Even though a peer may have already received a
non-zero value for "RDS_EXTHDR_NPATHS" from a node in the past,
the current peer may not.
Therefore it is important to initiate another rds_send_ping()
after a re-connect to any peer:
It is unknown at that time if we're still talking to the same
instance of RDS kernel modules on the other side.
Otherwise, the peer may just operate on a single lane
("c_npaths == 0"), not knowing that more lanes are available.
However, if "c_with_sport_idx" is supported,
we also need to check that the connection we accepted on lane#0
meets the proper source port modulo requirement, as we fan out:
Since the exchange of "RDS_EXTHDR_NPATHS" and "RDS_EXTHDR_SPORT_IDX"
is asynchronous, initially we have no choice but to accept an incoming
connection (via "accept") in the first slot ("cp_index == 0")
for backwards compatibility.
But that very connection may have come from a different lane
with "cp_index != 0", since the peer thought that we already understood
and handled "c_with_sport_idx" properly, as indicated by a previous
exchange before a module was reloaded.
In short:
If a module gets reloaded, we recover from that, but do *not*
allow a downgrade to support fewer lanes.
Downgrades would require us to merge messages from separate lanes,
which is rather tricky with the current RDS design.
Each lane has its own sequence number space and all messages
would need to be re-sequenced as we merge, all while
handling "RDS_FLAG_RETRANSMITTED" and "cp_retrans" properly.
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260203055723.1085751-9-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
RDS/TCP differs from RDS/RDMA in that message acknowledgment
is done based on TCP sequence numbers:
As soon as the last byte of a message has been acknowledged by the
TCP stack of a peer, rds_tcp_write_space() goes on to discard
prior messages from the send queue.
Which is fine, for as long as the receiver never throws any messages
away.
The dequeuing of messages in RDS/TCP is done either from the
"sk_data_ready" callback pointing to rds_tcp_data_ready()
(the most common case), or from the receive worker pointing
to rds_tcp_recv_path() which is called for as long as the
connection is "RDS_CONN_UP".
However, as soon as rds_conn_path_drop() is called for whatever reason,
including "DR_USER_RESET", "cp_state" transitions to "RDS_CONN_ERROR",
and rds_tcp_restore_callbacks() ends up restoring the callbacks
and thereby disabling message receipt.
So messages already acknowledged to the sender were dropped.
Furthermore, the "->shutdown" callback was always called
with an invalid parameter ("RCV_SHUTDOWN | SEND_SHUTDOWN == 3"),
instead of the correct pre-increment value ("SHUT_RDWR == 2").
inet_shutdown() returns "-EINVAL" in such cases, rendering
this call a NOOP.
So we change rds_tcp_conn_path_shutdown() to do the proper
"->shutdown(SHUT_WR)" call in order to signal EOF to the peer
and make it transition to "TCP_CLOSE_WAIT" (RFC 793).
This should make the peer also enter rds_tcp_conn_path_shutdown()
and do the same.
This allows us to dequeue all messages already received
and acknowledged to the peer.
We do so, until we know that the receive queue no longer has data
(skb_queue_empty()) and that we couldn't have any data
in flight anymore, because the socket transitioned to
any of the states "CLOSING", "TIME_WAIT", "CLOSE_WAIT",
"LAST_ACK", or "CLOSE" (RFC 793).
However, if we do just that, we suddenly see duplicate RDS
messages being delivered to the application.
So what gives?
Turns out that with MPRDS and its multitude of backend connections,
retransmitted messages ("RDS_FLAG_RETRANSMITTED") can outrace
the dequeuing of their original counterparts.
And the duplicate check implemented in rds_recv_local() only
discards duplicates if flag "RDS_FLAG_RETRANSMITTED" is set.
Rather curious, because a duplicate is a duplicate; it shouldn't
matter which copy is looked at and delivered first.
To avoid this entire situation, we simply make the sender discard
messages from the send-queue right from within
rds_tcp_conn_path_shutdown(). Just like rds_tcp_write_space() would
have done, were it called in time or still called.
This makes sure that we no longer have messages that we know
the receiver already dequeued sitting in our send-queue,
and therefore avoid the entire "RDS_FLAG_RETRANSMITTED" fiasco.
Now we got rid of the duplicate RDS message delivery, but we
still run into cases where RDS messages are dropped.
This time it is due to the delayed setting of the socket-callbacks
in rds_tcp_accept_one() via either rds_tcp_reset_callbacks()
or rds_tcp_set_callbacks().
By the time rds_tcp_accept_one() gets there, the socket
may already have transitioned into state "TCP_CLOSE_WAIT",
but rds_tcp_state_change() was never called.
Subsequently, "->shutdown(SHUT_WR)" did not happen either.
So the peer ends up getting stuck in state "TCP_FIN_WAIT2".
We fix that by checking for states "TCP_CLOSE_WAIT", "TCP_LAST_ACK",
or "TCP_CLOSE" and drop the freshly accepted socket in that case.
This problem is observable by running "rds-stress --reset"
frequently on either of the two sides of a RDS connection,
or both while other "rds-stress" processes are exchanging data.
Those "rds-stress" processes reported out-of-sequence
errors, with the expected sequence number being smaller
than the one actually received (due to the dropped messages).
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260203055723.1085751-4-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Upon "sendmsg", RDS/TCP selects a backend connection based
on a hash calculated from the source-port ("RDS_MPATH_HASH").
However, "rds_tcp_accept_one" accepts connections
in the order they arrive, which is non-deterministic.
Therefore the mapping of the sender's "cp->cp_index"
to that of the receiver changes if the backend
connections are dropped and reconnected.
However, connection state that's preserved across reconnects
(e.g. "cp_next_rx_seq") relies on that sender<->receiver
mapping to never change.
So we make sure that client and server of the TCP connection
have the exact same "cp->cp_index" across reconnects by
encoding "cp->cp_index" in the lower three bits of the
client's TCP source port.
A new extension "RDS_EXTHDR_SPORT_IDX" is introduced,
that allows the server to tell the difference between
clients that do the "cp->cp_index" encoding, and
legacy clients that pick source ports randomly.
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260203055723.1085751-3-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
RDS/TCP differs from RDS/RDMA in that message acknowledgment
is done based on TCP sequence numbers:
As soon as the last byte of a message has been acknowledged
by the TCP stack of a peer, "rds_tcp_write_space()" goes on
to discard prior messages from the send queue.
Which is fine, for as long as the receiver never throws any messages away.
Unfortunately, that is *not* the case since the introduction of MPRDS:
commit 1a0e100fb2 "RDS: TCP: Enable multipath RDS for TCP"
A new function "rds_tcp_accept_one_path" was introduced,
which is entitled to return "NULL", if no connection path is currently
available.
Unfortunately, this happens after the "->accept()" call, and the new socket
often already contains messages, since the peer already transitioned
to "RDS_CONN_UP" on behalf of "TCP_ESTABLISHED".
That's also the case after this [1]:
commit 1a0e100fb2 "RDS: TCP: Force every connection to be initiated by
numerically smaller IP address"
which tried to address the situation of pending data by only transitioning
connections from a smaller IP address to "RDS_CONN_UP".
But even in those cases, and in particular if the "RDS_EXTHDR_NPATHS"
handshake has not occurred yet, and therefore we're working with
"c_npaths <= 1", "c_conn[0]" may be in a state distinct from
"RDS_CONN_DOWN", and therefore all messages on the just accepted socket
will be tossed away.
This fix changes "rds_tcp_accept_one":
* If connected from a peer with a larger IP address, the new socket
will continue to get closed right away.
With commit [1] above, there should not be any messages
in the socket receive buffer, since the peer never transitioned
to "RDS_CONN_UP".
Therefore it should be okay to not make any efforts to dispatch
the socket receive buffer.
* If connected from a peer with a smaller IP address,
we call "rds_tcp_accept_one_path" to find a free slot/"path".
If found, business goes on as usual.
If none was found, we save/stash the newly accepted socket
into "rds_tcp_accepted_sock", in order to not lose any
messages that may have arrived already.
We then return from "rds_tcp_accept_one" with "-ENOBUFS".
Later on, when a slot/"path" does become available again
(e.g. state transitioned to "RDS_CONN_DOWN",
or HS extension header was received with "c_npaths > 1")
we call "rds_tcp_conn_slots_available" that simply re-issues
a "rds_tcp_accept_one_path" worker-callback and picks
up the new socket from "rds_tcp_accepted_sock", and thereby
continuing where it left with "-ENOBUFS" last time.
Since a new slot has become available, those messages
won't be lost, since processing proceeds as if that slot
had been available the first time around.
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Jack Vogel <jack.vogel@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260122055213.83608-3-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 39de828179 ("RDS: Main header file") declared but never implemented
rds_trans_init() and rds_trans_exit(), remove it.
Commit d37c935905 ("RDS: Move loop-only function to loop.c") removed the
implementation rds_message_inc_free() but not the declaration.
Since commit 55b7ed0b58 ("RDS: Common RDMA transport code")
rds_rdma_conn_connect() is never implemented and used.
rds_tcp_map_seq() is never implemented and used since
commit 70041088e3 ("RDS: Add TCP transport to RDS").
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet is reporting addition on 0 problem at rds_tcp_tune(), for
delayed works queued in rds_wq might be invoked after a net namespace's
refcount already reached 0.
Since rds_tcp_exit_net() from cleanup_net() calls flush_workqueue(rds_wq),
it is guaranteed that we can instead use maybe_get_net() from delayed work
functions until rds_tcp_exit_net() returns.
Note that I'm not convinced that all works which might access a net
namespace are already queued in rds_wq by the moment rds_tcp_exit_net()
calls flush_workqueue(rds_wq). If some race is there, rds_tcp_exit_net()
will fail to wait for work functions, and kmem_cache_free() could be
called from net_free() before maybe_get_net() is called from
rds_tcp_tune().
Reported-by: Eric Dumazet <edumazet@google.com>
Fixes: 3a58f13a88 ("net: rds: acquire refcount on TCP sockets")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/41d09faf-bc78-1a87-dfd1-c6d1b5984b61@I-love.SAKURA.ne.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When TCP is used as transport and a program on the
system connects to RDS port 16385, connection is
accepted but denied per the rules of RDS. However,
RDS connections object is left in the list. Next
loopback connection will select that connection
object as it is at the head of list. The connection
attempt will hang as the connection object is set
to connect over TCP which is not allowed
The issue can be reproduced easily, use rds-ping
to ping a local IP address. After that use any
program like ncat to connect to the same IP
address and port 16385. This will hang so ctrl-c out.
Now try rds-ping, it will hang.
To fix the issue this patch adds checks to disallow
the connection object creation and destroys the
connection object.
Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_KEEPCNT sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_NODELAY sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the SO_LINGER sockopt from kernel space
with onoff set to true and a linger time of 0 without going through a
fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch enables RDS to use IPv6 addresses. For RDS/TCP, the
listener is now an IPv6 endpoint which accepts both IPv4 and IPv6
connection requests. RDS/RDMA/IB uses a private data (struct
rds_ib_connect_private) exchange between endpoints at RDS connection
establishment time to support RDMA. This private data exchange uses a
32 bit integer to represent an IP address. This needs to be changed in
order to support IPv6. A new private data struct
rds6_ib_connect_private is introduced to handle this. To ensure
backward compatibility, an IPv6 capable RDS stack uses another RDMA
listener port (RDS_CM_PORT) to accept IPv6 connection. And it
continues to use the original RDS_PORT for IPv4 RDS connections. When
it needs to communicate with an IPv6 peer, it uses the RDS_CM_PORT to
send the connection set up request.
v5: Fixed syntax problem (David Miller).
v4: Changed port history comments in rds.h (Sowmini Varadhan).
v3: Added support to set up IPv4 connection using mapped address
(David Miller).
Added support to set up connection between link local and non-link
addresses.
Various review comments from Santosh Shilimkar and Sowmini Varadhan.
v2: Fixed bound and peer address scope mismatched issue.
Added back rds_connect() IPv6 changes.
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>
en_rx_am.c was deleted in 'net-next' but had a bug fixed in it in
'net'.
The esp{4,6}_offload.c conflicts were overlapping changes.
The 'out' label is removed so we just return ERR_PTR(-EINVAL)
directly.
Signed-off-by: David S. Miller <davem@davemloft.net>
rds-tcp uses m_ack_seq to track the tcp ack# that indicates
that the peer has received a rds_message. The m_ack_seq is
used in rds_tcp_is_acked() to figure out when it is safe to
drop the rds_message from the RDS retransmit queue.
The m_ack_seq must be calculated as an offset from the right
edge of the in-flight tcp buffer, i.e., it should be based on
the ->write_seq, not the ->snd_nxt.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rds_tcp_kill_sock() function parses the rds_tcp_conn_list
to find the rds_connection entries marked for deletion as part
of the netns deletion under the protection of the rds_tcp_conn_lock.
Since the rds_tcp_conn_list tracks rds_tcp_connections (which
have a 1:1 mapping with rds_conn_path), multiple tc entries in
the rds_tcp_conn_list will map to a single rds_connection, and will
be deleted as part of the rds_conn_destroy() operation that is
done outside the rds_tcp_conn_lock.
The rds_tcp_conn_list traversal done under the protection of
rds_tcp_conn_lock should not leave any doomed tc entries in
the list after the rds_tcp_conn_lock is released, else another
concurrently executiong netns delete (for a differnt netns) thread
may trip on these entries.
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If we are unloading the rds_tcp module, we can set linger to 1
and drop pending packets to accelerate reconnect. The peer will
end up resetting the connection based on new generation numbers
of the new incarnation, so hanging on to unsent TCP packets via
linger is mostly pointless in this case.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Jenny Xu <jenny.x.xu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit a93d01f577 ("RDS: TCP: avoid bad page reference in
rds_tcp_listen_data_ready") added the function
rds_tcp_listen_sock_def_readable() to handle the case when a
partially set-up acceptor socket drops into rds_tcp_listen_data_ready().
However, if the listen socket (rtn->rds_tcp_listen_sock) is itself going
through a tear-down via rds_tcp_listen_stop(), the (*ready)() will be
null and we would hit a panic of the form
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: (null)
:
? rds_tcp_listen_data_ready+0x59/0xb0 [rds_tcp]
tcp_data_queue+0x39d/0x5b0
tcp_rcv_established+0x2e5/0x660
tcp_v4_do_rcv+0x122/0x220
tcp_v4_rcv+0x8b7/0x980
:
In the above case, it is not fatal to encounter a NULL value for
ready- we should just drop the packet and let the flush of the
acceptor thread finish gracefully.
In general, the tear-down sequence for listen() and accept() socket
that is ensured by this commit is:
rtn->rds_tcp_listen_sock = NULL; /* prevent any new accepts */
In rds_tcp_listen_stop():
serialize with, and prevent, further callbacks using lock_sock()
flush rds_wq
flush acceptor workq
sock_release(listen socket)
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the existing comments in rds_tcp_listen_data_ready() indicate,
it is possible under some race-windows to get to this function with the
accept() socket. If that happens, we could run into a sequence whereby
thread 1 thread 2
rds_tcp_accept_one() thread
sets up new_sock via ->accept().
The sk_user_data is now
sock_def_readable
data comes in for new_sock,
->sk_data_ready is called, and
we land in rds_tcp_listen_data_ready
rds_tcp_set_callbacks()
takes the sk_callback_lock and
sets up sk_user_data to be the cp
read_lock sk_callback_lock
ready = cp
unlock sk_callback_lock
page fault on ready
In the above sequence, we end up with a panic on a bad page reference
when trying to execute (*ready)(). Instead we need to call
sock_def_readable() safely, which is what this patch achieves.
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>
This patch adds ->conn_path_connect callbacks in the rds_transport
that are used to set up a single connection path.
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>
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>
The socket callbacks should all operate on a struct rds_conn_path,
in preparation for a MP capable RDS-TCP.
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>
The struct rds_tcp_connection is the transport-specific private
data structure that tracks TCP information per rds_conn_path.
Modify this structure to have a back-pointer to the rds_conn_path
for which it is the ->cp_transport_data.
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>
Refactor code to avoid separate indirections for single-path
and multipath transports. All transports (both single and mp-capable)
will get a pointer to the rds_conn_path, and can trivially derive
the rds_connection from the ->cp_conn.
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>
Fix coding style issues in the following files:
ib_cm.c: add space
loop.c: convert spaces to tabs
sysctl.c: add space
tcp.h: convert spaces to tabs
tcp_connect.c:remove extra indentation in switch statement
tcp_recv.c: convert spaces to tabs
tcp_send.c: convert spaces to tabs
transport.c: move brace up one line on for statement
Signed-off-by: Joshua Houghton <josh@awful.name>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When rds_tcp_accept_one() has to replace the existing tcp socket
with a newer tcp socket (duelling-syn resolution), it must lock_sock()
to suppress the rds_tcp_data_recv() path while callbacks are being
changed. Also, existing RDS datagram reassembly state must be reset,
so that the next datagram on the new socket does not have corrupted
state. Similarly when resetting the newly accepted socket, appropriate
locks and synchronization is needed.
This commit ensures correct synchronization by invoking
kernel_sock_shutdown to reset a newly accepted sock, and by taking
appropriate lock_sock()s (for old and new sockets) when resetting
existing callbacks.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An arbitration scheme for duelling SYNs is implemented as part of
commit 241b271952 ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") which ensures that both nodes
involved will arrive at the same arbitration decision. However, this
needs to be synchronized with an outgoing SYN to be generated by
rds_tcp_conn_connect(). This commit achieves the synchronization
through the t_conn_lock mutex in struct rds_tcp_connection.
The rds_conn_state is checked in rds_tcp_conn_connect() after acquiring
the t_conn_lock mutex. A SYN is sent out only if the RDS connection is
not already UP (an UP would indicate that rds_tcp_accept_one() has
completed 3WH, so no SYN needs to be generated).
Similarly, the rds_conn_state is checked in rds_tcp_accept_one() after
acquiring the t_conn_lock mutex. The only acceptable states (to
allow continuation of the arbitration logic) are UP (i.e., outgoing SYN
was SYN-ACKed by peer after it sent us the SYN) or CONNECTING (we sent
outgoing SYN before we saw incoming SYN).
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Register pernet subsys init/stop functions that will set up
and tear down per-net RDS-TCP listen endpoints. Unregister
pernet subusys functions on 'modprobe -r' to clean up these
end points.
Enable keepalive on both accept and connect socket endpoints.
The keepalive timer expiration will ensure that client socket
endpoints will be removed as appropriate from the netns when
an interface is removed from a namespace.
Register a device notifier callback that will clean up all
sockets (and thus avoid the need to wait for keepalive timeout)
when the loopback device is unregistered from the netns indicating
that the netns is getting deleted.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several spots in the kernel perform a sequence like:
skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.
Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.
And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.
So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.
Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.
Signed-off-by: David S. Miller <davem@davemloft.net>
The RDS protocol has lots of functions that should be
declared static. rds_message_get/add_version_extension is
removed since it defined but never used.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We now ask the transport to give us a rm for the congestion
map, and then we handle it normally. Previously, the
transport defined a function that we would call to send
a congestion map.
Convert TCP and loop transports to new cong map method.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
This code allows RDS to be tunneled over a TCP connection.
RDMA operations are disabled when using TCP transport,
but this frees RDS from the IB/RDMA stack dependency, and allows
it to be used with standard Ethernet adapters, or in a VM.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
