1. 07 Jul, 2022 2 commits
    • Dave Chinner's avatar
      xfs: track CIL ticket reservation in percpu structure · 1dd2a2c1
      Dave Chinner authored
      To get it out from under the cil spinlock.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      1dd2a2c1
    • Dave Chinner's avatar
      xfs: implement percpu cil space used calculation · 7c8ade21
      Dave Chinner authored
      Now that we have the CIL percpu structures in place, implement the
      space used counter as a per-cpu counter.
      
      We have to be really careful now about ensuring that the checks and
      updates run without arbitrary delays, which means they need to run
      with pre-emption disabled. We do this by careful placement of
      the get_cpu_ptr/put_cpu_ptr calls to access the per-cpu structures
      for that CPU.
      
      We need to be able to reliably detect that the CIL has reached
      the hard limit threshold so we can take extra reservations for the
      iclog headers when the space used overruns the original reservation.
      hence we factor out xlog_cil_over_hard_limit() from
      xlog_cil_push_background().
      
      The global CIL space used is an atomic variable that is backed by
      per-cpu aggregation to minimise the number of atomic updates we do
      to the global state in the fast path. While we are under the soft
      limit, we aggregate only when the per-cpu aggregation is over the
      proportion of the soft limit assigned to that CPU. This means that
      all CPUs can use all but one byte of their aggregation threshold
      and we will not go over the soft limit.
      
      Hence once we detect that we've gone over both a per-cpu aggregation
      threshold and the soft limit, we know that we have only
      exceeded the soft limit by one per-cpu aggregation threshold. Even
      if all CPUs hit this at the same time, we can't be over the hard
      limit, so we can run an aggregation back into the atomic counter
      at this point and still be under the hard limit.
      
      At this point, we will be over the soft limit and hence we'll
      aggregate into the global atomic used space directly rather than the
      per-cpu counters, hence providing accurate detection of hard limit
      excursion for accounting and reservation purposes.
      
      Hence we get the best of both worlds - lockless, scalable per-cpu
      fast path plus accurate, atomic detection of hard limit excursion.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      7c8ade21
  2. 01 Jul, 2022 5 commits
    • Dave Chinner's avatar
      xfs: introduce per-cpu CIL tracking structure · af1c2146
      Dave Chinner authored
      The CIL push lock is highly contended on larger machines, becoming a
      hard bottleneck that about 700,000 transaction commits/s on >16p
      machines. To address this, start moving the CIL tracking
      infrastructure to utilise per-CPU structures.
      
      We need to track the space used, the amount of log reservation space
      reserved to write the CIL, the log items in the CIL and the busy
      extents that need to be completed by the CIL commit.  This requires
      a couple of per-cpu counters, an unordered per-cpu list and a
      globally ordered per-cpu list.
      
      Create a per-cpu structure to hold these and all the management
      interfaces needed, as well as the hooks to handle hotplug CPUs.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      
      af1c2146
    • Dave Chinner's avatar
      xfs: rework per-iclog header CIL reservation · 31151cc3
      Dave Chinner authored
      For every iclog that a CIL push will use up, we need to ensure we
      have space reserved for the iclog header in each iclog. It is
      extremely difficult to do this accurately with a per-cpu counter
      without expensive summing of the counter in every commit. However,
      we know what the maximum CIL size is going to be because of the
      hard space limit we have, and hence we know exactly how many iclogs
      we are going to need to write out the CIL.
      
      We are constrained by the requirement that small transactions only
      have reservation space for a single iclog header built into them.
      At commit time we don't know how much of the current transaction
      reservation is made up of iclog header reservations as calculated by
      xfs_log_calc_unit_res() when the ticket was reserved. As larger
      reservations have multiple header spaces reserved, we can steal
      more than one iclog header reservation at a time, but we only steal
      the exact number needed for the given log vector size delta.
      
      As a result, we don't know exactly when we are going to steal iclog
      header reservations, nor do we know exactly how many we are going to
      need for a given CIL.
      
      To make things simple, start by calculating the worst case number of
      iclog headers a full CIL push will require. Record this into an
      atomic variable in the CIL. Then add a byte counter to the log
      ticket that records exactly how much iclog header space has been
      reserved in this ticket by xfs_log_calc_unit_res(). This tells us
      exactly how much space we can steal from the ticket at transaction
      commit time.
      
      Now, at transaction commit time, we can check if the CIL has a full
      iclog header reservation and, if not, steal the entire reservation
      the current ticket holds for iclog headers. This minimises the
      number of times we need to do atomic operations in the fast path,
      but still guarantees we get all the reservations we need.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      31151cc3
    • Dave Chinner's avatar
      xfs: lift init CIL reservation out of xc_cil_lock · 12380d23
      Dave Chinner authored
      The xc_cil_lock is the most highly contended lock in XFS now. To
      start the process of getting rid of it, lift the initial reservation
      of the CIL log space out from under the xc_cil_lock.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      12380d23
    • Dave Chinner's avatar
      xfs: use the CIL space used counter for emptiness checks · 88591e7f
      Dave Chinner authored
      In the next patches we are going to make the CIL list itself
      per-cpu, and so we cannot use list_empty() to check is the list is
      empty. Replace the list_empty() checks with a flag in the CIL to
      indicate we have committed at least one transaction to the CIL and
      hence the CIL is not empty.
      
      We need this flag to be an atomic so that we can clear it without
      holding any locks in the commit fast path, but we also need to be
      careful to avoid atomic operations in the fast path. Hence we use
      the fact that test_bit() is not an atomic op to first check if the
      flag is set and then run the atomic test_and_clear_bit() operation
      to clear it and steal the initial unit reservation for the CIL
      context checkpoint.
      
      When we are switching to a new context in a push, we place the
      setting of the XLOG_CIL_EMPTY flag under the xc_push_lock. THis
      allows all the other places that need to check whether the CIL is
      empty to use test_bit() and still be serialised correctly with the
      CIL context swaps that set the bit.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      88591e7f
    • Darrick J. Wong's avatar
      xfs: prevent a UAF when log IO errors race with unmount · 7561cea5
      Darrick J. Wong authored
      KASAN reported the following use after free bug when running
      generic/475:
      
       XFS (dm-0): Mounting V5 Filesystem
       XFS (dm-0): Starting recovery (logdev: internal)
       XFS (dm-0): Ending recovery (logdev: internal)
       Buffer I/O error on dev dm-0, logical block 20639616, async page read
       Buffer I/O error on dev dm-0, logical block 20639617, async page read
       XFS (dm-0): log I/O error -5
       XFS (dm-0): Filesystem has been shut down due to log error (0x2).
       XFS (dm-0): Unmounting Filesystem
       XFS (dm-0): Please unmount the filesystem and rectify the problem(s).
       ==================================================================
       BUG: KASAN: use-after-free in do_raw_spin_lock+0x246/0x270
       Read of size 4 at addr ffff888109dd84c4 by task 3:1H/136
      
       CPU: 3 PID: 136 Comm: 3:1H Not tainted 5.19.0-rc4-xfsx #rc4 8e53ab5ad0fddeb31cee5e7063ff9c361915a9c4
       Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
       Workqueue: xfs-log/dm-0 xlog_ioend_work [xfs]
       Call Trace:
        <TASK>
        dump_stack_lvl+0x34/0x44
        print_report.cold+0x2b8/0x661
        ? do_raw_spin_lock+0x246/0x270
        kasan_report+0xab/0x120
        ? do_raw_spin_lock+0x246/0x270
        do_raw_spin_lock+0x246/0x270
        ? rwlock_bug.part.0+0x90/0x90
        xlog_force_shutdown+0xf6/0x370 [xfs 4ad76ae0d6add7e8183a553e624c31e9ed567318]
        xlog_ioend_work+0x100/0x190 [xfs 4ad76ae0d6add7e8183a553e624c31e9ed567318]
        process_one_work+0x672/0x1040
        worker_thread+0x59b/0xec0
        ? __kthread_parkme+0xc6/0x1f0
        ? process_one_work+0x1040/0x1040
        ? process_one_work+0x1040/0x1040
        kthread+0x29e/0x340
        ? kthread_complete_and_exit+0x20/0x20
        ret_from_fork+0x1f/0x30
        </TASK>
      
       Allocated by task 154099:
        kasan_save_stack+0x1e/0x40
        __kasan_kmalloc+0x81/0xa0
        kmem_alloc+0x8d/0x2e0 [xfs]
        xlog_cil_init+0x1f/0x540 [xfs]
        xlog_alloc_log+0xd1e/0x1260 [xfs]
        xfs_log_mount+0xba/0x640 [xfs]
        xfs_mountfs+0xf2b/0x1d00 [xfs]
        xfs_fs_fill_super+0x10af/0x1910 [xfs]
        get_tree_bdev+0x383/0x670
        vfs_get_tree+0x7d/0x240
        path_mount+0xdb7/0x1890
        __x64_sys_mount+0x1fa/0x270
        do_syscall_64+0x2b/0x80
        entry_SYSCALL_64_after_hwframe+0x46/0xb0
      
       Freed by task 154151:
        kasan_save_stack+0x1e/0x40
        kasan_set_track+0x21/0x30
        kasan_set_free_info+0x20/0x30
        ____kasan_slab_free+0x110/0x190
        slab_free_freelist_hook+0xab/0x180
        kfree+0xbc/0x310
        xlog_dealloc_log+0x1b/0x2b0 [xfs]
        xfs_unmountfs+0x119/0x200 [xfs]
        xfs_fs_put_super+0x6e/0x2e0 [xfs]
        generic_shutdown_super+0x12b/0x3a0
        kill_block_super+0x95/0xd0
        deactivate_locked_super+0x80/0x130
        cleanup_mnt+0x329/0x4d0
        task_work_run+0xc5/0x160
        exit_to_user_mode_prepare+0xd4/0xe0
        syscall_exit_to_user_mode+0x1d/0x40
        entry_SYSCALL_64_after_hwframe+0x46/0xb0
      
      This appears to be a race between the unmount process, which frees the
      CIL and waits for in-flight iclog IO; and the iclog IO completion.  When
      generic/475 runs, it starts fsstress in the background, waits a few
      seconds, and substitutes a dm-error device to simulate a disk falling
      out of a machine.  If the fsstress encounters EIO on a pure data write,
      it will exit but the filesystem will still be online.
      
      The next thing the test does is unmount the filesystem, which tries to
      clean the log, free the CIL, and wait for iclog IO completion.  If an
      iclog was being written when the dm-error switch occurred, it can race
      with log unmounting as follows:
      
      Thread 1				Thread 2
      
      					xfs_log_unmount
      					xfs_log_clean
      					xfs_log_quiesce
      xlog_ioend_work
      <observe error>
      xlog_force_shutdown
      test_and_set_bit(XLOG_IOERROR)
      					xfs_log_force
      					<log is shut down, nop>
      					xfs_log_umount_write
      					<log is shut down, nop>
      					xlog_dealloc_log
      					xlog_cil_destroy
      					<wait for iclogs>
      spin_lock(&log->l_cilp->xc_push_lock)
      <KABOOM>
      
      Therefore, free the CIL after waiting for the iclogs to complete.  I
      /think/ this race has existed for quite a few years now, though I don't
      remember the ~2014 era logging code well enough to know if it was a real
      threat then or if the actual race was exposed only more recently.
      
      Fixes: ac983517 ("xfs: don't sleep in xlog_cil_force_lsn on shutdown")
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      7561cea5
  3. 29 Jun, 2022 3 commits
    • Darrick J. Wong's avatar
      xfs: dont treat rt extents beyond EOF as eofblocks to be cleared · 8944c6fb
      Darrick J. Wong authored
      On a system with a realtime volume and a 28k realtime extent,
      generic/491 fails because the test opens a file on a frozen filesystem
      and closing it causes xfs_release -> xfs_can_free_eofblocks to
      mistakenly think that the the blocks of the realtime extent beyond EOF
      are posteof blocks to be freed.  Realtime extents cannot be partially
      unmapped, so this is pointless.  Worse yet, this triggers posteof
      cleanup, which stalls on a transaction allocation, which is why the test
      fails.
      
      Teach the predicate to account for realtime extents properly.
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      8944c6fb
    • Darrick J. Wong's avatar
      xfs: don't hold xattr leaf buffers across transaction rolls · e53bcffa
      Darrick J. Wong authored
      Now that we've established (again!) that empty xattr leaf buffers are
      ok, we no longer need to bhold them to transactions when we're creating
      new leaf blocks.  Get rid of the entire mechanism, which should simplify
      the xattr code quite a bit.
      
      The original justification for using bhold here was to prevent the AIL
      from trying to write the empty leaf block into the fs during the brief
      time that we release the buffer lock.  The reason for /that/ was to
      prevent recovery from tripping over the empty ondisk block.
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      e53bcffa
    • Darrick J. Wong's avatar
      xfs: empty xattr leaf header blocks are not corruption · 7be3bd88
      Darrick J. Wong authored
      TLDR: Revert commit 51e6104f ("xfs: detect empty attr leaf blocks in
      xfs_attr3_leaf_verify") because it was wrong.
      
      Every now and then we get a corruption report from the kernel or
      xfs_repair about empty leaf blocks in the extended attribute structure.
      We've long thought that these shouldn't be possible, but prior to 5.18
      one would shake loose in the recoveryloop fstests about once a month.
      
      A new addition to the xattr leaf block verifier in 5.19-rc1 makes this
      happen every 7 minutes on my testing cloud.  I added a ton of logging to
      detect any time we set the header count on an xattr leaf block to zero.
      This produced the following dmesg output on generic/388:
      
      XFS (sda4): ino 0x21fcbaf leaf 0x129bf78 hdcount==0!
      Call Trace:
       <TASK>
       dump_stack_lvl+0x34/0x44
       xfs_attr3_leaf_create+0x187/0x230
       xfs_attr_shortform_to_leaf+0xd1/0x2f0
       xfs_attr_set_iter+0x73e/0xa90
       xfs_xattri_finish_update+0x45/0x80
       xfs_attr_finish_item+0x1b/0xd0
       xfs_defer_finish_noroll+0x19c/0x770
       __xfs_trans_commit+0x153/0x3e0
       xfs_attr_set+0x36b/0x740
       xfs_xattr_set+0x89/0xd0
       __vfs_setxattr+0x67/0x80
       __vfs_setxattr_noperm+0x6e/0x120
       vfs_setxattr+0x97/0x180
       setxattr+0x88/0xa0
       path_setxattr+0xc3/0xe0
       __x64_sys_setxattr+0x27/0x30
       do_syscall_64+0x35/0x80
       entry_SYSCALL_64_after_hwframe+0x46/0xb0
      
      So now we know that someone is creating empty xattr leaf blocks as part
      of converting a sf xattr structure into a leaf xattr structure.  The
      conversion routine logs any existing sf attributes in the same
      transaction that creates the leaf block, so we know this is a setxattr
      to a file that has no attributes at all.
      
      Next, g/388 calls the shutdown ioctl and cycles the mount to trigger log
      recovery.  I also augmented buffer item recovery to call ->verify_struct
      on any attr leaf blocks and complain if it finds a failure:
      
      XFS (sda4): Unmounting Filesystem
      XFS (sda4): Mounting V5 Filesystem
      XFS (sda4): Starting recovery (logdev: internal)
      XFS (sda4): xattr leaf daddr 0x129bf78 hdrcount == 0!
      Call Trace:
       <TASK>
       dump_stack_lvl+0x34/0x44
       xfs_attr3_leaf_verify+0x3b8/0x420
       xlog_recover_buf_commit_pass2+0x60a/0x6c0
       xlog_recover_items_pass2+0x4e/0xc0
       xlog_recover_commit_trans+0x33c/0x350
       xlog_recovery_process_trans+0xa5/0xe0
       xlog_recover_process_data+0x8d/0x140
       xlog_do_recovery_pass+0x19b/0x720
       xlog_do_log_recovery+0x62/0xc0
       xlog_do_recover+0x33/0x1d0
       xlog_recover+0xda/0x190
       xfs_log_mount+0x14c/0x360
       xfs_mountfs+0x517/0xa60
       xfs_fs_fill_super+0x6bc/0x950
       get_tree_bdev+0x175/0x280
       vfs_get_tree+0x1a/0x80
       path_mount+0x6f5/0xaa0
       __x64_sys_mount+0x103/0x140
       do_syscall_64+0x35/0x80
       entry_SYSCALL_64_after_hwframe+0x46/0xb0
      RIP: 0033:0x7fc61e241eae
      
      And a moment later, the _delwri_submit of the recovered buffers trips
      the same verifier and recovery fails:
      
      XFS (sda4): Metadata corruption detected at xfs_attr3_leaf_verify+0x393/0x420 [xfs], xfs_attr3_leaf block 0x129bf78
      XFS (sda4): Unmount and run xfs_repair
      XFS (sda4): First 128 bytes of corrupted metadata buffer:
      00000000: 00 00 00 00 00 00 00 00 3b ee 00 00 00 00 00 00  ........;.......
      00000010: 00 00 00 00 01 29 bf 78 00 00 00 00 00 00 00 00  .....).x........
      00000020: a5 1b d0 02 b2 9a 49 df 8e 9c fb 8d f8 31 3e 9d  ......I......1>.
      00000030: 00 00 00 00 02 1f cb af 00 00 00 00 10 00 00 00  ................
      00000040: 00 50 0f b0 00 00 00 00 00 00 00 00 00 00 00 00  .P..............
      00000050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      XFS (sda4): Corruption of in-memory data (0x8) detected at _xfs_buf_ioapply+0x37f/0x3b0 [xfs] (fs/xfs/xfs_buf.c:1518).  Shutting down filesystem.
      XFS (sda4): Please unmount the filesystem and rectify the problem(s)
      XFS (sda4): log mount/recovery failed: error -117
      XFS (sda4): log mount failed
      
      I think I see what's going on here -- setxattr is racing with something
      that shuts down the filesystem:
      
      Thread 1				Thread 2
      --------				--------
      xfs_attr_sf_addname
      xfs_attr_shortform_to_leaf
      <create empty leaf>
      xfs_trans_bhold(leaf)
      xattri_dela_state = XFS_DAS_LEAF_ADD
      <roll transaction>
      					<flush log>
      					<shut down filesystem>
      xfs_trans_bhold_release(leaf)
      <discover fs is dead, bail>
      
      Thread 3
      --------
      <cycle mount, start recovery>
      xlog_recover_buf_commit_pass2
      xlog_recover_do_reg_buffer
      <replay empty leaf buffer from recovered buf item>
      xfs_buf_delwri_queue(leaf)
      xfs_buf_delwri_submit
      _xfs_buf_ioapply(leaf)
      xfs_attr3_leaf_write_verify
      <trip over empty leaf buffer>
      <fail recovery>
      
      As you can see, the bhold keeps the leaf buffer locked and thus prevents
      the *AIL* from tripping over the ichdr.count==0 check in the write
      verifier.  Unfortunately, it doesn't prevent the log from getting
      flushed to disk, which sets up log recovery to fail.
      
      So.  It's clear that the kernel has always had the ability to persist
      attr leaf blocks with ichdr.count==0, which means that it's part of the
      ondisk format now.
      
      Unfortunately, this check has been added and removed multiple times
      throughout history.  It first appeared in[1] kernel 3.10 as part of the
      early V5 format patches.  The check was later discovered to break log
      recovery and hence disabled[2] during log recovery in kernel 4.10.
      Simultaneously, the check was added[3] to xfs_repair 4.9.0 to try to
      weed out the empty leaf blocks.  This was still not correct because log
      recovery would recover an empty attr leaf block successfully only for
      regular xattr operations to trip over the empty block during of the
      block during regular operation.  Therefore, the check was removed
      entirely[4] in kernel 5.7 but removal of the xfs_repair check was
      forgotten.  The continued complaints from xfs_repair lead to us
      mistakenly re-adding[5] the verifier check for kernel 5.19.  Remove it
      once again.
      
      [1] 517c2220 ("xfs: add CRCs to attr leaf blocks")
      [2] 2e1d2337 ("xfs: ignore leaf attr ichdr.count in verifier
                         during log replay")
      [3] f7140161 ("xfs_repair: junk leaf attribute if count == 0")
      [4] f28cef9e ("xfs: don't fail verifier on empty attr3 leaf
                         block")
      [5] 51e6104f ("xfs: detect empty attr leaf blocks in
                         xfs_attr3_leaf_verify")
      
      Looking at the rest of the xattr code, it seems that files with empty
      leaf blocks behave as expected -- listxattr reports no attributes;
      getxattr on any xattr returns nothing as expected; removexattr does
      nothing; and setxattr can add attributes just fine.
      
      Original-bug: 517c2220 ("xfs: add CRCs to attr leaf blocks")
      Still-not-fixed-by: 2e1d2337 ("xfs: ignore leaf attr ichdr.count in verifier during log replay")
      Removed-in: f28cef9e ("xfs: don't fail verifier on empty attr3 leaf block")
      Fixes: 51e6104f ("xfs: detect empty attr leaf blocks in xfs_attr3_leaf_verify")
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      7be3bd88
  4. 26 Jun, 2022 4 commits
    • Darrick J. Wong's avatar
      xfs: clean up the end of xfs_attri_item_recover · f94e08b6
      Darrick J. Wong authored
      The end of this function could use some cleanup -- the EAGAIN
      conditionals make it harder to figure out what's going on with the
      disposal of xattri_leaf_bp, and the dual error/ret variables aren't
      needed.  Turn the EAGAIN case into a separate block documenting all the
      subtleties of recovering in the middle of an xattr update chain, which
      makes the rest of the prologue much simpler.
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      f94e08b6
    • Darrick J. Wong's avatar
      xfs: always free xattri_leaf_bp when cancelling a deferred op · b822ea17
      Darrick J. Wong authored
      While running the following fstest with logged xattrs DISabled, I
      noticed the following:
      
      # FSSTRESS_AVOID="-z -f unlink=1 -f rmdir=1 -f creat=2 -f mkdir=2 -f
      getfattr=3 -f listfattr=3 -f attr_remove=4 -f removefattr=4 -f
      setfattr=20 -f attr_set=60" ./check generic/475
      
      INFO: task u9:1:40 blocked for more than 61 seconds.
            Tainted: G           O      5.19.0-rc2-djwx #rc2
      "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
      task:u9:1            state:D stack:12872 pid:   40 ppid:     2 flags:0x00004000
      Workqueue: xfs-cil/dm-0 xlog_cil_push_work [xfs]
      Call Trace:
       <TASK>
       __schedule+0x2db/0x1110
       schedule+0x58/0xc0
       schedule_timeout+0x115/0x160
       __down_common+0x126/0x210
       down+0x54/0x70
       xfs_buf_lock+0x2d/0xe0 [xfs 0532c1cb1d67dd81d15cb79ac6e415c8dec58f73]
       xfs_buf_item_unpin+0x227/0x3a0 [xfs 0532c1cb1d67dd81d15cb79ac6e415c8dec58f73]
       xfs_trans_committed_bulk+0x18e/0x320 [xfs 0532c1cb1d67dd81d15cb79ac6e415c8dec58f73]
       xlog_cil_committed+0x2ea/0x360 [xfs 0532c1cb1d67dd81d15cb79ac6e415c8dec58f73]
       xlog_cil_push_work+0x60f/0x690 [xfs 0532c1cb1d67dd81d15cb79ac6e415c8dec58f73]
       process_one_work+0x1df/0x3c0
       worker_thread+0x53/0x3b0
       kthread+0xea/0x110
       ret_from_fork+0x1f/0x30
       </TASK>
      
      This appears to be the result of shortform_to_leaf creating a new leaf
      buffer as part of adding an xattr to a file.  The new leaf buffer is
      held and attached to the xfs_attr_intent structure, but then the
      filesystem shuts down.  Instead of the usual path (which adds the attr
      to the held leaf buffer which releases the hold), we instead cancel the
      entire deferred operation.
      
      Unfortunately, xfs_attr_cancel_item doesn't release any attached leaf
      buffers, so we leak the locked buffer.  The CIL cannot do anything
      about that, and hangs.  Fix this by teaching it to release leaf buffers,
      and make XFS a little more careful about not leaving a dangling
      reference.
      
      The prologue of xfs_attri_item_recover is (in this author's opinion) a
      little hard to figure out, so I'll clean that up in the next patch.
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      b822ea17
    • Kaixu Xia's avatar
      xfs: use invalidate_lock to check the state of mmap_lock · 82af8806
      Kaixu Xia authored
      We should use invalidate_lock and XFS_MMAPLOCK_SHARED to check the state
      of mmap_lock rw_semaphore in xfs_isilocked(), rather than i_rwsem and
      XFS_IOLOCK_SHARED.
      
      Fixes: 2433480a ("xfs: Convert to use invalidate_lock")
      Signed-off-by: default avatarKaixu Xia <kaixuxia@tencent.com>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      82af8806
    • Kaixu Xia's avatar
      xfs: factor out the common lock flags assert · ca76a761
      Kaixu Xia authored
      There are similar lock flags assert in xfs_ilock(), xfs_ilock_nowait(),
      xfs_iunlock(), thus we can factor it out into a helper that is clear.
      Signed-off-by: default avatarKaixu Xia <kaixuxia@tencent.com>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      ca76a761
  5. 23 Jun, 2022 2 commits
    • Dave Chinner's avatar
      xfs: introduce xfs_inodegc_push() · 5e672cd6
      Dave Chinner authored
      The current blocking mechanism for pushing the inodegc queue out to
      disk can result in systems becoming unusable when there is a long
      running inodegc operation. This is because the statfs()
      implementation currently issues a blocking flush of the inodegc
      queue and a significant number of common system utilities will call
      statfs() to discover something about the underlying filesystem.
      
      This can result in userspace operations getting stuck on inodegc
      progress, and when trying to remove a heavily reflinked file on slow
      storage with a full journal, this can result in delays measuring in
      hours.
      
      Avoid this problem by adding "push" function that expedites the
      flushing of the inodegc queue, but doesn't wait for it to complete.
      
      Convert xfs_fs_statfs() and xfs_qm_scall_getquota() to use this
      mechanism so they don't block but still ensure that queued
      operations are expedited.
      
      Fixes: ab23a776 ("xfs: per-cpu deferred inode inactivation queues")
      Reported-by: default avatarChris Dunlop <chris@onthe.net.au>
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      [djwong: fix _getquota_next to use _inodegc_push too]
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      5e672cd6
    • Dave Chinner's avatar
      xfs: bound maximum wait time for inodegc work · 7cf2b0f9
      Dave Chinner authored
      Currently inodegc work can sit queued on the per-cpu queue until
      the workqueue is either flushed of the queue reaches a depth that
      triggers work queuing (and later throttling). This means that we
      could queue work that waits for a long time for some other event to
      trigger flushing.
      
      Hence instead of just queueing work at a specific depth, use a
      delayed work that queues the work at a bound time. We can still
      schedule the work immediately at a given depth, but we no long need
      to worry about leaving a number of items on the list that won't get
      processed until external events prevail.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      7cf2b0f9
  6. 16 Jun, 2022 3 commits
    • Darrick J. Wong's avatar
      xfs: preserve DIFLAG2_NREXT64 when setting other inode attributes · e89ab76d
      Darrick J. Wong authored
      It is vitally important that we preserve the state of the NREXT64 inode
      flag when we're changing the other flags2 fields.
      
      Fixes: 9b7d16e3 ("xfs: Introduce XFS_DIFLAG2_NREXT64 and associated helpers")
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChandan Babu R <chandan.babu@oracle.com>
      Reviewed-by: default avatarAllison Henderson <allison.henderson@oracle.com>
      e89ab76d
    • Darrick J. Wong's avatar
      xfs: fix variable state usage · 10930b25
      Darrick J. Wong authored
      The variable @args is fed to a tracepoint, and that's the only place
      it's used.  This is fine for the kernel, but for userspace, tracepoints
      are #define'd out of existence, which results in this warning on gcc
      11.2:
      
      xfs_attr.c: In function ‘xfs_attr_node_try_addname’:
      xfs_attr.c:1440:42: warning: unused variable ‘args’ [-Wunused-variable]
       1440 |         struct xfs_da_args              *args = attr->xattri_da_args;
            |                                          ^~~~
      
      Clean this up.
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarAllison Henderson <allison.henderson@oracle.com>
      10930b25
    • Darrick J. Wong's avatar
      xfs: fix TOCTOU race involving the new logged xattrs control knob · f4288f01
      Darrick J. Wong authored
      I found a race involving the larp control knob, aka the debugging knob
      that lets developers enable logging of extended attribute updates:
      
      Thread 1			Thread 2
      
      echo 0 > /sys/fs/xfs/debug/larp
      				setxattr(REPLACE)
      				xfs_has_larp (returns false)
      				xfs_attr_set
      
      echo 1 > /sys/fs/xfs/debug/larp
      
      				xfs_attr_defer_replace
      				xfs_attr_init_replace_state
      				xfs_has_larp (returns true)
      				xfs_attr_init_remove_state
      
      				<oops, wrong DAS state!>
      
      This isn't a particularly severe problem right now because xattr logging
      is only enabled when CONFIG_XFS_DEBUG=y, and developers *should* know
      what they're doing.
      
      However, the eventual intent is that callers should be able to ask for
      the assistance of the log in persisting xattr updates.  This capability
      might not be required for /all/ callers, which means that dynamic
      control must work correctly.  Once an xattr update has decided whether
      or not to use logged xattrs, it needs to stay in that mode until the end
      of the operation regardless of what subsequent parallel operations might
      do.
      
      Therefore, it is an error to continue sampling xfs_globals.larp once
      xfs_attr_change has made a decision about larp, and it was not correct
      for me to have told Allison that ->create_intent functions can sample
      the global log incompat feature bitfield to decide to elide a log item.
      
      Instead, create a new op flag for the xfs_da_args structure, and convert
      all other callers of xfs_has_larp and xfs_sb_version_haslogxattrs within
      the attr update state machine to look for the operations flag.
      Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
      Reviewed-by: default avatarAllison Henderson <allison.henderson@oracle.com>
      f4288f01
  7. 12 Jun, 2022 10 commits
  8. 11 Jun, 2022 9 commits
    • Linus Torvalds's avatar
      Merge tag 'gpio-fixes-for-v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux · 7a68065e
      Linus Torvalds authored
      Pull gpio fixes from Bartosz Golaszewski:
       "A set of fixes. Most address the new warning we emit at build time
        when irq chips are not immutable with some additional tweaks to
        gpio-crystalcove from Andy and a small tweak to gpio-dwapd.
      
         - make irq_chip structs immutable in several Diolan and intel drivers
           to get rid of the new warning we emit when fiddling with irq chips
      
         - don't print error messages on probe deferral in gpio-dwapb"
      
      * tag 'gpio-fixes-for-v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
        gpio: dwapb: Don't print error on -EPROBE_DEFER
        gpio: dln2: make irq_chip immutable
        gpio: sch: make irq_chip immutable
        gpio: merrifield: make irq_chip immutable
        gpio: wcove: make irq_chip immutable
        gpio: crystalcove: Join function declarations and long lines
        gpio: crystalcove: Use specific type and API for IRQ number
        gpio: crystalcove: make irq_chip immutable
      7a68065e
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · cecb3540
      Linus Torvalds authored
      Pull SCSI fixes from James Bottomley:
       "Driver fixes and and one core patch.
      
        Nine of the driver patches are minor fixes and reworks to lpfc and the
        rest are trivial and minor fixes elsewhere"
      
      * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
        scsi: pmcraid: Fix missing resource cleanup in error case
        scsi: ipr: Fix missing/incorrect resource cleanup in error case
        scsi: mpt3sas: Fix out-of-bounds compiler warning
        scsi: lpfc: Update lpfc version to 14.2.0.4
        scsi: lpfc: Allow reduced polling rate for nvme_admin_async_event cmd completion
        scsi: lpfc: Add more logging of cmd and cqe information for aborted NVMe cmds
        scsi: lpfc: Fix port stuck in bypassed state after LIP in PT2PT topology
        scsi: lpfc: Resolve NULL ptr dereference after an ELS LOGO is aborted
        scsi: lpfc: Address NULL pointer dereference after starget_to_rport()
        scsi: lpfc: Resolve some cleanup issues following SLI path refactoring
        scsi: lpfc: Resolve some cleanup issues following abort path refactoring
        scsi: lpfc: Correct BDE type for XMIT_SEQ64_WQE in lpfc_ct_reject_event()
        scsi: vmw_pvscsi: Expand vcpuHint to 16 bits
        scsi: sd: Fix interpretation of VPD B9h length
      cecb3540
    • Linus Torvalds's avatar
      Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost · abe71eb3
      Linus Torvalds authored
      Pull virtio fixes from Michael Tsirkin:
       "Fixes all over the place, most notably fixes for latent bugs in
        drivers that got exposed by suppressing interrupts before DRIVER_OK,
        which in turn has been done by 8b4ec69d ("virtio: harden vring
        IRQ")"
      
      * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
        um: virt-pci: set device ready in probe()
        vdpa: make get_vq_group and set_group_asid optional
        virtio: Fix all occurences of the "the the" typo
        vduse: Fix NULL pointer dereference on sysfs access
        vringh: Fix loop descriptors check in the indirect cases
        vdpa/mlx5: clean up indenting in handle_ctrl_vlan()
        vdpa/mlx5: fix error code for deleting vlan
        virtio-mmio: fix missing put_device() when vm_cmdline_parent registration failed
        vdpa/mlx5: Fix syntax errors in comments
        virtio-rng: make device ready before making request
      abe71eb3
    • Linus Torvalds's avatar
      Merge tag 'loongarch-fixes-5.19-1' of... · 0678afa6
      Linus Torvalds authored
      Merge tag 'loongarch-fixes-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
      
      Pull LoongArch fixes from Huacai Chen.
       "Fix build errors and a stale comment"
      
      * tag 'loongarch-fixes-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
        LoongArch: Remove MIPS comment about cycle counter
        LoongArch: Fix copy_thread() build errors
        LoongArch: Fix the !CONFIG_SMP build
      0678afa6
    • Linus Torvalds's avatar
      iov_iter: fix build issue due to possible type mis-match · 1c27f1fc
      Linus Torvalds authored
      Commit 6c776766 ("iov_iter: Fix iter_xarray_get_pages{,_alloc}()")
      introduced a problem on some 32-bit architectures (at least arm, xtensa,
      csky,sparc and mips), that have a 'size_t' that is 'unsigned int'.
      
      The reason is that we now do
      
          min(nr * PAGE_SIZE - offset, maxsize);
      
      where 'nr' and 'offset' and both 'unsigned int', and PAGE_SIZE is
      'unsigned long'.  As a result, the normal C type rules means that the
      first argument to 'min()' ends up being 'unsigned long'.
      
      In contrast, 'maxsize' is of type 'size_t'.
      
      Now, 'size_t' and 'unsigned long' are always the same physical type in
      the kernel, so you'd think this doesn't matter, and from an actual
      arithmetic standpoint it doesn't.
      
      But on 32-bit architectures 'size_t' is commonly 'unsigned int', even if
      it could also be 'unsigned long'.  In that situation, both are unsigned
      32-bit types, but they are not the *same* type.
      
      And as a result 'min()' will complain about the distinct types (ignore
      the "pointer types" part of the error message: that's an artifact of the
      way we have made 'min()' check types for being the same):
      
        lib/iov_iter.c: In function 'iter_xarray_get_pages':
        include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast [-Werror]
           20 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
              |                                   ^~
        lib/iov_iter.c:1464:16: note: in expansion of macro 'min'
         1464 |         return min(nr * PAGE_SIZE - offset, maxsize);
              |                ^~~
      
      This was not visible on 64-bit architectures (where we always define
      'size_t' to be 'unsigned long').
      
      Force these cases to use 'min_t(size_t, x, y)' to make the type explicit
      and avoid the issue.
      
      [ Nit-picky note: technically 'size_t' doesn't have to match 'unsigned
        long' arithmetically. We've certainly historically seen environments
        with 16-bit address spaces and 32-bit 'unsigned long'.
      
        Similarly, even in 64-bit modern environments, 'size_t' could be its
        own type distinct from 'unsigned long', even if it were arithmetically
        identical.
      
        So the above type commentary is only really descriptive of the kernel
        environment, not some kind of universal truth for the kinds of wild
        and crazy situations that are allowed by the C standard ]
      Reported-by: default avatarSudip Mukherjee <sudipm.mukherjee@gmail.com>
      Link: https://lore.kernel.org/all/YqRyL2sIqQNDfky2@debian/
      Cc: Jeff Layton <jlayton@kernel.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1c27f1fc
    • Jason A. Donenfeld's avatar
      wireguard: selftests: use maximum cpu features and allow rng seeding · 17b0128a
      Jason A. Donenfeld authored
      By forcing the maximum CPU that QEMU has available, we expose additional
      capabilities, such as the RNDR instruction, which increases test
      coverage. This then allows the CI to skip the fake seeding step in some
      cases. Also enable STRICT_KERNEL_RWX to catch issues related to early
      jump labels when the RNG is initialized at boot.
      Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
      17b0128a
    • Kuan-Ying Lee's avatar
      scripts/gdb: change kernel config dumping method · 1f7a6cf6
      Kuan-Ying Lee authored
      MAGIC_START("IKCFG_ST") and MAGIC_END("IKCFG_ED") are moved out
      from the kernel_config_data variable.
      
      Thus, we parse kernel_config_data directly instead of considering
      offset of MAGIC_START and MAGIC_END.
      
      Fixes: 13610aa9 ("kernel/configs: use .incbin directive to embed config_data.gz")
      Signed-off-by: default avatarKuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
      Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      1f7a6cf6
    • Vincent Whitchurch's avatar
      um: virt-pci: set device ready in probe() · eacea844
      Vincent Whitchurch authored
      Call virtio_device_ready() to make this driver work after commit
      b4ec69d7e09 ("virtio: harden vring IRQ"), since the driver uses the
      virtqueues in the probe function.  (The virtio core sets the device
      ready when probe returns.)
      
      Fixes: 8b4ec69d ("virtio: harden vring IRQ")
      Fixes: 68f5d3f3 ("um: add PCI over virtio emulation driver")
      Signed-off-by: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
      Message-Id: <20220610151203.3492541-1-vincent.whitchurch@axis.com>
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Tested-by: default avatarJohannes Berg <johannes@sipsolutions.net>
      eacea844
    • Linus Torvalds's avatar
      Merge tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux · 0885eacd
      Linus Torvalds authored
      Pull nfsd fixes from Chuck Lever:
       "Notable changes:
      
         - There is now a backup maintainer for NFSD
      
        Notable fixes:
      
         - Prevent array overruns in svc_rdma_build_writes()
      
         - Prevent buffer overruns when encoding NFSv3 READDIR results
      
         - Fix a potential UAF in nfsd_file_put()"
      
      * tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
        SUNRPC: Remove pointer type casts from xdr_get_next_encode_buffer()
        SUNRPC: Clean up xdr_get_next_encode_buffer()
        SUNRPC: Clean up xdr_commit_encode()
        SUNRPC: Optimize xdr_reserve_space()
        SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()
        SUNRPC: Trap RDMA segment overflows
        NFSD: Fix potential use-after-free in nfsd_file_put()
        MAINTAINERS: reciprocal co-maintainership for file locking and nfsd
      0885eacd
  9. 10 Jun, 2022 2 commits