1. 16 Sep, 2019 34 commits
  2. 15 Sep, 2019 2 commits
    • Linus Torvalds's avatar
      Linux 5.3 · 4d856f72
      Linus Torvalds authored
      4d856f72
    • Linus Torvalds's avatar
      Revert "ext4: make __ext4_get_inode_loc plug" · 72dbcf72
      Linus Torvalds authored
      This reverts commit b03755ad.
      
      This is sad, and done for all the wrong reasons.  Because that commit is
      good, and does exactly what it says: avoids a lot of small disk requests
      for the inode table read-ahead.
      
      However, it turns out that it causes an entirely unrelated problem: the
      getrandom() system call was introduced back in 2014 by commit
      c6e9d6f3
      
       ("random: introduce getrandom(2) system call"), and people
      use it as a convenient source of good random numbers.
      
      But part of the current semantics for getrandom() is that it waits for
      the entropy pool to fill at least partially (unlike /dev/urandom).  And
      at least ArchLinux apparently has a systemd that uses getrandom() at
      boot time, and the improvements in IO patterns means that existing
      installations suddenly start hanging, waiting for entropy that will
      never happen.
      
      It seems to be an unlucky combination of not _quite_ enough entropy,
      together with a particular systemd version and configuration.  Lennart
      says that the systemd-random-seed process (which is what does this early
      access) is supposed to not block any other boot activity, but sadly that
      doesn't actually seem to be the case (possibly due bogus dependencies on
      cryptsetup for encrypted swapspace).
      
      The correct fix is to fix getrandom() to not block when it's not
      appropriate, but that fix is going to take a lot more discussion.  Do we
      just make it act like /dev/urandom by default, and add a new flag for
      "wait for entropy"? Do we add a boot-time option? Or do we just limit
      the amount of time it will wait for entropy?
      
      So in the meantime, we do the revert to give us time to discuss the
      eventual fix for the fundamental problem, at which point we can re-apply
      the ext4 inode table access optimization.
      
      Reported-by: default avatarAhmed S. Darwish <darwish.07@gmail.com>
      Cc: Ted Ts'o <tytso@mit.edu>
      Cc: Willy Tarreau <w@1wt.eu>
      Cc: Alexander E. Patrakov <patrakov@gmail.com>
      Cc: Lennart Poettering <mzxreary@0pointer.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      72dbcf72
  3. 14 Sep, 2019 4 commits
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 1609d760
      Linus Torvalds authored
      Pull kvm fixes from Paolo Bonzini:
       "The main change here is a revert of reverts. We recently simplified
        some code that was thought unnecessary; however, since then KVM has
        grown quite a few cond_resched()s and for that reason the simplified
        code is prone to livelocks---one CPUs tries to empty a list of guest
        page tables while the others keep adding to them. This adds back the
        generation-based zapping of guest page tables, which was not
        unnecessary after all.
      
        On top of this, there is a fix for a kernel memory leak and a couple
        of s390 fixlets as well"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
        KVM: x86/mmu: Reintroduce fast invalidate/zap for flushing memslot
        KVM: x86: work around leak of uninitialized stack contents
        KVM: nVMX: handle page fault in vmread
        KVM: s390: Do not leak kernel stack data in the KVM_S390_INTERRUPT ioctl
        KVM: s390: kvm_s390_vm_start_migration: check dirty_bitmap before using it as target for memset()
      1609d760
    • Linus Torvalds's avatar
      Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost · 1f9c632c
      Linus Torvalds authored
      Pull virtio fix from Michael Tsirkin:
       "A last minute revert
      
        The 32-bit build got broken by the latest defence in depth patch.
        Revert and we'll try again in the next cycle"
      
      * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
        Revert "vhost: block speculation of translated descriptors"
      1f9c632c
    • Linus Torvalds's avatar
      Merge tag 'riscv/for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux · b03c036e
      Linus Torvalds authored
      Pull RISC-V fix from Paul Walmsley:
       "Last week, Palmer and I learned that there was an error in the RISC-V
        kernel image header format that could make it less compatible with the
        ARM64 kernel image header format. I had missed this error during my
        original reviews of the patch.
      
        The kernel image header format is an interface that impacts
        bootloaders, QEMU, and other user tools. Those packages must be
        updated to align with whatever is merged in the kernel. We would like
        to avoid proliferating these image formats by keeping the RISC-V
        header as close as possible to the existing ARM64 header. Since the
        arch/riscv patch that adds support for the image header was merged
        with our v5.3-rc1 pull request as commit 0f327f2a ("RISC-V: Add
        an Image header that boot loader can parse."), we think it wise to try
        to fix this error before v5.3 is released.
      
        The fix itself should be backwards-compatible with any project that
        has already merged support for premature versions of this interface.
        It primarily involves ensuring that the RISC-V image header has
        something useful in the same field as the ARM64 image header"
      
      * tag 'riscv/for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
        riscv: modify the Image header to improve compatibility with the ARM64 header
      b03c036e
    • Michael S. Tsirkin's avatar
      Revert "vhost: block speculation of translated descriptors" · 0d4a3f2a
      Michael S. Tsirkin authored
      This reverts commit a89db445
      
      .
      
      I was hasty to include this patch, and it breaks the build on 32 bit.
      Defence in depth is good but let's do it properly.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      0d4a3f2a