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rds_conn_shutdown() finishes by moving the path from
RDS_CONN_DISCONNECTING to RDS_CONN_DOWN, and also accepts
RDS_CONN_ERROR as the starting state of that final transition, so that
a FIN processed in softirq context during the teardown does not derail
the shutdown into a noisy error path.
But consuming that RDS_CONN_ERROR also consumes the shutdown pass that
came with it: rds_conn_path_drop() sets RDS_CONN_ERROR and then queues
cp_down_w, and a pass that starts on a path already in RDS_CONN_DOWN
is a no-op. For the FIN case that is harmless - the socket the FIN
arrived on is the very socket the teardown just released. It is not
harmless for a dropper that attached something to the path first.
rds_tcp_accept_one() is such a dropper. Its path claim in
rds_tcp_accept_one_path() transitions RDS_CONN_DOWN ->
RDS_CONN_CONNECTING, and a concurrent drop - a FIN on a previous
socket in softirq context, an administrative reset - can put the path
into RDS_CONN_ERROR between that claim and the state check that
follows, which accepts RDS_CONN_ERROR. The accept then installs the
freshly accepted socket with rds_tcp_set_callbacks() while the queued
teardown - which sampled tc->t_sock before this socket existed - is
still running. rds_connect_path_complete() fails its transition to
RDS_CONN_UP and drops the path again, queueing the pass that should
reap the socket it just installed. If the in-flight shutdown's final
transition consumes that drop's RDS_CONN_ERROR, the queued pass finds
the path in RDS_CONN_DOWN and does nothing. The installed socket is
never torn down: it sits established with its callbacks armed and its
rds_tcp_connection on rds_tcp_tc_list, the peer sees a connection that
nothing ever reads, and the path is wedged in RDS_CONN_DOWN until some
later event drops it again. Reproduced with widened race windows as
an ever-growing receive queue on a socket owned by a path stuck in
RDS_CONN_DOWN, with the peer's send path wedged behind it.
Make the final transition only DISCONNECTING -> DOWN. If it fails
because the path is in RDS_CONN_ERROR, a drop raced the teardown:
cancel the reconnect timer and clear RDS_RECONNECT_PENDING - the one
piece of the skipped tail that must not be left behind - and return,
letting the pass the drop queued finish the job: it tears down
whatever attached to the path in the meantime, completes the
transition to RDS_CONN_DOWN, and re-arms the reconnect from its own
tail.
The timer quiesce in that branch matters because the racing drop does
not always queue that pass: rds_conn_path_drop() returns without
queueing when a destroy is pending - exactly the situation during a
netns teardown or module unload, when a FIN on the dying socket is
processed while rds_conn_path_destroy() flushes cp_down_w. If the
flushed pass is the one that takes this return, no later pass exists,
and rds_conn_path_destroy() would find cp_conn_w still armed
(WARN_ON) and then free a path whose reconnect timer can still fire.
With the cancel in the branch, every exit of a shutdown pass leaves
the timer quiesced no matter which pass completes the transition.
The FIN case keeps making progress, one pass later and still without
noisy logging. Any other state keeps today's rds_conn_path_error()
handling; no current cp_state writer can leave a DISCONNECTING path
in anything but RDS_CONN_ERROR (every other writer is a cmpxchg from
a non-DISCONNECTING state), so that branch is defensive.
On kernels without the preceding patches the same hazard exists with
the sample-based quiesce; the fix applies there equally.
Fixes: e97656d03ca0 ("rds: tcp: allow progress of rds_conn_shutdown if the rds_connection is marked ERROR by an intervening FIN")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-8-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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rds_conn_shutdown() quiesces the transmit and receive-refill paths by
waiting for RDS_IN_XMIT and RDS_RECV_REFILL to be sampled clear, and
then runs the transport shutdown and rds_conn_path_reset(). Sampling
the bits clear is not the same as owning them: the moment after the
wait_event() returns, rds_send_xmit() can re-acquire RDS_IN_XMIT (or
rds_ib_recv_refill() can re-acquire RDS_RECV_REFILL) and run
concurrently with the teardown.
The sender does recheck the connection state after taking the lock,
but that recheck is a classic store-buffering pattern: teardown writes
the state and reads the bit while the sender writes the bit and reads
the state. acquire_in_xmit() is only an acquire operation, so on
weakly ordered architectures both sides can miss each other's write,
and the transmit path then runs while the transport zeroes its rings
(e.g. rds_ib_ring_init()) and rds_send_path_reset() rewrites the
transmit state under it.
Oracle UEK fixed the same class of crashes - a 14-year tail of
BUG_ON()s in rds_ib_sub_signaled(), unexpected op-codes and NULL
dereferences in rds_ib_send_cqe_handler() during failover testing -
by making the teardown path *acquire* the fastpath bit locks instead
of testing them ("rds: Make sure transmit path and connection
tear-down does not run concurrently"). Ownership of a single word is
decided by RMW atomicity, so no cross-variable ordering is needed.
Do the same here: take both locks before calling the transport
shutdown, hold them across rds_conn_path_reset(), and release them
explicitly with a wake-up afterwards. Both are released with
clear_bit_unlock(), so that the ring re-initialization done by the
transport shutdown and the transmit state rewritten by
rds_send_path_reset() are ordered before either bit is seen clear by
the next acquire_in_xmit() or acquire_refill().
The fastpath users of these bits - rds_send_xmit() and
rds_ib_recv_refill() - are trylock style and back off while teardown
owns the locks, so no new lock dependency is introduced for them.
rds_tcp_reset_callbacks() is different: since the previous patch it
acquires RDS_IN_XMIT as well, and it blocks doing so, so its wait now
spans the teardown instead of at most one send batch. That waiter
runs from rds_tcp_accept_one() on the single-threaded krdsd workqueue
and holds rds_tcp_accept_lock and t_conn_path_lock while it waits, so
a duelling SYN accepted while its path is being torn down parks
accept processing for the duration of the teardown - for TCP bounded
by the (up to 5 s) drain loop in rds_tcp_conn_path_shutdown(). An IB
path's drain in rds_ib_conn_path_shutdown() has no round cap, but no
blocking waiter either: rds_tcp_reset_callbacks() is the only blocking
acquirer of these bits and waits only on its own TCP path, and the
fastpaths are trylock-and-back-off on both transports, so a long IB
drain lengthens only that path's own quiesce. The
window is narrow: the accept-side state check has to pass before the
teardown moves the path to RDS_CONN_DISCONNECTING.
Because krdsd is a single global workqueue, everything else queued
there - accept processing for other connections and network
namespaces, and the flush_workqueue(rds_wq) in rds_tcp_listen_stop()
during namespace teardown - waits behind the parked accept worker for
that time. It cannot deadlock, although the waits do point at each
other: the teardown blocks until the bit's holder releases it, and
the holder may be that krdsd accept worker. The holder finishes
without needing anything the teardown owns: the sync cancels
rds_tcp_reset_callbacks() issues target cp_send_w and cp_recv_w on
the path's ordered cp_wq, whose only execution slot is occupied by
the blocked cp_down_w itself, so they are pending at most and cancel
without flushing - a reliance on cp_wq being ordered that is now
noted next to those cancels (on the allocation-failure fallback where
a path shares rds_wq, the work items simply serialize).
Nor is the blocking wait itself new: rds_tcp_reset_callbacks() has
waited on RDS_IN_XMIT from the krdsd work item since
commit 335b48d980f6 ("RDS: TCP: Add/use rds_tcp_reset_callbacks to
reset tcp socket safely"); this patch stretches its worst case from
a sender's batch to the teardown's drain. The alternative to parking
is the accept path racing the teardown, which is what these patches
close; making the teardown itself non-blocking is a separate item.
One observable side effect: the SENDING flag reported by rds-info has
always mirrored RDS_IN_XMIT, so it now also covers the window where
teardown owns the bit.
The comments that describe the old sample-based handshake or name
rds_send_xmit() as the only other holder of these bits - in
rds_send_xmit(), above rds_conn_path_reset(), in rds_ib_recv_refill()
and in rds_tcp_reset_callbacks() - are updated to match.
For anyone backporting this patch standalone: it depends on
"net/rds: clear cp_flags bits individually in rds_conn_path_reset()"
and "net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()"
earlier in this series. Without the former, the blanket cp_flags
clear in rds_conn_path_reset() would drop both held bits in the middle
of the teardown; without the latter, rds_tcp_reset_callbacks() would
still sample t_sock without owning RDS_IN_XMIT. "net/rds: use
clear_bit_unlock() in release_refill()" is needed for the refill
side's release to pair with the acquire added here, and the follow-up
"net/rds: don't let rds_conn_shutdown() consume a concurrent drop"
completes the teardown-state handling for the waiter this patch
parks; a backport should carry all four.
Fixes: 0f4b1c7e89e6 ("rds: fix rds_send_xmit() serialization")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
[achender: reimplement for net-next shutdown path: acquire the existing
RDS_IN_XMIT/RDS_RECV_REFILL bit locks in rds_conn_shutdown() and release
after teardown; update comments and commit message]
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-7-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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rds_conn_path_reset() wipes the whole flag word with a plain
cp->cp_flags = 0 store. Every other accessor of that word uses
atomic bitops, and some of them can run concurrently with the reset:
RDS_LL_SEND_FULL is set from rds_send_xmit() and cleared from the
transport completion paths, neither of which holds anything that
excludes the shutdown worker. A plain store racing an atomic
read-modify-write on the same word is a data race, and whichever
side loses has its update silently discarded.
Clear the two bits the reset is actually responsible for instead.
RDS_IN_XMIT and RDS_RECV_REFILL need no store at all here: they
belong to the caller, rds_conn_shutdown(), which waits for both to be
clear before calling the transport shutdown and this reset.
This also gives every bit in cp_flags a single well-defined writer
discipline, which the following patches rely on when they turn
RDS_IN_XMIT and RDS_RECV_REFILL into bit locks held across the
teardown: a blanket store mid-teardown would destroy lock ownership
that an atomic clear preserves.
Oracle UEK carries the same conversion ("net/rds: Preserve essential
connection state flags"), motivated by its asynchronous shutdown
state machine, whose progress and destroy flags must survive the
reset. UEK's variant also clears RDS_IN_XMIT and RDS_RECV_REFILL
because there the reset runs as the final step of a teardown that
owns both bits, making those clears its unlock. Upstream that
release belongs in rds_conn_shutdown(): once a later patch in this
series turns the two bits into locks held across the teardown, ending
ownership needs release semantics and a wake-up that a plain clear
inside the reset would not provide.
Based on Oracle UEK commit "net/rds: Preserve essential connection
state flags" by Gerd Rausch.
Fixes: 00e0f34c6166 ("RDS: Connection handling")
Signed-off-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260828223921.202913-4-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The RDS_INFO_* family of getsockopt(2) options reads several
file-scope global lists that are not per-netns:
rds_sock_info / rds6_sock_info,
rds_sock_inc_info / rds6_sock_inc_info -> rds_sock_list
rds_tcp_tc_info / rds6_tcp_tc_info -> rds_tcp_tc_list
rds_conn_info / rds6_conn_info,
rds_conn_message_info_cmn (for the *_SEND_MESSAGES and
*_RETRANS_MESSAGES variants),
rds_for_each_conn_info (for RDS_INFO_IB_CONNECTIONS)
-> rds_conn_hash[]
The handlers do not filter by the caller's network namespace.
rds_info_getsockopt() has no netns or capable() check, and
rds_create() has no capable() check, so AF_RDS is reachable from
an unprivileged user namespace. As a result, an unprivileged
caller in a fresh user_ns plus netns can read the bound address
and sock inode of every RDS socket on the host, the peer address
of incoming messages on every RDS socket on the host, the peer
address and TCP sequence numbers of every rds-tcp connection on
the host, and the peer address and RDS sequence numbers of every
RDS connection on the host.
The rds-tcp transport is reachable from a non-initial netns (see
rds_set_transport()), so a one-shot init_net gate at
rds_info_getsockopt() would deny legitimate per-netns visibility
to rds-tcp callers. Instead, filter at each handler by comparing
the netns of the caller's socket to the netns of the list entry,
or to rds_conn_net(conn) for connection paths. Only copy entries
whose netns matches the caller. Counters (RDS_INFO_COUNTERS) are
aggregate statistics and remain global.
Reproducer (KASAN VM, rds and rds_tcp loaded): an AF_RDS socket
binds 127.0.0.1:4242 in init_net as root. A child process enters
a fresh user_ns plus netns and opens AF_RDS there, then calls
getsockopt(SOL_RDS, RDS_INFO_SOCKETS). Before this change, the
child sees the init_net socket. After this change, the child
sees zero entries.
Drop the rds_sock_count, rds_tcp_tc_count, and rds6_tcp_tc_count
globals. v2 used them for the size precheck and lens->nr; v3
replaced the precheck with a per-ns count from a first pass over
the list, so the globals have no remaining readers. The matching
increments and decrements in rds_create()/rds_destroy_sock() and
rds_tcp_set_callbacks()/rds_tcp_restore_callbacks() go away with
them. Reported by the kernel test robot under clang W=1.
Suggested-by: Allison Henderson <achender@kernel.org>
Suggested-by: Simon Horman <horms@kernel.org>
Reviewed-by: Allison Henderson <achender@kernel.org>
Co-developed-by: Praveen Kakkolangara <praveen.kakkolangara@aumovio.com>
Signed-off-by: Praveen Kakkolangara <praveen.kakkolangara@aumovio.com>
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Link: https://patch.msgid.link/20260520084236.2724349-1-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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rds_for_each_conn_info() and rds_walk_conn_path_info() both hand a
caller-allocated on-stack u64 buffer to a per-connection visitor and
then copy the full item_len bytes back to user space via
rds_info_copy() regardless of how much of the buffer the visitor
actually wrote.
rds_ib_conn_info_visitor() and rds6_ib_conn_info_visitor() only
write a subset of their output struct when the underlying
rds_connection is not in state RDS_CONN_UP (src/dst addr, tos, sl
and the two GIDs via explicit memsets). Several u32 fields
(max_send_wr, max_recv_wr, max_send_sge, rdma_mr_max, rdma_mr_size,
cache_allocs) and the 2-byte alignment hole between sl and
cache_allocs remain as whatever stack contents preceded the visitor
call and are then memcpy_to_user()'d out to user space.
struct rds_info_rdma_connection and struct rds6_info_rdma_connection
are the only rds_info_* structs in include/uapi/linux/rds.h that are
not marked __attribute__((packed)), so they have a real alignment
hole. The other info visitors (rds_conn_info_visitor,
rds6_conn_info_visitor, rds_tcp_tc_info, ...) write all fields of
their packed output struct today and are not known to be vulnerable,
but a future visitor that adds a conditional write-path would have
the same bug.
Reproduction on a kernel built without CONFIG_INIT_STACK_ALL_ZERO=y:
a local unprivileged user opens AF_RDS, sets SO_RDS_TRANSPORT=IB,
binds to a local address on an RDMA-capable netdev (rxe soft-RoCE on
any netdev is sufficient), sendto()'s any peer on the same subnet
(fails cleanly but installs an rds_connection in the global hash in
RDS_CONN_CONNECTING), then calls getsockopt(SOL_RDS,
RDS_INFO_IB_CONNECTIONS). The returned 68-byte item contains 26
bytes of stack garbage including kernel text/data pointers:
0..7 0a 63 00 01 0a 63 00 02 src=10.99.0.1 dst=10.99.0.2
8..39 00 ... gids (memset-zeroed)
40..47 e0 92 a3 81 ff ff ff ff kernel pointer (max_send_wr)
48..55 7f 37 b5 81 ff ff ff ff kernel pointer (rdma_mr_max)
56..59 01 00 08 00 rdma_mr_size (garbage)
60..61 00 00 tos, sl
62..63 00 00 alignment padding
64..67 18 00 00 00 cache_allocs (garbage)
Fix by zeroing the per-item buffer in both rds_for_each_conn_info()
and rds_walk_conn_path_info() before invoking the visitor. This
covers the IPv4/IPv6 IB visitors and hardens all current and future
visitors against the same class of bug.
No functional change for visitors that fully populate their output.
Changes in v2:
- retarget at the net tree (subject prefix "[PATCH net v2]",
net/rds: prefix in the title)
- pick up Reviewed-by tags from Sharath Srinivasan and
Allison Henderson
Fixes: ec16227e1414 ("RDS/IB: Infiniband transport")
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Reviewed-by: Sharath Srinivasan <sharath.srinivasan@oracle.com>
Reviewed-by: Allison Henderson <achender@kernel.org>
Assisted-by: Claude:claude-opus-4-7
Link: https://patch.msgid.link/20260418141047.3398203-1-michael.bommarito@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from IPsec, Bluetooth and netfilter
Current release - regressions:
- wifi: fix dev_alloc_name() return value check
- rds: fix recursive lock in rds_tcp_conn_slots_available
Current release - new code bugs:
- vsock: lock down child_ns_mode as write-once
Previous releases - regressions:
- core:
- do not pass flow_id to set_rps_cpu()
- consume xmit errors of GSO frames
- netconsole: avoid OOB reads, msg is not nul-terminated
- netfilter: h323: fix OOB read in decode_choice()
- tcp: re-enable acceptance of FIN packets when RWIN is 0
- udplite: fix null-ptr-deref in __udp_enqueue_schedule_skb().
- wifi: brcmfmac: fix potential kernel oops when probe fails
- phy: register phy led_triggers during probe to avoid AB-BA deadlock
- eth:
- bnxt_en: fix deleting of Ntuple filters
- wan: farsync: fix use-after-free bugs caused by unfinished tasklets
- xscale: check for PTP support properly
Previous releases - always broken:
- tcp: fix potential race in tcp_v6_syn_recv_sock()
- kcm: fix zero-frag skb in frag_list on partial sendmsg error
- xfrm:
- fix race condition in espintcp_close()
- always flush state and policy upon NETDEV_UNREGISTER event
- bluetooth:
- purge error queues in socket destructors
- fix response to L2CAP_ECRED_CONN_REQ
- eth:
- mlx5:
- fix circular locking dependency in dump
- fix "scheduling while atomic" in IPsec MAC address query
- gve: fix incorrect buffer cleanup for QPL
- team: avoid NETDEV_CHANGEMTU event when unregistering slave
- usb: validate USB endpoints"
* tag 'net-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits)
netfilter: nf_conntrack_h323: fix OOB read in decode_choice()
dpaa2-switch: validate num_ifs to prevent out-of-bounds write
net: consume xmit errors of GSO frames
vsock: document write-once behavior of the child_ns_mode sysctl
vsock: lock down child_ns_mode as write-once
selftests/vsock: change tests to respect write-once child ns mode
net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query
net/mlx5: Fix missing devlink lock in SRIOV enable error path
net/mlx5: E-switch, Clear legacy flag when moving to switchdev
net/mlx5: LAG, disable MPESW in lag_disable_change()
net/mlx5: DR, Fix circular locking dependency in dump
selftests: team: Add a reference count leak test
team: avoid NETDEV_CHANGEMTU event when unregistering slave
net: mana: Fix double destroy_workqueue on service rescan PCI path
MAINTAINERS: Update maintainer entry for QUALCOMM ETHQOS ETHERNET DRIVER
dpll: zl3073x: Remove redundant cleanup in devm_dpll_init()
selftests/net: packetdrill: Verify acceptance of FIN packets when RWIN is 0
tcp: re-enable acceptance of FIN packets when RWIN is 0
vsock: Use container_of() to get net namespace in sysctl handlers
net: usb: kaweth: validate USB endpoints
...
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syzbot reported a recursive lock warning in rds_tcp_get_peer_sport() as
it calls inet6_getname() which acquires the socket lock that was already
held by __release_sock().
kworker/u8:6/2985 is trying to acquire lock:
ffff88807a07aa20 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline]
ffff88807a07aa20 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: inet6_getname+0x15d/0x650 net/ipv6/af_inet6.c:533
but task is already holding lock:
ffff88807a07aa20 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline]
ffff88807a07aa20 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_sock_set_cork+0x2c/0x2e0 net/ipv4/tcp.c:3694
lock_sock_nested+0x48/0x100 net/core/sock.c:3780
lock_sock include/net/sock.h:1709 [inline]
inet6_getname+0x15d/0x650 net/ipv6/af_inet6.c:533
rds_tcp_get_peer_sport net/rds/tcp_listen.c:70 [inline]
rds_tcp_conn_slots_available+0x288/0x470 net/rds/tcp_listen.c:149
rds_recv_hs_exthdrs+0x60f/0x7c0 net/rds/recv.c:265
rds_recv_incoming+0x9f6/0x12d0 net/rds/recv.c:389
rds_tcp_data_recv+0x7f1/0xa40 net/rds/tcp_recv.c:243
__tcp_read_sock+0x196/0x970 net/ipv4/tcp.c:1702
rds_tcp_read_sock net/rds/tcp_recv.c:277 [inline]
rds_tcp_data_ready+0x369/0x950 net/rds/tcp_recv.c:331
tcp_rcv_established+0x19e9/0x2670 net/ipv4/tcp_input.c:6675
tcp_v6_do_rcv+0x8eb/0x1ba0 net/ipv6/tcp_ipv6.c:1609
sk_backlog_rcv include/net/sock.h:1185 [inline]
__release_sock+0x1b8/0x3a0 net/core/sock.c:3213
Reading from the socket struct directly is safe from possible paths. For
rds_tcp_accept_one(), the socket has just been accepted and is not yet
exposed to concurrent access. For rds_tcp_conn_slots_available(), direct
access avoids the recursive deadlock seen during backlog processing
where the socket lock is already held from the __release_sock().
However, rds_tcp_conn_slots_available() is also called from the normal
softirq path via tcp_data_ready() where the lock is not held. This is
also safe because inet_dport is a stable 16 bits field. A READ_ONCE()
annotation as the value might be accessed lockless in a concurrent
access context.
Note that it is also safe to call rds_tcp_conn_slots_available() from
rds_conn_shutdown() because the fan-out is disabled.
Fixes: 9d27a0fb122f ("net/rds: Trigger rds_send_ping() more than once")
Reported-by: syzbot+5efae91f60932839f0a5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5efae91f60932839f0a5
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260219075738.4403-1-fmancera@suse.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
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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>
|
|
When canceling the reconnect worker, care must be taken to reset the
reconnect-pending bit. If the reconnect worker has not yet been
scheduled before it is canceled, the reconnect-pending bit will stay
on forever.
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260203055723.1085751-6-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 1a0e100fb2c96 "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 1a0e100fb2c96 "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>
|
|
RDS connections carry a state "rds_conn_path::cp_state"
and transitions from one state to another and are conditional
upon an expected state: "rds_conn_path_transition."
There is one exception to this conditionality, which is
"RDS_CONN_ERROR" that can be enforced by "rds_conn_path_drop"
regardless of what state the condition is currently in.
But as soon as a connection enters state "RDS_CONN_ERROR",
the connection handling code expects it to go through the
shutdown-path.
The RDS/TCP multipath changes added a shortcut out of
"RDS_CONN_ERROR" straight back to "RDS_CONN_CONNECTING"
via "rds_tcp_accept_one_path" (e.g. after "rds_tcp_state_change").
A subsequent "rds_tcp_reset_callbacks" can then transition
the state to "RDS_CONN_RESETTING" with a shutdown-worker queued.
That'll trip up "rds_conn_init_shutdown", which was
never adjusted to handle "RDS_CONN_RESETTING" and subsequently
drops the connection with the dreaded "DR_INV_CONN_STATE",
which leaves "RDS_SHUTDOWN_WORK_QUEUED" on forever.
So we do two things here:
a) Don't shortcut "RDS_CONN_ERROR", but take the longer
path through the shutdown code.
b) Add "RDS_CONN_RESETTING" to the expected states in
"rds_conn_init_shutdown" so that we won't error out
and get stuck, if we ever hit weird state transitions
like this again."
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260122055213.83608-2-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
RDS was written to require ordered workqueues for "cp->cp_wq":
Work is executed in the order scheduled, one item at a time.
If these workqueues are shared across connections,
then work executed on behalf of one connection blocks work
scheduled for a different and unrelated connection.
Luckily we don't need to share these workqueues.
While it obviously makes sense to limit the number of
workers (processes) that ought to be allocated on a system,
a workqueue that doesn't have a rescue worker attached,
has a tiny footprint compared to the connection as a whole:
A workqueue costs ~900 bytes, including the workqueue_struct,
pool_workqueue, workqueue_attrs, wq_node_nr_active and the
node_nr_active flex array. Each connection can have up to 8
(RDS_MPATH_WORKERS) paths for a worst case of ~7 KBytes per
connection. While an RDS/IB connection totals only ~5 MBytes.
So we're getting a signficant performance gain
(90% of connections fail over under 3 seconds vs. 40%)
for a less than 0.02% overhead.
RDS doesn't even benefit from the additional rescue workers:
of all the reasons that RDS blocks workers, allocation under
memory pressue is the least of our concerns. And even if RDS
was stalling due to the memory-reclaim process, the work
executed by the rescue workers are highly unlikely to free up
any memory. If anything, they might try to allocate even more.
By giving each connection path its own workqueues, we allow
RDS to better utilize the unbound workers that the system
has available.
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260109224843.128076-3-achender@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
This patch adds a per connection workqueue which can be initialized
and used independently of the globally shared rds_wq.
This patch is the first in a series that aims to address tcp ack
timeouts during the tcp socket shutdown sequence.
This initial refactoring lays the ground work needed to alleviate
queue congestion during heavy reads and writes. The independently
managed queues will allow shutdowns and reconnects respond more quickly
before the peer(s) timeout waiting for the proper acks.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260109224843.128076-2-achender@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
__ipv6_addr_jhash (wrapper around jhash2()) and __inet_ehashfn (wrapper
around jhash_3words()) work with u32 (host endian) values but accept big
endian inputs. Declare the local variables as big endian to avoid
unnecessary casts.
Flagged by Sparse.
Signed-off-by: Ujwal Kundur <ujwal.kundur@gmail.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20250820175550.498-3-ujwal.kundur@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The strncpy() function is actively dangerous to use since it may not
NULL-terminate the destination string, resulting in potential memory
content exposures, unbounded reads, or crashes.
Link: https://github.com/KSPP/linux/issues/90
In addition, strscpy_pad is more appropriate because it also zero-fills
any remaining space in the destination if the source is shorter than
the provided buffer size.
Signed-off-by: Baris Can Goral <goralbaris@gmail.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20250521161036.14489-1-goralbaris@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
|
|
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://lore.kernel.org/r/20240124075801.471330-1-chentao@kylinos.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
__rds_conn_create() did not release conn->c_path when loop_trans != 0 and
trans->t_prefer_loopback != 0 and is_outgoing == 0.
Fixes: aced3ce57cd3 ("RDS tcp loopback connection can hang")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Sharath Srinivasan <sharath.srinivasan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
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>
|
|
In testing with mprds enabled, Oracle Cluster nodes after reboot were
not able to communicate with others nodes and so failed to rejoin
the cluster. Peers with lower IP address initiated connection but the
node could not respond as it choose a different path and could not
initiate a connection as it had a higher IP address.
With this patch, when a node sends out a packet and the selected path
is down, all other paths are also checked and any down paths are
re-connected.
Reviewed-by: Ka-cheong Poon <ka-cheong.poon@oracle.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The proper "tos" value needs to be returned
to user-space (sockopt RDS_INFO_CONNECTIONS).
Fixes: 3eb450367d08 ("rds: add type of service(tos) infrastructure")
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
|
|
RDS Service type (TOS) is user-defined and needs to be configured
via RDS IOCTL interface. It must be set before initiating any
traffic and once set the TOS can not be changed. All out-going
traffic from the socket will be associated with its TOS.
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>
|
|
Mark RDSv3.1 as compat version and add v4.1 version macro's.
Subsequent patches enable TOS(Type of Service) feature which is
tied with v4.1 for RDMA transport.
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>
|
|
This patch removes the IPv6 dependency from RDS.
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>
|
|
There are many data structures (RDS socket options) used by RDS apps
which use a 32 bit integer to store IP address. To support IPv6,
struct in6_addr needs to be used. To ensure backward compatibility, a
new data structure is introduced for each of those data structures
which use a 32 bit integer to represent an IP address. And new socket
options are introduced to use those new structures. This means that
existing apps should work without a problem with the new RDS module.
For apps which want to use IPv6, those new data structures and socket
options can be used. IPv4 mapped address is used to represent IPv4
address in the new data structures.
v4: Revert changes to SO_RDS_TRANSPORT
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>
|
|
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>
|
|
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>
|
|
The RDS core module creates rds_connections based on callbacks
from rds_loop_transport when sending/receiving packets to local
addresses.
These connections will need to be cleaned up when they are
created from a netns that is not init_net, and that netns is deleted.
Add the changes aligned with the changes from
commit ebeeb1ad9b8a ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management") for
rds_loop_transport
Reported-and-tested-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com
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>
|
|
Avoid VLA[1] by using an already allocated buffer passed
by the caller.
[1] https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
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Avoid VLA[1] by using an already allocated buffer passed
by the caller.
[1] https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Commit ebeeb1ad9b8a ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management")
adds an rcu read critical section to __rd_conn_create. The
memory allocations in that critcal section need to use
GFP_ATOMIC to avoid sleeping.
This patch was verified with syzkaller reproducer.
Reported-by: syzbot+a0564419941aaae3fe3c@syzkaller.appspotmail.com
Fixes: ebeeb1ad9b8a ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management")
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>
|
|
rds connection/workq management
An rds_connection can get added during netns deletion between lines 528
and 529 of
506 static void rds_tcp_kill_sock(struct net *net)
:
/* code to pull out all the rds_connections that should be destroyed */
:
528 spin_unlock_irq(&rds_tcp_conn_lock);
529 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
530 rds_conn_destroy(tc->t_cpath->cp_conn);
Such an rds_connection would miss out the rds_conn_destroy()
loop (that cancels all pending work) and (if it was scheduled
after netns deletion) could trigger the use-after-free.
A similar race-window exists for the module unload path
in rds_tcp_exit -> rds_tcp_destroy_conns
Concurrency with netns deletion (rds_tcp_kill_sock()) must be handled
by checking check_net() before enqueuing new work or adding new
connections.
Concurrency with module-unload is handled by maintaining a module
specific flag that is set at the start of the module exit function,
and must be checked before enqueuing new work or adding new connections.
This commit refactors existing RDS_DESTROY_PENDING checks added by
commit 3db6e0d172c9 ("rds: use RCU to synchronize work-enqueue with
connection teardown") and consolidates all the concurrency checks
listed above into the function rds_destroy_pending().
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>
|
|
rds_sendmsg() can enqueue work on cp_send_w from process context, but
it should not enqueue this work if connection teardown has commenced
(else we risk enquing work after rds_conn_path_destroy() has assumed that
all work has been cancelled/flushed).
Similarly some other functions like rds_cong_queue_updates
and rds_tcp_data_ready are called in softirq context, and may end
up enqueuing work on rds_wq after rds_conn_path_destroy() has assumed
that all workqs are quiesced.
Check the RDS_DESTROY_PENDING bit and use rcu synchronization to avoid
all these races.
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>
|
|
Replace c_destroy_in_prog by using a bit in cp_flags that
can set/tested atomically.
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>
|
|
t_name cannot be NULL since it is an array field of a struct.
Replacing null check on static array with string length check using
strnlen()
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Commit 8edc3affc077 ("rds: tcp: Take explicit refcounts on struct net")
introduces a regression in rds-tcp netns cleanup. The cleanup_net(),
(and thus rds_tcp_dev_event notification) is only called from put_net()
when all netns refcounts go to 0, but this cannot happen if the
rds_connection itself is holding a c_net ref that it expects to
release in rds_tcp_kill_sock.
Instead, the rds_tcp_kill_sock callback should make sure to
tear down state carefully, ensuring that the socket teardown
is only done after all data-structures and workqs that depend
on it are quiesced.
The original motivation for commit 8edc3affc077 ("rds: tcp: Take explicit
refcounts on struct net") was to resolve a race condition reported by
syzkaller where workqs for tx/rx/connect were triggered after the
namespace was deleted. Those worker threads should have been
cancelled/flushed before socket tear-down and indeed,
rds_conn_path_destroy() does try to sequence this by doing
/* cancel cp_send_w */
/* cancel cp_recv_w */
/* flush cp_down_w */
/* free data structures */
Here the "flush cp_down_w" will trigger rds_conn_shutdown and thus
invoke rds_tcp_conn_path_shutdown() to close the tcp socket, so that
we ought to have satisfied the requirement that "socket-close is
done after all other dependent state is quiesced". However,
rds_conn_shutdown has a bug in that it *always* triggers the reconnect
workq (and if connection is successful, we always restart tx/rx
workqs so with the right timing, we risk the race conditions reported
by syzkaller).
Netns deletion is like module teardown- no need to restart a
reconnect in this case. We can use the c_destroy_in_prog bit
to avoid restarting the reconnect.
Fixes: 8edc3affc077 ("rds: tcp: Take explicit refcounts on struct net")
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>
|
|
RDS over IB does not use multipath RDS, so the array
of additional rds_conn_path structures is always superfluous
in this case. Reduce the memory footprint of the rds module
by making this a dynamic allocation predicated on whether
the transport is mp_capable.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Tested-by: Efrain Galaviz <efrain.galaviz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
We could end up executing rds_conn_shutdown before the rds_recv_worker
thread, then rds_conn_shutdown -> rds_tcp_conn_shutdown can do a
sock_release and set sock->sk to null, which may interleave in bad
ways with rds_recv_worker, e.g., it could result in:
"BUG: unable to handle kernel NULL pointer dereference at 0000000000000078"
[ffff881769f6fd70] release_sock at ffffffff815f337b
[ffff881769f6fd90] rds_tcp_recv at ffffffffa043c888 [rds_tcp]
[ffff881769f6fdb0] rds_recv_worker at ffffffffa04a4810 [rds]
[ffff881769f6fde0] process_one_work at ffffffff810a14c1
[ffff881769f6fe40] worker_thread at ffffffff810a1940
[ffff881769f6fec0] kthread at ffffffff810a6b1e
Also, do not enqueue any new shutdown workq items when the connection is
shutting down (this may happen for rds-tcp in softirq mode, if a FIN
or CLOSE is received while the modules is in the middle of an unload)
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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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>
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After commit 1a0e100fb2c9 ("RDS: TCP: Force every connection to be
initiated by numerically smaller IP address") we no longer need
the logic associated with cp_outgoing, so clean up usage of this
field.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Imanti Mendez <imanti.mendez@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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marked ERROR by an intervening FIN
rds_conn_shutdown() runs in workq context, and marks the rds_connection
as DISCONNECTING before quiescing Tx/Rx paths. However, after all I/O
has quiesced, we may still find the rds_connection state to be
RDS_CONN_ERROR if an intervening FIN was processed in softirq context.
This is not a fatal error: rds_conn_shutdown() should continue the
shutdown, and there is no need to log noisy messages about this event.
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>
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It is incorrect for the rds_connection to piggyback on the
sock_net() refcount for the netns because this gives rise to
a chicken-and-egg problem during rds_conn_destroy. Instead explicitly
take a ref on the net, and hold the netns down till the connection
tear-down is complete.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fixes below warnings:
warning: symbol 'rds_send_probe' was not declared. Should it be static?
warning: symbol 'rds_send_ping' was not declared. Should it be static?
warning: symbol 'rds_tcp_accept_one_path' was not declared. Should it be static?
warning: symbol 'rds_walk_conn_path_info' was not declared. Should it be static?
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
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address
When 2 RDS peers initiate an RDS-TCP connection simultaneously,
there is a potential for "duelling syns" on either/both sides.
See commit 241b271952eb ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") for a description of this
condition, and the arbitration logic which ensures that the
numerically large IP address in the TCP connection is bound to the
RDS_TCP_PORT ("canonical ordering").
The rds_connection should not be marked as RDS_CONN_UP until the
arbitration logic has converged for the following reason. The sender
may start transmitting RDS datagrams as soon as RDS_CONN_UP is set,
and since the sender removes all datagrams from the rds_connection's
cp_retrans queue based on TCP acks. If the TCP ack was sent from
a tcp socket that got reset as part of duel aribitration (but
before data was delivered to the receivers RDS socket layer),
the sender may end up prematurely freeing the datagram, and
the datagram is no longer reliably deliverable.
This patch remedies that condition by making sure that, upon
receipt of 3WH completion state change notification of TCP_ESTABLISHED
in rds_tcp_state_change, we mark the rds_connection as RDS_CONN_UP
if, and only if, the IP addresses and ports for the connection are
canonically ordered. In all other cases, rds_tcp_state_change will
force an rds_conn_path_drop(), and rds_queue_reconnect() on
both peers will restart the connection to ensure canonical ordering.
A side-effect of enforcing this condition in rds_tcp_state_change()
is that rds_tcp_accept_one_path() can now be refactored for simplicity.
It is also no longer possible to encounter an RDS_CONN_UP connection in
the arbitration logic in rds_tcp_accept_one().
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>
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The RDS transport has to be able to distinguish between
two types of failure events:
(a) when the transport fails (e.g., TCP connection reset)
but the RDS socket/connection layer on both sides stays
the same
(b) when the peer's RDS layer itself resets (e.g., due to module
reload or machine reboot at the peer)
In case (a) both sides must reconnect and continue the RDS messaging
without any message loss or disruption to the message sequence numbers,
and this is achieved by rds_send_path_reset().
In case (b) we should reset all rds_connection state to the
new incarnation of the peer. Examples of state that needs to
be reset are next expected rx sequence number from, or messages to be
retransmitted to, the new incarnation of the peer.
To achieve this, the RDS handshake probe added as part of
commit 5916e2c1554f ("RDS: TCP: Enable multipath RDS for TCP")
is enhanced so that sender and receiver of the RDS ping-probe
will add a generation number as part of the RDS_EXTHDR_GEN_NUM
extension header. Each peer stores local and remote generation
numbers as part of each rds_connection. Changes in generation
number will be detected via incoming handshake probe ping
request or response and will allow the receiver to reset rds_connection
state.
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>
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This macro's last use was removed in commit d769ef81d5b59
("RDS: Update rds_conn_shutdown to work with rds_conn_path")
so make the macro and the __rds_conn_error function definition
and declaration disappear.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Use RDS probe-ping to compute how many paths may be used with
the peer, and to synchronously start the multiple paths. If mprds is
supported, hash outgoing traffic to one of multiple paths in rds_sendmsg()
when multipath RDS is supported by the transport.
CC: Santosh Shilimkar <santosh.shilimkar@oracle.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>
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When reconnecting, the peer with the smaller IP address will initiate
the reconnect, to avoid needless duelling SYN issues.
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>
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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>
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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>
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