1. 07 Oct, 2019 31 commits
  2. 05 Oct, 2019 9 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.9.195 · 6eea609a
      Greg Kroah-Hartman authored
      6eea609a
    • Filipe Manana's avatar
      Btrfs: fix race setting up and completing qgroup rescan workers · 94fe757c
      Filipe Manana authored
      [ Upstream commit 13fc1d27 ]
      
      There is a race between setting up a qgroup rescan worker and completing
      a qgroup rescan worker that can lead to callers of the qgroup rescan wait
      ioctl to either not wait for the rescan worker to complete or to hang
      forever due to missing wake ups. The following diagram shows a sequence
      of steps that illustrates the race.
      
              CPU 1                                                         CPU 2                                  CPU 3
      
       btrfs_ioctl_quota_rescan()
        btrfs_qgroup_rescan()
         qgroup_rescan_init()
          mutex_lock(&fs_info->qgroup_rescan_lock)
          spin_lock(&fs_info->qgroup_lock)
      
          fs_info->qgroup_flags |=
            BTRFS_QGROUP_STATUS_FLAG_RESCAN
      
          init_completion(
            &fs_info->qgroup_rescan_completion)
      
          fs_info->qgroup_rescan_running = true
      
          mutex_unlock(&fs_info->qgroup_rescan_lock)
          spin_unlock(&fs_info->qgroup_lock)
      
          btrfs_init_work()
           --> starts the worker
      
                                                              btrfs_qgroup_rescan_worker()
                                                               mutex_lock(&fs_info->qgroup_rescan_lock)
      
                                                               fs_info->qgroup_flags &=
                                                                 ~BTRFS_QGROUP_STATUS_FLAG_RESCAN
      
                                                               mutex_unlock(&fs_info->qgroup_rescan_lock)
      
                                                               starts transaction, updates qgroup status
                                                               item, etc
      
                                                                                                                 btrfs_ioctl_quota_rescan()
                                                                                                                  btrfs_qgroup_rescan()
                                                                                                                   qgroup_rescan_init()
                                                                                                                    mutex_lock(&fs_info->qgroup_rescan_lock)
                                                                                                                    spin_lock(&fs_info->qgroup_lock)
      
                                                                                                                    fs_info->qgroup_flags |=
                                                                                                                      BTRFS_QGROUP_STATUS_FLAG_RESCAN
      
                                                                                                                    init_completion(
                                                                                                                      &fs_info->qgroup_rescan_completion)
      
                                                                                                                    fs_info->qgroup_rescan_running = true
      
                                                                                                                    mutex_unlock(&fs_info->qgroup_rescan_lock)
                                                                                                                    spin_unlock(&fs_info->qgroup_lock)
      
                                                                                                                    btrfs_init_work()
                                                                                                                     --> starts another worker
      
                                                               mutex_lock(&fs_info->qgroup_rescan_lock)
      
                                                               fs_info->qgroup_rescan_running = false
      
                                                               mutex_unlock(&fs_info->qgroup_rescan_lock)
      
      							 complete_all(&fs_info->qgroup_rescan_completion)
      
      Before the rescan worker started by the task at CPU 3 completes, if
      another task calls btrfs_ioctl_quota_rescan(), it will get -EINPROGRESS
      because the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN is set at
      fs_info->qgroup_flags, which is expected and correct behaviour.
      
      However if other task calls btrfs_ioctl_quota_rescan_wait() before the
      rescan worker started by the task at CPU 3 completes, it will return
      immediately without waiting for the new rescan worker to complete,
      because fs_info->qgroup_rescan_running is set to false by CPU 2.
      
      This race is making test case btrfs/171 (from fstests) to fail often:
      
        btrfs/171 9s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad)
      #      --- tests/btrfs/171.out     2018-09-16 21:30:48.505104287 +0100
      #      +++ /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad      2019-09-19 02:01:36.938486039 +0100
      #      @@ -1,2 +1,3 @@
      #       QA output created by 171
      #      +ERROR: quota rescan failed: Operation now in progress
      #       Silence is golden
      #      ...
      #      (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/btrfs/171.out /home/fdmanana/git/hub/xfstests/results//btrfs/171.out.bad'  to see the entire diff)
      
      That is because the test calls the btrfs-progs commands "qgroup quota
      rescan -w", "qgroup assign" and "qgroup remove" in a sequence that makes
      calls to the rescan start ioctl fail with -EINPROGRESS (note the "btrfs"
      commands 'qgroup assign' and 'qgroup remove' often call the rescan start
      ioctl after calling the qgroup assign ioctl,
      btrfs_ioctl_qgroup_assign()), since previous waits didn't actually wait
      for a rescan worker to complete.
      
      Another problem the race can cause is missing wake ups for waiters,
      since the call to complete_all() happens outside a critical section and
      after clearing the flag BTRFS_QGROUP_STATUS_FLAG_RESCAN. In the sequence
      diagram above, if we have a waiter for the first rescan task (executed
      by CPU 2), then fs_info->qgroup_rescan_completion.wait is not empty, and
      if after the rescan worker clears BTRFS_QGROUP_STATUS_FLAG_RESCAN and
      before it calls complete_all() against
      fs_info->qgroup_rescan_completion, the task at CPU 3 calls
      init_completion() against fs_info->qgroup_rescan_completion which
      re-initilizes its wait queue to an empty queue, therefore causing the
      rescan worker at CPU 2 to call complete_all() against an empty queue,
      never waking up the task waiting for that rescan worker.
      
      Fix this by clearing BTRFS_QGROUP_STATUS_FLAG_RESCAN and setting
      fs_info->qgroup_rescan_running to false in the same critical section,
      delimited by the mutex fs_info->qgroup_rescan_lock, as well as doing the
      call to complete_all() in that same critical section. This gives the
      protection needed to avoid rescan wait ioctl callers not waiting for a
      running rescan worker and the lost wake ups problem, since setting that
      rescan flag and boolean as well as initializing the wait queue is done
      already in a critical section delimited by that mutex (at
      qgroup_rescan_init()).
      
      Fixes: 57254b6e ("Btrfs: add ioctl to wait for qgroup rescan completion")
      Fixes: d2c609b8 ("btrfs: properly track when rescan worker is running")
      CC: stable@vger.kernel.org # 4.4+
      Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
      Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      94fe757c
    • Lu Fengqi's avatar
      btrfs: qgroup: Drop quota_root and fs_info parameters from update_qgroup_status_item · d15aa4bd
      Lu Fengqi authored
      [ Upstream commit 2e980acd ]
      
      They can be fetched from the transaction handle.
      Signed-off-by: default avatarLu Fengqi <lufq.fnst@cn.fujitsu.com>
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
      Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      d15aa4bd
    • Pavel Shilovsky's avatar
      CIFS: Fix oplock handling for SMB 2.1+ protocols · 7d778376
      Pavel Shilovsky authored
      commit a016e279 upstream.
      
      There may be situations when a server negotiates SMB 2.1
      protocol version or higher but responds to a CREATE request
      with an oplock rather than a lease.
      
      Currently the client doesn't handle such a case correctly:
      when another CREATE comes in the server sends an oplock
      break to the initial CREATE and the client doesn't send
      an ack back due to a wrong caching level being set (READ
      instead of RWH). Missing an oplock break ack makes the
      server wait until the break times out which dramatically
      increases the latency of the second CREATE.
      
      Fix this by properly detecting oplocks when using SMB 2.1
      protocol version and higher.
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      Reviewed-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7d778376
    • Murphy Zhou's avatar
      CIFS: fix max ea value size · 4b8d7cf8
      Murphy Zhou authored
      commit 63d37fb4 upstream.
      
      It should not be larger then the slab max buf size. If user
      specifies a larger size, it passes this check and goes
      straightly to SMB2_set_info_init performing an insecure memcpy.
      Signed-off-by: default avatarMurphy Zhou <jencce.kernel@gmail.com>
      Reviewed-by: default avatarAurelien Aptel <aaptel@suse.com>
      CC: Stable <stable@vger.kernel.org>
      Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4b8d7cf8
    • Chris Brandt's avatar
      i2c: riic: Clear NACK in tend isr · 75aaa6f6
      Chris Brandt authored
      commit a71e2ac1 upstream.
      
      The NACKF flag should be cleared in INTRIICNAKI interrupt processing as
      description in HW manual.
      
      This issue shows up quickly when PREEMPT_RT is applied and a device is
      probed that is not plugged in (like a touchscreen controller). The result
      is endless interrupts that halt system boot.
      
      Fixes: 310c18a4 ("i2c: riic: add driver")
      Cc: stable@vger.kernel.org
      Reported-by: default avatarChien Nguyen <chien.nguyen.eb@rvc.renesas.com>
      Signed-off-by: default avatarChris Brandt <chris.brandt@renesas.com>
      Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      75aaa6f6
    • Laurent Vivier's avatar
      hwrng: core - don't wait on add_early_randomness() · a4ded68d
      Laurent Vivier authored
      commit 78887832 upstream.
      
      add_early_randomness() is called by hwrng_register() when the
      hardware is added. If this hardware and its module are present
      at boot, and if there is no data available the boot hangs until
      data are available and can't be interrupted.
      
      For instance, in the case of virtio-rng, in some cases the host can be
      not able to provide enough entropy for all the guests.
      
      We can have two easy ways to reproduce the problem but they rely on
      misconfiguration of the hypervisor or the egd daemon:
      
      - if virtio-rng device is configured to connect to the egd daemon of the
      host but when the virtio-rng driver asks for data the daemon is not
      connected,
      
      - if virtio-rng device is configured to connect to the egd daemon of the
      host but the egd daemon doesn't provide data.
      
      The guest kernel will hang at boot until the virtio-rng driver provides
      enough data.
      
      To avoid that, call rng_get_data() in non-blocking mode (wait=0)
      from add_early_randomness().
      Signed-off-by: default avatarLaurent Vivier <lvivier@redhat.com>
      Fixes: d9e79726 ("hwrng: add randomness to system from rng...")
      Cc: <stable@vger.kernel.org>
      Reviewed-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a4ded68d
    • Chao Yu's avatar
      quota: fix wrong condition in is_quota_modification() · 1fcdaaaa
      Chao Yu authored
      commit 6565c182 upstream.
      
      Quoted from
      commit 3da40c7b ("ext4: only call ext4_truncate when size <= isize")
      
      " At LSF we decided that if we truncate up from isize we shouldn't trim
        fallocated blocks that were fallocated with KEEP_SIZE and are past the
       new i_size.  This patch fixes ext4 to do this. "
      
      And generic/092 of fstest have covered this case for long time, however
      is_quota_modification() didn't adjust based on that rule, so that in
      below condition, we will lose to quota block change:
      - fallocate blocks beyond EOF
      - remount
      - truncate(file_path, file_size)
      
      Fix it.
      
      Link: https://lore.kernel.org/r/20190911093650.35329-1-yuchao0@huawei.com
      Fixes: 3da40c7b ("ext4: only call ext4_truncate when size <= isize")
      CC: stable@vger.kernel.org
      Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1fcdaaaa
    • Theodore Ts'o's avatar
      ext4: fix punch hole for inline_data file systems · 4820f7e1
      Theodore Ts'o authored
      commit c1e8220b upstream.
      
      If a program attempts to punch a hole on an inline data file, we need
      to convert it to a normal file first.
      
      This was detected using ext4/032 using the adv configuration.  Simple
      reproducer:
      
      mke2fs -Fq -t ext4 -O inline_data /dev/vdc
      mount /vdc
      echo "" > /vdc/testfile
      xfs_io -c 'truncate 33554432' /vdc/testfile
      xfs_io -c 'fpunch 0 1048576' /vdc/testfile
      umount /vdc
      e2fsck -fy /dev/vdc
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4820f7e1