/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #include #include #include #include #include "bpf_helpers.h" struct bpf_map_def SEC("maps") my_map = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(long), .value_size = sizeof(u64), .max_entries = 4096, }; /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe * example will no longer be meaningful */ SEC("kprobe/blk_start_request") int bpf_prog1(struct pt_regs *ctx) { long rq = PT_REGS_PARM1(ctx); u64 val = bpf_ktime_get_ns(); bpf_map_update_elem(&my_map, &rq, &val, BPF_ANY); return 0; } static unsigned int log2l(unsigned long long n) { #define S(k) if (n >= (1ull << k)) { i += k; n >>= k; } int i = -(n == 0); S(32); S(16); S(8); S(4); S(2); S(1); return i; #undef S } #define SLOTS 100 struct bpf_map_def SEC("maps") lat_map = { .type = BPF_MAP_TYPE_PERCPU_ARRAY, .key_size = sizeof(u32), .value_size = sizeof(u64), .max_entries = SLOTS, }; SEC("kprobe/blk_account_io_completion") int bpf_prog2(struct pt_regs *ctx) { long rq = PT_REGS_PARM1(ctx); u64 *value, l, base; u32 index; value = bpf_map_lookup_elem(&my_map, &rq); if (!value) return 0; u64 cur_time = bpf_ktime_get_ns(); u64 delta = cur_time - *value; bpf_map_delete_elem(&my_map, &rq); /* the lines below are computing index = log10(delta)*10 * using integer arithmetic * index = 29 ~ 1 usec * index = 59 ~ 1 msec * index = 89 ~ 1 sec * index = 99 ~ 10sec or more * log10(x)*10 = log2(x)*10/log2(10) = log2(x)*3 */ l = log2l(delta); base = 1ll << l; index = (l * 64 + (delta - base) * 64 / base) * 3 / 64; if (index >= SLOTS) index = SLOTS - 1; value = bpf_map_lookup_elem(&lat_map, &index); if (value) *value += 1; return 0; } char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE; te-remove&id=059aa734824165507c65fd30a55ff000afd14983'>commitdiff
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authorChuck Lever <chuck.lever@oracle.com>2017-01-22 14:04:29 -0500
committerTrond Myklebust <trond.myklebust@primarydata.com>2017-01-24 12:50:47 -0500
commit059aa734824165507c65fd30a55ff000afd14983 (patch)
tree63defb4adb0656c4af72a05081b181b163f94b3e /net/caif/caif_socket.c
parent8ac092519ad91931c96d306c4bfae2c6587c325f (diff)
nfs: Don't increment lock sequence ID after NFS4ERR_MOVED
Xuan Qi reports that the Linux NFSv4 client failed to lock a file that was migrated. The steps he observed on the wire: 1. The client sent a LOCK request to the source server 2. The source server replied NFS4ERR_MOVED 3. The client switched to the destination server 4. The client sent the same LOCK request to the destination server with a bumped lock sequence ID 5. The destination server rejected the LOCK request with NFS4ERR_BAD_SEQID RFC 3530 section 8.1.5 provides a list of NFS errors which do not bump a lock sequence ID. However, RFC 3530 is now obsoleted by RFC 7530. In RFC 7530 section 9.1.7, this list has been updated by the addition of NFS4ERR_MOVED. Reported-by: Xuan Qi <xuan.qi@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org # v3.7+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'net/caif/caif_socket.c')