(), which can result in the NFSv4.0 lease to expire on a server side, and servers returning NFS4ERR_EXPIRED or NFS4ERR_STALE_CLIENTID. This can easily be reproduced by frequently unmounting a sub-mount, then stat'ing it to get it mounted again, which will delay or even completely prevent client from sending RENEW operations if no other NFS operations are issued. Eventually nfs server will expire client's lease and return an error on file access or next RENEW. This can also happen when a sub-mount is automatically unmounted due to inactivity (after nfs_mountpoint_expiry_timeout), then it is mounted again via stat(). This can result in a short window during which client's lease will expire on a server but not on a client. This specific case was observed on production systems. This patch removes the implicit lease renewal from nfs4_do_fsinfo(). Fixes: 83ca7f5ab31f ("NFS: Avoid PUTROOTFH when managing leases") Signed-off-by: Robert Milkowski <rmilkowski@gmail.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-02-03NFSv4: Try to return the delegation immediately when marked for return on closeTrond Myklebust1-0/+1
Add a routine to return the delegation immediately upon close of the file if it was marked for return-on-close. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15NFS4: Remove unneeded semicolonzhengbin1-1/+1
Fixes coccicheck warning: fs/nfs/nfs4state.c:1138:2-3: Unneeded semicolon fs/nfs/nfs4proc.c:6862:2-3: Unneeded semicolon fs/nfs/nfs4proc.c:8629:2-3: Unneeded semicolon Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-11-18NFS4: Trace lock reclaimsChuck Lever1-0/+1
One of the most frustrating messages our sustaining team sees is the "Lock reclaim failed!" message. Add some observability in the client's lock reclaim logic so we can capture better data the first time a problem occurs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-11-18NFS4: Trace state recovery operationChuck Lever1-0/+3
Add a trace point in the main state manager loop to observe state recovery operation. Help track down state recovery bugs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-11-06Merge branch 'linux-ssc-for-5.5'Trond Myklebust1-5/+35
2019-11-03NFS: nfs_inode_find_state_and_recover() fix stateid matchingTrond Myklebust1-3/+4
In nfs_inode_find_state_and_recover() we want to mark for recovery only those stateids that match or are older than the supplied stateid parameter. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-10-09NFS: handle source server rebootOlga Kornievskaia1-5/+21
When the source server reboots after a server-to-server copy was issued, we need to retry the copy from COPY_NOTIFY. We need to detect that the source server rebooted and there is a copy waiting on a destination server and wake it up. Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
2019-10-09NFS: skip recovery of copy open on dest serverOlga Kornievskaia1-0/+14
Mark the open created for the source file on the destination server. Then if this open is going thru a recovery, then fail the recovery as we don't need to be recoving a "fake" open. We need to fail the ongoing READs and vfs_copy_file_range(). Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
2019-09-20NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADETrond Myklebust1-16/+0
If a CLOSE or OPEN_DOWNGRADE operation receives a NFS4ERR_OLD_STATEID then bump the seqid before resending. Ensure we only bump the seqid by 1. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-21NFSv4: Fix a memory leak bugWenwen Wang1-2/+4
In nfs4_try_migration(), if nfs4_begin_drain_session() fails, the previously allocated 'page' and 'locations' are not deallocated, leading to memory leaks. To fix this issue, go to the 'out' label to free 'page' and 'locations' before returning the error. Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-08-07NFSv4: Ensure state recovery handles ETIMEDOUT correctlyTrond Myklebust1-2/+5
Ensure that the state recovery code handles ETIMEDOUT correctly, and also that we set RPC_TASK_TIMEOUT when recovering open state. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-04NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim()Trond Myklebust1-5/+22
John Hubbard reports seeing the following stack trace: nfs4_do_reclaim rcu_read_lock /* we are now in_atomic() and must not sleep */ nfs4_purge_state_owners nfs4_free_state_owner nfs4_destroy_seqid_counter rpc_destroy_wait_queue cancel_delayed_work_sync __cancel_work_timer __flush_work start_flush_work might_sleep: (kernel/workqueue.c:2975: BUG) The solution is to separate out the freeing of the state owners from nfs4_purge_state_owners(), and perform that outside the atomic context. Reported-by: John Hubbard <jhubbard@nvidia.com> Fixes: 0aaaf5c424c7f ("NFS: Cache state owners after files are closed") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-04NFSv4: When recovering state fails with EAGAIN, retry the same recoveryTrond Myklebust1-1/+8
If the server returns with EAGAIN when we're trying to recover from a server reboot, we currently delay for 1 second, but then mark the stateid as needing recovery after the grace period has expired. Instead, we should just retry the same recovery process immediately after the 1 second delay. Break out of the loop after 10 retries. Fixes: 35a61606a612 ("NFS: Reduce indentation of the switch statement...") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-08-04NFSv4: Print an error in the syslog when state is marked as irrecoverableTrond Myklebust1-2/+4
When error recovery fails due to a fatal error on the server, ensure we log it in the syslog. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-18NFSv4: Don't use the zero stateid with layoutgetTrond Myklebust1-2/+1
The NFSv4.1 protocol explicitly forbids us from using the zero stateid together with layoutget, so when we see that nfs4_select_rw_stateid() is unable to return a valid delegation, lock or open stateid, then we should initiate recovery and retry. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-13nfs4.0: Refetch lease_time after clientid updateDonald Buczek1-22/+22
RFC 7530 requires us to refetch the lease time attribute once a new clientID is established. This is already implemented for the nfs4.1(+) clients by nfs41_init_clientid, which calls nfs41_finish_session_reset, which calls nfs4_setup_state_renewal. To make nfs4_setup_state_renewal available for nfs4.0, move it further to the top of the source file to include it regardles of CONFIG_NFS_V4_1 and to save a forward declaration. Call nfs4_setup_state_renewal from nfs4_init_clientid. Signed-off-by: Donald Buczek <buczek@molgen.mpg.de> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-13nfs4: Rename nfs41_setup_state_renewalDonald Buczek1-2/+2
The function nfs41_setup_state_renewal is useful to the nfs 4.0 client as well, so rename the function to nfs4_setup_state_renewal. Signed-off-by: Donald Buczek <buczek@molgen.mpg.de> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-05-09NFSv4: don't mark all open state for recovery when handling recallable state revoked flagScott Mayhew1-2/+1
Only delegations and layouts can be recalled, so it shouldn't be necessary to recover all opens when handling the status bit SEQ4_STATUS_RECALLABLE_STATE_REVOKED. We'll still wind up calling nfs41_open_expired() when a TEST_STATEID returns NFS4ERR_DELEG_REVOKED. Signed-off-by: Scott Mayhew <smayhew@redhat.com> Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-05-09NFS4: Fix v4.0 client state corruption when mountZhangXiaoxu1-0/+4
stat command with soft mount never return after server is stopped. When alloc a new client, the state of the client will be set to NFS4CLNT_LEASE_EXPIRED. When the server is stopped, the state manager will work, and accord the state to recover. But the state is NFS4CLNT_LEASE_EXPIRED, it will drain the slot table and lead other task to wait queue, until the client recovered. Then the stat command is hung. When discover server trunking, the client will renew the lease, but check the client state, it lead the client state corruption. So, we need to call state manager to recover it when detect server ip trunking. Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-02-20NFS: Fix up documentation warningsTrond Myklebust1-0/+1
Fix up some compiler warnings about function parameters, etc not being correctly described or formatted. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-01-02NFSv4.2 fix async copy reboot recoveryOlga Kornievskaia1-1/+1
Original commit (e4648aa4f98a "NFS recover from destination server reboot for copies") used memcmp() and then it was changed to use nfs4_stateid_match_other() but that function returns opposite of memcmp. As the result, recovery can't find the copy leading to copy hanging. Fixes: 80f42368868e ("NFSv4: Split out NFS v4.2 copy completion functions") Fixes: cb7a8384dc02 ("NFS: Split out the body of nfs4_reclaim_open_state") Signed-of-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.NeilBrown1-45/+47
SUNRPC has two sorts of credentials, both of which appear as "struct rpc_cred". There are "generic credentials" which are supplied by clients such as NFS and passed in 'struct rpc_message' to indicate which user should be used to authorize the request, and there are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS which describe the credential to be sent over the wires. This patch replaces all the generic credentials by 'struct cred' pointers - the credential structure used throughout Linux. For machine credentials, there is a special 'struct cred *' pointer which is statically allocated and recognized where needed as having a special meaning. A look-up of a low-level cred will map this to a machine credential. Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19NFS/SUNRPC: don't lookup machine credential until rpcauth_bindcred().NeilBrown1-17/+4
When NFS creates a machine credential, it is a "generic" credential, not tied to any auth protocol, and is really just a container for the princpal name. This doesn't get linked to a genuine credential until rpcauth_bindcred() is called. The lookup always succeeds, so various places that test if the machine credential is NULL, are pointless. As a step towards getting rid of generic credentials, this patch gets rid of generic machine credentials. The nfs_client and rpc_client just hold a pointer to a constant principal name. When a machine credential is wanted, a special static 'struct rpc_cred' pointer is used. rpcauth_bindcred() recognizes this, finds the principal from the client, and binds the correct credential. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19NFSv4: don't require lock for get_renew_cred or get_machine_credNeilBrown1-16/+10
This lock is no longer necessary. If nfs4_get_renew_cred() needs to hunt through the open-state creds for a user cred, it still takes the lock to stablize the rbtree, but otherwise there are no races. Note that this completely removes the lock from nfs4_renew_state(). It appears that the original need for the locking here was removed long ago, and there is no longer anything to protect. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19NFSv4: add cl_root_cred for use when machine cred is not available.NeilBrown1-8/+12
NFSv4 state management tries a root credential when no machine credential is available, as can happen with kerberos. It does this by replacing the cl_machine_cred with a root credential. This means that any user of the machine credential needs to take a lock while getting a reference to the machine credential, which is a little cumbersome. So introduce an explicit cl_root_cred, and never free either credential until client shutdown. This means that no locking is needed to reference these credentials. Future patches will make use of this. This is only a temporary addition. both cl_machine_cred and cl_root_cred will disappear later in the series. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-11-19NFSv4: Fix a NFSv4 state manager deadlockTrond Myklebust1-5/+11
Fix a deadlock whereby the NFSv4 state manager can get stuck in the delegation return code, waiting for a layout return to complete in another thread. If the server reboots before that other thread completes, then we need to be able to start a second state manager thread in order to perform recovery. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-11-12NFSv4: Ensure that the state manager exits the loop on SIGKILLTrond Myklebust1-1/+1
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-11-12NFSv4: Don't exit the state manager without clearing NFS4CLNT_MANAGER_RUNNINGTrond Myklebust1-3/+5
If we exit the NFSv4 state manager due to a umount, then we can end up leaving the NFS4CLNT_MANAGER_RUNNING flag set. If another mount causes the nfs4_client to be rereferenced before it is destroyed, then we end up never being able to recover state. Fixes: 47c2199b6eb5 ("NFSv4.1: Ensure state manager thread dies on last ...") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: stable@vger.kernel.org # v4.15+
2018-09-30NFSv4: Split out NFS v4.2 copy completion functionsAnna Schumaker1-15/+26
The convention in the rest of the code is to have a separate function for anything that might be ifdef-ed out. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30NFS: Reduce indentation of nfs4_recovery_handle_error()Anna Schumaker1-32/+32
This is to match kernel coding style for switch statements. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30NFS: Reduce indentation of the switch statement in nfs4_reclaim_open_state()Anna Schumaker1-37/+33
Most places in the kernel tend to line up cases with the switch to reduce indentation, so move this over to match that style. Additionally, I handle the (status >= 0) case in the switch so that we only "goto restart" from a single place after error handling. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30NFS: Split out the body of nfs4_reclaim_open_state()Anna Schumaker1-36/+47
Moving all of this into a new function removes the need for cramped indentation, making the code overall easier to look at. I also take this chance to switch copy recovery over to using nfs4_stateid_match_other() Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30NFSv4: Convert struct nfs4_state to use refcount_tTrond Myklebust1-4/+4
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30NFSv4: Convert open state lookup to use RCUTrond Myklebust1-6/+6
Further reduce contention on the inode->i_lock. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-30NFS: Convert lookups of the open context to RCUTrond Myklebust1-6/+6
Reduce contention on the inode->i_lock by ensuring that we use RCU when looking up the NFS open context. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-09-14NFSv4.1 fix infinite loop on I/O.Trond Myklebust1-0/+2
The previous fix broke recovery of delegated stateids because it assumes that if we did not mark the delegation as suspect, then the delegation has effectively been revoked, and so it removes that delegation irrespectively of whether or not it is valid and still in use. While this is "mostly harmless" for ordinary I/O, we've seen pNFS fail with LAYOUTGET spinning in an infinite loop while complaining that we're using an invalid stateid (in this case the all-zero stateid). What we rather want to do here is ensure that the delegation is always correctly marked as needing testing when that is the case. So we want to close the loophole offered by nfs4_schedule_stateid_recovery(), which marks the state as needing to be reclaimed, but not the delegation that may be backing it. Fixes: 0e3d3e5df07dc ("NFSv4.1 fix infinite loop on IO BAD_STATEID error") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-08-13NFSv4: Don't busy wait if NFSv4 session draining is interruptedTrond Myklebust1-5/+13
Catch the ERESTARTSYS error so that it can be processed by the callers. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-08-13NFS recover from destination server reboot for copiesOlga Kornievskaia1-0/+16
Mark the destination state to indicate a server-side copy is happening. On detecting a reboot and recovering open state check if any state is engaged in a server-side copy, if so, find the copy and mark it and then signal the waiting thread. Upon wakeup, if copy was marked then propage EAGAIN to the nfsd_copy_file_range and restart the copy from scratch. Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-08-08NFS: Mark expected switch fall-throughsGustavo A. R. Silva1-0/+6
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Warning level 2 was used: -Wimplicit-fallthrough=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-05-31pnfs: Add LAYOUTGET to OPEN of a new fileFred Isaman1-0/+8
This triggers when have no pre-existing inode to attach to. The preexisting case is saved for later. Signed-off-by: Fred Isaman <fred.isaman@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-04-10nfs: Use ida_simple APIMatthew Wilcox1-12/+10
Allocate the owner_id when we allocate the state and free it when we free the state. That lets us get rid of a gnarly ida_pre_get() / ida_get_new() loop. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-01-14NFSv4: always set NFS_LOCK_LOST when a lock is lost.NeilBrown1-1/+4
There are 2 comments in the NFSv4 code which suggest that SIGLOST should possibly be sent to a process. In these cases a lock has been lost. The current practice is to set NFS_LOCK_LOST so that read/write returns EIO when a lock is lost. So change these comments to code when sets NFS_LOCK_LOST. One case is when lock recovery after apparent server restart fails with NFS4ERR_DENIED, NFS4ERR_RECLAIM_BAD, or NFS4ERRO_RECLAIM_CONFLICT. The other case is when a lock attempt as part of lease recovery fails with NFS4ERR_DENIED. In an ideal world, these should not happen. However I have a packet trace showing an NFSv4.1 session getting NFS4ERR_BADSESSION after an extended network parition. The NFSv4.1 client treats this like server reboot until/unless it get NFS4ERR_NO_GRACE, in which case it switches over to "nograce" recovery mode. In this network trace, the client attempts to recover a lock and the server (incorrectly) reports NFS4ERR_DENIED rather than NFS4ERR_NO_GRACE. This leads to the ineffective comment and the client then continues to write using the OPEN stateid. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-11-29NFSv4: Ensure gcc 4.4.4 can compile initialiser for "invalid_stateid"Trond Myklebust1-2/+2
gcc 4.4.4 is too old to have full C11 anonymous union support, so the current initialiser fails to compile. Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> (compile-)Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17NFSv4: Replace closed stateids with the "invalid special stateid"Trond Myklebust1-0/+8
When decoding a CLOSE, replace the stateid returned by the server with the "invalid special stateid" described in RFC5661, Section 8.2.3. In nfs_set_open_stateid_locked, ignore stateids from closed state. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17NFSv4: Check the open stateid when searching for expired stateTrond Myklebust1-0/+5
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17NFSv4: Don't try to CLOSE if the stateid 'other' field has changedTrond Myklebust1-2/+7
If the stateid is no longer recognised on the server, either due to a restart, or due to a competing CLOSE call, then we do not have to retry. Any open contexts that triggered a reopen of the file, will also act as triggers for any CLOSE for the updated stateids. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID.Trond Myklebust1-0/+16
If we're racing with an OPEN, then retry the operation instead of declaring it a success. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> [Andrew W Elble: Fix a typo in nfs4_refresh_open_stateid] Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17NFSv4: Fix OPEN / CLOSE raceTrond Myklebust1-0/+1
Ben Coddington has noted the following race between OPEN and CLOSE on a single client. Process 1 Process 2 Server ========= ========= ====== 1) OPEN file 2) OPEN file 3) Process OPEN (1) seqid=1 4) Process OPEN (2) seqid=2 5) Reply OPEN (2) 6) Receive reply (2) 7) new stateid, seqid=2 8) CLOSE file, using stateid w/ seqid=2 9) Reply OPEN (1) 10( Process CLOSE (8) 11) Reply CLOSE (8) 12) Forget stateid file closed 13) Receive reply (7) 14) Forget stateid file closed. 15) Receive reply (1). 16) New stateid seqid=1 is really the same stateid that was closed. IOW: the reply to the first OPEN is delayed. Since "Process 2" does not wait before closing the file, and it does not cache the closed stateid, then when the delayed reply is finally received, it is treated as setting up a new stateid by the client. The fix is to ensure that the client processes the OPEN and CLOSE calls in the same order in which the server processed them. This commit ensures that we examine the seqid of the stateid returned by OPEN. If it is a new stateid, we assume the seqid must be equal to the value 1, and that each state transition increments the seqid value by 1 (See RFC7530, Section 9.1.4.2, and RFC5661, Section 8.2.2). If the tracker sees that an OPEN returns with a seqid that is greater than the cached seqid + 1, then it bumps a flag to ensure that the caller waits for the RPCs carrying the missing seqids to complete. Note that there can still be pathologies where the server crashes before it can even send us the missing seqids. Since the OPEN call is still holding a slot when it waits here, that could cause the recovery to stall forever. To avoid that, we time out after a 5 second wait. Reported-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17fs, nfs: convert nfs_client.cl_count from atomic_t to refcount_tElena Reshetova1-3/+3
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable nfs_client.cl_count is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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