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2018-03-19nfsd: move nfs4_client allocation to dedicated slabcacheJeff Layton1-5/+13
On x86_64, it's 1152 bytes, so we can avoid wasting 896 bytes each. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-03-19nfsd4: send the special close_stateid in v4.0 replies as wellJeff Layton1-4/+15
We already send it for v4.1, but RFC7530 also notes that the stateid in the close reply is bogus. Always send the special close stateid, even in v4.0 responses. No client should put any meaning on it whatsoever. For now, we continue to increment the stateid value, though that might not be necessary either. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-03-19nfsd: remove blocked locks on client teardownJeff Layton1-19/+43
We had some reports of panics in nfsd4_lm_notify, and that showed a nfs4_lockowner that had outlived its so_client. Ensure that we walk any leftover lockowners after tearing down all of the stateids, and remove any blocked locks that they hold. With this change, we also don't need to walk the nbl_lru on nfsd_net shutdown, as that will happen naturally when we tear down the clients. Fixes: 76d348fadff5 (nfsd: have nfsd4_lock use blocking locks for v4.1+ locks) Reported-by: Frank Sorenson <fsorenso@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: stable@vger.kernel.org # 4.9 Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-02-05nfsd4: don't set lock stateid's sc_type to CLOSEDJ. Bruce Fields1-4/+1
There's no point I can see to stp->st_stid.sc_type = NFS4_CLOSED_STID; given release_lock_stateid immediately sets sc_type to 0. That set of sc_type to 0 should be enough to prevent it being used where we don't want it to be; NFS4_CLOSED_STID should only be needed for actual open stateid's that are actually closed. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-02-05nfsd: Detect unhashed stids in nfsd4_verify_open_stid()Trond Myklebust1-0/+1
The state of the stid is guaranteed by 2 locks: - The nfs4_client 'cl_lock' spinlock - The nfs4_ol_stateid 'st_mutex' mutex so it is quite possible for the stid to be unhashed after lookup, but before calling nfsd4_lock_ol_stateid(). So we do need to check for a zero value for 'sc_type' in nfsd4_verify_open_stid(). Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Tested-by: Checuk Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org Fixes: 659aefb68eca "nfsd: Ensure we don't recognise lock stateids..." Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27lockd: fix "list_add double add" caused by legacy signal interfaceVasily Averin1-3/+4
restart_grace() uses hardcoded init_net. It can cause to "list_add double add" in following scenario: 1) nfsd and lockd was started in several net namespaces 2) nfsd in init_net was stopped (lockd was not stopped because it have users from another net namespaces) 3) lockd got signal, called restart_grace() -> set_grace_period() and enabled lock_manager in hardcoded init_net. 4) nfsd in init_net is started again, its lockd_up() calls set_grace_period() and tries to add lock_manager into init_net 2nd time. Jeff Layton suggest: "Make it safe to call locks_start_grace multiple times on the same lock_manager. If it's already on the global grace_list, then don't try to add it again. (But we don't intentionally add twice, so for now we WARN about that case.) With this change, we also need to ensure that the nfsd4 lock manager initializes the list before we call locks_start_grace. While we're at it, move the rest of the nfsd_net initialization into nfs4_state_create_net. I see no reason to have it spread over two functions like it is today." Suggested patch was updated to generate warning in described situation. Suggested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: check for use of the closed special stateidAndrew Elble1-2/+5
Prevent the use of the closed (invalid) special stateid by clients. Signed-off-by: Andrew Elble <aweits@rit.edu> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: fix panic in posix_unblock_lock called from nfs4_laundromatNaofumi Honda1-2/+2
From kernel 4.9, my two nfsv4 servers sometimes suffer from "panic: unable to handle kernel page request" in posix_unblock_lock() called from nfs4_laundromat(). These panics diseappear if we revert the commit "nfsd: add a LRU list for blocked locks". The cause appears to be a typo in nfs4_laundromat(), which is also present in nfs4_state_shutdown_net(). Cc: stable@vger.kernel.org Fixes: 7919d0a27f1e "nfsd: add a LRU list for blocked locks" Cc: jlayton@redhat.com Reveiwed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: fix locking validator warning on nfs4_ol_stateid->st_mutex classAndrew Elble1-3/+8
The use of the st_mutex has been confusing the validator. Use the proper nested notation so as to not produce warnings. Signed-off-by: Andrew Elble <aweits@rit.edu> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: Fix races with check_stateid_generation()Trond Myklebust1-3/+19
The various functions that call check_stateid_generation() in order to compare a client-supplied stateid with the nfs4_stid state, usually need to atomically check for closed state. Those that perform the check after locking the st_mutex using nfsd4_lock_ol_stateid() should now be OK, but we do want to fix up the others. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: Ensure we check stateid validity in the seqid operation checksTrond Myklebust1-9/+3
After taking the stateid st_mutex, we want to know that the stateid still represents valid state before performing any non-idempotent actions. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: Fix race in lock stateid creationTrond Myklebust1-28/+42
If we're looking up a new lock state, and the creation fails, then we want to unhash it, just like we do for OPEN. However in order to do so, we need to that no other LOCK requests can grab the mutex until we have unhashed it (and marked it as closed). Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd4: move find_lock_stateidTrond Myklebust1-19/+19
Trivial cleanup to simplify following patch. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: Ensure we don't recognise lock stateids after freeing themTrond Myklebust1-11/+8
In order to deal with lookup races, nfsd4_free_lock_stateid() needs to be able to signal to other stateful functions that the lock stateid is no longer valid. Right now, nfsd_lock() will check whether or not an existing stateid is still hashed, but only in the "new lock" path. To ensure the stateid invalidation is also recognised by the "existing lock" path, and also by a second call to nfsd4_free_lock_stateid() itself, we can change the type to NFS4_CLOSED_STID under the stp->st_mutex. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: CLOSE SHOULD return the invalid special stateid for NFSv4.x (x>0)Trond Myklebust1-0/+8
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: Fix another OPEN stateid raceTrond Myklebust1-15/+13
If nfsd4_process_open2() is initialising a new stateid, and yet the call to nfs4_get_vfs_file() fails for some reason, then we must declare the stateid closed, and unhash it before dropping the mutex. Right now, we unhash the stateid after dropping the mutex, and without changing the stateid type, meaning that another OPEN could theoretically look it up and attempt to use it. Reported-by: Andrew W Elble <aweits@rit.edu> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-27nfsd: Fix stateid races between OPEN and CLOSETrond Myklebust1-8/+59
Open file stateids can linger on the nfs4_file list of stateids even after they have been closed. In order to avoid reusing such a stateid, and confusing the client, we need to recheck the nfs4_stid's type after taking the mutex. Otherwise, we risk reusing an old stateid that was already closed, which will confuse clients that expect new stateids to conform to RFC7530 Sections 9.1.4.2 and 16.2.5 or RFC5661 Sections 8.2.2 and 18.2.4. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07nfsd: deal with revoked delegations appropriatelyAndrew Elble1-1/+24
If a delegation has been revoked by the server, operations using that delegation should error out with NFS4ERR_DELEG_REVOKED in the >4.1 case, and NFS4ERR_BAD_STATEID otherwise. The server needs NFSv4.1 clients to explicitly free revoked delegations. If the server returns NFS4ERR_DELEG_REVOKED, the client will do that; otherwise it may just forget about the delegation and be unable to recover when it later sees SEQ4_STATUS_RECALLABLE_STATE_REVOKED set on a SEQUENCE reply. That can cause the Linux 4.1 client to loop in its stage manager. Signed-off-by: Andrew Elble <aweits@rit.edu> Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07nfsd: use nfs->ns.inum as net IDVasily Averin1-2/+2
Publishing of net pointer is not safe, let's use nfs->ns.inum instead Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07fs, nfsd: convert nfs4_file.fi_ref 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 nfs4_file.fi_ref 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: J. Bruce Fields <bfields@redhat.com>
2017-11-07fs, nfsd: convert nfs4_cntl_odstate.co_odcount 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 nfs4_cntl_odstate.co_odcount 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: J. Bruce Fields <bfields@redhat.com>
2017-11-07fs, nfsd: convert nfs4_stid.sc_count from atomic_t to refcount_tElena Reshetova1-12/+12
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 nfs4_stid.sc_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: J. Bruce Fields <bfields@redhat.com>
2017-11-07nfsd4: catch some false session retriesJ. Bruce Fields1-1/+36
The spec allows us to return NFS4ERR_SEQ_FALSE_RETRY if we notice that the client is making a call that matches a previous (slot, seqid) pair but that *isn't* actually a replay, because some detail of the call doesn't actually match the previous one. Catching every such case is difficult, but we may as well catch a few easy ones. This also handles the case described in the previous patch, in a different way. The spec does however require us to catch the case where the difference is in the rpc credentials. This prevents somebody from snooping another user's replies by fabricating retries. (But the practical value of the attack is limited by the fact that the replies with the most sensitive data are READ replies, which are not normally cached.) Tested-by: Olga Kornievskaia <aglo@umich.edu> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-11-07nfsd4: fix cached replies to solo SEQUENCE compoundsJ. Bruce Fields1-5/+15
Currently our handling of 4.1+ requests without "cachethis" set is confusing and not quite correct. Suppose a client sends a compound consisting of only a single SEQUENCE op, and it matches the seqid in a session slot (so it's a retry), but the previous request with that seqid did not have "cachethis" set. The obvious thing to do might be to return NFS4ERR_RETRY_UNCACHED_REP, but the protocol only allows that to be returned on the op following the SEQUENCE, and there is no such op in this case. The protocol permits us to cache replies even if the client didn't ask us to. And it's easy to do so in the case of solo SEQUENCE compounds. So, when we get a solo SEQUENCE, we can either return the previously cached reply or NFSERR_SEQ_FALSE_RETRY if we notice it differs in some way from the original call. Currently, we're returning a corrupt reply in the case a solo SEQUENCE matches a previous compound with more ops. This actually matters because the Linux client recently started doing this as a way to recover from lost replies to idempotent operations in the case the process doing the original reply was killed: in that case it's difficult to keep the original arguments around to do a real retry, and the client no longer cares what the result is anyway, but it would like to make sure that the slot's sequence id has been incremented, and the solo SEQUENCE assures that: if the server never got the original reply, it will increment the sequence id. If it did get the original reply, it won't increment, and nothing else that about the reply really matters much. But we can at least attempt to return valid xdr! Tested-by: Olga Kornievskaia <aglo@umich.edu> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-10-04nfsd: give out fewer session slots as limit approachesJ. Bruce Fields1-0/+5
Instead of granting client's full requests until we hit our DRC size limit and then failing CREATE_SESSIONs (and hence mounts) completely, start granting clients smaller slot tables as we approach the limit. The factor chosen here is pretty much arbitrary. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-05-15nfsd4: properly type op_func callbacksChristoph Hellwig1-30/+52
Pass union nfsd4_op_u to the op_func callbacks instead of using unsafe function pointer casts. It also adds two missing structures to struct nfsd4_op.u to facilitate this. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15nfsd4: properly type op_get_currentstateid callbacksChristoph Hellwig1-16/+24
Pass union nfsd4_op_u to the op_set_currentstateid callbacks instead of using unsafe function pointer casts. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15nfsd4: properly type op_set_currentstateid callbacksChristoph Hellwig1-8/+12
Given the args union in struct nfsd4_op a name, and pass it to the op_set_currentstateid callbacks instead of using unsafe function pointer casts. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-04-25nfsd4: remove pointless strdup_if_nonnullNeilBrown1-19/+6
kstrdup() already checks for NULL. (Brought to our attention by Jason Yann noticing (from sparse output) that it should have been declared static.) Signed-off-by: NeilBrown <neilb@suse.com> Reported-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-24nfsd: remove superfluous KERN_INFORasmus Villemoes1-1/+1
dprintk already provides a KERN_* prefix; this KERN_INFO just shows up as some odd characters in the output. Simplify the message a bit while we're there. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-02-17nfsd/callback: Cleanup callback cred on shutdownKinglong Mee1-4/+6
The rpccred gotten from rpc_lookup_machine_cred() should be put when state is shutdown. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31NFSD: Fix a null reference case in find_or_create_lock_stateid()Kinglong Mee1-11/+8
nfsd assigns the nfs4_free_lock_stateid to .sc_free in init_lock_stateid(). If nfsd doesn't go through init_lock_stateid() and put stateid at end, there is a NULL reference to .sc_free when calling nfs4_put_stid(ns). This patch let the nfs4_stid.sc_free assignment to nfs4_alloc_stid(). Cc: stable@vger.kernel.org Fixes: 356a95ece7aa "nfsd: clean up races in lock stateid searching..." Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-11-01nfsd: Fix general protection fault in release_lock_stateid()Chuck Lever1-6/+4
When I push NFSv4.1 / RDMA hard, (xfstests generic/089, for example), I get this crash on the server: Oct 28 22:04:30 klimt kernel: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC Oct 28 22:04:30 klimt kernel: Modules linked in: cts rpcsec_gss_krb5 iTCO_wdt iTCO_vendor_support sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm btrfs irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd xor pcspkr raid6_pq i2c_i801 i2c_smbus lpc_ich mfd_core sg mei_me mei ioatdma shpchp wmi ipmi_si ipmi_msghandler rpcrdma ib_ipoib rdma_ucm acpi_power_meter acpi_pad ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb ahci libahci ptp mlx4_core pps_core dca libata i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod Oct 28 22:04:30 klimt kernel: CPU: 7 PID: 1558 Comm: nfsd Not tainted 4.9.0-rc2-00005-g82cd754 #8 Oct 28 22:04:30 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015 Oct 28 22:04:30 klimt kernel: task: ffff880835c3a100 task.stack: ffff8808420d8000 Oct 28 22:04:30 klimt kernel: RIP: 0010:[<ffffffffa05a759f>] [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd] Oct 28 22:04:30 klimt kernel: RSP: 0018:ffff8808420dbce0 EFLAGS: 00010246 Oct 28 22:04:30 klimt kernel: RAX: ffff88084e6660f0 RBX: ffff88084e667020 RCX: 0000000000000000 Oct 28 22:04:30 klimt kernel: RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff88084e667020 Oct 28 22:04:30 klimt kernel: RBP: ffff8808420dbcf8 R08: 0000000000000001 R09: 0000000000000000 Oct 28 22:04:30 klimt kernel: R10: ffff880835c3a100 R11: ffff880835c3aca8 R12: 6b6b6b6b6b6b6b6b Oct 28 22:04:30 klimt kernel: R13: ffff88084e6670d8 R14: ffff880835f546f0 R15: ffff880835f1c548 Oct 28 22:04:30 klimt kernel: FS: 0000000000000000(0000) GS:ffff88087bdc0000(0000) knlGS:0000000000000000 Oct 28 22:04:30 klimt kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Oct 28 22:04:30 klimt kernel: CR2: 00007ff020389000 CR3: 0000000001c06000 CR4: 00000000001406e0 Oct 28 22:04:30 klimt kernel: Stack: Oct 28 22:04:30 klimt kernel: ffff88084e667020 0000000000000000 ffff88084e6670d8 ffff8808420dbd20 Oct 28 22:04:30 klimt kernel: ffffffffa05ac80d ffff880835f54548 ffff88084e640008 ffff880835f545b0 Oct 28 22:04:30 klimt kernel: ffff8808420dbd70 ffffffffa059803d ffff880835f1c768 0000000000000870 Oct 28 22:04:30 klimt kernel: Call Trace: Oct 28 22:04:30 klimt kernel: [<ffffffffa05ac80d>] nfsd4_free_stateid+0xfd/0x1b0 [nfsd] Oct 28 22:04:30 klimt kernel: [<ffffffffa059803d>] nfsd4_proc_compound+0x40d/0x690 [nfsd] Oct 28 22:04:30 klimt kernel: [<ffffffffa0583114>] nfsd_dispatch+0xd4/0x1d0 [nfsd] Oct 28 22:04:30 klimt kernel: [<ffffffffa047bbf9>] svc_process_common+0x3d9/0x700 [sunrpc] Oct 28 22:04:30 klimt kernel: [<ffffffffa047ca64>] svc_process+0xf4/0x330 [sunrpc] Oct 28 22:04:30 klimt kernel: [<ffffffffa05827ca>] nfsd+0xfa/0x160 [nfsd] Oct 28 22:04:30 klimt kernel: [<ffffffffa05826d0>] ? nfsd_destroy+0x170/0x170 [nfsd] Oct 28 22:04:30 klimt kernel: [<ffffffff810b367b>] kthread+0x10b/0x120 Oct 28 22:04:30 klimt kernel: [<ffffffff810b3570>] ? kthread_stop+0x280/0x280 Oct 28 22:04:30 klimt kernel: [<ffffffff8174e8ba>] ret_from_fork+0x2a/0x40 Oct 28 22:04:30 klimt kernel: Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 48 8b 87 b0 00 00 00 48 89 fb 4c 8b a0 98 00 00 00 <49> 8b 44 24 20 48 8d b8 80 03 00 00 e8 10 66 1a e1 48 89 df e8 Oct 28 22:04:30 klimt kernel: RIP [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd] Oct 28 22:04:30 klimt kernel: RSP <ffff8808420dbce0> Oct 28 22:04:30 klimt kernel: ---[ end trace cf5d0b371973e167 ]--- Jeff Layton says: > Hm...now that I look though, this is a little suspicious: > > struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner); > > I wonder if it's possible for the openstateid to have already been > destroyed at this point. > > We might be better off doing something like this to get the client pointer: > > stp->st_stid.sc_client; > > ...which should be more direct and less dependent on other stateids > staying valid. With the suggested change, I am no longer able to reproduce the above oops. v2: Fix unhash_lock_stateid() as well Fix-suggested-by: Jeff Layton <jlayton@redhat.com> Fixes: 42691398be08 ('nfsd: Fix race between FREE_STATEID and LOCK') Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-10-24nfsd: move blocked lock handling under a dedicated spinlockJeff Layton1-13/+15
Bruce was hitting some lockdep warnings in testing, showing that we could hit a deadlock with the new CB_NOTIFY_LOCK handling, involving a rather complex situation involving four different spinlocks. The crux of the matter is that we end up taking the nn->client_lock in the lm_notify handler. The simplest fix is to just declare a new per-nfsd_net spinlock to protect the new CB_NOTIFY_LOCK structures. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-10-13Merge tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-21/+216
Pull nfsd updates from Bruce Fields: "Some RDMA work and some good bugfixes, and two new features that could benefit from user testing: - Anna Schumacker contributed a simple NFSv4.2 COPY implementation. COPY is already supported on the client side, so a call to copy_file_range() on a recent client should now result in a server-side copy that doesn't require all the data to make a round trip to the client and back. - Jeff Layton implemented callbacks to notify clients when contended locks become available, which should reduce latency on workloads with contended locks" * tag 'nfsd-4.9' of git://linux-nfs.org/~bfields/linux: NFSD: Implement the COPY call nfsd: handle EUCLEAN nfsd: only WARN once on unmapped errors exportfs: be careful to only return expected errors. nfsd4: setclientid_confirm with unmatched verifier should fail nfsd: randomize SETCLIENTID reply to help distinguish servers nfsd: set the MAY_NOTIFY_LOCK flag in OPEN replies nfs: add a new NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK constant nfsd: add a LRU list for blocked locks nfsd: have nfsd4_lock use blocking locks for v4.1+ locks nfsd: plumb in a CB_NOTIFY_LOCK operation NFSD: fix corruption in notifier registration svcrdma: support Remote Invalidation svcrdma: Server-side support for rpcrdma_connect_private rpcrdma: RDMA/CM private message data structure svcrdma: Skip put_page() when send_reply() fails svcrdma: Tail iovec leaves an orphaned DMA mapping nfsd: fix dprintk in nfsd4_encode_getdeviceinfo nfsd: eliminate cb_minorversion field nfsd: don't set a FL_LAYOUT lease for flexfiles layouts
2016-10-07cred: simpler, 1D supplementary groupsAlexey Dobriyan1-1/+1
Current supplementary groups code can massively overallocate memory and is implemented in a way so that access to individual gid is done via 2D array. If number of gids is <= 32, memory allocation is more or less tolerable (140/148 bytes). But if it is not, code allocates full page (!) regardless and, what's even more fun, doesn't reuse small 32-entry array. 2D array means dependent shifts, loads and LEAs without possibility to optimize them (gid is never known at compile time). All of the above is unnecessary. Switch to the usual trailing-zero-len-array scheme. Memory is allocated with kmalloc/vmalloc() and only as much as needed. Accesses become simpler (LEA 8(gi,idx,4) or even without displacement). Maximum number of gids is 65536 which translates to 256KB+8 bytes. I think kernel can handle such allocation. On my usual desktop system with whole 9 (nine) aux groups, struct group_info shrinks from 148 bytes to 44 bytes, yay! Nice side effects: - "gi->gid[i]" is shorter than "GROUP_AT(gi, i)", less typing, - fix little mess in net/ipv4/ping.c should have been using GROUP_AT macro but this point becomes moot, - aux group allocation is persistent and should be accounted as such. Link: http://lkml.kernel.org/r/20160817201927.GA2096@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-26nfsd4: setclientid_confirm with unmatched verifier should failJ. Bruce Fields1-2/+3
A setclientid_confirm with (clientid, verifier) both matching an existing confirmed record is assumed to be a replay, but if the verifier doesn't match, it shouldn't be. This would be a very rare case, except that clients following https://tools.ietf.org/html/rfc7931#section-5.8 may depend on the failure. Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26nfsd: set the MAY_NOTIFY_LOCK flag in OPEN repliesJeff Layton1-2/+4
If we are using v4.1+, then we can send notification when contended locks become free. Inform the client of that fact. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26nfsd: add a LRU list for blocked locksJeff Layton1-0/+62
It's possible for a client to call in on a lock that is blocked for a long time, but discontinue polling for it. A malicious client could even set a lock on a file, and then spam the server with failing lock requests from different lockowners that pile up in a DoS attack. Add the blocked lock structures to a per-net namespace LRU when hashing them, and timestamp them. If the lock request is not revisited after a lease period, we'll drop it under the assumption that the client is no longer interested. This also gives us a mechanism to clean up these objects at server shutdown time as well. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-09-26nfsd: have nfsd4_lock use blocking locks for v4.1+ locksJeff Layton1-17/+147
Create a new per-lockowner+per-inode structure that contains a file_lock. Have nfsd4_lock add this structure to the lockowner's list prior to setting the lock. Then call the vfs and request a blocking lock (by setting FL_SLEEP). If we get anything besides FILE_LOCK_DEFERRED back, then we dequeue the block structure and free it. When the next lock request comes in, we'll look for an existing block for the same filehandle and dequeue and reuse it if there is one. When the lock comes free (a'la an lm_notify call), we dequeue it from the lockowner's list and kick off a CB_NOTIFY_LOCK callback to inform the client that it should retry the lock request. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-08-12nfsd: don't return an unhashed lock stateid after taking mutexJeff Layton1-5/+20
nfsd4_lock will take the st_mutex before working with the stateid it gets, but between the time when we drop the cl_lock and take the mutex, the stateid could become unhashed (a'la FREE_STATEID). If that happens the lock stateid returned to the client will be forgotten. Fix this by first moving the st_mutex acquisition into lookup_or_create_lock_state. Then, have it check to see if the lock stateid is still hashed after taking the mutex. If it's not, then put the stateid and try the find/create again. Signed-off-by: Jeff Layton <jlayton@redhat.com> Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com> Cc: stable@vger.kernel.org # feb9dad5 nfsd: Always lock state exclusively. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-08-11nfsd: Fix race between FREE_STATEID and LOCKChuck Lever1-12/+28
When running LTP's nfslock01 test, the Linux client can send a LOCK and a FREE_STATEID request at the same time. The outcome is: Frame 324 R OPEN stateid [2,O] Frame 115004 C LOCK lockowner_is_new stateid [2,O] offset 672000 len 64 Frame 115008 R LOCK stateid [1,L] Frame 115012 C WRITE stateid [0,L] offset 672000 len 64 Frame 115016 R WRITE NFS4_OK Frame 115019 C LOCKU stateid [1,L] offset 672000 len 64 Frame 115022 R LOCKU NFS4_OK Frame 115025 C FREE_STATEID stateid [2,L] Frame 115026 C LOCK lockowner_is_new stateid [2,O] offset 672128 len 64 Frame 115029 R FREE_STATEID NFS4_OK Frame 115030 R LOCK stateid [3,L] Frame 115034 C WRITE stateid [0,L] offset 672128 len 64 Frame 115038 R WRITE NFS4ERR_BAD_STATEID In other words, the server returns stateid L in a successful LOCK reply, but it has already released it. Subsequent uses of stateid L fail. To address this, protect the generation check in nfsd4_free_stateid with the st_mutex. This should guarantee that only one of two outcomes occurs: either LOCK returns a fresh valid stateid, or FREE_STATEID returns NFS4ERR_LOCKS_HELD. Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com> Fix-suggested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-15nfsd: Close race between nfsd4_release_lockowner and nfsd4_lockChuck Lever1-23/+17
nfsd4_release_lockowner finds a lock owner that has no lock state, and drops cl_lock. Then release_lockowner picks up cl_lock and unhashes the lock owner. During the window where cl_lock is dropped, I don't see anything preventing a concurrent nfsd4_lock from finding that same lock owner and adding lock state to it. Move release_lockowner() into nfsd4_release_lockowner and hang onto the cl_lock until after the lock owner's state cannot be found again. Found by inspection, we don't currently have a reproducer. Fixes: 2c41beb0e5cf ("nfsd: reduce cl_lock thrashing in ... ") Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13nfsd: Fix some indent inconsistancyChristophe JAILLET1-1/+1
Silent a few smatch warnings about indentation Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13nfsd: implement machine credential support for some operationsAndrew Elble1-0/+18
This addresses the conundrum referenced in RFC5661 18.35.3, and will allow clients to return state to the server using the machine credentials. The biggest part of the problem is that we need to allow the client to send a compound op with integrity/privacy on mounts that don't have it enabled. Add server support for properly decoding and using spo_must_enforce and spo_must_allow bits. Add support for machine credentials to be used for CLOSE, OPEN_DOWNGRADE, LOCKU, DELEGRETURN, and TEST/FREE STATEID. Implement a check so as to not throw WRONGSEC errors when these operations are used if integrity/privacy isn't turned on. Without this, Linux clients with credentials that expired while holding delegations were getting stuck in an endless loop. Signed-off-by: Andrew Elble <aweits@rit.edu> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-07-13nfsd: allow mach_creds_match to be used more broadlyAndrew Elble1-7/+7
Rename mach_creds_match() to nfsd4_mach_creds_match() and un-staticify Signed-off-by: Andrew Elble <aweits@rit.edu> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-15nfsd: Make init_open_stateid() a bit more wholeOleg Drokin1-15/+12
Move the state selection logic inside from the caller, always making it return correct stp to use. Signed-off-by: J . Bruce Fields <bfields@fieldses.org> Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-15nfsd: Extend the mutex holding region around in nfsd4_process_open2()Oleg Drokin1-3/+13
To avoid racing entry into nfs4_get_vfs_file(). Make init_open_stateid() return with locked stateid to be unlocked by the caller. Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-06-15nfsd: Always lock state exclusively.Oleg Drokin1-20/+20
It used to be the case that state had an rwlock that was locked for write by downgrades, but for read for upgrades (opens). Well, the problem is if there are two competing opens for the same state, they step on each other toes potentially leading to leaking file descriptors from the state structure, since access mode is a bitmap only set once. Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-05-13nfsd: handle seqid wraparound in nfsd4_preprocess_layout_stateidJeff Layton1-7/+1
Move the existing static function to an inline helper, and call it. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>