The ib_mr->length represents the length of the MR in bytes as per
the IBTA spec 1.3 section 11.2.10.3 (REGISTER PHYSICAL MEMORY REGION).

Currently ib_mr->length field is defined as only 32-bits field.
This might result into truncation and failed WRs of consumers who
registers more than 4GB bytes memory regions and whose WRs accessing
such MRs.

This patch makes the length 64-bit to avoid such truncation.

Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Faisal Latif <faisal.latif@intel.com>
Fixes: 4c67e2bf ("IB/core: Introduce new fast registration API")
Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
Signed-off-by: NParav Pandit <parav@mellanox.com>
Signed-off-by: NLeon Romanovsky <leon@kernel.org>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

RPC_TASK_NO_RETRANS_TIMEOUT is set when cl_noretranstimeo
is set, which happens when  RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT is set,
which happens when NFS_CS_NO_RETRANS_TIMEOUT is set.

This flag means "don't resend on a timeout, only resend if the
connection gets broken for some reason".

cl_discrtry is set when RPC_CLNT_CREATE_DISCRTRY is set, which
happens when NFS_CS_DISCRTRY is set.

This flag means "always disconnect before resending".

NFS_CS_NO_RETRANS_TIMEOUT and NFS_CS_DISCRTRY are both only set
in nfs4_init_client(), and it always sets both.

So we will never have a situation where only one of the flags is set.
So this code, which tests if timeout retransmits are allowed, and
disconnection is required, will never run.

So it makes sense to remove this code as it cannot be tested and
could confuse people reading the code (like me).

(alternately we could leave it there with a comment saying
 it is never actually used).
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Adopt the use of xprt_pin_rqst to eliminate contention between
Call-side users of rb_lock and the use of rb_lock in
rpcrdma_reply_handler.

This replaces the mechanism introduced in 431af645 ("xprtrdma:
Fix client lock-up after application signal fires").

Use recv_lock to quickly find the completing rqst, pin it, then
drop the lock. At that point invalidation and pull-up of the Reply
XDR can be done. Both are often expensive operations.

Finally, take recv_lock again to signal completion to the RPC
layer. It also protects adjustment of "cwnd".

This greatly reduces the amount of time a lock is held by the
reply handler. Comparing lock_stat results shows a marked decrease
in contention on rb_lock and recv_lock.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
[trond.myklebust@primarydata.com: Remove call to rpcrdma_buffer_put() from
   the "out_norqst:" path in rpcrdma_reply_handler.]
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The rdma_rw API adjusts max_send_wr upwards during the
rdma_create_qp() call. If the ULP actually wants to take advantage
of these extra resources, it must increase the size of its send
completion queue (created before rdma_create_qp is called) and
increase its send queue accounting limit.

Use the new rdma_rw_mr_factor API to figure out the correct value
to use for the Send Queue and Send Completion Queue depths.

And, ensure that the chosen Send Queue depth for a newly created
transport does not overrun the QP WR limit of the underlying device.

Lastly, there's no longer a need to carry the Send Queue depth in
struct svcxprt_rdma, since the value is used only in the
svc_rdma_accept() path.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Ensure that the chosen Receive Queue depth for a newly created
transport does not overrun the QP WR limit of the underlying device.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

So that NFS WRITE payloads can eventually be placed directly into a
file's page cache, enable the RPC-over-RDMA transport to present
these payloads in the xdr_buf's page list, while placing trailing
content (such as a GETATTR operation) in the xdr_buf's tail.

After this change, the RPC-over-RDMA's "copy tail" hack, added by
commit a97c331f ("svcrdma: Handle additional inline content"),
is no longer needed and can be removed.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Dan Carpenter <dan.carpenter@oracle.com> observed that the while()
loop in svc_rdma_build_read_chunk() does not document the assumption
that the loop interior is always executed at least once.

Defensive: the function now returns -EINVAL if this assumption
fails.
Suggested-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Close an attack vector by moving the arrays of per-server methods to
read-only memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Close an attack vector by moving the arrays of server-side transport
methods to read-only memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

While running nfs/connectathon tests kernel NULL-pointer exception
has been observed due to races in svcsock.c.

Race is appear when kernel accepts connection by kernel_accept
(which creates new socket) and start queuing ingress packets
to new socket. This happens in ksoftirq context which could run
concurrently on a different core while new socket setup is not done yet.

The fix is to re-order socket user data init sequence and add
write/read barrier calls to be sure that we got proper values
for callback pointers before actually calling them.

Test results: nfs/connectathon reports '0' failed tests for about 200+ iterations.

Crash log:
---<-snip->---
[ 6708.638984] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 6708.647093] pgd = ffff0000094e0000
[ 6708.650497] [00000000] *pgd=0000010ffff90003, *pud=0000010ffff90003, *pmd=0000010ffff80003, *pte=0000000000000000
[ 6708.660761] Internal error: Oops: 86000005 [#1] SMP
[ 6708.665630] Modules linked in: nfsv3 nfnetlink_queue nfnetlink_log nfnetlink rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache overlay xt_CONNSECMARK xt_SECMARK xt_conntrack iptable_security ip_tables ah4 xfrm4_mode_transport sctp tun binfmt_misc ext4 jbd2 mbcache loop tcp_diag udp_diag inet_diag rpcrdma ib_isert iscsi_target_mod ib_iser rdma_cm iw_cm libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib ib_ucm ib_uverbs ib_umad ib_cm ib_core nls_koi8_u nls_cp932 ts_kmp nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack vfat fat ghash_ce sha2_ce sha1_ce cavium_rng_vf i2c_thunderx sg thunderx_edac i2c_smbus edac_core cavium_rng nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c nicvf nicpf ast i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
[ 6708.736446]  ttm drm i2c_core thunder_bgx thunder_xcv mdio_thunder mdio_cavium dm_mirror dm_region_hash dm_log dm_mod [last unloaded: stap_3c300909c5b3f46dcacd49aab3334af_87021]
[ 6708.752275] CPU: 84 PID: 0 Comm: swapper/84 Tainted: G        W  OE   4.11.0-4.el7.aarch64 #1
[ 6708.760787] Hardware name: www.cavium.com CRB-2S/CRB-2S, BIOS 0.3 Mar 13 2017
[ 6708.767910] task: ffff810006842e80 task.stack: ffff81000689c000
[ 6708.773822] PC is at 0x0
[ 6708.776739] LR is at svc_data_ready+0x38/0x88 [sunrpc]
[ 6708.781866] pc : [<0000000000000000>] lr : [<ffff0000029d7378>] pstate: 60000145
[ 6708.789248] sp : ffff810ffbad3900
[ 6708.792551] x29: ffff810ffbad3900 x28: ffff000008c73d58
[ 6708.797853] x27: 0000000000000000 x26: ffff81000bbe1e00
[ 6708.803156] x25: 0000000000000020 x24: ffff800f7410bf28
[ 6708.808458] x23: ffff000008c63000 x22: ffff000008c63000
[ 6708.813760] x21: ffff800f7410bf28 x20: ffff81000bbe1e00
[ 6708.819063] x19: ffff810012412400 x18: 00000000d82a9df2
[ 6708.824365] x17: 0000000000000000 x16: 0000000000000000
[ 6708.829667] x15: 0000000000000000 x14: 0000000000000001
[ 6708.834969] x13: 0000000000000000 x12: 722e736f622e676e
[ 6708.840271] x11: 00000000f814dd99 x10: 0000000000000000
[ 6708.845573] x9 : 7374687225000000 x8 : 0000000000000000
[ 6708.850875] x7 : 0000000000000000 x6 : 0000000000000000
[ 6708.856177] x5 : 0000000000000028 x4 : 0000000000000000
[ 6708.861479] x3 : 0000000000000000 x2 : 00000000e5000000
[ 6708.866781] x1 : 0000000000000000 x0 : ffff81000bbe1e00
[ 6708.872084]
[ 6708.873565] Process swapper/84 (pid: 0, stack limit = 0xffff81000689c000)
[ 6708.880341] Stack: (0xffff810ffbad3900 to 0xffff8100068a0000)
[ 6708.886075] Call trace:
[ 6708.888513] Exception stack(0xffff810ffbad3710 to 0xffff810ffbad3840)
[ 6708.894942] 3700:                                   ffff810012412400 0001000000000000
[ 6708.902759] 3720: ffff810ffbad3900 0000000000000000 0000000060000145 ffff800f79300000
[ 6708.910577] 3740: ffff000009274d00 00000000000003ea 0000000000000015 ffff000008c63000
[ 6708.918395] 3760: ffff810ffbad3830 ffff800f79300000 000000000000004d 0000000000000000
[ 6708.926212] 3780: ffff810ffbad3890 ffff0000080f88dc ffff800f79300000 000000000000004d
[ 6708.934030] 37a0: ffff800f7930093c ffff000008c63000 0000000000000000 0000000000000140
[ 6708.941848] 37c0: ffff000008c2c000 0000000000040b00 ffff81000bbe1e00 0000000000000000
[ 6708.949665] 37e0: 00000000e5000000 0000000000000000 0000000000000000 0000000000000028
[ 6708.957483] 3800: 0000000000000000 0000000000000000 0000000000000000 7374687225000000
[ 6708.965300] 3820: 0000000000000000 00000000f814dd99 722e736f622e676e 0000000000000000
[ 6708.973117] [<          (null)>]           (null)
[ 6708.977824] [<ffff0000086f9fa4>] tcp_data_queue+0x754/0xc5c
[ 6708.983386] [<ffff0000086fa64c>] tcp_rcv_established+0x1a0/0x67c
[ 6708.989384] [<ffff000008704120>] tcp_v4_do_rcv+0x15c/0x22c
[ 6708.994858] [<ffff000008707418>] tcp_v4_rcv+0xaf0/0xb58
[ 6709.000077] [<ffff0000086df784>] ip_local_deliver_finish+0x10c/0x254
[ 6709.006419] [<ffff0000086dfea4>] ip_local_deliver+0xf0/0xfc
[ 6709.011980] [<ffff0000086dfad4>] ip_rcv_finish+0x208/0x3a4
[ 6709.017454] [<ffff0000086e018c>] ip_rcv+0x2dc/0x3c8
[ 6709.022328] [<ffff000008692fc8>] __netif_receive_skb_core+0x2f8/0xa0c
[ 6709.028758] [<ffff000008696068>] __netif_receive_skb+0x38/0x84
[ 6709.034580] [<ffff00000869611c>] netif_receive_skb_internal+0x68/0xdc
[ 6709.041010] [<ffff000008696bc0>] napi_gro_receive+0xcc/0x1a8
[ 6709.046690] [<ffff0000014b0fc4>] nicvf_cq_intr_handler+0x59c/0x730 [nicvf]
[ 6709.053559] [<ffff0000014b1380>] nicvf_poll+0x38/0xb8 [nicvf]
[ 6709.059295] [<ffff000008697a6c>] net_rx_action+0x2f8/0x464
[ 6709.064771] [<ffff000008081824>] __do_softirq+0x11c/0x308
[ 6709.070164] [<ffff0000080d14e4>] irq_exit+0x12c/0x174
[ 6709.075206] [<ffff00000813101c>] __handle_domain_irq+0x78/0xc4
[ 6709.081027] [<ffff000008081608>] gic_handle_irq+0x94/0x190
[ 6709.086501] Exception stack(0xffff81000689fdf0 to 0xffff81000689ff20)
[ 6709.092929] fde0:                                   0000810ff2ec0000 ffff000008c10000
[ 6709.100747] fe00: ffff000008c70ef4 0000000000000001 0000000000000000 ffff810ffbad9b18
[ 6709.108565] fe20: ffff810ffbad9c70 ffff8100169d3800 ffff810006843ab0 ffff81000689fe80
[ 6709.116382] fe40: 0000000000000bd0 0000ffffdf979cd0 183f5913da192500 0000ffff8a254ce4
[ 6709.124200] fe60: 0000ffff8a254b78 0000aaab10339808 0000000000000000 0000ffff8a0c2a50
[ 6709.132018] fe80: 0000ffffdf979b10 ffff000008d6d450 ffff000008c10000 ffff000008d6d000
[ 6709.139836] fea0: 0000000000000054 ffff000008cd3dbc 0000000000000000 0000000000000000
[ 6709.147653] fec0: 0000000000000000 0000000000000000 0000000000000000 ffff81000689ff20
[ 6709.155471] fee0: ffff000008085240 ffff81000689ff20 ffff000008085244 0000000060000145
[ 6709.163289] ff00: ffff81000689ff10 ffff00000813f1e4 ffffffffffffffff ffff00000813f238
[ 6709.171107] [<ffff000008082eb4>] el1_irq+0xb4/0x140
[ 6709.175976] [<ffff000008085244>] arch_cpu_idle+0x44/0x11c
[ 6709.181368] [<ffff0000087bf3b8>] default_idle_call+0x20/0x30
[ 6709.187020] [<ffff000008116d50>] do_idle+0x158/0x1e4
[ 6709.191973] [<ffff000008116ff4>] cpu_startup_entry+0x2c/0x30
[ 6709.197624] [<ffff00000808e7cc>] secondary_start_kernel+0x13c/0x160
[ 6709.203878] [<0000000001bc71c4>] 0x1bc71c4
[ 6709.207967] Code: bad PC value
[ 6709.211061] SMP: stopping secondary CPUs
[ 6709.218830] Starting crashdump kernel...
[ 6709.222749] Bye!
---<-snip>---
Signed-off-by: NVadim Lomovtsev <vlomovts@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

To reduce false cacheline sharing, separate counters that are likely
to be accessed in the Call path from those accessed in the Reply
path.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If you
 - mount and NFSv3 filesystem
 - do some file locking which requires the server
   to make a GRANT call back
 - unmount
 - mount again and do the same locking

then the second attempt at locking suffers a 30 second delay.
Unmounting and remounting causes lockd to stop and restart,
which causes it to bind to a new port.
The server still thinks the old port is valid and gets ECONNREFUSED
when trying to contact it.
ECONNREFUSED should be seen as a hard error that is not worth
retrying.  Rebinding is the only reasonable response.

This patch forces a rebind if that makes sense.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This further reduces contention with the transport_lock, and allows us
to convert to using a non-bh-safe spinlock, since the list is now never
accessed from a bh context.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Simplify the code to avoid a full copy of the struct xdr_skb_reader.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Ensure that we don't hog the workqueue thread by requeuing the job
every 64 loops.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The backchannel request has no associated task, so it is going nowhere
until we call xprt_complete_bc_request().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Instead add a mechanism to ensure that the request doesn't disappear
from underneath us while copying from the socket. We do this by
preventing xprt_release() from freeing the XDR buffers until the
flag RPC_TASK_MSG_RECV has been cleared from the request.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>

Re-arrange the pointer arithmetic in the chunk list encoders to
eliminate several more integer multiplication instructions during
Transport Header encoding.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Re-arrange the pointer arithmetic in rpcrdma_convert_iovs() to
eliminate several integer multiplication instructions during
Transport Header encoding.

Also, array overflow does not occur outside development
environments, so replace overflow checking with one spot check
at the end. This reduces the number of conditional branches in
the common case.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Same changes as in rpcrdma_marshal_req(). This removes
C-structure style encoding from the backchannel.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

While marshaling chunk lists which are variable-length XDR objects,
check for XDR buffer overflow at every step. Measurements show no
significant changes in CPU utilization.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Initialize an xdr_stream at the top of rpcrdma_marshal_req(), and
use it to encode the fixed transport header fields. This xdr_stream
will be used to encode the chunk lists in a subsequent patch.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: Remove a variable whose result is no longer used.
Commit 655fec69 ("xprtrdma: Use gathered Send for large inline
messages") should have removed it.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: The caller already has rpcrdma_xprt, so pass that directly
instead. And provide a documenting comment for this critical
function.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: Replace C-structure based XDR decoding for consistency
with other areas.

struct rpcrdma_rep is rearranged slightly so that the relevant fields
are in cache when the Receive completion handler is invoked.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This field is no longer used outside the Receive completion handler.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up: The opcode check is no longer necessary, because since
commit 2fa8f88d ("xprtrdma: Use new CQ API for RPC-over-RDMA
client send CQs"), this completion handler is invoked only for
RECV work requests.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up chunk list decoding by using the xdr_stream set up in
rpcrdma_reply_handler. This hardens decoding by checking for buffer
overflow at every step while unmarshaling variable-length XDR
objects.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Refactor the reply handler's transport header decoding logic to make
it easier to understand and update.

Convert some of the handler to use xdr_streams, which will enable
stricter validation of input data and enable the eventual addition
of support for new combinations of chunks, such as "Write + Reply"
or "PZRC + normal Read".
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Transport header decoding deals with untrusted input data, therefore
decoding this header needs to be hardened.

Adopt the same infrastructure that is used when XDR decoding NFS
replies. This is slightly more CPU-intensive than the replaced code,
but we're not adding new atomics, locking, or context switches. The
cost is manageable.

Start by initializing an xdr_stream in rpcrdma_reply_handler().
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

After transport instance creation, these function pointers never
change. Mark them as constant to prevent their use as an attack
vector for code injections.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit 3d476263 ("tcp: remove poll() flakes when receiving
RST") in v4.12 changed the order in which ->sk_state_change()
and ->sk_error_report() are called when a socket is shut
down - sk_state_change() is now called first.

This causes xs_tcp_state_change() -> xs_sock_mark_closed() ->
xprt_disconnect_done() to wake all pending tasked with -EAGAIN.
When the ->sk_error_report() callback arrives, it is too late to
pass the error on, and it is lost.

As easy way to demonstrate the problem caused is to try to start
rpc.nfsd while rcpbind isn't running.
nfsd will attempt a tcp connection to rpcbind.  A ECONNREFUSED
error is returned, but sunrpc code loses the error and keeps
retrying.  If it saw the ECONNREFUSED, it would abort.

To fix this, handle the sk->sk_err in the TCP_CLOSE branch of
xs_tcp_state_change().

Fixes: 3d476263 ("tcp: remove poll() flakes when receiving RST")
Cc: stable@vger.kernel.org (v4.12)
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Otherwise, we enable a MAC forgery via timing attack.
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up.

FASTREG and LOCAL_INV WRs are typically not signaled. localinv_wake
is used for the last LOCAL_INV WR in a chain, which is always
signaled. The documenting comments should reflect that.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up.

Reported by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up.

Commit 38f1932e ("xprtrdma: Remove FMRs from the unmap list
after unmapping") utilized list_del_init() to try to prevent some
list corruption. The corruption was actually caused by the reply
handler racing with a signal. Now that MR invalidation is properly
serialized, list_del_init() can safely be replaced.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Some have complained about the log messages generated when xprtrdma
opens or closes a connection to a server. When an NFS mount is
mostly idle these can appear every few minutes as the client idles
out the connection and reconnects.

Connection and disconnection is a normal part of operation, and not
exceptional, so change these to dprintk's for now. At some point
all of these will be converted to tracepoints, but that's for
another day.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Deferred MR recovery does a DMA-unmapping of the MW. However, ro_map
invokes rpcrdma_defer_mr_recovery in some error cases where the MW
has not even been DMA-mapped yet.

Avoid a DMA-unmapping error replacing rpcrdma_defer_mr_recovery.

Also note that if ib_dma_map_sg is asked to map 0 nents, it will
return 0. So the extra "if (i == 0)" check is no longer needed.

Fixes: 42fe28f6 ("xprtrdma: Do not leak an MW during a DMA ...")
Fixes: 505bbe64 ("xprtrdma: Refactor MR recovery work queues")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

When ib_post_send() fails, all LOCAL_INV WRs past @bad_wr have to be
examined, and the MRs reset by hand.

I'm not sure how the existing code can work by comparing R_keys.
Restructure the logic so that instead it walks the chain of WRs,
starting from the first bad one.

Make sure to wait for completion if at least one WR was actually
posted. Otherwise, if the ib_post_send fails, we can end up
DMA-unmapping the MR while LOCAL_INV operations are in flight.

Commit 7a89f9c6 ("xprtrdma: Honor ->send_request API contract")
added the rdma_disconnect() call site. The disconnect actually
causes more problems than it solves, and SQ overruns happen only as
a result of software bugs. So remove it.

Fixes: d7a21c1b ("xprtrdma: Reset MRs in frwr_op_unmap_sync()")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>