net: add missing includes of linux/sched/clock.h

Number of files depend on linux/sched/clock.h getting included
by linux/skbuff.h which soon will no longer be the case.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: add missing barrier to release_refill

The functions clear_bit and set_bit do not imply a memory barrier, thus it
may be possible that the waitqueue_active function (which does not take
any locks) is moved before clear_bit and it could miss a wakeup event.

Fix this bug by adding a memory barrier after clear_bit.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: stop using dmapool

RDMA ULPs should only perform DMA through the ib_dma_* API instead of
using the hidden dma_device directly. In addition using the dma coherent
API family that dmapool is a part of can be very ineffcient on plaforms
that are not DMA coherent. Switch to use slab allocations and the
ib_dma_* APIs instead.

Link: https://lore.kernel.org/r/20201106181941.1878556-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

net/rds: suppress page allocation failure error in recv buffer refill

RDS/IB tries to refill the recv buffer in softirq context using
GFP_NOWAIT flag. However alloc failure is handled by queueing a work to
refill the recv buffer with GFP_KERNEL flag. This means failure to
allocate with GFP_NOWAIT isn't fatal. Do not print the PAF warnings if
softirq context fails to refill the recv buffer. We will see the PAF
warnings when worker also fails to allocate.

Signed-off-by: Manjunath Patil <manjunath.b.patil@oracle.com>
Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/rds: Use DMA memory pool allocation for rds_header

Currently, RDS calls ib_dma_alloc_coherent() to allocate a large piece
of contiguous DMA coherent memory to store struct rds_header for
sending/receiving packets. The memory allocated is then partitioned
into struct rds_header. This is not necessary and can be costly at
times when memory is fragmented. Instead, RDS should use the DMA
memory pool interface to handle this. The DMA addresses of the pre-
allocated headers are stored in an array. At send/receive ring
initialization and refill time, this arrary is de-referenced to get
the DMA addresses. This array is not accessed at send/receive packet
processing.

Suggested-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds: Log vendor error if send/recv Work requests fail

Log vendor error if work requests fail. Vendor error provides
more information that is used for debugging the issue.

Signed-off-by: Sudhakar Dindukurti <sudhakar.dindukurti@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds: Whitelist rdma_cookie and rx_tstamp for usercopy

Add the RDMA cookie and RX timestamp to the usercopy whitelist.

After the introduction of hardened usercopy whitelisting
(https://lwn.net/Articles/727322/), a warning is displayed when the
RDMA cookie or RX timestamp is copied to userspace:

kernel: WARNING: CPU: 3 PID: 5750 at
mm/usercopy.c:81 usercopy_warn+0x8e/0xa6
[...]
kernel: Call Trace:
kernel: __check_heap_object+0xb8/0x11b
kernel: __check_object_size+0xe3/0x1bc
kernel: put_cmsg+0x95/0x115
kernel: rds_recvmsg+0x43d/0x620 [rds]
kernel: sock_recvmsg+0x43/0x4a
kernel: ___sys_recvmsg+0xda/0x1e6
kernel: ? __handle_mm_fault+0xcae/0xf79
kernel: __sys_recvmsg+0x51/0x8a
kernel: SyS_recvmsg+0x12/0x1c
kernel: do_syscall_64+0x79/0x1ae

When the whitelisting feature was introduced, the memory for the RDMA
cookie and RX timestamp in RDS was not added to the whitelist, causing
the warning above.

Signed-off-by: Dag Moxnes <dag.moxnes@oracle.com>
Tested-by: Jenny <jenny.x.xu@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: limit the number of times we loop in rds_send_xmit

This will kick the RDS worker thread if we have been looping
too long.

Original commit from 2012 updated to include a change by
Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
that triggers "must_wake" if "rds_ib_recv_refill_one" fails.

Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rds: fix memory leak when unload rds_rdma

When KASAN is enabled, after several rds connections are
created, then "rmmod rds_rdma" is run. The following will
appear.

"
BUG rds_ib_incoming (Not tainted): Objects remaining
in rds_ib_incoming on __kmem_cache_shutdown()

Call Trace:
dump_stack+0x71/0xab
slab_err+0xad/0xd0
__kmem_cache_shutdown+0x17d/0x370
shutdown_cache+0x17/0x130
kmem_cache_destroy+0x1df/0x210
rds_ib_recv_exit+0x11/0x20 [rds_rdma]
rds_ib_exit+0x7a/0x90 [rds_rdma]
__x64_sys_delete_module+0x224/0x2c0
? __ia32_sys_delete_module+0x2c0/0x2c0
do_syscall_64+0x73/0x190
entry_SYSCALL_64_after_hwframe+0x44/0xa9
"
This is rds connection memory leak. The root cause is:
When "rmmod rds_rdma" is run, rds_ib_remove_one will call
rds_ib_dev_shutdown to drop the rds connections.
rds_ib_dev_shutdown will call rds_conn_drop to drop rds
connections as below.
"
rds_conn_path_drop(&conn->c_path[0], false);
"
In the above, destroy is set to false.
void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
{
atomic_set(&cp->cp_state, RDS_CONN_ERROR);

rcu_read_lock();
if (!destroy && rds_destroy_pending(cp->cp_conn)) {
rcu_read_unlock();
return;
}
queue_work(rds_wq, &cp->cp_down_w);
rcu_read_unlock();
}
In the above function, destroy is set to false. rds_destroy_pending
is called. This does not move rds connections to ib_nodev_conns.
So destroy is set to true to move rds connections to ib_nodev_conns.
In rds_ib_unregister_client, flush_workqueue is called to make rds_wq
finsh shutdown rds connections. The function rds_ib_destroy_nodev_conns
is called to shutdown rds connections finally.
Then rds_ib_recv_exit is called to destroy slab.

void rds_ib_recv_exit(void)
{
kmem_cache_destroy(rds_ib_incoming_slab);
kmem_cache_destroy(rds_ib_frag_slab);
}
The above slab memory leak will not occur again.

>From tests,
256 rds connections
[root@ca-dev14 ~]# time rmmod rds_rdma

real 0m16.522s
user 0m0.000s
sys 0m8.152s
512 rds connections
[root@ca-dev14 ~]# time rmmod rds_rdma

real 0m32.054s
user 0m0.000s
sys 0m15.568s

To rmmod rds_rdma with 256 rds connections, about 16 seconds are needed.
And with 512 rds connections, about 32 seconds are needed.
>From ftrace, when one rds connection is destroyed,

"
19) | rds_conn_destroy [rds]() {
19) 7.782 us | rds_conn_path_drop [rds]();
15) | rds_shutdown_worker [rds]() {
15) | rds_conn_shutdown [rds]() {
15) 1.651 us | rds_send_path_reset [rds]();
15) 7.195 us | }
15) + 11.434 us | }
19) 2.285 us | rds_cong_remove_conn [rds]();
19) * 24062.76 us | }
"
So if many rds connections will be destroyed, this function
rds_ib_destroy_nodev_conns uses most of time.

Suggested-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: ib: force endiannes annotation

While the endiannes is being handled correctly as indicated by the comment
above the offending line - sparse was unhappy with the missing annotation
as be64_to_cpu() expects a __be64 argument. To mitigate this annotation
all involved variables are changed to a consistent __le64 and the
conversion to uint64_t delayed to the call to rds_cong_map_updated().

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: rdma: update rdma transport for tos

For RDMA transports, RDS TOS is an extension of IB QoS(Annex A13)
to provide clients the ability to segregate traffic flows for
different type of data. RDMA CM abstract it for ULPs using
rdma_set_service_type(). Internally, each traffic flow is
represented by a connection with all of its independent resources
like that of a normal connection, and is differentiated by
service type. In other words, there can be multiple qp connections
between an IP pair and each supports a unique service type.

The feature has been added from RDSv4.1 onwards and supports
rolling upgrades. RDMA connection metadata also carries the tos
information to set up SL on end to end context. The original
code was developed by Bang Nguyen in downstream kernel back in
2.6.32 kernel days and it has evolved over period of time.

Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
[yanjun.zhu@oracle.com: Adapted original patch with ipv6 changes]
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>

IB/core: Remove ib_sg_dma_address() and ib_sg_dma_len()

Keeping single line wrapper functions is not useful. Hence remove the
ib_sg_dma_address() and ib_sg_dma_len() functions. This patch does not
change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

rds: rds_ib_recv_alloc_cache() should call alloc_percpu_gfp() instead

Currently, rds_ib_conn_alloc() calls rds_ib_recv_alloc_caches()
without passing along the gfp_t flag. But rds_ib_recv_alloc_caches()
and rds_ib_recv_alloc_cache() should take a gfp_t parameter so that
rds_ib_recv_alloc_cache() can call alloc_percpu_gfp() using the
correct flag instead of calling alloc_percpu().

Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds: Simplify ib_post_(send|recv|srq_recv)() calls

Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL
as third argument to ib_post_(send|recv|srq_recv)().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

rds: Changing IP address internal representation to struct in6_addr

This patch changes the internal representation of an IP address to use
struct in6_addr. IPv4 address is stored as an IPv4 mapped address.
All the functions which take an IP address as argument are also
changed to use struct in6_addr. But RDS socket layer is not modified
such that it still does not accept IPv6 address from an application.
And RDS layer does not accept nor initiate IPv6 connections.

v2: Fixed sparse warnings.

Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds: Remove unnecessary variable

Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/rds: void function cannot return -1

Commit b6fb0df12db6 ("RDS/IB: Make ib_recv_refill return void") did
not change the comment accordingly.

Fixes: b6fb0df12db6 ("RDS/IB: Make ib_recv_refill return void")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.ccom>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: ib: Fix NULL pointer dereference in debug code

rds_ib_recv_refill() is a function that refills an IB receive
queue. It can be called from both the CQE handler (tasklet) and a
worker thread.

Just after the call to ib_post_recv(), a debug message is printed with
rdsdebug():

ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
rdsdebug("recv %p ibinc %p page %p addr %lu ret %d\n", recv,
recv->r_ibinc, sg_page(&recv->r_frag->f_sg),
(long) ib_sg_dma_address(
ic->i_cm_id->device,
&recv->r_frag->f_sg),
ret);

Now consider an invocation of rds_ib_recv_refill() from the worker
thread, which is preemptible. Further, assume that the worker thread
is preempted between the ib_post_recv() and rdsdebug() statements.

Then, if the preemption is due to a receive CQE event, the
rds_ib_recv_cqe_handler() will be invoked. This function processes
receive completions, including freeing up data structures, such as the
recv->r_frag.

In this scenario, rds_ib_recv_cqe_handler() will process the receive
WR posted above. That implies, that the recv->r_frag has been freed
before the above rdsdebug() statement has been executed. When it is
later executed, we will have a NULL pointer dereference:

[ 4088.068008] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
[ 4088.076754] IP: rds_ib_recv_refill+0x87/0x620 [rds_rdma]
[ 4088.082686] PGD 0 P4D 0
[ 4088.085515] Oops: 0000 [#1] SMP
[ 4088.089015] Modules linked in: rds_rdma(OE) rds(OE) rpcsec_gss_krb5(E) nfsv4(E) dns_resolver(E) nfs(E) fscache(E) mlx4_ib(E) ib_ipoib(E) rdma_ucm(E) ib_ucm(E) ib_uverbs(E) ib_umad(E) rdma_cm(E) ib_cm(E) iw_cm(E) ib_core(E) binfmt_misc(E) sb_edac(E) intel_powerclamp(E) coretemp(E) kvm_intel(E) kvm(E) irqbypass(E) crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) pcbc(E) aesni_intel(E) crypto_simd(E) iTCO_wdt(E) glue_helper(E) iTCO_vendor_support(E) sg(E) cryptd(E) pcspkr(E) ipmi_si(E) ipmi_devintf(E) ipmi_msghandler(E) shpchp(E) ioatdma(E) i2c_i801(E) wmi(E) lpc_ich(E) mei_me(E) mei(E) mfd_core(E) nfsd(E) auth_rpcgss(E) nfs_acl(E) lockd(E) grace(E) sunrpc(E) ip_tables(E) ext4(E) mbcache(E) jbd2(E) fscrypto(E) mgag200(E) i2c_algo_bit(E) drm_kms_helper(E) syscopyarea(E) sysfillrect(E) sysimgblt(E)
[ 4088.168486] fb_sys_fops(E) ahci(E) ixgbe(E) libahci(E) ttm(E) mdio(E) ptp(E) pps_core(E) drm(E) sd_mod(E) libata(E) crc32c_intel(E) mlx4_core(E) i2c_core(E) dca(E) megaraid_sas(E) dm_mirror(E) dm_region_hash(E) dm_log(E) dm_mod(E) [last unloaded: rds]
[ 4088.193442] CPU: 20 PID: 1244 Comm: kworker/20:2 Tainted: G OE 4.14.0-rc7.master.20171105.ol7.x86_64 #1
[ 4088.205097] Hardware name: Oracle Corporation ORACLE SERVER X5-2L/ASM,MOBO TRAY,2U, BIOS 31110000 03/03/2017
[ 4088.216074] Workqueue: ib_cm cm_work_handler [ib_cm]
[ 4088.221614] task: ffff885fa11d0000 task.stack: ffffc9000e598000
[ 4088.228224] RIP: 0010:rds_ib_recv_refill+0x87/0x620 [rds_rdma]
[ 4088.234736] RSP: 0018:ffffc9000e59bb68 EFLAGS: 00010286
[ 4088.240568] RAX: 0000000000000000 RBX: ffffc9002115d050 RCX: ffffc9002115d050
[ 4088.248535] RDX: ffffffffa0521380 RSI: ffffffffa0522158 RDI: ffffffffa0525580
[ 4088.256498] RBP: ffffc9000e59bbf8 R08: 0000000000000005 R09: 0000000000000000
[ 4088.264465] R10: 0000000000000339 R11: 0000000000000001 R12: 0000000000000000
[ 4088.272433] R13: ffff885f8c9d8000 R14: ffffffff81a0a060 R15: ffff884676268000
[ 4088.280397] FS: 0000000000000000(0000) GS:ffff885fbec80000(0000) knlGS:0000000000000000
[ 4088.289434] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4088.295846] CR2: 0000000000000020 CR3: 0000000001e09005 CR4: 00000000001606e0
[ 4088.303816] Call Trace:
[ 4088.306557] rds_ib_cm_connect_complete+0xe0/0x220 [rds_rdma]
[ 4088.312982] ? __dynamic_pr_debug+0x8c/0xb0
[ 4088.317664] ? __queue_work+0x142/0x3c0
[ 4088.321944] rds_rdma_cm_event_handler+0x19e/0x250 [rds_rdma]
[ 4088.328370] cma_ib_handler+0xcd/0x280 [rdma_cm]
[ 4088.333522] cm_process_work+0x25/0x120 [ib_cm]
[ 4088.338580] cm_work_handler+0xd6b/0x17aa [ib_cm]
[ 4088.343832] process_one_work+0x149/0x360
[ 4088.348307] worker_thread+0x4d/0x3e0
[ 4088.352397] kthread+0x109/0x140
[ 4088.355996] ? rescuer_thread+0x380/0x380
[ 4088.360467] ? kthread_park+0x60/0x60
[ 4088.364563] ret_from_fork+0x25/0x30
[ 4088.368548] Code: 48 89 45 90 48 89 45 98 eb 4d 0f 1f 44 00 00 48 8b 43 08 48 89 d9 48 c7 c2 80 13 52 a0 48 c7 c6 58 21 52 a0 48 c7 c7 80 55 52 a0 <4c> 8b 48 20 44 89 64 24 08 48 8b 40 30 49 83 e1 fc 48 89 04 24
[ 4088.389612] RIP: rds_ib_recv_refill+0x87/0x620 [rds_rdma] RSP: ffffc9000e59bb68
[ 4088.397772] CR2: 0000000000000020
[ 4088.401505] ---[ end trace fe922e6ccf004431 ]---

This bug was provoked by compiling rds out-of-tree with
EXTRA_CFLAGS="-DRDS_DEBUG -DDEBUG" and inserting an artificial delay
between the rdsdebug() and ib_ib_port_recv() statements:

/* XXX when can this fail? */
ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
+ if (can_wait)
+ usleep_range(1000, 5000);
rdsdebug("recv %p ibinc %p page %p addr %lu ret %d\n", recv,
recv->r_ibinc, sg_page(&recv->r_frag->f_sg),
(long) ib_sg_dma_address(

The fix is simply to move the rdsdebug() statement up before the
ib_post_recv() and remove the printing of ret, which is taken care of
anyway by the non-debug code.

Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Knut Omang <knut.omang@oracle.com>
Reviewed-by: Wei Lin Guay <wei.lin.guay@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: Reintroduce statistics counting

In commit 7e3f2952eeb1 ("rds: don't let RDS shutdown a connection
while senders are present"), refilling the receive queue was removed
from rds_ib_recv(), along with the increment of
s_ib_rx_refill_from_thread.

Commit 73ce4317bf98 ("RDS: make sure we post recv buffers")
re-introduces filling the receive queue from rds_ib_recv(), but does
not add the statistics counter. rds_ib_recv() was later renamed to
rds_ib_recv_path().

This commit reintroduces the statistics counting of
s_ib_rx_refill_from_thread and s_ib_rx_refill_from_cq.

Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Knut Omang <knut.omang@oracle.com>
Reviewed-by: Wei Lin Guay <wei.lin.guay@oracle.com>
Reviewed-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: add receive message trace used by application

Socket option to tap receive path latency in various stages
in nano seconds. It can be enabled on selective sockets using
using SO_RDS_MSG_RXPATH_LATENCY socket option. RDS will return
the data to application with RDS_CMSG_RXPATH_LATENCY in defined
format. Scope is left to add more trace points for future
without need of change in the interface.

Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

RDS: IB: add few useful cache stasts

Tracks the ib receive cache total, incoming and frag allocations.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

RDS: IB: include faddr in connection log

Also use pr_* for it.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

RDS: TCP: make receive path use the rds_conn_path

The ->sk_user_data contains a pointer to the rds_conn_path
for the socket. Use this consistently in the rds_tcp_data_ready
callbacks to get the rds_conn_path for rds_recv_incoming.

Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: split out connection specific state from rds_connection to rds_conn_path

In preparation for multipath RDS, split the rds_connection
structure into a base structure, and a per-path struct rds_conn_path.
The base structure tracks information and locks common to all
paths. The workqs for send/recv/shutdown etc are tracked per
rds_conn_path. Thus the workq callbacks now work with rds_conn_path.

This commit allows for one rds_conn_path per rds_connection, and will
be extended into multiple conn_paths in subsequent commits.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: fix congestion map corruption for PAGE_SIZE > 4k

When PAGE_SIZE > 4k single page can contain 2 RDS fragments. If
'rds_ib_cong_recv' ignore the RDS fragment offset in to the page it
then read the data fragment as far congestion map update and lead to
corruption of the RDS connection far congestion map.

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RDS: IB: ack more receive completions to improve performance

For better performance, we split the receive completion IRQ handler. That
lets us acknowledge several WCE events in one call. We also limit the WC
to max 32 to avoid latency. Acknowledging several completions in one call
instead of several calls each time will provide better performance since
less mutual exclusion locks are being performed.

In next patch, send completion is also split which re-uses the poll_cq()
and hence the code is moved to ib_cm.c

Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

rds/ib: Remove ib_get_dma_mr calls

The pd now has a local_dma_lkey member which completely replaces
ib_get_dma_mr, use it instead.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

RDS: fix the dangling reference to rds_ib_incoming_slab

On rds_ib_frag_slab allocation failure, ensure rds_ib_incoming_slab
is not pointing to the detsroyed memory.

Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: Fix improper gfp_t usage.

>> net/rds/ib_recv.c:382:28: sparse: incorrect type in initializer (different base types)
net/rds/ib_recv.c:382:28: expected int [signed] can_wait
net/rds/ib_recv.c:382:28: got restricted gfp_t
net/rds/ib_recv.c:828:23: sparse: cast to restricted __le64

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: make sure we post recv buffers

If we get an ENOMEM during rds_ib_recv_refill, we might never come
back and refill again later. Patch makes sure to kick krdsd into
helping out.

To achieve this we add RDS_RECV_REFILL flag and update in the refill
path based on that so that at least some therad will keep posting
receive buffers.

Since krdsd and softirq both might race for refill, we decide to
schedule on work queue based on ring_low instead of ring_empty.

Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: always free recv frag as we free its ring entry

We were still seeing rare occurrences of the WARN_ON(recv->r_frag) which
indicates that the recv refill path was finding allocated frags in ring
entries that were marked free. These were usually followed by OOM crashes.
They only seem to be occurring in the presence of completion errors and
connection resets.

This patch ensures that we free the frag as we mark the ring entry free.
This should stop the refill path from finding allocated frags in ring
entries that were marked free.

Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: Switch to generic logging helpers

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

rds: switch ->inc_copy_to_user() to passing iov_iter

instances get considerably simpler from that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch: Mass conversion of smp_mb__*()

Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

net: rds: fix per-cpu helper usage

commit ae4b46e9d "net: rds: use this_cpu_* per-cpu helper" broke per-cpu
handling for rds. chpfirst is the result of __this_cpu_read(), so it is
an absolute pointer and not __percpu. Therefore, __this_cpu_write()
should not operate on chpfirst, but rather on cache->percpu->first, just
like __this_cpu_read() did before.

Cc: <stable@vger.kernel.org> # 3.8+
Signed-off-byd Gerald Schaefer <gerald.schaefer@de.ibm.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

IB/rds: Correct ib_api use with gs_dma_address/sg_dma_len

0b088e00 ("RDS: Use page_remainder_alloc() for recv bufs")
added uses of sg_dma_len() and sg_dma_address(). This makes
RDS DOA with the qib driver.

IB ulps should use ib_sg_dma_len() and ib_sg_dma_address
respectively since some HCAs overload ib_sg_dma* operations.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rds: use this_cpu_* per-cpu helper

Signed-off-by: Shan Wei <davidshan@tencent.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rds: remove the second argument of k[un]map_atomic()

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>

rds: Fix typo in iw_recv.c and ib_recv.c

Correct spelling "inclue" to "include" in
net/rds/iw_recv.c and net/rds/ib_recv.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

RDS/IB: print string constants in more places

This prints the constant identifier for work completion status and rdma
cm event types, like we already do for IB event types.

A core string array helper is added that each string type uses.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

RDS: properly use sg_init_table

This is only needed to keep debugging code from bugging.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

RDS: remove __init and __exit annotation

The trivial amount of memory saved isn't worth the cost of dealing with section
mismatches.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

RDS/IB: Use SLAB_HWCACHE_ALIGN flag for kmem_cache_create()

We are *definitely* counting cycles as closely as DaveM, so
ensure hwcache alignment for our recv ring control structs.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS/IB: always process recv completions

The recv refill path was leaking fragments because the recv event handler had
marked a ring element as free without freeing its frag. This was happening
because it wasn't processing receives when the conn wasn't marked up or
connecting, as can be the case if it races with rmmod.

Two observations support always processing receives in the callback.

First, buildup should only post receives, thus triggering recv event handler
calls, once it has built up all the state to handle them. Teardown should
destroy the CQ and drain the ring before tearing down the state needed to
process recvs. Both appear to be true today.

Second, this test was fundamentally racy. There is nothing to stop rmmod and
connection destruction from swooping in the moment after the conn state was
sampled but before real receive procesing starts.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

RDS/IB: Make ib_recv_refill return void

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS: use friendly gfp masks for prefill

When prefilling the rds frags, we end up doing a lot of allocations.
We're not in atomic context here, and so there's no reason to dip into
atomic reserves. This changes the prefills to use masks that allow
waiting.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

RDS/IB: Add caching of frags and incs

This patch is based heavily on an initial patch by Chris Mason.
Instead of freeing slab memory and pages, it keeps them, and
funnels them back to be reused.

The lock minimization strategy uses xchg and cmpxchg atomic ops
for manipulation of pointers to list heads. We anchor the lists with a
pointer to a list_head struct instead of a static list_head struct.
We just have to carefully use the existing primitives with
the difference between a pointer and a static head struct.

For example, 'list_empty()' means that our anchor pointer points to a list with
a single item instead of meaning that our static head element doesn't point to
any list items.

Original patch by Chris, with significant mods and fixes by Andy and Zach.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: Zach Brown <zach.brown@oracle.com>

RDS/IB: Remove ib_recv_unmap_page()

All it does is call unmap_sg(), so just call that directly.

The comment above unmap_page also may be incorrect, so we
shouldn't hold on to it, either.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS: Assume recv->r_frag is always NULL in refill_one()

refill_one() should never be called on a recv struct that
doesn't need a new r_frag allocated. Add a WARN and remove
conditional around r_frag alloc code.

Also, add a comment to explain why r_ibinc may or may not
need refilling.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS: Use page_remainder_alloc() for recv bufs

Instead of splitting up a page into RDS_FRAG_SIZE chunks
ourselves, ask rds_page_remainder_alloc() to do it. While it
is possible PAGE_SIZE > FRAG_SIZE, on x86en it isn't, so having
duplicate "carve up a page into buffers" code seems excessive.

The other modification this spawns is the use of a single
struct scatterlist in rds_page_frag instead of a bare page ptr.
This causes verbosity to increase in some places, and decrease
in others.

Finally, I decided to unify the lifetimes and alloc/free of
rds_page_frag and its page. This is a nice simplification in itself,
but will be extra-nice once we come to adding cmason's recycling
patch.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

rds: don't let RDS shutdown a connection while senders are present

This is the first in a long line of patches that tries to fix races
between RDS connection shutdown and RDS traffic.

Here we are maintaining a count of active senders to make sure
the connection doesn't go away while they are using it.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

RDS: Refill recv ring directly from tasklet

Performance is better if we use allocations that don't block
to refill the receive ring. Since the whole reason we were
kicking out to the worker thread was so we could do blocking
allocs, we no longer need to do this.

Remove gfp params from rds_ib_recv_refill(); we always use
GFP_NOWAIT.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS/IB: Remove ib_[header/data]_sge() functions

These functions were to cope with differently ordered
sg entries depending on RDS 3.0 or 3.1+. Now that
we've dropped 3.0 compatibility we no longer need them.

Also, modify usage sites for these to refer to sge[0] or [1]
directly. Reorder code to initialize header sgs first.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS/IB: Disallow connections less than RDS 3.1

RDS 3.0 connections (in OFED 1.3 and earlier) put the
header at the end. 3.1 connections put it at the head.
The code has significant added complexity in order to
handle both configurations. In OFED 1.6 we can
drop this and simplify the code by only supporting
"header-first" configuration.

This patch checks the protocol version, and if prior
to 3.1, does not complete the connection.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS: inc_purge() transport function unused - remove it

Signed-off-by: Andy Grover <andy.grover@oracle.com>

RDS: cleanup: remove "== NULL"s and "!= NULL"s in ptr comparisons

Favor "if (foo)" style over "if (foo != NULL)".

Signed-off-by: Andy Grover <andy.grover@oracle.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

RDS: Do not BUG() on error returned from ib_post_send

BUGging on a runtime error code should be avoided. This
patch also eliminates all other BUG()s that have no real
reason to exist.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Move && and || to end of previous line

Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS/IB+IW: Move recv processing to a tasklet

Move receive processing from event handler to a tasklet.
This should help prevent hangcheck timer from going off
when RDS is under heavy load.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: Fix potential race around rds_i[bw]_allocation

"At rds_ib_recv_refill_one(), it first executes atomic_read(&rds_ib_allocation)
for if-condition checking,

and then executes atomic_inc(&rds_ib_allocation) if the condition was
not satisfied.

However, if any other code which updates rds_ib_allocation executes
between these two atomic operation executions,
it seems that it may result race condition. (especially when
rds_ib_allocation + 1 == rds_ib_sysctl_max_recv_allocation)"

This patch fixes this by using atomic_inc_unless to eliminate the
possibility of allocating more than rds_ib_sysctl_max_recv_allocation
and then decrementing the count if the allocation fails. It also
makes an identical change to the iwarp transport.

Reported-by: Shin Hong <hongshin@gmail.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS/IB: Rename byte_len to data_len to enhance readability

Of course len is in bytes. Calling it data_len hopefully indicates
a little better what the variable is actually for.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS/IB: Handle connections using RDS 3.0 wire protocol

The big differences between RDS 3.0 and 3.1 are protocol-level
flow control, and with 3.1 the header is in front of the data. The header
always ends up in the header buffer, and the data goes in the data page.

In 3.0 our "header" is a trailer, and will end up either in the data
page, the header buffer, or split across the two. Since 3.1 is backwards-
compatible with 3.0, we need to continue to support these cases. This
patch does that -- if using RDS 3.0 wire protocol, it will copy the header
from wherever it ended up into the header buffer.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS/IW+IB: Allow max credit advertise window.

Fix hack that restricts the credit advertisement to 127.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS: Use spinlock to protect 64b value update on 32b archs

We have a 64bit value that needs to be set atomically.
This is easy and quick on all 64bit archs, and can also be done
on x86/32 with set_64bit() (uses cmpxchg8b). However other
32b archs don't have this.

I actually changed this to the current state in preparation for
mainline because the old way (using a spinlock on 32b) resulted in
unsightly #ifdefs in the code. But obviously, being correct takes
precedence.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RDS/IB: Receive datagrams via IB

Header parsing, ring refill. It puts the incoming data into an
rds_incoming struct, which is passed up to rds-core.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>