summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2013-04-05NFSv4: Fix CB_RECALL_ANY to only return delegations that are not in useTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Clean up nfs_expire_all_delegationsTrond Myklebust
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Fix nfs_server_return_all_delegationsTrond Myklebust
If the state manager thread is already running, we may end up racing with it in nfs_client_return_marked_delegations. Better to just allow the state manager thread to do the job. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Be less aggressive about returning delegations for open filesTrond Myklebust
Currently, if the application that holds the file open isn't doing I/O, we may end up returning the delegation. This means that we can no longer cache the file as aggressively, and often also that we multiply the state that both the server and the client needs to track. This patch adds a check for open files to the routine that scans for delegations that are unreferenced. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Clean up delegation recall error handlingTrond Myklebust
Unify the error handling in nfs4_open_delegation_recall and nfs4_lock_delegation_recall. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Clean up nfs4_open_delegation_recallTrond Myklebust
Make it symmetric with nfs4_lock_delegation_recall Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Clean up nfs4_lock_delegation_recallTrond Myklebust
All error cases are handled by the switch() statement, meaning that the call to nfs4_handle_exception() is unreachable. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05NFSv4: Handle NFS4ERR_DELAY and NFS4ERR_GRACE in nfs4_open_delegation_recallTrond Myklebust
A server shouldn't normally return NFS4ERR_GRACE if the client holds a delegation, since no conflicting lock reclaims can be granted, however the spec does not require the server to grant the open in this instance Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2013-04-05NFSv4: Handle NFS4ERR_DELAY and NFS4ERR_GRACE in nfs4_lock_delegation_recallTrond Myklebust
A server shouldn't normally return NFS4ERR_GRACE if the client holds a delegation, since no conflicting lock reclaims can be granted, however the spec does not require the server to grant the lock in this instance. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org
2013-04-05sunrpc: drop "select NETVM"Paul Bolle
The Kconfig entry for SUNRPC_SWAP selects NETVM. That select statement was added in commit a564b8f0398636ba30b07c0eaebdef7ff7837249 ("nfs: enable swap on NFS"). But there's no Kconfig symbol NETVM. It apparently was only in used in development versions of the swap over nfs functionality but never entered mainline. Anyhow, it is a nop and can safely be dropped. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05nfs: allow the v4.1 callback thread to freezeJeff Layton
The v4.1 callback thread has set_freezable() at the top, but it doesn't ever try to freeze within the loop. Have it call try_to_freeze() at the top of the loop. If a freeze event occurs, recheck kthread_should_stop() after thawing. Reported-by: Yanchuan Nian <ycnian@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-05SUNRPC: Fix a potential memory leak in rpc_new_clientTrond Myklebust
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>
2013-04-05NFSv4/4.1: Fix bugs in nfs4[01]_walk_client_listTrond Myklebust
It is unsafe to use list_for_each_entry_safe() here, because when we drop the nn->nfs_client_lock, we pin the _current_ list entry and ensure that it stays in the list, but we don't do the same for the _next_ list entry. Use of list_for_each_entry() is therefore the correct thing to do. Also fix the refcounting in nfs41_walk_client_list(). Finally, ensure that the nfs_client has finished being initialised and, in the case of NFSv4.1, that the session is set up. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Bryan Schumaker <bjschuma@netapp.com> Cc: stable@vger.kernel.org [>= 3.7]
2013-04-05NFSv4: Fix a memory leak in nfs4_discover_server_trunkingTrond Myklebust
When we assign a new rpc_client to clp->cl_rpcclient, we need to destroy the old one. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org [>=3.7]
2013-04-05SUNRPC: Remove extra xprt_put()Chuck Lever
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>
2013-04-05NFSv4: Don't clear the machine cred when client establish returns EACCESTrond Myklebust
The expected behaviour is that the client will decide at mount time whether or not to use a krb5i machine cred, or AUTH_NULL. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Bryan Schumaker <bjschuma@netapp.com>
2013-04-05NFSv4: Fix issues in nfs4_discover_server_trunkingTrond Myklebust
- Ensure that we exit with ENOENT if the call to ops->get_clid_cred() fails. - Handle the case where ops->detect_trunking() exits with an unexpected error, and return EIO. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-04NFSv4: Fix the fallback to AUTH_NULL if krb5i is not availableTrond Myklebust
If the rpcsec_gss_krb5 module cannot be loaded, the attempt to create an rpc_client in nfs4_init_client will currently fail with an EINVAL. Fix is to retry with AUTH_NULL. Regression introduced by the commit "NFS: Use "krb5i" to establish NFSv4 state whenever possible" Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Bryan Schumaker <bjschuma@netapp.com>
2013-04-04NFS: Use server-recommended security flavor by default (NFSv3)Chuck Lever
Since commit ec88f28d in 2009, checking if the user-specified flavor is in the server's flavor list has been the source of a few noticeable regressions (now fixed), but there is one that is still vexing. An NFS server can list AUTH_NULL in its flavor list, which suggests a client should try to mount the server with the flavor of the client's choice, but the server will squash all accesses. In some cases, our client fails to mount a server because of this check, when the mount could have proceeded successfully. Skip this check if the user has specified "sec=" on the mount command line. But do consult the server-provided flavor list to choose a security flavor if no sec= option is specified on the mount command. If a server lists Kerberos pseudoflavors before "sys" in its export options, our client now chooses Kerberos over AUTH_UNIX for mount points, when no security flavor is specified by the mount command. This could be surprising to some administrators or users, who would then need to have Kerberos credentials to access the export. Or, a client administrator may not have enabled rpc.gssd. In this case, auth_rpcgss.ko might still be loadable, which is enough for the new logic to choose Kerberos over AUTH_UNIX. But the mount would fail since no GSS context can be created without rpc.gssd running. To retain the use of AUTH_UNIX by default: o The server administrator can ensure that "sys" is listed before Kerberos flavors in its export security options (see exports(5)), o The client administrator can explicitly specify "sec=sys" on its mount command line (see nfs(5)), o The client administrator can use "Sec=sys" in an appropriate section of /etc/nfsmount.conf (see nfsmount.conf(5)), or o The client administrator can blacklist auth_rpcgss.ko. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-04SUNRPC: Don't recognize RPC_AUTH_MAXFLAVORChuck Lever
RPC_AUTH_MAXFLAVOR is an invalid flavor, on purpose. Don't allow any processing whatsoever if a caller passes it to rpcauth_create() or rpcauth_get_gssinfo(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-04nfsd4: remove unused nfs4_check_deleg argumentJ. Bruce Fields
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-04nfsd4: make del_recall_lru per-network-namespaceJ. Bruce Fields
If nothing else this simplifies the nfs4_state_shutdown_net logic a tad. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-04nfsd4: shut down more of delegation earlierJ. Bruce Fields
Once we've unhashed the delegation, it's only hanging around for the benefit of an oustanding recall, which only needs the encoded filehandle, stateid, and dl_retries counter. No point keeping the file around any longer, or keeping it hashed. This also fixes a race: calls to idr_remove should really be serialized by the caller, but the nfs4_put_delegation call from the callback code isn't taking the state lock. (Better might be to cancel the callback before destroying the delegation, and remove any need for reference counting--but I don't see an easy way to cancel an rpc call.) Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-04nfsd4: minor cb_recall simplificationJ. Bruce Fields
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03SUNRPC/cache: add module_put() on error path in cache_open()Alexey Khoroshilov
If kmalloc() fails in cache_open(), module cd->owner left locked. The patch adds module_put(cd->owner) on this path. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: remove /proc/fs/nfs when create /proc/fs/nfs/exports errorfanchaoting
when create /proc/fs/nfs/exports error, we should remove /proc/fs/nfs, if don't do it, it maybe cause Memory leak. Signed-off-by: fanchaoting <fanchaoting@cn.fujitsu.com> Reviewed-by: chendt.fnst <chendt.fnst@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: don't run get_file if nfs4_preprocess_stateid_op return errorfanchaoting
we should return error status directly when nfs4_preprocess_stateid_op return error. Signed-off-by: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: convert the file_hashtbl to a hlistJeff Layton
We only ever traverse the hash chains in the forward direction, so a double pointer list head isn't really necessary. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: don't destroy in-use sessionJ. Bruce Fields
This changes session destruction to be similar to client destruction in that attempts to destroy a session while in use (which should be rare corner cases) result in DELAY. This simplifies things somewhat and helps meet a coming 4.2 requirement. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: don't destroy in-use clientsJ. Bruce Fields
When a setclientid_confirm or create_session confirms a client after a client reboot, it also destroys any previous state held by that client. The shutdown of that previous state must be careful not to free the client out from under threads processing other requests that refer to the client. This is a particular problem in the NFSv4.1 case when we hold a reference to a session (hence a client) throughout compound processing. The server attempts to handle this by unhashing the client at the time it's destroyed, then delaying the final free to the end. But this still leaves some races in the current code. I believe it's simpler just to fail the attempt to destroy the client by returning NFS4ERR_DELAY. This is a case that should never happen anyway. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: simplify bind_conn_to_session lockingJ. Bruce Fields
The locking here is very fiddly, and there's no reason for us to be setting cstate->session, since this is the only op in the compound. Let's just take the state lock and drop the reference counting. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: fix destroy_session raceJ. Bruce Fields
destroy_session uses the session and client without continuously holding any reference or locks. Put the whole thing under the state lock for now. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: clientid lookup cleanupJ. Bruce Fields
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: destroy_clientid simplificationJ. Bruce Fields
I'm not sure what the check for clientid expiry was meant to do here. The check for a matching session is redundant given the previous check for state: a client without state is, in particular, a client without sessions. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: remove some dprintk'sJ. Bruce Fields
E.g. printk's that just report the return value from an op are uninteresting as we already do that in the main proc_compound loop. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: STALE_STATEID cleanupJ. Bruce Fields
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: warn on odd create_session stateJ. Bruce Fields
This should never happen. (Note: the comparable case in setclientid_confirm *can* happen, since updating a client record can result in both confirmed and unconfirmed records with the same clientid.) Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: fix bug on nfs4 stateid deallocationycnian@gmail.com
NFS4_OO_PURGE_CLOSE is not handled properly. To avoid memory leak, nfs4 stateid which is pointed by oo_last_closed_stid is freed in nfsd4_close(), but NFS4_OO_PURGE_CLOSE isn't cleared meanwhile. So the stateid released in THIS close procedure may be freed immediately in the coming encoding function. Sorry that Signed-off-by was forgotten in last version. Signed-off-by: Yanchuan Nian <ycnian@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: remove unused macro in nfsv4Yanchuan Nian
lk_rflags is never used anywhere, and rflags is not defined in struct nfsd4_lock. Signed-off-by: Yanchuan Nian <ycnian@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: fix use-after-free of 4.1 client on connection lossJ. Bruce Fields
Once we drop the lock here there's nothing keeping the client around: the only lock still held is the xpt_lock on this socket, but this socket no longer has any connection with the client so there's no way for other code to know we're still using the client. The solution is simple: all nfsd4_probe_callback does is set a few variables and queue some work, so there's no reason we can't just keep it under the lock. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: fix race on client shutdownJ. Bruce Fields
Dropping the session's reference count after the client's means we leave a window where the session's se_client pointer is NULL. An xpt_user callback that encounters such a session may then crash: [ 303.956011] BUG: unable to handle kernel NULL pointer dereference at 0000000000000318 [ 303.959061] IP: [<ffffffff81481a8e>] _raw_spin_lock+0x1e/0x40 [ 303.959061] PGD 37811067 PUD 3d498067 PMD 0 [ 303.959061] Oops: 0002 [#8] PREEMPT SMP [ 303.959061] Modules linked in: md5 nfsd auth_rpcgss nfs_acl snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc microcode psmouse snd_timer serio_raw pcspkr evdev snd soundcore i2c_piix4 i2c_core intel_agp intel_gtt processor button nfs lockd sunrpc fscache ata_generic pata_acpi ata_piix uhci_hcd libata btrfs usbcore usb_common crc32c scsi_mod libcrc32c zlib_deflate floppy virtio_balloon virtio_net virtio_pci virtio_blk virtio_ring virtio [ 303.959061] CPU 0 [ 303.959061] Pid: 264, comm: nfsd Tainted: G D 3.8.0-ARCH+ #156 Bochs Bochs [ 303.959061] RIP: 0010:[<ffffffff81481a8e>] [<ffffffff81481a8e>] _raw_spin_lock+0x1e/0x40 [ 303.959061] RSP: 0018:ffff880037877dd8 EFLAGS: 00010202 [ 303.959061] RAX: 0000000000000100 RBX: ffff880037a2b698 RCX: ffff88003d879278 [ 303.959061] RDX: ffff88003d879278 RSI: dead000000100100 RDI: 0000000000000318 [ 303.959061] RBP: ffff880037877dd8 R08: ffff88003c5a0f00 R09: 0000000000000002 [ 303.959061] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 303.959061] R13: 0000000000000318 R14: ffff880037a2b680 R15: ffff88003c1cbe00 [ 303.959061] FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 [ 303.959061] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 303.959061] CR2: 0000000000000318 CR3: 000000003d49c000 CR4: 00000000000006f0 [ 303.959061] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 303.959061] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 303.959061] Process nfsd (pid: 264, threadinfo ffff880037876000, task ffff88003c1fd0a0) [ 303.959061] Stack: [ 303.959061] ffff880037877e08 ffffffffa03772ec ffff88003d879000 ffff88003d879278 [ 303.959061] ffff88003d879080 0000000000000000 ffff880037877e38 ffffffffa0222a1f [ 303.959061] 0000000000107ac0 ffff88003c22e000 ffff88003d879000 ffff88003c1cbe00 [ 303.959061] Call Trace: [ 303.959061] [<ffffffffa03772ec>] nfsd4_conn_lost+0x3c/0xa0 [nfsd] [ 303.959061] [<ffffffffa0222a1f>] svc_delete_xprt+0x10f/0x180 [sunrpc] [ 303.959061] [<ffffffffa0223d96>] svc_recv+0xe6/0x580 [sunrpc] [ 303.959061] [<ffffffffa03587c5>] nfsd+0xb5/0x140 [nfsd] [ 303.959061] [<ffffffffa0358710>] ? nfsd_destroy+0x90/0x90 [nfsd] [ 303.959061] [<ffffffff8107ae00>] kthread+0xc0/0xd0 [ 303.959061] [<ffffffff81010000>] ? perf_trace_xen_mmu_set_pte_at+0x50/0x100 [ 303.959061] [<ffffffff8107ad40>] ? kthread_freezable_should_stop+0x70/0x70 [ 303.959061] [<ffffffff814898ec>] ret_from_fork+0x7c/0xb0 [ 303.959061] [<ffffffff8107ad40>] ? kthread_freezable_should_stop+0x70/0x70 [ 303.959061] Code: ff ff 5d c3 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 65 48 8b 04 25 f0 c6 00 00 48 89 e5 83 80 44 e0 ff ff 01 b8 00 01 00 00 <3e> 66 0f c1 07 0f b6 d4 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f [ 303.959061] RIP [<ffffffff81481a8e>] _raw_spin_lock+0x1e/0x40 [ 303.959061] RSP <ffff880037877dd8> [ 303.959061] CR2: 0000000000000318 [ 304.001218] ---[ end trace 2d809cd4a7931f5a ]--- [ 304.001903] note: nfsd[264] exited with preempt_count 2 Reported-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: handle seqid-mutating open errors from xdr decodingJ. Bruce Fields
If a client sets an owner (or group_owner or acl) attribute on open for create, and the mapping of that owner to an id fails, then we return BAD_OWNER. But BAD_OWNER is a seqid-mutating error, so we can't shortcut the open processing that case: we have to at least look up the owner so we can find the seqid to bump. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd4: remove BUG_ONJ. Bruce Fields
This BUG_ON just crashes the thread a little earlier than it would otherwise--it doesn't seem useful. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: scale up the number of DRC hash buckets with cache sizeJeff Layton
We've now increased the size of the duplicate reply cache by quite a bit, but the number of hash buckets has not changed. So, we've gone from an average hash chain length of 16 in the old code to 4096 when the cache is its largest. Change the code to scale out the number of buckets with the max size of the cache. At the same time, we also need to fix the hash function since the existing one isn't really suitable when there are more than 256 buckets. Move instead to use the stock hash_32 function for this. Testing on a machine that had 2048 buckets showed that this gave a smaller longest:average ratio than the existing hash function: The formula here is longest hash bucket searched divided by average number of entries per bucket at the time that we saw that longest bucket: old hash: 68/(39258/2048) == 3.547404 hash_32: 45/(33773/2048) == 2.728807 Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: keep stats on worst hash balancing seen so farJeff Layton
The typical case with the DRC is a cache miss, so if we keep track of the max number of entries that we've ever walked over in a search, then we should have a reasonable estimate of the longest hash chain that we've ever seen. With that, we'll also keep track of the total size of the cache when we see the longest chain. In the case of a tie, we prefer to track the smallest total cache size in order to properly gauge the worst-case ratio of max vs. avg chain length. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: add new reply_cache_stats file in nfsdfsJeff Layton
For presenting statistics relating to duplicate reply cache. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: track memory utilization by the DRCJeff Layton
Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: break out comparator into separate functionJeff Layton
Break out the function that compares the rqstp and checksum against a reply cache entry. While we're at it, track the efficacy of the checksum over the NFS data by tracking the cases where we would have incorrectly matched a DRC entry if we had not tracked it or the length. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-03nfsd: eliminate one of the DRC cache searchesJeff Layton
The most common case is to do a search of the cache, followed by an insert. In the case where we have to allocate an entry off the slab, then we end up having to redo the search, which is wasteful. Better optimize the code for the common case by eliminating the initial search of the cache and always preallocating an entry. In the case of a cache hit, we'll end up just freeing that entry but that's preferable to an extra search. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-03-29NFS: Use "krb5i" to establish NFSv4 state whenever possibleChuck Lever
Currently our client uses AUTH_UNIX for state management on Kerberos NFS mounts in some cases. For example, if the first mount of a server specifies "sec=sys," the SETCLIENTID operation is performed with AUTH_UNIX. Subsequent mounts using stronger security flavors can not change the flavor used for lease establishment. This might be less security than an administrator was expecting. Dave Noveck's migration issues draft recommends the use of an integrity-protecting security flavor for the SETCLIENTID operation. Let's ignore the mount's sec= setting and use krb5i as the default security flavor for SETCLIENTID. If our client can't establish a GSS context (eg. because it doesn't have a keytab or the server doesn't support Kerberos) we fall back to using AUTH_NULL. For an operation that requires a machine credential (which never represents a particular user) AUTH_NULL is as secure as AUTH_UNIX. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>