CPU#0 CPU#1
----------------------------- -----------------------------
rpc_kill_sb
sn->pipefs_sb = NULL rpc_release_client
(UMOUNT_EVENT) rpc_free_auth
rpc_pipefs_event
rpc_get_client_for_event
!atomic_inc_not_zero(cl_count)
<skip the client>
atomic_inc(cl_count)
rpc_free_client
rpc_clnt_remove_pipedir
<skip client dir removing>
To fix this, this patch does the following:
1) Calls RPC_PIPEFS_UMOUNT notification with sn->pipefs_sb_lock being held.
2) Removes SUNRPC client from the list AFTER pipes destroying.
3) Doesn't hold RPC client on notification: if client in the list, then it
can't be destroyed while sn->pipefs_sb_lock in hold by notification caller.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Below are races, when RPC client can be created without PiepFS dentries
CPU#0 CPU#1
----------------------------- -----------------------------
rpc_new_client rpc_fill_super
rpc_setup_pipedir
mutex_lock(&sn->pipefs_sb_lock)
rpc_get_sb_net == NULL
(no per-net PipeFS superblock)
sn->pipefs_sb = sb;
notifier_call_chain(MOUNT)
(client is not in the list)
rpc_register_client
(client without pipes dentries)
To fix this patch:
1) makes PipeFS mount notification call with pipefs_sb_lock being held.
2) releases pipefs_sb_lock on new SUNRPC client creation only after
registration.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Pull more NFS client bugfixes from Trond Myklebust:
- Ensure that we match the 'sec=' mount flavour against the server list
- Fix the NFSv4 byte range locking in the presence of delegations
- Ensure that we conform to the NFSv4.1 spec w.r.t. freeing lock
stateids
- Fix a pNFS data server connection race
* tag 'nfs-for-3.10-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS4.1 Fix data server connection race
NFSv3: match sec= flavor against server list
NFSv4.1: Ensure that we free the lock stateid on the server
NFSv4: Convert nfs41_free_stateid to use an asynchronous RPC call
SUNRPC: Don't spam syslog with "Pseudoflavor not found" messages
NFSv4.x: Fix handling of partially delegated locks
Note conflict: Chuck's patches modified (and made static)
gss_mech_get_by_OID, which is still needed by gss-proxy patches.
The conflict resolution is a bit minimal; we may want some more cleanup.
This patch implements a sunrpc client to use the services of the gssproxy
userspace daemon.
In particular it allows to perform calls in user space using an RPC
call instead of custom hand-coded upcall/downcall messages.
Currently only accept_sec_context is implemented as that is all is needed for
the server case.
File server modules like NFS and CIFS can use full gssapi services this way,
once init_sec_context is also implemented.
For the NFS server case this code allow to lift the limit of max 2k krb5
tickets. This limit is prevents legitimate kerberos deployments from using krb5
authentication with the Linux NFS server as they have normally ticket that are
many kilobytes large.
It will also allow to lift the limitation on the size of the credential set
(uid,gid,gids) passed down from user space for users that have very many groups
associated. Currently the downcall mechanism used by rpc.svcgssd is limited
to around 2k secondary groups of the 65k allowed by kernel structures.
Signed-off-by: Simo Sorce <simo@redhat.com>
[bfields: containerization, concurrent upcalls, misc. fixes and cleanup]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
In the gss-proxy case we don't want to have to reconnect at random--we
want to connect only on gss-proxy startup when we can steal gss-proxy's
context to do the connect in the right namespace.
So, provide a flag that allows the rpc_create caller to turn off the
idle timeout.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This is mainly for use by NFSv4.1, where the session negotiation
ultimately wants to decide how many RPC slots we can fill.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch ensures that we throttle new RPC requests if there are
requests already waiting in the xprt->backlog queue. The reason for
doing this is to fix livelock issues that can occur when an existing
(high priority) task is waiting in the backlog queue, gets woken up
by xprt_free_slot(), but a new task then steals the slot.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the call to rpciod_up() fails, we currently leak a reference to the
struct rpc_xprt.
As part of the fix, we also remove the redundant check for xprt!=NULL.
This is already taken care of by the callers.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
While testing error cases where rpc_new_client() fails, I saw
some oopses.
If rpc_new_client() fails, it already invokes xprt_put(). Thus
__rpc_clone_client() does not need to invoke it again.
Introduced by commit 1b63a751 "SUNRPC: Refactor rpc_clone_client()"
Fri Sep 14, 2012.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org [>=3.7]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In the case of a SOFTCONN rpc task, we really want to ensure that it
reports errors like ENETUNREACH back to the caller. Currently, only
some of these errors are being reported back (connect errors are not),
and they are being converted by the RPC layer into EIO.
Reported-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Pull NFS client bugfixes from Trond Myklebust:
"We've just concluded another Connectathon interoperability testing
week, and so here are the fixes for the bugs that were discovered:
- Don't allow NFS silly-renamed files to be deleted
- Don't start the retransmission timer when out of socket space
- Fix a couple of pnfs-related Oopses.
- Fix one more NFSv4 state recovery deadlock
- Don't loop forever when LAYOUTGET returns NFS4ERR_LAYOUTTRYLATER"
* tag 'nfs-for-3.9-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
SUNRPC: One line comment fix
NFSv4.1: LAYOUTGET EDELAY loops timeout to the MDS
SUNRPC: add call to get configured timeout
PNFS: set the default DS timeout to 60 seconds
NFSv4: Fix another open/open_recovery deadlock
nfs: don't allow nfs_find_actor to match inodes of the wrong type
NFSv4.1: Hold reference to layout hdr in layoutget
pnfs: fix resend_to_mds for directio
SUNRPC: Don't start the retransmission timer when out of socket space
NFS: Don't allow NFS silly-renamed files to be deleted, no signal
Pull nfsd changes from J Bruce Fields:
"Miscellaneous bugfixes, plus:
- An overhaul of the DRC cache by Jeff Layton. The main effect is
just to make it larger. This decreases the chances of intermittent
errors especially in the UDP case. But we'll need to watch for any
reports of performance regressions.
- Containerized nfsd: with some limitations, we now support
per-container nfs-service, thanks to extensive work from Stanislav
Kinsbursky over the last year."
Some notes about conflicts, since there were *two* non-data semantic
conflicts here:
- idr_remove_all() had been added by a memory leak fix, but has since
become deprecated since idr_destroy() does it for us now.
- xs_local_connect() had been added by this branch to make AF_LOCAL
connections be synchronous, but in the meantime Trond had changed the
calling convention in order to avoid a RCU dereference.
There were a couple of more obvious actual source-level conflicts due to
the hlist traversal changes and one just due to code changes next to
each other, but those were trivial.
* 'for-3.9' of git://linux-nfs.org/~bfields/linux: (49 commits)
SUNRPC: make AF_LOCAL connect synchronous
nfsd: fix compiler warning about ambiguous types in nfsd_cache_csum
svcrpc: fix rpc server shutdown races
svcrpc: make svc_age_temp_xprts enqueue under sv_lock
lockd: nlmclnt_reclaim(): avoid stack overflow
nfsd: enable NFSv4 state in containers
nfsd: disable usermode helper client tracker in container
nfsd: use proper net while reading "exports" file
nfsd: containerize NFSd filesystem
nfsd: fix comments on nfsd_cache_lookup
SUNRPC: move cache_detail->cache_request callback call to cache_read()
SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function
SUNRPC: rework cache upcall logic
SUNRPC: introduce cache_detail->cache_request callback
NFS: simplify and clean cache library
NFS: use SUNRPC cache creation and destruction helper for DNS cache
nfsd4: free_stid can be static
nfsd: keep a checksum of the first 256 bytes of request
sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer
sunrpc: fix comment in struct xdr_buf definition
...
Returns the configured timeout for the xprt of the rpc client.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
These routines are used by server and client code, so having them in a
separate header would be best.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
tk_xprt is just a shortcut for tk_client->cl_xprt, however cl_xprt is
defined as an __rcu variable. Replace dereferences of tk_xprt with
non-rcu dereferences where it is safe to do so.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Partially revert commit (SUNRPC: add WARN_ON_ONCE for potential deadlock).
The looping behaviour has been tracked down to a knownn issue with
workqueues, and a workaround has now been implemented.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Weston Andros Adamson <dros@netapp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org [>= 3.7]
There are SUNRPC clients, which program doesn't have pipe_dir_name. These
clients can be skipped on PipeFS events, because nothing have to be created or
destroyed. But instead of breaking in case of such a client was found, search
for suitable client over clients list have to be continued. Otherwise some
clients could not be covered by PipeFS event handler.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: stable@vger.kernel.org [>= v3.4]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, when an RPCSEC_GSS context has expired or is non-existent
and the users (Kerberos) credentials have also expired or are non-existent,
the client receives the -EKEYEXPIRED error and tries to refresh the context
forever. If an application is performing I/O, or other work against the share,
the application hangs, and the user is not prompted to refresh/establish their
credentials. This can result in a denial of service for other users.
Users are expected to manage their Kerberos credential lifetimes to mitigate
this issue.
Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number
of times to refresh the gss_context, and then return -EACCES to the application.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We can and should use the rpc_create_args and __rpc_clone_client()
to change the program and version number on the resulting rpc_client.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Stanislav Kinsbursky
Linus Torvalds
Trond Myklebust
J. Bruce Fields
Simo Sorce
Chuck Lever
Weston Andros Adamson
Jeff Layton
Randy Dunlap
Andy Adamson