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2021-06-28Merge tag 'locking-core-2021-06-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: - Core locking & atomics: - Convert all architectures to ARCH_ATOMIC: move every architecture to ARCH_ATOMIC, then get rid of ARCH_ATOMIC and all the transitory facilities and #ifdefs. Much reduction in complexity from that series: 63 files changed, 756 insertions(+), 4094 deletions(-) - Self-test enhancements - Futexes: - Add the new FUTEX_LOCK_PI2 ABI, which is a variant that doesn't set FLAGS_CLOCKRT (.e. uses CLOCK_MONOTONIC). [ The temptation to repurpose FUTEX_LOCK_PI's implicit setting of FLAGS_CLOCKRT & invert the flag's meaning to avoid having to introduce a new variant was resisted successfully. ] - Enhance futex self-tests - Lockdep: - Fix dependency path printouts - Optimize trace saving - Broaden & fix wait-context checks - Misc cleanups and fixes. * tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) locking/lockdep: Correct the description error for check_redundant() futex: Provide FUTEX_LOCK_PI2 to support clock selection futex: Prepare futex_lock_pi() for runtime clock selection lockdep/selftest: Remove wait-type RCU_CALLBACK tests lockdep/selftests: Fix selftests vs PROVE_RAW_LOCK_NESTING lockdep: Fix wait-type for empty stack locking/selftests: Add a selftest for check_irq_usage() lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage() locking/lockdep: Remove the unnecessary trace saving locking/lockdep: Fix the dep path printing for backwards BFS selftests: futex: Add futex compare requeue test selftests: futex: Add futex wait test seqlock: Remove trailing semicolon in macros locking/lockdep: Reduce LOCKDEP dependency list locking/lockdep,doc: Improve readability of the block matrix locking/atomics: atomic-instrumented: simplify ifdeffery locking/atomic: delete !ARCH_ATOMIC remnants locking/atomic: xtensa: move to ARCH_ATOMIC locking/atomic: sparc: move to ARCH_ATOMIC locking/atomic: sh: move to ARCH_ATOMIC ...
2021-05-27xprtrdma: Revert 586a0787ce35Chuck Lever
Commit 9ed5af268e88 ("SUNRPC: Clean up the handling of page padding in rpc_prepare_reply_pages()") [Dec 2020] affects RPC Replies that have a data payload (i.e., Write chunks). rpcrdma_prepare_readch(), as its name suggests, sets up Read chunks which are data payloads within RPC Calls. Those payloads are constructed by xdr_write_pages(), which continues to stuff the call buffer's tail kvec with the payload's XDR roundup. Thus removing the tail buffer logic in rpcrdma_prepare_readch() was the wrong thing to do. Fixes: 586a0787ce35 ("xprtrdma: Clean up rpcrdma_prepare_readch()") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-26locking/atomic: net: use linux/atomic.h for xchg & cmpxchgMark Rutland
As xchg*() and cmpxchg*() may be instrumented by atomic-instrumented.h, it's necessary to include <linux/atomic.h> to use these, rather than <asm/cmpxchg.h>, which is effectively an arch-internal header. In a couple of places we include <asm/cmpxchg.h>, but get away with this as <linux/atomic.h> gets pulled in inidrectly by another include. Before we convert more architectures to use atomic-instrumented.h, let's fix these up to use <linux/atomic.h> so that we don't make things more fragile. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210525140232.53872-3-mark.rutland@arm.com
2021-05-26SUNRPC: More fixes for backlog congestionTrond Myklebust
Ensure that we fix the XPRT_CONGESTED starvation issue for RDMA as well as socket based transports. Ensure we always initialise the request after waking up from the backlog list. Fixes: e877a88d1f06 ("SUNRPC in case of backlog, hand free slots directly to waiting task") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-20SUNRPC: Fix Oops in xs_tcp_send_request() when transport is disconnectedTrond Myklebust
If a disconnection occurs while we're trying to reply to a server callback, then we may end up calling xs_tcp_send_request() with a NULL value for transport->inet, which trips up the call to tcp_sock_set_cork(). Fixes: d737e5d41870 ("SUNRPC: Set TCP_CORK until the transmit queue is empty") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-20SUNRPC in case of backlog, hand free slots directly to waiting taskNeilBrown
If sunrpc.tcp_max_slot_table_entries is small and there are tasks on the backlog queue, then when a request completes it is freed and the first task on the queue is woken. The expectation is that it will wake and claim that request. However if it was a sync task and the waiting process was killed at just that moment, it will wake and NOT claim the request. As long as TASK_CONGESTED remains set, requests can only be claimed by tasks woken from the backlog, and they are woken only as requests are freed, so when a task doesn't claim a request, no other task can ever get that request until TASK_CONGESTED is cleared. Each time this happens the number of available requests is decreased by one. With a sufficiently high workload and sufficiently low setting of max_slot (16 in the case where this was seen), TASK_CONGESTED can remain set for an extended period, and the above scenario (of a process being killed just as its task was woken) can repeat until no requests can be allocated. Then traffic stops. This patch addresses the problem by introducing a positive handover of a request from a completing task to a backlog task - the request is never freed when there is a backlog. When a task is woken it might not already have a request attached in which case it is *not* freed (as with current code) but is initialised (if needed) and used. If it isn't used it will eventually be freed by rpc_exit_task(). xprt_release() is enhanced to be able to correctly release an uninitialised request. Fixes: ba60eb25ff6b ("SUNRPC: Fix a livelock problem in the xprt->backlog queue") Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-07Merge tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - Add validation of the UDP retrans parameter to prevent shift out-of-bounds - Don't discard pNFS layout segments that are marked for return Bugfixes: - Fix a NULL dereference crash in xprt_complete_bc_request() when the NFSv4.1 server misbehaves. - Fix the handling of NFS READDIR cookie verifiers - Sundry fixes to ensure attribute revalidation works correctly when the server does not return post-op attributes. - nfs4_bitmask_adjust() must not change the server global bitmasks - Fix major timeout handling in the RPC code. - NFSv4.2 fallocate() fixes. - Fix the NFSv4.2 SEEK_HOLE/SEEK_DATA end-of-file handling - Copy offload attribute revalidation fixes - Fix an incorrect filehandle size check in the pNFS flexfiles driver - Fix several RDMA transport setup/teardown races - Fix several RDMA queue wrapping issues - Fix a misplaced memory read barrier in sunrpc's call_decode() Features: - Micro optimisation of the TCP transmission queue using TCP_CORK - statx() performance improvements by further splitting up the tracking of invalid cached file metadata. - Support the NFSv4.2 'change_attr_type' attribute and use it to optimise handling of change attribute updates" * tag 'nfs-for-5.13-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (85 commits) xprtrdma: Fix a NULL dereference in frwr_unmap_sync() sunrpc: Fix misplaced barrier in call_decode NFSv4.2: Remove ifdef CONFIG_NFSD from NFSv4.2 client SSC code. xprtrdma: Move fr_mr field to struct rpcrdma_mr xprtrdma: Move the Work Request union to struct rpcrdma_mr xprtrdma: Move fr_linv_done field to struct rpcrdma_mr xprtrdma: Move cqe to struct rpcrdma_mr xprtrdma: Move fr_cid to struct rpcrdma_mr xprtrdma: Remove the RPC/RDMA QP event handler xprtrdma: Don't display r_xprt memory addresses in tracepoints xprtrdma: Add an rpcrdma_mr_completion_class xprtrdma: Add tracepoints showing FastReg WRs and remote invalidation xprtrdma: Avoid Send Queue wrapping xprtrdma: Do not wake RPC consumer on a failed LocalInv xprtrdma: Do not recycle MR after FastReg/LocalInv flushes xprtrdma: Clarify use of barrier in frwr_wc_localinv_done() xprtrdma: Rename frwr_release_mr() xprtrdma: rpcrdma_mr_pop() already does list_del_init() xprtrdma: Delete rpcrdma_recv_buffer_put() xprtrdma: Fix cwnd update ordering ...
2021-05-05Merge tag 'nfsd-5.13-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull more nfsd updates from Chuck Lever: "Additional fixes and clean-ups for NFSD since tags/nfsd-5.13, including a fix to grant read delegations for files open for writing" * tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: SUNRPC: Fix null pointer dereference in svc_rqst_free() SUNRPC: fix ternary sign expansion bug in tracing nfsd: Fix fall-through warnings for Clang nfsd: grant read delegations to clients holding writes nfsd: reshuffle some code nfsd: track filehandle aliasing in nfs4_files nfsd: hash nfs4_files by inode number nfsd: ensure new clients break delegations nfsd: removed unused argument in nfsd_startup_generic() nfsd: remove unused function svcrdma: Pass a useful error code to the send_err tracepoint svcrdma: Rename goto labels in svc_rdma_sendto() svcrdma: Don't leak send_ctxt on Send errors
2021-05-01xprtrdma: Fix a NULL dereference in frwr_unmap_sync()Chuck Lever
The normal mechanism that invalidates and unmaps MRs is frwr_unmap_async(). frwr_unmap_sync() is used only when an RPC Reply bearing Write or Reply chunks has been lost (ie, almost never). Coverity found that after commit 9a301cafc861 ("xprtrdma: Move fr_linv_done field to struct rpcrdma_mr"), the while() loop in frwr_unmap_sync() exits only once @mr is NULL, unconditionally causing subsequent dereferences of @mr to Oops. I've tested this fix by creating a client that skips invoking frwr_unmap_async() when RPC Replies complete. That forces all invalidation tasks to fall upon frwr_unmap_sync(). Simple workloads with this fix applied to the adulterated client work as designed. Reported-by: coverity-bot <keescook+coverity-bot@chromium.org> Addresses-Coverity-ID: 1504556 ("Null pointer dereferences") Fixes: 9a301cafc861 ("xprtrdma: Move fr_linv_done field to struct rpcrdma_mr") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-05-01sunrpc: Fix misplaced barrier in call_decodeBaptiste Lepers
Fix a misplaced barrier in call_decode. The struct rpc_rqst is modified as follows by xprt_complete_rqst: req->rq_private_buf.len = copied; /* Ensure all writes are done before we update */ /* req->rq_reply_bytes_recvd */ smp_wmb(); req->rq_reply_bytes_recvd = copied; And currently read as follows by call_decode: smp_rmb(); // misplaced if (!req->rq_reply_bytes_recvd) goto out; req->rq_rcv_buf.len = req->rq_private_buf.len; This patch places the smp_rmb after the if to ensure that rq_reply_bytes_recvd and rq_private_buf.len are read in order. Fixes: 9ba828861c56a ("SUNRPC: Don't try to parse incomplete RPC messages") Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-30SUNRPC: refresh rq_pages using a bulk page allocatorChuck Lever
Reduce the rate at which nfsd threads hammer on the page allocator. This improves throughput scalability by enabling the threads to run more independently of each other. [mgorman: Update interpretation of alloc_pages_bulk return value] Link: https://lkml.kernel.org/r/20210325114228.27719-8-mgorman@techsingularity.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30SUNRPC: set rq_page_end differentlyChuck Lever
Patch series "SUNRPC consumer for the bulk page allocator" This patch set and the measurements below are based on yesterday's bulk allocator series: git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-bulk-rebase-v5r9 The patches change SUNRPC to invoke the array-based bulk allocator instead of alloc_page(). The micro-benchmark results are promising. I ran a mixture of 256KB reads and writes over NFSv3. The server's kernel is built with KASAN enabled, so the comparison is exaggerated but I believe it is still valid. I instrumented svc_recv() to measure the latency of each call to svc_alloc_arg() and report it via a trace point. The following results are averages across the trace events. Single page: 25.007 us per call over 532,571 calls Bulk list: 6.258 us per call over 517,034 calls Bulk array: 4.590 us per call over 517,442 calls This patch (of 2) Refactor: I'm about to use the loop variable @i for something else. As far as the "i++" is concerned, that is a post-increment. The value of @i is not used subsequently, so the increment operator is unnecessary and can be removed. Also note that nfsd_read_actor() was renamed nfsd_splice_actor() by commit cf8208d0eabd ("sendfile: convert nfsd to splice_direct_to_actor()"). Link: https://lkml.kernel.org/r/20210325114228.27719-7-mgorman@techsingularity.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-26xprtrdma: Move fr_mr field to struct rpcrdma_mrChuck Lever
Clean up: The last remaining field in struct rpcrdma_frwr has been removed, so the struct can be eliminated. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Move the Work Request union to struct rpcrdma_mrChuck Lever
Clean up. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Move fr_linv_done field to struct rpcrdma_mrChuck Lever
Clean up: Move more of struct rpcrdma_frwr into its parent. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Move cqe to struct rpcrdma_mrChuck Lever
Clean up. - Simplify variable initialization in the completion handlers. - Move another field out of struct rpcrdma_frwr. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Move fr_cid to struct rpcrdma_mrChuck Lever
Clean up (for several purposes): - The MR's cid is initialized sooner so that tracepoints can show something reasonable even if the MR is never posted. - The MR's res.id doesn't change so the cid won't change either. Initializing the cid once is sufficient. - struct rpcrdma_frwr is going away soon. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Remove the RPC/RDMA QP event handlerChuck Lever
Clean up: The handler only recorded a trace event. If indeed no action is needed by the RPC/RDMA consumer, then the event can be ignored. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Add tracepoints showing FastReg WRs and remote invalidationChuck Lever
The Send signaling logic is a little subtle, so add some observability around it. For every xprtrdma_mr_fastreg event, there should be an xprtrdma_mr_localinv or xprtrdma_mr_reminv event. When these tracepoints are enabled, we can see exactly when an MR is DMA-mapped, registered, invalidated (either locally or remotely) and then DMA-unmapped. kworker/u25:2-190 [000] 787.979512: xprtrdma_mr_map: task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE) kworker/u25:2-190 [000] 787.979515: xprtrdma_chunk_read: task:351@5 pos=148 5608@0x8679e0c8f6f56000:0x00000503 (last) kworker/u25:2-190 [000] 787.979519: xprtrdma_marshal: task:351@5 xid=0x8679e0c8: hdr=52 xdr=148/5608/0 read list/inline kworker/u25:2-190 [000] 787.979525: xprtrdma_mr_fastreg: task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE) kworker/u25:2-190 [000] 787.979526: xprtrdma_post_send: task:351@5 cq.id=0 cid=73 (2 SGEs) ... kworker/5:1H-219 [005] 787.980567: xprtrdma_wc_receive: cq.id=1 cid=161 status=SUCCESS (0/0x0) received=164 kworker/5:1H-219 [005] 787.980571: xprtrdma_post_recvs: peer=[192.168.100.55]:20049 r_xprt=0xffff8884974d4000: 0 new recvs, 70 active (rc 0) kworker/5:1H-219 [005] 787.980573: xprtrdma_reply: task:351@5 xid=0x8679e0c8 credits=64 kworker/5:1H-219 [005] 787.980576: xprtrdma_mr_reminv: task:351@5 mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE) kworker/5:1H-219 [005] 787.980577: xprtrdma_mr_unmap: mr.id=4 nents=2 5608@0x8679e0c8f6f56000:0x00000503 (TO_DEVICE) Note that I've moved the xprtrdma_post_send tracepoint so that event always appears after the xprtrdma_mr_fastreg tracepoint. Otherwise the event log looks counterintuitive (FastReg is always supposed to happen before Send). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Avoid Send Queue wrappingChuck Lever
Send WRs can be signalled or unsignalled. A signalled Send WR always has a matching Send completion, while a unsignalled Send has a completion only if the Send WR fails. xprtrdma has a Send account mechanism that is designed to reduce the number of signalled Send WRs. This in turn mitigates the interrupt rate of the underlying device. RDMA consumers can't leave all Sends unsignaled, however, because providers rely on Send completions to maintain their Send Queue head and tail pointers. xprtrdma counts the number of unsignaled Send WRs that have been posted to ensure that Sends are signalled often enough to prevent the Send Queue from wrapping. This mechanism neglected to account for FastReg WRs, which are posted on the Send Queue but never signalled. As a result, the Send Queue wrapped on occasion, resulting in duplication completions of FastReg and LocalInv WRs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Do not wake RPC consumer on a failed LocalInvChuck Lever
Throw away any reply where the LocalInv flushes or could not be posted. The registered memory region is in an unknown state until the disconnect completes. rpcrdma_xprt_disconnect() will find and release the MR. No need to put it back on the MR free list in this case. The client retransmits pending RPC requests once it reestablishes a fresh connection, so a replacement reply should be forthcoming on the next connection instance. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Do not recycle MR after FastReg/LocalInv flushesChuck Lever
Better not to touch MRs involved in a flush or post error until the Send and Receive Queues are drained and the transport is fully quiescent. Simply don't insert such MRs back onto the free list. They remain on mr_all and will be released when the connection is torn down. I had thought that recycling would prevent hardware resources from being tied up for a long time. However, since v5.7, a transport disconnect destroys the QP and other hardware-owned resources. The MRs get cleaned up nicely at that point. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Clarify use of barrier in frwr_wc_localinv_done()Chuck Lever
Clean up: The comment and the placement of the memory barrier is confusing. Humans want to read the function statements from head to tail. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Rename frwr_release_mr()Chuck Lever
Clean up: To be consistent with other functions in this source file, follow the naming convention of putting the object being acted upon before the action itself. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: rpcrdma_mr_pop() already does list_del_init()Chuck Lever
The rpcrdma_mr_pop() earlier in the function has already cleared out mr_list, so it must not be done again in the error path. Fixes: 847568942f93 ("xprtrdma: Remove fr_state") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Delete rpcrdma_recv_buffer_put()Chuck Lever
Clean up: The name recv_buffer_put() is a vestige of older code, and the function is just a wrapper for the newer rpcrdma_rep_put(). In most of the existing call sites, a pointer to the owning rpcrdma_buffer is already available. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Fix cwnd update orderingChuck Lever
After a reconnect, the reply handler is opening the cwnd (and thus enabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs() can post enough Receive WRs to receive their replies. This causes an RNR and the new connection is lost immediately. The race is most clearly exposed when KASAN and disconnect injection are enabled. This slows down rpcrdma_rep_create() enough to allow the send side to post a bunch of RPC Calls before the Receive completion handler can invoke ib_post_recv(). Fixes: 2ae50ad68cd7 ("xprtrdma: Close window between waking RPC senders and posting Receives") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Improve locking around rpcrdma_rep creationChuck Lever
Defensive clean up: Protect the rb_all_reps list during rep creation. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Improve commentary around rpcrdma_reps_unmap()Chuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Improve locking around rpcrdma_rep destructionChuck Lever
Currently rpcrdma_reps_destroy() assumes that, at transport tear-down, the content of the rb_free_reps list is the same as the content of the rb_all_reps list. Although that is usually true, using the rb_all_reps list should be more reliable because of the way it's managed. And, rpcrdma_reps_unmap() uses rb_all_reps; these two functions should both traverse the "all" list. Ensure that all rpcrdma_reps are always destroyed whether they are on the rep free list or not. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Put flushed Receives on free list instead of destroying themChuck Lever
Defer destruction of an rpcrdma_rep until transport tear-down to preserve the rb_all_reps list while Receives flush. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Do not refresh Receive Queue while it is drainingChuck Lever
Currently the Receive completion handler refreshes the Receive Queue whenever a successful Receive completion occurs. On disconnect, xprtrdma drains the Receive Queue. The first few Receive completions after a disconnect are typically successful, until the first flushed Receive. This means the Receive completion handler continues to post more Receive WRs after the drain sentinel has been posted. The late- posted Receives flush after the drain sentinel has completed, leading to a crash later in rpcrdma_xprt_disconnect(). To prevent this crash, xprtrdma has to ensure that the Receive handler stops posting Receives before ib_drain_rq() posts its drain sentinel. Suggested-by: Tom Talpey <tom@talpey.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-26xprtrdma: Avoid Receive Queue wrappingChuck Lever
Commit e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") increased the number of Receive WRs that are posted by the client, but did not increase the size of the Receive Queue allocated during transport set-up. This is usually not an issue because RPCRDMA_BACKWARD_WRS is defined as (32) when SUNRPC_BACKCHANNEL is defined. In cases where it isn't, there is a real risk of Receive Queue wrapping. Fixes: e340c2d6ef2a ("xprtrdma: Reduce the doorbell rate (Receive)") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-23SUNRPC: Fix null pointer dereference in svc_rqst_free()Yunjian Wang
When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). Fix it by adding a null check. Addresses-Coverity: ("Dereference after null check") Fixes: 5191955d6fc6 ("SUNRPC: Prepare for xdr_stream-style decoding on the server-side") Signed-off-by: Yunjian Wang <wangyunjian@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-22SUNRPC: fix ternary sign expansion bug in tracingDan Carpenter
This code is supposed to pass negative "err" values for tracing but it passes positive values instead. The problem is that the trace_svcsock_tcp_send() function takes a long but "err" is an int and "sent" is a u32. The negative is first type promoted to u32 so it becomes a high positive then it is promoted to long and it stays positive. Fix this by casting "err" directly to long. Fixes: 998024dee197 ("SUNRPC: Add more svcsock tracepoints") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14svcrdma: Pass a useful error code to the send_err tracepointChuck Lever
Capture error codes in @ret, which is passed to the send_err tracepoint, so that they can be logged when something goes awry. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14svcrdma: Rename goto labels in svc_rdma_sendto()Chuck Lever
Clean up: Make the goto labels consistent with other similar functions. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14svcrdma: Don't leak send_ctxt on Send errorsChuck Lever
Address a rare send_ctxt leak in the svc_rdma_sendto() error paths. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-14SUNRPC: Handle major timeout in xprt_adjust_timeout()Chris Dion
Currently if a major timeout value is reached, but the minor value has not been reached, an ETIMEOUT will not be sent back to the caller. This can occur if the v4 server is not responding to requests and retrans is configured larger than the default of two. For example, A TCP mount with a configured timeout value of 50 and a retransmission count of 3 to a v4 server which is not responding: 1. Initial value and increment set to 5s, maxval set to 20s, retries at 3 2. Major timeout is set to 20s, minor timeout set to 5s initially 3. xport_adjust_timeout() is called after 5s, retry with 10s timeout, minor timeout is bumped to 10s 4. And again after another 10s, 15s total time with minor timeout set to 15s 5. After 20s total time xport_adjust_timeout is called as major timeout is reached, but skipped because the minor timeout is not reached - After this time the cpu spins continually calling xport_adjust_timeout() and returning 0 for 10 seconds. As seen on perf sched: 39243.913182 [0005] mount.nfs[3794] 4607.938 0.017 9746.863 6. This continues until the 15s minor timeout condition is reached (in this case for 10 seconds). After which the ETIMEOUT is processed back to the caller, the cpu spinning stops, and normal operations continue Fixes: 7de62bc09fe6 ("SUNRPC dont update timeout value on connection reset") Signed-off-by: Chris Dion <Christopher.Dion@dell.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14SUNRPC: Remove trace_xprt_transmit_queuedChuck Lever
This tracepoint can crash when dereferencing snd_task because when some transports connect, they put a cookie in that field instead of a pointer to an rpc_task. BUG: KASAN: use-after-free in trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc] Read of size 2 at addr ffff8881a83bd3a0 by task git/331872 CPU: 11 PID: 331872 Comm: git Tainted: G S 5.12.0-rc2-00007-g3ab6e585a7f9 #1453 Hardware name: Supermicro SYS-6028R-T/X10DRi, BIOS 1.1a 10/16/2015 Call Trace: dump_stack+0x9c/0xcf print_address_description.constprop.0+0x18/0x239 kasan_report+0x174/0x1b0 trace_event_raw_event_xprt_writelock_event+0x141/0x18e [sunrpc] xprt_prepare_transmit+0x8e/0xc1 [sunrpc] call_transmit+0x4d/0xc6 [sunrpc] Fixes: 9ce07ae5eb1d ("SUNRPC: Replace dprintk() call site in xprt_prepare_transmit") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14SUNRPC: Add tracepoint that fires when an RPC is retransmittedChuck Lever
A separate tracepoint can be left enabled all the time to capture rare but important retransmission events. So for example: kworker/u26:3-568 [009] 156.967933: xprt_retransmit: task:44093@5 xid=0xa25dbc79 nfsv3 WRITE ntrans=2 Or, for example, enable all nfs and nfs4 tracepoints, and set up a trigger to disable tracing when xprt_retransmit fires to capture everything that leads up to it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-14SUNRPC: Move fault injection call sitesChuck Lever
I've hit some crashes that occur in the xprt_rdma_inject_disconnect path. It appears that, for some provides, rdma_disconnect() can take so long that the transport can disconnect and release its hardware resources while rdma_disconnect() is still running, resulting in a UAF in the provider. The transport's fault injection method may depend on the stability of transport data structures. That means it needs to be invoked only from contexts that hold the transport write lock. Fixes: 4a0682583988 ("SUNRPC: Transport fault injection") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-06sunrpc: Remove unused function ip_map_lookupJiapeng Chong
Fix the following clang warnings: net/sunrpc/svcauth_unix.c:306:30: warning: unused function 'ip_map_lookup' [-Wunused-function]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-04-05SUNRPC: Ensure the transport backchannel associationBenjamin Coddington
If the server sends CB_ calls on a connection that is not associated with the backchannel, refuse to process the call and shut down the connection. This avoids a NULL dereference crash in xprt_complete_bc_request(). There's not much more we can do in this situation unless we want to look into allowing all connections to be associated with the fore and back channel. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05sunrpc: honor rpc_task's timeout value in rpcb_create()Eryu Guan
Currently rpcbind client is created without setting rpc timeout (thus using the default value). But if the rpc_task already has a customized timeout in its tk_client field, it's also ignored. Let's use the same timeout setting in rpc_task->tk_client->cl_timeout for rpcbind connection. Signed-off-by: Eryu Guan <eguan@linux.alibaba.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-04-05SUNRPC: Set TCP_CORK until the transmit queue is emptyTrond Myklebust
When we have multiple RPC requests queued up, it makes sense to set the TCP_CORK option while the transmit queue is non-empty. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-03-31svcrdma: Clean up dto_q critical section in svc_rdma_recvfrom()Chuck Lever
This, to me, seems less cluttered and less redundant. I was hoping it could help reduce lock contention on the dto_q lock by reducing the size of the critical section, but alas, the only improvement is readability. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31svcrdma: Remove svc_rdma_recv_ctxt::rc_pages and ::rc_argChuck Lever
These fields are no longer used. The size of struct svc_rdma_recv_ctxt is now less than 300 bytes on x86_64, down from 2440 bytes. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31svcrdma: Remove sc_read_complete_qChuck Lever
Now that svc_rdma_recvfrom() waits for Read completion, sc_read_complete_q is no longer used. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-31svcrdma: Single-stage RDMA ReadChuck Lever
Currently the generic RPC server layer calls svc_rdma_recvfrom() twice to retrieve an RPC message that uses Read chunks. I'm not exactly sure why this design was chosen originally. Instead, let's wait for the Read chunk completion inline in the first call to svc_rdma_recvfrom(). The goal is to eliminate some page allocator churn. rdma_read_complete() replaces pages in the second svc_rqst by calling put_page() repeatedly while the upper layer waits for the request to be constructed, which adds unnecessary NFS WRITE round- trip latency. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Tom Talpey <tom@talpey.com>