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  1. Mar 24, 2017
  2. Mar 22, 2017
    • Martin KaFai Lau's avatar
      bpf: Add hash of maps support · bcc6b1b7
      Martin KaFai Lau authored
      
      
      This patch adds hash of maps support (hashmap->bpf_map).
      BPF_MAP_TYPE_HASH_OF_MAPS is added.
      
      A map-in-map contains a pointer to another map and lets call
      this pointer 'inner_map_ptr'.
      
      Notes on deleting inner_map_ptr from a hash map:
      
      1. For BPF_F_NO_PREALLOC map-in-map, when deleting
         an inner_map_ptr, the htab_elem itself will go through
         a rcu grace period and the inner_map_ptr resides
         in the htab_elem.
      
      2. For pre-allocated htab_elem (!BPF_F_NO_PREALLOC),
         when deleting an inner_map_ptr, the htab_elem may
         get reused immediately.  This situation is similar
         to the existing prealloc-ated use cases.
      
         However, the bpf_map_fd_put_ptr() calls bpf_map_put() which calls
         inner_map->ops->map_free(inner_map) which will go
         through a rcu grace period (i.e. all bpf_map's map_free
         currently goes through a rcu grace period).  Hence,
         the inner_map_ptr is still safe for the rcu reader side.
      
      This patch also includes BPF_MAP_TYPE_HASH_OF_MAPS to the
      check_map_prealloc() in the verifier.  preallocation is a
      must for BPF_PROG_TYPE_PERF_EVENT.  Hence, even we don't expect
      heavy updates to map-in-map, enforcing BPF_F_NO_PREALLOC for map-in-map
      is impossible without disallowing BPF_PROG_TYPE_PERF_EVENT from using
      map-in-map first.
      
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bcc6b1b7
    • Martin KaFai Lau's avatar
      bpf: Add array of maps support · 56f668df
      Martin KaFai Lau authored
      
      
      This patch adds a few helper funcs to enable map-in-map
      support (i.e. outer_map->inner_map).  The first outer_map type
      BPF_MAP_TYPE_ARRAY_OF_MAPS is also added in this patch.
      The next patch will introduce a hash of maps type.
      
      Any bpf map type can be acted as an inner_map.  The exception
      is BPF_MAP_TYPE_PROG_ARRAY because the extra level of
      indirection makes it harder to verify the owner_prog_type
      and owner_jited.
      
      Multi-level map-in-map is not supported (i.e. map->map is ok
      but not map->map->map).
      
      When adding an inner_map to an outer_map, it currently checks the
      map_type, key_size, value_size, map_flags, max_entries and ops.
      The verifier also uses those map's properties to do static analysis.
      map_flags is needed because we need to ensure BPF_PROG_TYPE_PERF_EVENT
      is using a preallocated hashtab for the inner_hash also.  ops and
      max_entries are needed to generate inlined map-lookup instructions.
      For simplicity reason, a simple '==' test is used for both map_flags
      and max_entries.  The equality of ops is implied by the equality of
      map_type.
      
      During outer_map creation time, an inner_map_fd is needed to create an
      outer_map.  However, the inner_map_fd's life time does not depend on the
      outer_map.  The inner_map_fd is merely used to initialize
      the inner_map_meta of the outer_map.
      
      Also, for the outer_map:
      
      * It allows element update and delete from syscall
      * It allows element lookup from bpf_prog
      
      The above is similar to the current fd_array pattern.
      
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      56f668df
    • Joel Scherpelz's avatar
      net: ipv6: Add sysctl for minimum prefix len acceptable in RIOs. · bbea124b
      Joel Scherpelz authored
      
      
      This commit adds a new sysctl accept_ra_rt_info_min_plen that
      defines the minimum acceptable prefix length of Route Information
      Options. The new sysctl is intended to be used together with
      accept_ra_rt_info_max_plen to configure a range of acceptable
      prefix lengths. It is useful to prevent misconfigurations from
      unintentionally blackholing too much of the IPv6 address space
      (e.g., home routers announcing RIOs for fc00::/7, which is
      incorrect).
      
      Signed-off-by: default avatarJoel Scherpelz <jscherpelz@google.com>
      Acked-by: default avatarLorenzo Colitti <lorenzo@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bbea124b
    • andy zhou's avatar
      openvswitch: Optimize sample action for the clone use cases · 798c1661
      andy zhou authored
      
      
      With the introduction of open flow 'clone' action, the OVS user space
      can now translate the 'clone' action into kernel datapath 'sample'
      action, with 100% probability, to ensure that the clone semantics,
      which is that the packet seen by the clone action is the same as the
      packet seen by the action after clone, is faithfully carried out
      in the datapath.
      
      While the sample action in the datpath has the matching semantics,
      its implementation is only optimized for its original use.
      Specifically, there are two limitation: First, there is a 3 level of
      nesting restriction, enforced at the flow downloading time. This
      limit turns out to be too restrictive for the 'clone' use case.
      Second, the implementation avoid recursive call only if the sample
      action list has a single userspace action.
      
      The main optimization implemented in this series removes the static
      nesting limit check, instead, implement the run time recursion limit
      check, and recursion avoidance similar to that of the 'recirc' action.
      This optimization solve both #1 and #2 issues above.
      
      One related optimization attempts to avoid copying flow key as
      long as the actions enclosed does not change the flow key. The
      detection is performed only once at the flow downloading time.
      
      Another related optimization is to rewrite the action list
      at flow downloading time in order to save the fast path from parsing
      the sample action list in its original form repeatedly.
      
      Signed-off-by: default avatarAndy Zhou <azhou@ovn.org>
      Acked-by: default avatarPravin B Shelar <pshelar@ovn.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      798c1661
    • Josh Hunt's avatar
      sock: introduce SO_MEMINFO getsockopt · a2d133b1
      Josh Hunt authored
      
      
      Allows reading of SK_MEMINFO_VARS via socket option. This way an
      application can get all meminfo related information in single socket
      option call instead of multiple calls.
      
      Adds helper function, sk_get_meminfo(), and uses that for both
      getsockopt and sock_diag_put_meminfo().
      
      Suggested by Eric Dumazet.
      
      Signed-off-by: default avatarJosh Hunt <johunt@akamai.com>
      Reviewed-by: default avatarJason Baron <jbaron@akamai.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a2d133b1
  3. Mar 17, 2017
    • Soheil Hassas Yeganeh's avatar
      tcp: remove tcp_tw_recycle · 4396e461
      Soheil Hassas Yeganeh authored
      
      
      The tcp_tw_recycle was already broken for connections
      behind NAT, since the per-destination timestamp is not
      monotonically increasing for multiple machines behind
      a single destination address.
      
      After the randomization of TCP timestamp offsets
      in commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets
      for each connection), the tcp_tw_recycle is broken for all
      types of connections for the same reason: the timestamps
      received from a single machine is not monotonically increasing,
      anymore.
      
      Remove tcp_tw_recycle, since it is not functional. Also, remove
      the PAWSPassive SNMP counter since it is only used for
      tcp_tw_recycle, and simplify tcp_v4_route_req and tcp_v6_route_req
      since the strict argument is only set when tcp_tw_recycle is
      enabled.
      
      Signed-off-by: default avatarSoheil Hassas Yeganeh <soheil@google.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
      Cc: Lutz Vieweg <lvml@5t9.de>
      Cc: Florian Westphal <fw@strlen.de>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      4396e461
  4. Mar 15, 2017
  5. Mar 13, 2017
    • Robert Shearman's avatar
      mpls: allow TTL propagation from IP packets to be configured · a59166e4
      Robert Shearman authored
      
      
      Allow TTL propagation from IP packets to MPLS packets to be
      configured. Add a new optional LWT attribute, MPLS_IPTUNNEL_TTL, which
      allows the TTL to be set in the resulting MPLS packet, with the value
      of 0 having the semantics of enabling propagation of the TTL from the
      IP header (i.e. non-zero values disable propagation).
      
      Also allow the configuration to be overridden globally by reusing the
      same sysctl to control whether the TTL is propagated from IP packets
      into the MPLS header. If the per-LWT attribute is set then it
      overrides the global configuration. If the TTL isn't propagated then a
      default TTL value is used which can be configured via a new sysctl,
      "net.mpls.default_ttl". This is kept separate from the configuration
      of whether IP TTL propagation is enabled as it can be used in the
      future when non-IP payloads are supported (i.e. where there is no
      payload TTL that can be propagated).
      
      Signed-off-by: default avatarRobert Shearman <rshearma@brocade.com>
      Acked-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
      Tested-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a59166e4
    • Robert Shearman's avatar
      mpls: allow TTL propagation to IP packets to be configured · 5b441ac8
      Robert Shearman authored
      
      
      Provide the ability to control on a per-route basis whether the TTL
      value from an MPLS packet is propagated to an IPv4/IPv6 packet when
      the last label is popped as per the theoretical model in RFC 3443
      through a new route attribute, RTA_TTL_PROPAGATE which can be 0 to
      mean disable propagation and 1 to mean enable propagation.
      
      In order to provide the ability to change the behaviour for packets
      arriving with IPv4/IPv6 Explicit Null labels and to provide an easy
      way for a user to change the behaviour for all existing routes without
      having to reprogram them, a global knob is provided. This is done
      through the addition of a new per-namespace sysctl,
      "net.mpls.ip_ttl_propagate", which defaults to enabled. If the
      per-route attribute is set (either enabled or disabled) then it
      overrides the global configuration.
      
      Signed-off-by: default avatarRobert Shearman <rshearma@brocade.com>
      Acked-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
      Tested-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5b441ac8
    • Phil Sutter's avatar
      netfilter: nft_fib: Support existence check · 055c4b34
      Phil Sutter authored
      
      
      Instead of the actual interface index or name, set destination register
      to just 1 or 0 depending on whether the lookup succeeded or not if
      NFTA_FIB_F_PRESENT was set in userspace.
      
      Signed-off-by: default avatarPhil Sutter <phil@nwl.cc>
      Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
      055c4b34
    • Florian Westphal's avatar
      netfilter: nft_ct: add helper set support · 1a64edf5
      Florian Westphal authored
      
      
      this allows to assign connection tracking helpers to
      connections via nft objref infrastructure.
      
      The idea is to first specifiy a helper object:
      
       table ip filter {
          ct helper some-name {
            type "ftp"
            protocol tcp
            l3proto ip
          }
       }
      
      and then assign it via
      
      nft add ... ct helper set "some-name"
      
      helper assignment works for new conntracks only as we cannot expand the
      conntrack extension area once it has been committed to the main conntrack
      table.
      
      ipv4 and ipv6 protocols are tracked stored separately so
      we can also handle families that observe both ipv4 and ipv6 traffic.
      
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
      1a64edf5
    • Dmitry V. Levin's avatar
      uapi: fix drm/omap_drm.h userspace compilation errors · 337ba7fb
      Dmitry V. Levin authored
      
      
      Consistently use types from linux/types.h like in other uapi drm/*_drm.h
      header files to fix the following drm/omap_drm.h userspace compilation
      errors:
      
      /usr/include/drm/omap_drm.h:36:2: error: unknown type name 'uint64_t'
        uint64_t param;   /* in */
      /usr/include/drm/omap_drm.h:37:2: error: unknown type name 'uint64_t'
        uint64_t value;   /* in (set_param), out (get_param) */
      /usr/include/drm/omap_drm.h:56:2: error: unknown type name 'uint32_t'
        uint32_t bytes;  /* (for non-tiled formats) */
      /usr/include/drm/omap_drm.h:58:3: error: unknown type name 'uint16_t'
         uint16_t width;
      /usr/include/drm/omap_drm.h:59:3: error: unknown type name 'uint16_t'
         uint16_t height;
      /usr/include/drm/omap_drm.h:65:2: error: unknown type name 'uint32_t'
        uint32_t flags;   /* in */
      /usr/include/drm/omap_drm.h:66:2: error: unknown type name 'uint32_t'
        uint32_t handle;  /* out */
      /usr/include/drm/omap_drm.h:67:2: error: unknown type name 'uint32_t'
        uint32_t __pad;
      /usr/include/drm/omap_drm.h:77:2: error: unknown type name 'uint32_t'
        uint32_t handle;  /* buffer handle (in) */
      /usr/include/drm/omap_drm.h:78:2: error: unknown type name 'uint32_t'
        uint32_t op;   /* mask of omap_gem_op (in) */
      /usr/include/drm/omap_drm.h:82:2: error: unknown type name 'uint32_t'
        uint32_t handle;  /* buffer handle (in) */
      /usr/include/drm/omap_drm.h:83:2: error: unknown type name 'uint32_t'
        uint32_t op;   /* mask of omap_gem_op (in) */
      /usr/include/drm/omap_drm.h:88:2: error: unknown type name 'uint32_t'
        uint32_t nregions;
      /usr/include/drm/omap_drm.h:89:2: error: unknown type name 'uint32_t'
        uint32_t __pad;
      /usr/include/drm/omap_drm.h:93:2: error: unknown type name 'uint32_t'
        uint32_t handle;  /* buffer handle (in) */
      /usr/include/drm/omap_drm.h:94:2: error: unknown type name 'uint32_t'
        uint32_t pad;
      /usr/include/drm/omap_drm.h:95:2: error: unknown type name 'uint64_t'
        uint64_t offset;  /* mmap offset (out) */
      /usr/include/drm/omap_drm.h:102:2: error: unknown type name 'uint32_t'
        uint32_t size;   /* virtual size for mmap'ing (out) */
      /usr/include/drm/omap_drm.h:103:2: error: unknown type name 'uint32_t'
        uint32_t __pad;
      
      Fixes: ef6503e8 ("drm: Kbuild: add omap_drm.h to the installed headers")
      Signed-off-by: default avatarDmitry V. Levin <ldv@altlinux.org>
      Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
      337ba7fb
    • Xin Long's avatar
      sctp: add get and set sockopt for reconf_enable · c0d8bab6
      Xin Long authored
      
      
      This patchset is to add SCTP_RECONFIG_SUPPORTED sockopt, it would
      set and get asoc reconf_enable value when asoc_id is set, or it
      would set and get ep reconf_enalbe value if asoc_id is 0.
      
      It is also to add sysctl interface for users to set the default
      value for reconf_enable.
      
      After this patch, stream reconf will work.
      
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c0d8bab6
    • Xin Long's avatar
      sctp: add support for generating add stream change event notification · b444153f
      Xin Long authored
      
      
      This patch is to add Stream Change Event described in rfc6525
      section 6.1.3.
      
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b444153f
    • Xin Long's avatar
      sctp: add support for generating assoc reset event notification · c95129d1
      Xin Long authored
      
      
      This patch is to add Association Reset Event described in rfc6525
      section 6.1.2.
      
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c95129d1
    • Jiri Kosina's avatar
      net: sched: make default fifo qdiscs appear in the dump · 49b49971
      Jiri Kosina authored
      The original reason [1] for having hidden qdiscs (potential scalability
      issues in qdisc_match_from_root() with single linked list in case of large
      amount of qdiscs) has been invalidated by 59cc1f61 ("net: sched: convert
      qdisc linked list to hashtable").
      
      This allows us for bringing more clarity and determinism into the dump by
      making default pfifo qdiscs visible.
      
      We're not turning this on by default though, at it was deemed [2] too
      intrusive / unnecessary change of default behavior towards userspace.
      Instead, TCA_DUMP_INVISIBLE netlink attribute is introduced, which allows
      applications to request complete qdisc hierarchy dump, including the
      ones that have always been implicit/invisible.
      
      Singleton noop_qdisc stays invisible, as teaching the whole infrastructure
      about singletons would require quite some surgery with very little gain
      (seeing no qdisc or seeing noop qdisc in the dump is probably setting
      the same user expectation).
      
      [1] http://lkml.kernel.org/r/1460732328.10638.74.camel@edumazet-glaptop3.roam.corp.google.com
      [2] http://lkml.kernel.org/r/20161021.105935.1907696543877061916.davem@davemloft.net
      
      
      
      Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      49b49971
  6. Mar 10, 2017
    • Andrea Arcangeli's avatar
      userfaultfd: non-cooperative: rollback userfaultfd_exit · dd0db88d
      Andrea Arcangeli authored
      Patch series "userfaultfd non-cooperative further update for 4.11 merge
      window".
      
      Unfortunately I noticed one relevant bug in userfaultfd_exit while doing
      more testing.  I've been doing testing before and this was also tested
      by kbuild bot and exercised by the selftest, but this bug never
      reproduced before.
      
      I dropped userfaultfd_exit as result.  I dropped it because of
      implementation difficulty in receiving signals in __mmput and because I
      think -ENOSPC as result from the background UFFDIO_COPY should be enough
      already.
      
      Before I decided to remove userfaultfd_exit, I noticed userfaultfd_exit
      wasn't exercised by the selftest and when I tried to exercise it, after
      moving it to a more correct place in __mmput where it would make more
      sense and where the vma list is stable, it resulted in the
      event_wait_completion in D state.  So then I added the second patch to
      be sure even if we call userfaultfd_event_wait_completion too late
      during task exit(), we won't risk to generate tasks in D state.  The
      same check exists in handle_userfault() for the same reason, except it
      makes a difference there, while here is just a robustness check and it's
      run under WARN_ON_ONCE.
      
      While looking at the userfaultfd_event_wait_completion() function I
      looked back at its callers too while at it and I think it's not ok to
      stop executing dup_fctx on the fcs list because we relay on
      userfaultfd_event_wait_completion to execute
      userfaultfd_ctx_put(fctx->orig) which is paired against
      userfaultfd_ctx_get(fctx->orig) in dup_userfault just before
      list_add(fcs).  This change only takes care of fctx->orig but this area
      also needs further review looking for similar problems in fctx->new.
      
      The only patch that is urgent is the first because it's an use after
      free during a SMP race condition that affects all processes if
      CONFIG_USERFAULTFD=y.  Very hard to reproduce though and probably
      impossible without SLUB poisoning enabled.
      
      This patch (of 3):
      
      I once reproduced this oops with the userfaultfd selftest, it's not
      easily reproducible and it requires SLUB poisoning to reproduce.
      
          general protection fault: 0000 [#1] SMP
          Modules linked in:
          CPU: 2 PID: 18421 Comm: userfaultfd Tainted: G               ------------ T 3.10.0+ #15
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
          task: ffff8801f83b9440 ti: ffff8801f833c000 task.ti: ffff8801f833c000
          RIP: 0010:[<ffffffff81451299>]  [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0
          RSP: 0018:ffff8801f833fe80  EFLAGS: 00010202
          RAX: ffff8801f833ffd8 RBX: 6b6b6b6b6b6b6b6b RCX: ffff8801f83b9440
          RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800baf18600
          RBP: ffff8801f833fee8 R08: 0000000000000000 R09: 0000000000000001
          R10: 0000000000000000 R11: ffffffff8127ceb3 R12: 0000000000000000
          R13: ffff8800baf186b0 R14: ffff8801f83b99f8 R15: 00007faed746c700
          FS:  0000000000000000(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000
          CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
          CR2: 00007faf0966f028 CR3: 0000000001bc6000 CR4: 00000000000006e0
          DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
          DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
          Call Trace:
            do_exit+0x297/0xd10
            SyS_exit+0x17/0x20
            tracesys+0xdd/0xe2
          Code: 00 00 66 66 66 66 90 55 48 89 e5 41 54 53 48 83 ec 58 48 8b 1f 48 85 db 75 11 eb 73 66 0f 1f 44 00 00 48 8b 5b 10 48 85 db 74 64 <4c> 8b a3 b8 00 00 00 4d 85 e4 74 eb 41 f6 84 24 2c 01 00 00 80
          RIP  [<ffffffff81451299>] userfaultfd_exit+0x29/0xa0
           RSP <ffff8801f833fe80>
          ---[ end trace 9fecd6dcb442846a ]---
      
      In the debugger I located the "mm" pointer in the stack and walking
      mm->mmap->vm_next through the end shows the vma->vm_next list is fully
      consistent and it is null terminated list as expected.  So this has to
      be an SMP race condition where userfaultfd_exit was running while the
      vma list was being modified by another CPU.
      
      When userfaultfd_exit() run one of the ->vm_next pointers pointed to
      SLAB_POISON (RBX is the vma pointer and is 0x6b6b..).
      
      The reason is that it's not running in __mmput but while there are still
      other threads running and it's not holding the mmap_sem (it can't as it
      has to wait the even to be received by the manager).  So this is an use
      after free that was happening for all processes.
      
      One more implementation problem aside from the race condition:
      userfaultfd_exit has really to check a flag in mm->flags before walking
      the vma or it's going to slowdown the exit() path for regular tasks.
      
      One more implementation problem: at that point signals can't be
      delivered so it would also create a task in D state if the manager
      doesn't read the event.
      
      The major design issue: it overall looks superfluous as the manager can
      check for -ENOSPC in the background transfer:
      
      	if (mmget_not_zero(ctx->mm)) {
      [..]
      	} else {
      		return -ENOSPC;
      	}
      
      It's safer to roll it back and re-introduce it later if at all.
      
      [rppt@linux.vnet.ibm.com: documentation fixup after removal of UFFD_EVENT_EXIT]
        Link: http://lkml.kernel.org/r/1488345437-4364-1-git-send-email-rppt@linux.vnet.ibm.com
      Link: http://lkml.kernel.org/r/20170224181957.19736-2-aarcange@redhat.com
      
      
      Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
      Signed-off-by: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
      Acked-by: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
      Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
      Cc: Mike Kravetz <mike.kravetz@oracle.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dd0db88d
  7. Mar 09, 2017
  8. Mar 07, 2017
  9. Mar 06, 2017
    • Laura Garcia Liebana's avatar
      netfilter: nft_hash: support of symmetric hash · 3206cade
      Laura Garcia Liebana authored
      
      
      This patch provides symmetric hash support according to source
      ip address and port, and destination ip address and port.
      
      For this purpose, the __skb_get_hash_symmetric() is used to
      identify the flow as it uses FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL
      flag by default.
      
      The new attribute NFTA_HASH_TYPE has been included to support
      different types of hashing functions. Currently supported
      NFT_HASH_JENKINS through jhash and NFT_HASH_SYM through symhash.
      
      The main difference between both types are:
       - jhash requires an expression with sreg, symhash doesn't.
       - symhash supports modulus and offset, but not seed.
      
      Examples:
      
       nft add rule ip nat prerouting ct mark set jhash ip saddr mod 2
       nft add rule ip nat prerouting ct mark set symhash mod 2
      
      By default, jenkins hash will be used if no hash type is
      provided for compatibility reasons.
      
      Signed-off-by: default avatarLaura Garcia Liebana <laura.garcia@zevenet.com>
      Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
      3206cade
  10. Mar 03, 2017
    • David Howells's avatar
      statx: Add a system call to make enhanced file info available · a528d35e
      David Howells authored
      
      
      Add a system call to make extended file information available, including
      file creation and some attribute flags where available through the
      underlying filesystem.
      
      The getattr inode operation is altered to take two additional arguments: a
      u32 request_mask and an unsigned int flags that indicate the
      synchronisation mode.  This change is propagated to the vfs_getattr*()
      function.
      
      Functions like vfs_stat() are now inline wrappers around new functions
      vfs_statx() and vfs_statx_fd() to reduce stack usage.
      
      ========
      OVERVIEW
      ========
      
      The idea was initially proposed as a set of xattrs that could be retrieved
      with getxattr(), but the general preference proved to be for a new syscall
      with an extended stat structure.
      
      A number of requests were gathered for features to be included.  The
      following have been included:
      
       (1) Make the fields a consistent size on all arches and make them large.
      
       (2) Spare space, request flags and information flags are provided for
           future expansion.
      
       (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
           __s64).
      
       (4) Creation time: The SMB protocol carries the creation time, which could
           be exported by Samba, which will in turn help CIFS make use of
           FS-Cache as that can be used for coherency data (stx_btime).
      
           This is also specified in NFSv4 as a recommended attribute and could
           be exported by NFSD [Steve French].
      
       (5) Lightweight stat: Ask for just those details of interest, and allow a
           netfs (such as NFS) to approximate anything not of interest, possibly
           without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
           Dilger] (AT_STATX_DONT_SYNC).
      
       (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
           its cached attributes are up to date [Trond Myklebust]
           (AT_STATX_FORCE_SYNC).
      
      And the following have been left out for future extension:
      
       (7) Data version number: Could be used by userspace NFS servers [Aneesh
           Kumar].
      
           Can also be used to modify fill_post_wcc() in NFSD which retrieves
           i_version directly, but has just called vfs_getattr().  It could get
           it from the kstat struct if it used vfs_xgetattr() instead.
      
           (There's disagreement on the exact semantics of a single field, since
           not all filesystems do this the same way).
      
       (8) BSD stat compatibility: Including more fields from the BSD stat such
           as creation time (st_btime) and inode generation number (st_gen)
           [Jeremy Allison, Bernd Schubert].
      
       (9) Inode generation number: Useful for FUSE and userspace NFS servers
           [Bernd Schubert].
      
           (This was asked for but later deemed unnecessary with the
           open-by-handle capability available and caused disagreement as to
           whether it's a security hole or not).
      
      (10) Extra coherency data may be useful in making backups [Andreas Dilger].
      
           (No particular data were offered, but things like last backup
           timestamp, the data version number and the DOS archive bit would come
           into this category).
      
      (11) Allow the filesystem to indicate what it can/cannot provide: A
           filesystem can now say it doesn't support a standard stat feature if
           that isn't available, so if, for instance, inode numbers or UIDs don't
           exist or are fabricated locally...
      
           (This requires a separate system call - I have an fsinfo() call idea
           for this).
      
      (12) Store a 16-byte volume ID in the superblock that can be returned in
           struct xstat [Steve French].
      
           (Deferred to fsinfo).
      
      (13) Include granularity fields in the time data to indicate the
           granularity of each of the times (NFSv4 time_delta) [Steve French].
      
           (Deferred to fsinfo).
      
      (14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
           Note that the Linux IOC flags are a mess and filesystems such as Ext4
           define flags that aren't in linux/fs.h, so translation in the kernel
           may be a necessity (or, possibly, we provide the filesystem type too).
      
           (Some attributes are made available in stx_attributes, but the general
           feeling was that the IOC flags were to ext[234]-specific and shouldn't
           be exposed through statx this way).
      
      (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
           Michael Kerrisk].
      
           (Deferred, probably to fsinfo.  Finding out if there's an ACL or
           seclabal might require extra filesystem operations).
      
      (16) Femtosecond-resolution timestamps [Dave Chinner].
      
           (A __reserved field has been left in the statx_timestamp struct for
           this - if there proves to be a need).
      
      (17) A set multiple attributes syscall to go with this.
      
      ===============
      NEW SYSTEM CALL
      ===============
      
      The new system call is:
      
      	int ret = statx(int dfd,
      			const char *filename,
      			unsigned int flags,
      			unsigned int mask,
      			struct statx *buffer);
      
      The dfd, filename and flags parameters indicate the file to query, in a
      similar way to fstatat().  There is no equivalent of lstat() as that can be
      emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
      also no equivalent of fstat() as that can be emulated by passing a NULL
      filename to statx() with the fd of interest in dfd.
      
      Whether or not statx() synchronises the attributes with the backing store
      can be controlled by OR'ing a value into the flags argument (this typically
      only affects network filesystems):
      
       (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
           respect.
      
       (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
           its attributes with the server - which might require data writeback to
           occur to get the timestamps correct.
      
       (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
           network filesystem.  The resulting values should be considered
           approximate.
      
      mask is a bitmask indicating the fields in struct statx that are of
      interest to the caller.  The user should set this to STATX_BASIC_STATS to
      get the basic set returned by stat().  It should be noted that asking for
      more information may entail extra I/O operations.
      
      buffer points to the destination for the data.  This must be 256 bytes in
      size.
      
      ======================
      MAIN ATTRIBUTES RECORD
      ======================
      
      The following structures are defined in which to return the main attribute
      set:
      
      	struct statx_timestamp {
      		__s64	tv_sec;
      		__s32	tv_nsec;
      		__s32	__reserved;
      	};
      
      	struct statx {
      		__u32	stx_mask;
      		__u32	stx_blksize;
      		__u64	stx_attributes;
      		__u32	stx_nlink;
      		__u32	stx_uid;
      		__u32	stx_gid;
      		__u16	stx_mode;
      		__u16	__spare0[1];
      		__u64	stx_ino;
      		__u64	stx_size;
      		__u64	stx_blocks;
      		__u64	__spare1[1];
      		struct statx_timestamp	stx_atime;
      		struct statx_timestamp	stx_btime;
      		struct statx_timestamp	stx_ctime;
      		struct statx_timestamp	stx_mtime;
      		__u32	stx_rdev_major;
      		__u32	stx_rdev_minor;
      		__u32	stx_dev_major;
      		__u32	stx_dev_minor;
      		__u64	__spare2[14];
      	};
      
      The defined bits in request_mask and stx_mask are:
      
      	STATX_TYPE		Want/got stx_mode & S_IFMT
      	STATX_MODE		Want/got stx_mode & ~S_IFMT
      	STATX_NLINK		Want/got stx_nlink
      	STATX_UID		Want/got stx_uid
      	STATX_GID		Want/got stx_gid
      	STATX_ATIME		Want/got stx_atime{,_ns}
      	STATX_MTIME		Want/got stx_mtime{,_ns}
      	STATX_CTIME		Want/got stx_ctime{,_ns}
      	STATX_INO		Want/got stx_ino
      	STATX_SIZE		Want/got stx_size
      	STATX_BLOCKS		Want/got stx_blocks
      	STATX_BASIC_STATS	[The stuff in the normal stat struct]
      	STATX_BTIME		Want/got stx_btime{,_ns}
      	STATX_ALL		[All currently available stuff]
      
      stx_btime is the file creation time, stx_mask is a bitmask indicating the
      data provided and __spares*[] are where as-yet undefined fields can be
      placed.
      
      Time fields are structures with separate seconds and nanoseconds fields
      plus a reserved field in case we want to add even finer resolution.  Note
      that times will be negative if before 1970; in such a case, the nanosecond
      fields will also be negative if not zero.
      
      The bits defined in the stx_attributes field convey information about a
      file, how it is accessed, where it is and what it does.  The following
      attributes map to FS_*_FL flags and are the same numerical value:
      
      	STATX_ATTR_COMPRESSED		File is compressed by the fs
      	STATX_ATTR_IMMUTABLE		File is marked immutable
      	STATX_ATTR_APPEND		File is append-only
      	STATX_ATTR_NODUMP		File is not to be dumped
      	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs
      
      Within the kernel, the supported flags are listed by:
      
      	KSTAT_ATTR_FS_IOC_FLAGS
      
      [Are any other IOC flags of sufficient general interest to be exposed
      through this interface?]
      
      New flags include:
      
      	STATX_ATTR_AUTOMOUNT		Object is an automount trigger
      
      These are for the use of GUI tools that might want to mark files specially,
      depending on what they are.
      
      Fields in struct statx come in a number of classes:
      
       (0) stx_dev_*, stx_blksize.
      
           These are local system information and are always available.
      
       (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
           stx_size, stx_blocks.
      
           These will be returned whether the caller asks for them or not.  The
           corresponding bits in stx_mask will be set to indicate whether they
           actually have valid values.
      
           If the caller didn't ask for them, then they may be approximated.  For
           example, NFS won't waste any time updating them from the server,
           unless as a byproduct of updating something requested.
      
           If the values don't actually exist for the underlying object (such as
           UID or GID on a DOS file), then the bit won't be set in the stx_mask,
           even if the caller asked for the value.  In such a case, the returned
           value will be a fabrication.
      
           Note that there are instances where the type might not be valid, for
           instance Windows reparse points.
      
       (2) stx_rdev_*.
      
           This will be set only if stx_mode indicates we're looking at a
           blockdev or a chardev, otherwise will be 0.
      
       (3) stx_btime.
      
           Similar to (1), except this will be set to 0 if it doesn't exist.
      
      =======
      TESTING
      =======
      
      The following test program can be used to test the statx system call:
      
      	samples/statx/test-statx.c
      
      Just compile and run, passing it paths to the files you want to examine.
      The file is built automatically if CONFIG_SAMPLES is enabled.
      
      Here's some example output.  Firstly, an NFS directory that crosses to
      another FSID.  Note that the AUTOMOUNT attribute is set because transiting
      this directory will cause d_automount to be invoked by the VFS.
      
      	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
      	statx(/warthog/data) = 0
      	results=7ff
      	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
      	Device: 00:26           Inode: 1703937     Links: 125
      	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
      	Access: 2016-11-24 09:02:12.219699527+0000
      	Modify: 2016-11-17 10:44:36.225653653+0000
      	Change: 2016-11-17 10:44:36.225653653+0000
      	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
      
      Secondly, the result of automounting on that directory.
      
      	[root@andromeda ~]# /tmp/test-statx /warthog/data
      	statx(/warthog/data) = 0
      	results=7ff
      	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
      	Device: 00:27           Inode: 2           Links: 125
      	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
      	Access: 2016-11-24 09:02:12.219699527+0000
      	Modify: 2016-11-17 10:44:36.225653653+0000
      	Change: 2016-11-17 10:44:36.225653653+0000
      
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      a528d35e
  11. Mar 02, 2017
  12. Feb 28, 2017
  13. Feb 27, 2017
  14. Feb 25, 2017
  15. Feb 23, 2017
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