1. 31 Jan, 2019 28 commits
  2. 26 Jan, 2019 12 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.9.153 · 189b75ad
      Greg Kroah-Hartman authored
      189b75ad
    • Dave Airlie's avatar
      locking/qspinlock: Pull in asm/byteorder.h to ensure correct endianness · 4b527f25
      Dave Airlie authored
      This commit is not required upstream, but is required for the 4.9.y
      stable series.
      
      Upstream commit 101110f6 ("Kbuild: always define endianess in
      kconfig.h") ensures that either __LITTLE_ENDIAN or __BIG_ENDIAN is
      defined to reflect the endianness of the target CPU architecture
      regardless of whether or not <asm/byteorder.h> has been #included. The
      upstream definition of 'struct qspinlock' relies on this property.
      
      Unfortunately, the 4.9.y stable series does not provide this guarantee,
      so the 'spin_unlock()' routine can erroneously treat the underlying
      lockword as big-endian on little-endian architectures using native
      qspinlock (i.e. x86_64 without PV) if the caller has not included
      <asm/byteorder.h>. This can lead to hangs such as the one in
      'i915_gem_request()' reported via bugzilla:
      
        https://bugzilla.kernel.org/show_bug.cgi?id=202063
      
      Fix the issue by ensuring that <asm/byteorder.h> is #included in
      <asm/qspinlock_types.h>, where 'struct qspinlock' is defined.
      
      Cc: <stable@vger.kernel.org> # 4.9
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      [will: wrote commit message]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4b527f25
    • Corey Minyard's avatar
      ipmi:ssif: Fix handling of multi-part return messages · cac2590d
      Corey Minyard authored
      commit 7d6380cd upstream.
      
      The block number was not being compared right, it was off by one
      when checking the response.
      
      Some statistics wouldn't be incremented properly in some cases.
      
      Check to see if that middle-part messages always have 31 bytes of
      data.
      Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
      Cc: stable@vger.kernel.org # 4.4
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cac2590d
    • Michal Hocko's avatar
      mm, proc: be more verbose about unstable VMA flags in /proc/<pid>/smaps · 28aeb4c9
      Michal Hocko authored
      [ Upstream commit 7550c607 ]
      
      Patch series "THP eligibility reporting via proc".
      
      This series of three patches aims at making THP eligibility reporting much
      more robust and long term sustainable.  The trigger for the change is a
      regression report [2] and the long follow up discussion.  In short the
      specific application didn't have good API to query whether a particular
      mapping can be backed by THP so it has used VMA flags to workaround that.
      These flags represent a deep internal state of VMAs and as such they
      should be used by userspace with a great deal of caution.
      
      A similar has happened for [3] when users complained that VM_MIXEDMAP is
      no longer set on DAX mappings.  Again a lack of a proper API led to an
      abuse.
      
      The first patch in the series tries to emphasise that that the semantic of
      flags might change and any application consuming those should be really
      careful.
      
      The remaining two patches provide a more suitable interface to address [2]
      and provide a consistent API to query the THP status both for each VMA and
      process wide as well.  [1]
      
      http://lkml.kernel.org/r/20181120103515.25280-1-mhocko@kernel.org [2]
      http://lkml.kernel.org/r/http://lkml.kernel.org/r/alpine.DEB.2.21.1809241054050.224429@chino.kir.corp.google.com
      [3] http://lkml.kernel.org/r/20181002100531.GC4135@quack2.suse.cz
      
      This patch (of 3):
      
      Even though vma flags exported via /proc/<pid>/smaps are explicitly
      documented to be not guaranteed for future compatibility the warning
      doesn't go far enough because it doesn't mention semantic changes to those
      flags.  And they are important as well because these flags are a deep
      implementation internal to the MM code and the semantic might change at
      any time.
      
      Let's consider two recent examples:
      http://lkml.kernel.org/r/20181002100531.GC4135@quack2.suse.cz
      : commit e1fb4a08 "dax: remove VM_MIXEDMAP for fsdax and device dax" has
      : removed VM_MIXEDMAP flag from DAX VMAs. Now our testing shows that in the
      : mean time certain customer of ours started poking into /proc/<pid>/smaps
      : and looks at VMA flags there and if VM_MIXEDMAP is missing among the VMA
      : flags, the application just fails to start complaining that DAX support is
      : missing in the kernel.
      
      http://lkml.kernel.org/r/alpine.DEB.2.21.1809241054050.224429@chino.kir.corp.google.com
      : Commit 18600332 ("mm: make PR_SET_THP_DISABLE immediately active")
      : introduced a regression in that userspace cannot always determine the set
      : of vmas where thp is ineligible.
      : Userspace relies on the "nh" flag being emitted as part of /proc/pid/smaps
      : to determine if a vma is eligible to be backed by hugepages.
      : Previous to this commit, prctl(PR_SET_THP_DISABLE, 1) would cause thp to
      : be disabled and emit "nh" as a flag for the corresponding vmas as part of
      : /proc/pid/smaps.  After the commit, thp is disabled by means of an mm
      : flag and "nh" is not emitted.
      : This causes smaps parsing libraries to assume a vma is eligible for thp
      : and ends up puzzling the user on why its memory is not backed by thp.
      
      In both cases userspace was relying on a semantic of a specific VMA flag.
      The primary reason why that happened is a lack of a proper interface.
      While this has been worked on and it will be fixed properly, it seems that
      our wording could see some refinement and be more vocal about semantic
      aspect of these flags as well.
      
      Link: http://lkml.kernel.org/r/20181211143641.3503-2-mhocko@kernel.orgSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarJan Kara <jack@suse.cz>
      Acked-by: default avatarDan Williams <dan.j.williams@intel.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Acked-by: default avatarMike Rapoport <rppt@linux.ibm.com>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Paul Oppenheimer <bepvte@gmail.com>
      Cc: William Kucharski <william.kucharski@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      28aeb4c9
    • Brian Foster's avatar
      mm/page-writeback.c: don't break integrity writeback on ->writepage() error · c6e4be62
      Brian Foster authored
      [ Upstream commit 3fa750dc ]
      
      write_cache_pages() is used in both background and integrity writeback
      scenarios by various filesystems.  Background writeback is mostly
      concerned with cleaning a certain number of dirty pages based on various
      mm heuristics.  It may not write the full set of dirty pages or wait for
      I/O to complete.  Integrity writeback is responsible for persisting a set
      of dirty pages before the writeback job completes.  For example, an
      fsync() call must perform integrity writeback to ensure data is on disk
      before the call returns.
      
      write_cache_pages() unconditionally breaks out of its processing loop in
      the event of a ->writepage() error.  This is fine for background
      writeback, which had no strict requirements and will eventually come
      around again.  This can cause problems for integrity writeback on
      filesystems that might need to clean up state associated with failed page
      writeouts.  For example, XFS performs internal delayed allocation
      accounting before returning a ->writepage() error, where applicable.  If
      the current writeback happens to be associated with an unmount and
      write_cache_pages() completes the writeback prematurely due to error, the
      filesystem is unmounted in an inconsistent state if dirty+delalloc pages
      still exist.
      
      To handle this problem, update write_cache_pages() to always process the
      full set of pages for integrity writeback regardless of ->writepage()
      errors.  Save the first encountered error and return it to the caller once
      complete.  This facilitates XFS (or any other fs that expects integrity
      writeback to process the entire set of dirty pages) to clean up its
      internal state completely in the event of persistent mapping errors.
      Background writeback continues to exit on the first error encountered.
      
      [akpm@linux-foundation.org: fix typo in comment]
      Link: http://lkml.kernel.org/r/20181116134304.32440-1-bfoster@redhat.comSigned-off-by: default avatarBrian Foster <bfoster@redhat.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      c6e4be62
    • Junxiao Bi's avatar
      ocfs2: fix panic due to unrecovered local alloc · 3cc44695
      Junxiao Bi authored
      [ Upstream commit 532e1e54 ]
      
      mount.ocfs2 ignore the inconsistent error that journal is clean but
      local alloc is unrecovered.  After mount, local alloc not empty, then
      reserver cluster didn't alloc a new local alloc window, reserveration
      map is empty(ocfs2_reservation_map.m_bitmap_len = 0), that triggered the
      following panic.
      
      This issue was reported at
      
        https://oss.oracle.com/pipermail/ocfs2-devel/2015-May/010854.html
      
      and was advised to fixed during mount.  But this is a very unusual
      inconsistent state, usually journal dirty flag should be cleared at the
      last stage of umount until every other things go right.  We may need do
      further debug to check that.  Any way to avoid possible futher
      corruption, mount should be abort and fsck should be run.
      
        (mount.ocfs2,1765,1):ocfs2_load_local_alloc:353 ERROR: Local alloc hasn't been recovered!
        found = 6518, set = 6518, taken = 8192, off = 15912372
        ocfs2: Mounting device (202,64) on (node 0, slot 3) with ordered data mode.
        o2dlm: Joining domain 89CEAC63CC4F4D03AC185B44E0EE0F3F ( 0 1 2 3 4 5 6 8 ) 8 nodes
        ocfs2: Mounting device (202,80) on (node 0, slot 3) with ordered data mode.
        o2hb: Region 89CEAC63CC4F4D03AC185B44E0EE0F3F (xvdf) is now a quorum device
        o2net: Accepted connection from node yvwsoa17p (num 7) at 172.22.77.88:7777
        o2dlm: Node 7 joins domain 64FE421C8C984E6D96ED12C55FEE2435 ( 0 1 2 3 4 5 6 7 8 ) 9 nodes
        o2dlm: Node 7 joins domain 89CEAC63CC4F4D03AC185B44E0EE0F3F ( 0 1 2 3 4 5 6 7 8 ) 9 nodes
        ------------[ cut here ]------------
        kernel BUG at fs/ocfs2/reservations.c:507!
        invalid opcode: 0000 [#1] SMP
        Modules linked in: ocfs2 rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs fscache lockd grace ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sunrpc ipt_REJECT nf_reject_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 ovmapi ppdev parport_pc parport xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea acpi_cpufreq pcspkr i2c_piix4 i2c_core sg ext4 jbd2 mbcache2 sr_mod cdrom xen_blkfront pata_acpi ata_generic ata_piix floppy dm_mirror dm_region_hash dm_log dm_mod
        CPU: 0 PID: 4349 Comm: startWebLogic.s Not tainted 4.1.12-124.19.2.el6uek.x86_64 #2
        Hardware name: Xen HVM domU, BIOS 4.4.4OVM 09/06/2018
        task: ffff8803fb04e200 ti: ffff8800ea4d8000 task.ti: ffff8800ea4d8000
        RIP: 0010:[<ffffffffa05e96a8>]  [<ffffffffa05e96a8>] __ocfs2_resv_find_window+0x498/0x760 [ocfs2]
        Call Trace:
          ocfs2_resmap_resv_bits+0x10d/0x400 [ocfs2]
          ocfs2_claim_local_alloc_bits+0xd0/0x640 [ocfs2]
          __ocfs2_claim_clusters+0x178/0x360 [ocfs2]
          ocfs2_claim_clusters+0x1f/0x30 [ocfs2]
          ocfs2_convert_inline_data_to_extents+0x634/0xa60 [ocfs2]
          ocfs2_write_begin_nolock+0x1c6/0x1da0 [ocfs2]
          ocfs2_write_begin+0x13e/0x230 [ocfs2]
          generic_perform_write+0xbf/0x1c0
          __generic_file_write_iter+0x19c/0x1d0
          ocfs2_file_write_iter+0x589/0x1360 [ocfs2]
          __vfs_write+0xb8/0x110
          vfs_write+0xa9/0x1b0
          SyS_write+0x46/0xb0
          system_call_fastpath+0x18/0xd7
        Code: ff ff 8b 75 b8 39 75 b0 8b 45 c8 89 45 98 0f 84 e5 fe ff ff 45 8b 74 24 18 41 8b 54 24 1c e9 56 fc ff ff 85 c0 0f 85 48 ff ff ff <0f> 0b 48 8b 05 cf c3 de ff 48 ba 00 00 00 00 00 00 00 10 48 85
        RIP   __ocfs2_resv_find_window+0x498/0x760 [ocfs2]
         RSP <ffff8800ea4db668>
        ---[ end trace 566f07529f2edf3c ]---
        Kernel panic - not syncing: Fatal exception
        Kernel Offset: disabled
      
      Link: http://lkml.kernel.org/r/20181121020023.3034-2-junxiao.bi@oracle.comSigned-off-by: default avatarJunxiao Bi <junxiao.bi@oracle.com>
      Reviewed-by: default avatarYiwen Jiang <jiangyiwen@huawei.com>
      Acked-by: default avatarJoseph Qi <jiangqi903@gmail.com>
      Cc: Jun Piao <piaojun@huawei.com>
      Cc: Mark Fasheh <mfasheh@versity.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Changwei Ge <ge.changwei@h3c.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      3cc44695
    • Qian Cai's avatar
      scsi: megaraid: fix out-of-bound array accesses · 7e4c9c47
      Qian Cai authored
      [ Upstream commit c7a082e4 ]
      
      UBSAN reported those with MegaRAID SAS-3 3108,
      
      [   77.467308] UBSAN: Undefined behaviour in drivers/scsi/megaraid/megaraid_sas_fp.c:117:32
      [   77.475402] index 255 is out of range for type 'MR_LD_SPAN_MAP [1]'
      [   77.481677] CPU: 16 PID: 333 Comm: kworker/16:1 Not tainted 4.20.0-rc5+ #1
      [   77.488556] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.50 06/01/2018
      [   77.495791] Workqueue: events work_for_cpu_fn
      [   77.500154] Call trace:
      [   77.502610]  dump_backtrace+0x0/0x2c8
      [   77.506279]  show_stack+0x24/0x30
      [   77.509604]  dump_stack+0x118/0x19c
      [   77.513098]  ubsan_epilogue+0x14/0x60
      [   77.516765]  __ubsan_handle_out_of_bounds+0xfc/0x13c
      [   77.521767]  mr_update_load_balance_params+0x150/0x158 [megaraid_sas]
      [   77.528230]  MR_ValidateMapInfo+0x2cc/0x10d0 [megaraid_sas]
      [   77.533825]  megasas_get_map_info+0x244/0x2f0 [megaraid_sas]
      [   77.539505]  megasas_init_adapter_fusion+0x9b0/0xf48 [megaraid_sas]
      [   77.545794]  megasas_init_fw+0x1ab4/0x3518 [megaraid_sas]
      [   77.551212]  megasas_probe_one+0x2c4/0xbe0 [megaraid_sas]
      [   77.556614]  local_pci_probe+0x7c/0xf0
      [   77.560365]  work_for_cpu_fn+0x34/0x50
      [   77.564118]  process_one_work+0x61c/0xf08
      [   77.568129]  worker_thread+0x534/0xa70
      [   77.571882]  kthread+0x1c8/0x1d0
      [   77.575114]  ret_from_fork+0x10/0x1c
      
      [   89.240332] UBSAN: Undefined behaviour in drivers/scsi/megaraid/megaraid_sas_fp.c:117:32
      [   89.248426] index 255 is out of range for type 'MR_LD_SPAN_MAP [1]'
      [   89.254700] CPU: 16 PID: 95 Comm: kworker/u130:0 Not tainted 4.20.0-rc5+ #1
      [   89.261665] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.50 06/01/2018
      [   89.268903] Workqueue: events_unbound async_run_entry_fn
      [   89.274222] Call trace:
      [   89.276680]  dump_backtrace+0x0/0x2c8
      [   89.280348]  show_stack+0x24/0x30
      [   89.283671]  dump_stack+0x118/0x19c
      [   89.287167]  ubsan_epilogue+0x14/0x60
      [   89.290835]  __ubsan_handle_out_of_bounds+0xfc/0x13c
      [   89.295828]  MR_LdRaidGet+0x50/0x58 [megaraid_sas]
      [   89.300638]  megasas_build_io_fusion+0xbb8/0xd90 [megaraid_sas]
      [   89.306576]  megasas_build_and_issue_cmd_fusion+0x138/0x460 [megaraid_sas]
      [   89.313468]  megasas_queue_command+0x398/0x3d0 [megaraid_sas]
      [   89.319222]  scsi_dispatch_cmd+0x1dc/0x8a8
      [   89.323321]  scsi_request_fn+0x8e8/0xdd0
      [   89.327249]  __blk_run_queue+0xc4/0x158
      [   89.331090]  blk_execute_rq_nowait+0xf4/0x158
      [   89.335449]  blk_execute_rq+0xdc/0x158
      [   89.339202]  __scsi_execute+0x130/0x258
      [   89.343041]  scsi_probe_and_add_lun+0x2fc/0x1488
      [   89.347661]  __scsi_scan_target+0x1cc/0x8c8
      [   89.351848]  scsi_scan_channel.part.3+0x8c/0xc0
      [   89.356382]  scsi_scan_host_selected+0x130/0x1f0
      [   89.361002]  do_scsi_scan_host+0xd8/0xf0
      [   89.364927]  do_scan_async+0x9c/0x320
      [   89.368594]  async_run_entry_fn+0x138/0x420
      [   89.372780]  process_one_work+0x61c/0xf08
      [   89.376793]  worker_thread+0x13c/0xa70
      [   89.380546]  kthread+0x1c8/0x1d0
      [   89.383778]  ret_from_fork+0x10/0x1c
      
      This is because when populating Driver Map using firmware raid map, all
      non-existing VDs set their ldTgtIdToLd to 0xff, so it can be skipped later.
      
      From drivers/scsi/megaraid/megaraid_sas_base.c ,
      memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
      
      From drivers/scsi/megaraid/megaraid_sas_fp.c ,
      /* For non existing VDs, iterate to next VD*/
      if (ld >= (MAX_LOGICAL_DRIVES_EXT - 1))
      	continue;
      
      However, there are a few places that failed to skip those non-existing VDs
      due to off-by-one errors. Then, those 0xff leaked into MR_LdRaidGet(0xff,
      map) and triggered the out-of-bound accesses.
      
      Fixes: 51087a86 ("megaraid_sas : Extended VD support")
      Signed-off-by: default avatarQian Cai <cai@lca.pw>
      Acked-by: default avatarSumit Saxena <sumit.saxena@broadcom.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      7e4c9c47
    • Kevin Barnett's avatar
      scsi: smartpqi: correct lun reset issues · 1da52f24
      Kevin Barnett authored
      [ Upstream commit 2ba55c98 ]
      
      Problem:
      The Linux kernel takes a logical volume offline after a LUN reset.  This is
      generally accompanied by this message in the dmesg output:
      
      Device offlined - not ready after error recovery
      
      Root Cause:
      The root cause is a "quirk" in the timeout handling in the Linux SCSI
      layer. The Linux kernel places a 30-second timeout on most media access
      commands (reads and writes) that it send to device drivers.  When a media
      access command times out, the Linux kernel goes into error recovery mode
      for the LUN that was the target of the command that timed out. Every
      command that timed out is kept on a list inside of the Linux kernel to be
      retried later. The kernel attempts to recover the command(s) that timed out
      by issuing a LUN reset followed by a TEST UNIT READY. If the LUN reset and
      TEST UNIT READY commands are successful, the kernel retries the command(s)
      that timed out.
      
      Each SCSI command issued by the kernel has a result field associated with
      it. This field indicates the final result of the command (success or
      error). When a command times out, the kernel places a value in this result
      field indicating that the command timed out.
      
      The "quirk" is that after the LUN reset and TEST UNIT READY commands are
      completed, the kernel checks each command on the timed-out command list
      before retrying it. If the result field is still "timed out", the kernel
      treats that command as not having been successfully recovered for a
      retry. If the number of commands that are in this state are greater than
      two, the kernel takes the LUN offline.
      
      Fix:
      When our RAIDStack receives a LUN reset, it simply waits until all
      outstanding commands complete. Generally, all of these outstanding commands
      complete successfully. Therefore, the fix in the smartpqi driver is to
      always set the command result field to indicate success when a request
      completes successfully. This normally isn’t necessary because the result
      field is always initialized to success when the command is submitted to the
      driver. So when the command completes successfully, the result field is
      left untouched. But in this case, the kernel changes the result field
      behind the driver’s back and then expects the field to be changed by the
      driver as the commands that timed-out complete.
      Reviewed-by: default avatarDave Carroll <david.carroll@microsemi.com>
      Reviewed-by: default avatarScott Teel <scott.teel@microsemi.com>
      Signed-off-by: default avatarKevin Barnett <kevin.barnett@microsemi.com>
      Signed-off-by: default avatarDon Brace <don.brace@microsemi.com>
      Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      1da52f24
    • Daniel Vetter's avatar
      sysfs: Disable lockdep for driver bind/unbind files · 54e6f64e
      Daniel Vetter authored
      [ Upstream commit 4f4b3743 ]
      
      This is the much more correct fix for my earlier attempt at:
      
      https://lkml.org/lkml/2018/12/10/118
      
      Short recap:
      
      - There's not actually a locking issue, it's just lockdep being a bit
        too eager to complain about a possible deadlock.
      
      - Contrary to what I claimed the real problem is recursion on
        kn->count. Greg pointed me at sysfs_break_active_protection(), used
        by the scsi subsystem to allow a sysfs file to unbind itself. That
        would be a real deadlock, which isn't what's happening here. Also,
        breaking the active protection means we'd need to manually handle
        all the lifetime fun.
      
      - With Rafael we discussed the task_work approach, which kinda works,
        but has two downsides: It's a functional change for a lockdep
        annotation issue, and it won't work for the bind file (which needs
        to get the errno from the driver load function back to userspace).
      
      - Greg also asked why this never showed up: To hit this you need to
        unregister a 2nd driver from the unload code of your first driver. I
        guess only gpus do that. The bug has always been there, but only
        with a recent patch series did we add more locks so that lockdep
        built a chain from unbinding the snd-hda driver to the
        acpi_video_unregister call.
      
      Full lockdep splat:
      
      [12301.898799] ============================================
      [12301.898805] WARNING: possible recursive locking detected
      [12301.898811] 4.20.0-rc7+ #84 Not tainted
      [12301.898815] --------------------------------------------
      [12301.898821] bash/5297 is trying to acquire lock:
      [12301.898826] 00000000f61c6093 (kn->count#39){++++}, at: kernfs_remove_by_name_ns+0x3b/0x80
      [12301.898841] but task is already holding lock:
      [12301.898847] 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190
      [12301.898856] other info that might help us debug this:
      [12301.898862]  Possible unsafe locking scenario:
      [12301.898867]        CPU0
      [12301.898870]        ----
      [12301.898874]   lock(kn->count#39);
      [12301.898879]   lock(kn->count#39);
      [12301.898883] *** DEADLOCK ***
      [12301.898891]  May be due to missing lock nesting notation
      [12301.898899] 5 locks held by bash/5297:
      [12301.898903]  #0: 00000000cd800e54 (sb_writers#4){.+.+}, at: vfs_write+0x17f/0x1b0
      [12301.898915]  #1: 000000000465e7c2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xd3/0x190
      [12301.898925]  #2: 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190
      [12301.898936]  #3: 00000000414ef7ac (&dev->mutex){....}, at: device_release_driver_internal+0x34/0x240
      [12301.898950]  #4: 000000003218fbdf (register_count_mutex){+.+.}, at: acpi_video_unregister+0xe/0x40
      [12301.898960] stack backtrace:
      [12301.898968] CPU: 1 PID: 5297 Comm: bash Not tainted 4.20.0-rc7+ #84
      [12301.898974] Hardware name: Hewlett-Packard HP EliteBook 8460p/161C, BIOS 68SCF Ver. F.01 03/11/2011
      [12301.898982] Call Trace:
      [12301.898989]  dump_stack+0x67/0x9b
      [12301.898997]  __lock_acquire+0x6ad/0x1410
      [12301.899003]  ? kernfs_remove_by_name_ns+0x3b/0x80
      [12301.899010]  ? find_held_lock+0x2d/0x90
      [12301.899017]  ? mutex_spin_on_owner+0xe4/0x150
      [12301.899023]  ? find_held_lock+0x2d/0x90
      [12301.899030]  ? lock_acquire+0x90/0x180
      [12301.899036]  lock_acquire+0x90/0x180
      [12301.899042]  ? kernfs_remove_by_name_ns+0x3b/0x80
      [12301.899049]  __kernfs_remove+0x296/0x310
      [12301.899055]  ? kernfs_remove_by_name_ns+0x3b/0x80
      [12301.899060]  ? kernfs_name_hash+0xd/0x80
      [12301.899066]  ? kernfs_find_ns+0x6c/0x100
      [12301.899073]  kernfs_remove_by_name_ns+0x3b/0x80
      [12301.899080]  bus_remove_driver+0x92/0xa0
      [12301.899085]  acpi_video_unregister+0x24/0x40
      [12301.899127]  i915_driver_unload+0x42/0x130 [i915]
      [12301.899160]  i915_pci_remove+0x19/0x30 [i915]
      [12301.899169]  pci_device_remove+0x36/0xb0
      [12301.899176]  device_release_driver_internal+0x185/0x240
      [12301.899183]  unbind_store+0xaf/0x180
      [12301.899189]  kernfs_fop_write+0x104/0x190
      [12301.899195]  __vfs_write+0x31/0x180
      [12301.899203]  ? rcu_read_lock_sched_held+0x6f/0x80
      [12301.899209]  ? rcu_sync_lockdep_assert+0x29/0x50
      [12301.899216]  ? __sb_start_write+0x13c/0x1a0
      [12301.899221]  ? vfs_write+0x17f/0x1b0
      [12301.899227]  vfs_write+0xb9/0x1b0
      [12301.899233]  ksys_write+0x50/0xc0
      [12301.899239]  do_syscall_64+0x4b/0x180
      [12301.899247]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
      [12301.899253] RIP: 0033:0x7f452ac7f7a4
      [12301.899259] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 aa f0 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
      [12301.899273] RSP: 002b:00007ffceafa6918 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
      [12301.899282] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f452ac7f7a4
      [12301.899288] RDX: 000000000000000d RSI: 00005612a1abf7c0 RDI: 0000000000000001
      [12301.899295] RBP: 00005612a1abf7c0 R08: 000000000000000a R09: 00005612a1c46730
      [12301.899301] R10: 000000000000000a R11: 0000000000000246 R12: 000000000000000d
      [12301.899308] R13: 0000000000000001 R14: 00007f452af4a740 R15: 000000000000000d
      
      Looking around I've noticed that usb and i2c already handle similar
      recursion problems, where a sysfs file can unbind the same type of
      sysfs somewhere else in the hierarchy. Relevant commits are:
      
      commit 356c05d5
      Author: Alan Stern <stern@rowland.harvard.edu>
      Date:   Mon May 14 13:30:03 2012 -0400
      
          sysfs: get rid of some lockdep false positives
      
      commit e9b526fe
      Author: Alexander Sverdlin <alexander.sverdlin@nsn.com>
      Date:   Fri May 17 14:56:35 2013 +0200
      
          i2c: suppress lockdep warning on delete_device
      
      Implement the same trick for driver bind/unbind.
      
      v2: Put the macro into bus.c (Greg).
      Reviewed-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Cc: Ramalingam C <ramalingam.c@intel.com>
      Cc: Arend van Spriel <aspriel@gmail.com>
      Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
      Cc: Geert Uytterhoeven <geert+renesas@glider.be>
      Cc: Bartosz Golaszewski <brgl@bgdev.pl>
      Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
      Cc: Vivek Gautam <vivek.gautam@codeaurora.org>
      Cc: Joe Perches <joe@perches.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      54e6f64e
    • Takashi Sakamoto's avatar
      ALSA: bebob: fix model-id of unit for Apogee Ensemble · d9c8a99f
      Takashi Sakamoto authored
      [ Upstream commit 644b2e97 ]
      
      This commit fixes hard-coded model-id for an unit of Apogee Ensemble with
      a correct value. This unit uses DM1500 ASIC produced ArchWave AG (formerly
      known as BridgeCo AG).
      
      I note that this model supports three modes in the number of data channels
      in tx/rx streams; 8 ch pairs, 10 ch pairs, 18 ch pairs. The mode is
      switched by Vendor-dependent AV/C command, like:
      
      $ cd linux-firewire-utils
      $ ./firewire-request /dev/fw1 fcp 0x00ff000003dbeb0600000000 (8ch pairs)
      $ ./firewire-request /dev/fw1 fcp 0x00ff000003dbeb0601000000 (10ch pairs)
      $ ./firewire-request /dev/fw1 fcp 0x00ff000003dbeb0602000000 (18ch pairs)
      
      When switching between different mode, the unit disappears from IEEE 1394
      bus, then appears on the bus with different combination of stream formats.
      In a mode of 18 ch pairs, available sampling rate is up to 96.0 kHz, else
      up to 192.0 kHz.
      
      $ ./hinawa-config-rom-printer /dev/fw1
      { 'bus-info': { 'adj': False,
                      'bmc': True,
                      'chip_ID': 21474898341,
                      'cmc': True,
                      'cyc_clk_acc': 100,
                      'generation': 2,
                      'imc': True,
                      'isc': True,
                      'link_spd': 2,
                      'max_ROM': 1,
                      'max_rec': 512,
                      'name': '1394',
                      'node_vendor_ID': 987,
                      'pmc': False},
        'root-directory': [ ['HARDWARE_VERSION', 19],
                            [ 'NODE_CAPABILITIES',
                              { 'addressing': {'64': True, 'fix': True, 'prv': False},
                                'misc': {'int': False, 'ms': False, 'spt': True},
                                'state': { 'atn': False,
                                           'ded': False,
                                           'drq': True,
                                           'elo': False,
                                           'init': False,
                                           'lst': True,
                                           'off': False},
                                'testing': {'bas': False, 'ext': False}}],
                            ['VENDOR', 987],
                            ['DESCRIPTOR', 'Apogee Electronics'],
                            ['MODEL', 126702],
                            ['DESCRIPTOR', 'Ensemble'],
                            ['VERSION', 5297],
                            [ 'UNIT',
                              [ ['SPECIFIER_ID', 41005],
                                ['VERSION', 65537],
                                ['MODEL', 126702],
                                ['DESCRIPTOR', 'Ensemble']]],
                            [ 'DEPENDENT_INFO',
                              [ ['SPECIFIER_ID', 2037],
                                ['VERSION', 1],
                                [(58, 'IMMEDIATE'), 16777159],
                                [(59, 'IMMEDIATE'), 1048576],
                                [(60, 'IMMEDIATE'), 16777159],
                                [(61, 'IMMEDIATE'), 6291456]]]]}
      Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      d9c8a99f
    • Nikos Tsironis's avatar
      dm snapshot: Fix excessive memory usage and workqueue stalls · 69855b55
      Nikos Tsironis authored
      [ Upstream commit 721b1d98 ]
      
      kcopyd has no upper limit to the number of jobs one can allocate and
      issue. Under certain workloads this can lead to excessive memory usage
      and workqueue stalls. For example, when creating multiple dm-snapshot
      targets with a 4K chunk size and then writing to the origin through the
      page cache. Syncing the page cache causes a large number of BIOs to be
      issued to the dm-snapshot origin target, which itself issues an even
      larger (because of the BIO splitting taking place) number of kcopyd
      jobs.
      
      Running the following test, from the device mapper test suite [1],
      
        dmtest run --suite snapshot -n many_snapshots_of_same_volume_N
      
      , with 8 active snapshots, results in the kcopyd job slab cache growing
      to 10G. Depending on the available system RAM this can lead to the OOM
      killer killing user processes:
      
      [463.492878] kthreadd invoked oom-killer: gfp_mask=0x6040c0(GFP_KERNEL|__GFP_COMP),
                    nodemask=(null), order=1, oom_score_adj=0
      [463.492894] kthreadd cpuset=/ mems_allowed=0
      [463.492948] CPU: 7 PID: 2 Comm: kthreadd Not tainted 4.19.0-rc7 #3
      [463.492950] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
      [463.492952] Call Trace:
      [463.492964]  dump_stack+0x7d/0xbb
      [463.492973]  dump_header+0x6b/0x2fc
      [463.492987]  ? lockdep_hardirqs_on+0xee/0x190
      [463.493012]  oom_kill_process+0x302/0x370
      [463.493021]  out_of_memory+0x113/0x560
      [463.493030]  __alloc_pages_slowpath+0xf40/0x1020
      [463.493055]  __alloc_pages_nodemask+0x348/0x3c0
      [463.493067]  cache_grow_begin+0x81/0x8b0
      [463.493072]  ? cache_grow_begin+0x874/0x8b0
      [463.493078]  fallback_alloc+0x1e4/0x280
      [463.493092]  kmem_cache_alloc_node+0xd6/0x370
      [463.493098]  ? copy_process.part.31+0x1c5/0x20d0
      [463.493105]  copy_process.part.31+0x1c5/0x20d0
      [463.493115]  ? __lock_acquire+0x3cc/0x1550
      [463.493121]  ? __switch_to_asm+0x34/0x70
      [463.493129]  ? kthread_create_worker_on_cpu+0x70/0x70
      [463.493135]  ? finish_task_switch+0x90/0x280
      [463.493165]  _do_fork+0xe0/0x6d0
      [463.493191]  ? kthreadd+0x19f/0x220
      [463.493233]  kernel_thread+0x25/0x30
      [463.493235]  kthreadd+0x1bf/0x220
      [463.493242]  ? kthread_create_on_cpu+0x90/0x90
      [463.493248]  ret_from_fork+0x3a/0x50
      [463.493279] Mem-Info:
      [463.493285] active_anon:20631 inactive_anon:4831 isolated_anon:0
      [463.493285]  active_file:80216 inactive_file:80107 isolated_file:435
      [463.493285]  unevictable:0 dirty:51266 writeback:109372 unstable:0
      [463.493285]  slab_reclaimable:31191 slab_unreclaimable:3483521
      [463.493285]  mapped:526 shmem:4903 pagetables:1759 bounce:0
      [463.493285]  free:33623 free_pcp:2392 free_cma:0
      ...
      [463.493489] Unreclaimable slab info:
      [463.493513] Name                      Used          Total
      [463.493522] bio-6                   1028KB       1028KB
      [463.493525] bio-5                   1028KB       1028KB
      [463.493528] dm_snap_pending_exception     236783KB     243789KB
      [463.493531] dm_exception              41KB         42KB
      [463.493534] bio-4                   1216KB       1216KB
      [463.493537] bio-3                 439396KB     439396KB
      [463.493539] kcopyd_job           6973427KB    6973427KB
      ...
      [463.494340] Out of memory: Kill process 1298 (ruby2.3) score 1 or sacrifice child
      [463.494673] Killed process 1298 (ruby2.3) total-vm:435740kB, anon-rss:20180kB, file-rss:4kB, shmem-rss:0kB
      [463.506437] oom_reaper: reaped process 1298 (ruby2.3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
      
      Moreover, issuing a large number of kcopyd jobs results in kcopyd
      hogging the CPU, while processing them. As a result, processing of work
      items, queued for execution on the same CPU as the currently running
      kcopyd thread, is stalled for long periods of time, hurting performance.
      Running the aforementioned test we get, in dmesg, messages like the
      following:
      
      [67501.194592] BUG: workqueue lockup - pool cpus=4 node=0 flags=0x0 nice=0 stuck for 27s!
      [67501.195586] Showing busy workqueues and worker pools:
      [67501.195591] workqueue events: flags=0x0
      [67501.195597]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
      [67501.195611]     pending: cache_reap
      [67501.195641] workqueue mm_percpu_wq: flags=0x8
      [67501.195645]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
      [67501.195656]     pending: vmstat_update
      [67501.195682] workqueue kblockd: flags=0x18
      [67501.195687]   pwq 5: cpus=2 node=0 flags=0x0 nice=-20 active=1/256
      [67501.195698]     pending: blk_timeout_work
      [67501.195753] workqueue kcopyd: flags=0x8
      [67501.195757]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
      [67501.195768]     pending: do_work [dm_mod]
      [67501.195802] workqueue kcopyd: flags=0x8
      [67501.195806]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
      [67501.195817]     pending: do_work [dm_mod]
      [67501.195834] workqueue kcopyd: flags=0x8
      [67501.195838]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
      [67501.195848]     pending: do_work [dm_mod]
      [67501.195881] workqueue kcopyd: flags=0x8
      [67501.195885]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=1/256
      [67501.195896]     pending: do_work [dm_mod]
      [67501.195920] workqueue kcopyd: flags=0x8
      [67501.195924]   pwq 8: cpus=4 node=0 flags=0x0 nice=0 active=2/256
      [67501.195935]     in-flight: 67:do_work [dm_mod]
      [67501.195945]     pending: do_work [dm_mod]
      [67501.195961] pool 8: cpus=4 node=0 flags=0x0 nice=0 hung=27s workers=3 idle: 129 23765
      
      The root cause for these issues is the way dm-snapshot uses kcopyd. In
      particular, the lack of an explicit or implicit limit to the maximum
      number of in-flight COW jobs. The merging path is not affected because
      it implicitly limits the in-flight kcopyd jobs to one.
      
      Fix these issues by using a semaphore to limit the maximum number of
      in-flight kcopyd jobs. We grab the semaphore before allocating a new
      kcopyd job in start_copy() and start_full_bio() and release it after the
      job finishes in copy_callback().
      
      The initial semaphore value is configurable through a module parameter,
      to allow fine tuning the maximum number of in-flight COW jobs. Setting
      this parameter to zero initializes the semaphore to INT_MAX.
      
      A default value of 2048 maximum in-flight kcopyd jobs was chosen. This
      value was decided experimentally as a trade-off between memory
      consumption, stalling the kernel's workqueues and maintaining a high
      enough throughput.
      
      Re-running the aforementioned test:
      
        * Workqueue stalls are eliminated
        * kcopyd's job slab cache uses a maximum of 130MB
        * The time taken by the test to write to the snapshot-origin target is
          reduced from 05m20.48s to 03m26.38s
      
      [1] https://github.com/jthornber/device-mapper-test-suiteSigned-off-by: default avatarNikos Tsironis <ntsironis@arrikto.com>
      Signed-off-by: default avatarIlias Tsitsimpis <iliastsi@arrikto.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      69855b55
    • Arnaldo Carvalho de Melo's avatar
      tools lib subcmd: Don't add the kernel sources to the include path · 7a6da629
      Arnaldo Carvalho de Melo authored
      [ Upstream commit ece98049 ]
      
      At some point we decided not to directly include kernel sources files
      when building tools/perf/, but when tools/lib/subcmd/ was forked from
      tools/perf it somehow ended up adding it via these two lines in its
      Makefile:
      
        CFLAGS += -I$(srctree)/include/uapi
        CFLAGS += -I$(srctree)/include
      
      As $(srctree) points to the kernel sources.
      
      Removing those lines and keeping just:
      
        CFLAGS += -I$(srctree)/tools/include/
      
      Is enough to build tools/perf and tools/objtool.
      
      This fixes the build when building from the sources in environments such
      as the Android NDK crossbuilding from a fedora:26 system:
      
        subcmd-util.h:11:15: error: expected ',' or ';' before 'void'
         static inline void report(const char *prefix, const char *err, va_list params)
                       ^
        In file included from /git/perf/include/uapi/linux/stddef.h:2:0,
                         from /git/perf/include/uapi/linux/posix_types.h:5,
                         from /opt/android-ndk-r12b/platforms/android-24/arch-arm/usr/include/sys/types.h:36,
                         from /opt/android-ndk-r12b/platforms/android-24/arch-arm/usr/include/unistd.h:33,
                         from run-command.c:2:
        subcmd-util.h:18:17: error: '__no_instrument_function__' attribute applies only to functions
      
      The /opt/android-ndk-r12b/platforms/android-24/arch-arm/usr/include/sys/types.h
      file that includes linux/posix_types.h ends up getting the one in the kernel
      sources causing the breakage. Fix it.
      
      Test built tools/objtool/ too.
      Reported-by: default avatarJiri Olsa <jolsa@kernel.org>
      Tested-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Fixes: 4b6ab94e ("perf subcmd: Create subcmd library")
      Link: https://lkml.kernel.org/n/tip-5lhaoecrj12t0bqwvpiu14sm@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      7a6da629