kernel/git/next/linux-next.git/net/rds, branch master

Merge branch 'headers' of git://git.infradead.org/users/willy/pagecache.git

2026-09-04T18:38:02+00:00

# Conflicts: # net/ceph/osd_client.c

net/rds: don't let rds_conn_shutdown() consume a concurrent drop

2026-09-03T02:42:24+00:00

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 Link: https://patch.msgid.link/20260828223921.202913-8-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: acquire the fastpath locks in rds_conn_shutdown()

2026-09-03T02:42:23+00:00

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 [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 Link: https://patch.msgid.link/20260828223921.202913-7-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()

2026-09-03T02:42:23+00:00

rds_tcp_reset_callbacks() quiesces the transmit path by setting the path state to RDS_CONN_RESETTING and then waiting for RDS_IN_XMIT to be sampled clear before swapping the underlying socket and calling rds_send_path_reset(). Sampling the bit clear is not the same as owning it: rds_send_xmit() can re-acquire RDS_IN_XMIT right after the wait_event() returns. Its state recheck after taking the lock is a store-buffering pattern (the resetter writes the state and reads the bit, the sender writes the bit and reads the state) and 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 concurrently with rds_send_path_reset() rewriting cp_xmit_* state - which is exactly what the comment above rds_send_path_reset() tells its callers to prevent. Take the lock instead, hold it across the socket swap and rds_send_path_reset(), and release it with a wake-up at the end. The lock-ordering constraint documented above the wait still holds: the lock is acquired before lock_sock(), so a sender inside tcp_sendmsg() can never be waited on while we hold the socket lock. Two details of the old code go away with the same change: - t_sock is now read only after the lock is acquired. The old code cached it before waiting; the teardown in rds_conn_shutdown() releases that socket and clears t_sock, so a pointer cached before the wait can be stale by the time the accept path resumes. Reading it under RDS_IN_XMIT is what makes the exclusion complete once the teardown owns the same lock, which the next patch arranges; until then the teardown still only samples the bit, and the two paths remain as exposed to each other as they are today. - The old !osock early path called rds_send_path_reset() with no serialization at all. It now runs under the lock like the normal path. The conditional RDS_CONN_RESETTING transition of the previous patch happens before the socket check either way: a path found without a socket is either still connecting (its reconnect worker blocked on t_conn_path_lock) and legitimately goes RESETTING -> UP on the new socket, or it has been torn down meanwhile and is dropped. The in-function comment describing the old wait-based quiesce is rewritten to describe the lock-based one, and the stale block comment above the function (which still described a return value and an incomplete list of t_sock writers) is refreshed to name all four writers - the connect, accept, teardown and swap paths - and what serializes each of them. Fixes: 335b48d980f6 ("RDS: TCP: Add/use rds_tcp_reset_callbacks to reset tcp socket safely") Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260828223921.202913-6-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: tcp: don't force RDS_CONN_RESETTING over a concurrent shutdown

2026-09-03T02:42:23+00:00

rds_tcp_reset_callbacks() resolves a duelling SYN by storing RDS_CONN_RESETTING into cp_state unconditionally. Nothing serializes that store against the shutdown path: rds_tcp_accept_one() checks for RDS_CONN_CONNECTING or RDS_CONN_ERROR under t_conn_path_lock, but neither rds_conn_path_drop(), which forces RDS_CONN_ERROR, nor rds_conn_shutdown(), which moves the path to RDS_CONN_DISCONNECTING under cp_cm_lock, takes that lock. The store can therefore land on top of a shutdown that is already in progress, or that gets queued right after the accept-side check. When it does, the shutdown worker's final DISCONNECTING -> DOWN transition fails and the path goes through rds_conn_path_error() and a second drop/shutdown cycle instead of a clean reconnect, tearing down the socket the accept path has just installed. Before commit ad22d24be635 ("net/rds: No shortcut out of RDS_CONN_ERROR") a path found in RDS_CONN_RESETTING even made rds_conn_shutdown() bail out altogether. Make the transition conditional: move CONNECTING -> RESETTING (or stay in RESETTING from an earlier duel), and drop the path in any other state. The drop has side effects of its own: it replaces the shutdown's RDS_CONN_DISCONNECTING (or RDS_CONN_ERROR) with RDS_CONN_ERROR and queues one more cp_down_w run. The difference is that rds_conn_shutdown() accepts RDS_CONN_ERROR in its final transition to RDS_CONN_DOWN, so the shutdown in flight completes normally instead of through rds_conn_path_error(); the extra down-work pass then finds the path already down and falls through to the reconnect check, or catches a reconnect that has already started and restarts it. The accept path still installs the new socket, rds_connect_path_complete() then fails its RESETTING -> UP transition and drops it: the raced socket ends up torn down as it does today. The comment at that call site, which promised that rds_connect_path_complete() marks the path RDS_CONN_UP, is updated to name this outcome as well. The state can change again between the failed transitions and the drop. That is inherent to rds_conn_path_drop(), which the socket state-change callbacks also call unconditionally, and costs at most one extra drop/reconnect cycle. Based on Oracle UEK commit "net/rds: Don't force state RDS_CONN_RESETTING" by Gerd Rausch. Fixes: 9c79440e2c5e ("RDS: TCP: fix race windows in send-path quiescence by rds_tcp_accept_one()") Signed-off-by: Gerd Rausch [achender: port to net-next: use the two-argument rds_conn_path_transition()/rds_conn_path_drop() and rewrite the changelog for the upstream shutdown path] Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260828223921.202913-5-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: clear cp_flags bits individually in rds_conn_path_reset()

2026-09-03T02:42:23+00:00

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 Link: https://patch.msgid.link/20260828223921.202913-4-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: use clear_bit_unlock() in release_refill()

2026-09-03T02:42:23+00:00

release_refill() drops the RDS_RECV_REFILL bit with a plain clear_bit(). clear_bit() has no ordering semantics, and the smp_mb__after_atomic() that follows it sits on the wrong side for a lock release: it orders the clear against the waitqueue_active() load below it, but does nothing to order the refill critical section's ring and descriptor stores before the clear itself. That matters once connection teardown owns RDS_RECV_REFILL as a lock across the transport shutdown and path reset, rather than sampling it clear, which "net/rds: acquire the fastpath locks in rds_conn_shutdown()" later in this series arranges: on a weakly ordered architecture the teardown can win the bit and start the shutdown and reset while some of the refill's stores are not yet visible to it. The same gap existed under the sample-based scheme - a waiter that saw the bit clear had no guarantee it also observed the refill's stores - but taking the bit as a lock makes the missing release pairing load-bearing. Switch to clear_bit_unlock(), which orders the critical section before the release, and replace the open-coded barrier-plus-waitqueue_active() with wq_has_sleeper(), whose internal full barrier keeps the store-buffering guarantee between clearing the bit and checking for sleepers. This mirrors what "net/rds: use wq_has_sleeper() in release_in_xmit()" does for RDS_IN_XMIT. The fast-path acquire side, acquire_refill(), uses test_and_set_bit(), a full-barrier RMW that pairs with this release. The teardown at this point in the series still samples the bit, so on its own this change is release-side hardening; the shutdown-conversion patch named above makes the teardown acquire the bit with the same RMW, completing the pairing at the end of the series. Fixes: 73ce4317bf98 ("RDS: make sure we post recv buffers") Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260828223921.202913-3-achender@kernel.org Signed-off-by: Jakub Kicinski

net/rds: use wq_has_sleeper() in release_in_xmit()

2026-09-03T02:42:23+00:00

release_in_xmit() clears RDS_IN_XMIT with clear_bit_unlock() and then checks waitqueue_active() to decide whether anyone needs waking. clear_bit_unlock() is only a release operation: it orders the critical section before the bit clear, but does not order the subsequent plain load of the wait queue head after it. The waiter side does the mirror image - it adds itself to the wait queue and then tests the bit. That is the classic store-buffering pattern: the releasing CPU can read the wait queue as empty while the waiting CPU still reads the bit as set, so the sleeper is never woken. The waiters are rds_conn_shutdown() and rds_tcp_reset_callbacks(), both in uninterruptible wait_event() with no timeout. A lost wake-up strands the shutdown worker on its single-threaded workqueue until some other sender releases the bit again - and on a connection that is being torn down precisely because it failed, there may never be another sender. The barrier used to be there: release_in_xmit() did clear_bit() followed by smp_mb__after_atomic() until commit 1422f28826d2 ("rds: introduce acquire/release ordering in acquire/release_in_xmit()") folded both into clear_bit_unlock(), which strengthened the lock hand-off but silently dropped the full barrier the wake-up check depends on. The refill counterpart, release_refill() in net/rds/ib_recv.c, still carries its smp_mb__after_atomic() for exactly this reason. Use wq_has_sleeper(), which is waitqueue_active() preceded by the required full barrier. Fixes: 1422f28826d2 ("rds: introduce acquire/release ordering in acquire/release_in_xmit()") Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260828223921.202913-2-achender@kernel.org Signed-off-by: Jakub Kicinski

Merge tag 'net-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-08-27T20:53:43+00:00

Pull networking fixes from Jakub Kicinski: "Including fixes from Bluetooth, IPSec and Netfilter. Current release - fix to a fix: - netfilter: ipset: remove need to allocate memory on delete operations Current release - regressions: - macb: drop CONFIG_OF #if block, fix build Previous releases - always broken: - stream of fixes for SCTP continues - inet: frags: strip GSO state from fragments before reassembly - virtio-net: ensure that TCP packets don't overflow gso_segs - tcp-ao: fix use-after-free of current_key on reconnect to another peer - page_pool: remove zone/policy GFP flags when allocating XArray entries - Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN - tls: device: fix out-of-bounds write in tls_append_frag() - eth: bnxt: - ring the doorbell when SW USO exits early, avoid packets stuck in Tx - gate TPH enablement behind BNXT_SUPPORTS_QUEUE_API check, avoid users of older NICs seeing non-actionable warning messages - eth: qede: fix NULL pointer dereference in TPA fragment processing" * tag 'net-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (216 commits) inet: frags: strip GSO state from fragments before reassembly net/sched: sch_htb: limit htb_classify inner-class filter hops selftests/net: packetdrill: add tcp_urg_ptr_retransmit tcp: fix corruption of urgent data on multi-segment retransmit usb: atm: usbatm: fix invalid ci_range initialization net: fec: only stop PTP if it was initialized slip: remove slip_hangup() to fix use-after-free in slip_receive_buf() net: bridge: mcast: fix use-after-free of a master VLAN's multicast context net/sched: bound qdisc_pkt_len to prevent qdisc soft lockup net: dsa: mxl862xx: enable assisted learning on CPU port net: stmmac: restore NET_IP_ALIGN in the RX DMA offset net: stmmac: drop gso_enabled_types and rely on netdev features net: stmmac: selftests: Don't test flow control for small rx fifos net: stmmac: selftests: Account for the UC filter list for filtering tests net: stmmac: dwxgmac: Account for the primary MAC address for UC filtering net: stmmac: dwmac4: Account for the primary MAC address for UC filtering net: stmmac: dwmac1000: Account for the primary MAC address for UC filtering net: stmmac: selftests: Check multiple MMC counters selftests: net: Fix slow configurations in big_tcp_tunnels.sh selftests: net: Lower threshold with csum offload off in big_tcp_tunnels.sh ...

net: Remove includes of pagemap.h

2026-08-25T19:12:27+00:00

Two ceph files call __page_cache_alloc(), so need to include pagemap.h. I'm not sure that they should be allocating memory using this interface, but that's a question for later. net/ is largely free of indirect dependencies on pagemap.h at this point. Signed-off-by: Matthew Wilcox (Oracle)