From 642afd4d7c911f58e7f01ac34763f3b1f1732c48 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Mar 27 2019 19:53:41 +0000 Subject: Add NFS fix This was present on F29 but is applicable for all 5.0 branches. --- diff --git a/kernel.spec b/kernel.spec index 129895b..221dfd1 100644 --- a/kernel.spec +++ b/kernel.spec @@ -622,6 +622,9 @@ Patch511: 0001-virt-vbox-Implement-passing-requestor-info-to-the-ho.patch # rhbz 1688283 Patch512: v3-tpm-fix-an-invalid-condition-in-tpm_common_poll.patch +# rhbz 1683382 +Patch515: nfsv4.1-avoid-false-retries.patch + # END OF PATCH DEFINITIONS %endif diff --git a/nfsv4.1-avoid-false-retries.patch b/nfsv4.1-avoid-false-retries.patch new file mode 100644 index 0000000..ebec54d --- /dev/null +++ b/nfsv4.1-avoid-false-retries.patch @@ -0,0 +1,260 @@ +From 675f11241a9f5b434effc7aee9eb84bf3d17d685 Mon Sep 17 00:00:00 2001 +From: Trond Myklebust +Date: Wed, 20 Jun 2018 17:53:34 -0400 +Subject: [PATCH] NFSv4.1: Avoid false retries when RPC calls are interrupted + +A 'false retry' in NFSv4.1 occurs when the client attempts to transmit a +new RPC call using a slot+sequence number combination that references an +already cached one. Currently, the Linux NFS client will do this if a +user process interrupts an RPC call that is in progress. +The problem with doing so is that we defeat the main mechanism used by +the server to differentiate between a new call and a replayed one. Even +if the server is able to perfectly cache the arguments of the old call, +it cannot know if the client intended to replay or send a new call. + +The obvious fix is to bump the sequence number pre-emptively if an +RPC call is interrupted, but in order to deal with the corner cases +where the interrupted call is not actually received and processed by +the server, we need to interpret the error NFS4ERR_SEQ_MISORDERED +as a sign that we need to either wait or locate a correct sequence +number that lies between the value we sent, and the last value that +was acked by a SEQUENCE call on that slot. + +Signed-off-by: Trond Myklebust +--- + fs/nfs/nfs4proc.c | 105 ++++++++++++++++++++----------------------- + fs/nfs/nfs4session.c | 5 ++- + fs/nfs/nfs4session.h | 5 ++- + 3 files changed, 55 insertions(+), 60 deletions(-) + +diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c +index 64ac80ec6b7b..3a6a9c9ee369 100644 +--- a/fs/nfs/nfs4proc.c ++++ b/fs/nfs/nfs4proc.c +@@ -730,13 +730,25 @@ static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res) + res->sr_slot = NULL; + } + ++static void nfs4_slot_sequence_record_sent(struct nfs4_slot *slot, ++ u32 seqnr) ++{ ++ if ((s32)(seqnr - slot->seq_nr_highest_sent) > 0) ++ slot->seq_nr_highest_sent = seqnr; ++} ++static void nfs4_slot_sequence_acked(struct nfs4_slot *slot, ++ u32 seqnr) ++{ ++ slot->seq_nr_highest_sent = seqnr; ++ slot->seq_nr_last_acked = seqnr; ++} ++ + static int nfs41_sequence_process(struct rpc_task *task, + struct nfs4_sequence_res *res) + { + struct nfs4_session *session; + struct nfs4_slot *slot = res->sr_slot; + struct nfs_client *clp; +- bool interrupted = false; + int ret = 1; + + if (slot == NULL) +@@ -747,16 +759,12 @@ static int nfs41_sequence_process(struct rpc_task *task, + + session = slot->table->session; + +- if (slot->interrupted) { +- if (res->sr_status != -NFS4ERR_DELAY) +- slot->interrupted = 0; +- interrupted = true; +- } +- + trace_nfs4_sequence_done(session, res); + /* Check the SEQUENCE operation status */ + switch (res->sr_status) { + case 0: ++ /* Mark this sequence number as having been acked */ ++ nfs4_slot_sequence_acked(slot, slot->seq_nr); + /* Update the slot's sequence and clientid lease timer */ + slot->seq_done = 1; + clp = session->clp; +@@ -771,9 +779,9 @@ static int nfs41_sequence_process(struct rpc_task *task, + * sr_status remains 1 if an RPC level error occurred. + * The server may or may not have processed the sequence + * operation.. +- * Mark the slot as having hosted an interrupted RPC call. + */ +- slot->interrupted = 1; ++ nfs4_slot_sequence_record_sent(slot, slot->seq_nr); ++ slot->seq_done = 1; + goto out; + case -NFS4ERR_DELAY: + /* The server detected a resend of the RPC call and +@@ -784,6 +792,7 @@ static int nfs41_sequence_process(struct rpc_task *task, + __func__, + slot->slot_nr, + slot->seq_nr); ++ nfs4_slot_sequence_acked(slot, slot->seq_nr); + goto out_retry; + case -NFS4ERR_RETRY_UNCACHED_REP: + case -NFS4ERR_SEQ_FALSE_RETRY: +@@ -791,6 +800,7 @@ static int nfs41_sequence_process(struct rpc_task *task, + * The server thinks we tried to replay a request. + * Retry the call after bumping the sequence ID. + */ ++ nfs4_slot_sequence_acked(slot, slot->seq_nr); + goto retry_new_seq; + case -NFS4ERR_BADSLOT: + /* +@@ -801,21 +811,28 @@ static int nfs41_sequence_process(struct rpc_task *task, + goto session_recover; + goto retry_nowait; + case -NFS4ERR_SEQ_MISORDERED: ++ nfs4_slot_sequence_record_sent(slot, slot->seq_nr); + /* +- * Was the last operation on this sequence interrupted? +- * If so, retry after bumping the sequence number. ++ * Were one or more calls using this slot interrupted? ++ * If the server never received the request, then our ++ * transmitted slot sequence number may be too high. + */ +- if (interrupted) +- goto retry_new_seq; +- /* +- * Could this slot have been previously retired? +- * If so, then the server may be expecting seq_nr = 1! +- */ +- if (slot->seq_nr != 1) { +- slot->seq_nr = 1; ++ if ((s32)(slot->seq_nr - slot->seq_nr_last_acked) > 1) { ++ slot->seq_nr--; + goto retry_nowait; + } +- goto session_recover; ++ /* ++ * RFC5661: ++ * A retry might be sent while the original request is ++ * still in progress on the replier. The replier SHOULD ++ * deal with the issue by returning NFS4ERR_DELAY as the ++ * reply to SEQUENCE or CB_SEQUENCE operation, but ++ * implementations MAY return NFS4ERR_SEQ_MISORDERED. ++ * ++ * Restart the search after a delay. ++ */ ++ slot->seq_nr = slot->seq_nr_highest_sent; ++ goto out_retry; + default: + /* Just update the slot sequence no. */ + slot->seq_done = 1; +@@ -906,17 +923,6 @@ static const struct rpc_call_ops nfs41_call_sync_ops = { + .rpc_call_done = nfs41_call_sync_done, + }; + +-static void +-nfs4_sequence_process_interrupted(struct nfs_client *client, +- struct nfs4_slot *slot, const struct cred *cred) +-{ +- struct rpc_task *task; +- +- task = _nfs41_proc_sequence(client, cred, slot, true); +- if (!IS_ERR(task)) +- rpc_put_task_async(task); +-} +- + #else /* !CONFIG_NFS_V4_1 */ + + static int nfs4_sequence_process(struct rpc_task *task, struct nfs4_sequence_res *res) +@@ -937,14 +943,6 @@ int nfs4_sequence_done(struct rpc_task *task, + } + EXPORT_SYMBOL_GPL(nfs4_sequence_done); + +-static void +-nfs4_sequence_process_interrupted(struct nfs_client *client, +- struct nfs4_slot *slot, const struct cred *cred) +-{ +- WARN_ON_ONCE(1); +- slot->interrupted = 0; +-} +- + #endif /* !CONFIG_NFS_V4_1 */ + + static void nfs41_sequence_res_init(struct nfs4_sequence_res *res) +@@ -985,26 +983,19 @@ int nfs4_setup_sequence(struct nfs_client *client, + task->tk_timeout = 0; + } + +- for (;;) { +- spin_lock(&tbl->slot_tbl_lock); +- /* The state manager will wait until the slot table is empty */ +- if (nfs4_slot_tbl_draining(tbl) && !args->sa_privileged) +- goto out_sleep; +- +- slot = nfs4_alloc_slot(tbl); +- if (IS_ERR(slot)) { +- /* Try again in 1/4 second */ +- if (slot == ERR_PTR(-ENOMEM)) +- task->tk_timeout = HZ >> 2; +- goto out_sleep; +- } +- spin_unlock(&tbl->slot_tbl_lock); ++ spin_lock(&tbl->slot_tbl_lock); ++ /* The state manager will wait until the slot table is empty */ ++ if (nfs4_slot_tbl_draining(tbl) && !args->sa_privileged) ++ goto out_sleep; + +- if (likely(!slot->interrupted)) +- break; +- nfs4_sequence_process_interrupted(client, +- slot, task->tk_msg.rpc_cred); ++ slot = nfs4_alloc_slot(tbl); ++ if (IS_ERR(slot)) { ++ /* Try again in 1/4 second */ ++ if (slot == ERR_PTR(-ENOMEM)) ++ task->tk_timeout = HZ >> 2; ++ goto out_sleep; + } ++ spin_unlock(&tbl->slot_tbl_lock); + + nfs4_sequence_attach_slot(args, res, slot); + +diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c +index a5489d70a724..39962c19744f 100644 +--- a/fs/nfs/nfs4session.c ++++ b/fs/nfs/nfs4session.c +@@ -110,6 +110,8 @@ static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table *tbl, + slot->table = tbl; + slot->slot_nr = slotid; + slot->seq_nr = seq_init; ++ slot->seq_nr_highest_sent = seq_init; ++ slot->seq_nr_last_acked = seq_init - 1; + } + return slot; + } +@@ -276,7 +278,8 @@ static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl, + p = &tbl->slots; + while (*p) { + (*p)->seq_nr = ivalue; +- (*p)->interrupted = 0; ++ (*p)->seq_nr_highest_sent = ivalue; ++ (*p)->seq_nr_last_acked = ivalue - 1; + p = &(*p)->next; + } + tbl->highest_used_slotid = NFS4_NO_SLOT; +diff --git a/fs/nfs/nfs4session.h b/fs/nfs/nfs4session.h +index 3c550f297561..230509b77121 100644 +--- a/fs/nfs/nfs4session.h ++++ b/fs/nfs/nfs4session.h +@@ -23,8 +23,9 @@ struct nfs4_slot { + unsigned long generation; + u32 slot_nr; + u32 seq_nr; +- unsigned int interrupted : 1, +- privileged : 1, ++ u32 seq_nr_last_acked; ++ u32 seq_nr_highest_sent; ++ unsigned int privileged : 1, + seq_done : 1; + }; + +-- +2.20.1 +