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  1. 11 Mar, 2022 11 commits
  3. 06 Mar, 2022 5 commits
    • Linus Torvalds's avatar
      Linux 5.17-rc7 · ffb217a1
      Linus Torvalds authored
      ffb217a1
    • Linus Torvalds's avatar
      Merge tag 'for-5.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux · 3ee65c0f
      Linus Torvalds authored 
      Pull btrfs fixes from David Sterba:
 "A few more fixes for various problems that have user visible effects
  or seem to be urgent:

   - fix corruption when combining DIO and non-blocking io_uring over
     multiple extents (seen on MariaDB)

   - fix relocation crash due to premature return from commit

   - fix quota deadlock between rescan and qgroup removal

   - fix item data bounds checks in tree-checker (found on a fuzzed
     image)

   - fix fsync of prealloc extents after EOF

   - add missing run of delayed items after unlink during log replay

   - don't start relocation until snapshot drop is finished

   - fix reversed condition for subpage writers locking

   - fix warning on page error"

* tag 'for-5.17-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fallback to blocking mode when doing async dio over multiple extents
  btrfs: add missing run of delayed items after unlink during log replay
  btrfs: qgroup: fix deadlock between rescan worker and remove qgroup
  btrfs: fix relocation crash due to premature return from btrfs_commit_transaction()
  btrfs: do not start relocation until in progress drops are done
  btrfs: tree-checker: use u64 for item data end to avoid overflow
  btrfs: do not WARN_ON() if we have PageError set
  btrfs: fix lost prealloc extents beyond eof after full fsync
  btrfs: subpage: fix a wrong check on subpage->writers
      3ee65c0f
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · f81664f7
      Linus Torvalds authored 
      Pull kvm fixes from Paolo Bonzini:
 "x86 guest:

   - Tweaks to the paravirtualization code, to avoid using them when
     they're pointless or harmful

  x86 host:

   - Fix for SRCU lockdep splat

   - Brown paper bag fix for the propagation of errno"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: pull kvm->srcu read-side to kvm_arch_vcpu_ioctl_run
  KVM: x86/mmu: Passing up the error state of mmu_alloc_shadow_roots()
  KVM: x86: Yield to IPI target vCPU only if it is busy
  x86/kvmclock: Fix Hyper-V Isolated VM's boot issue when vCPUs > 64
  x86/kvm: Don't waste memory if kvmclock is disabled
  x86/kvm: Don't use PV TLB/yield when mwait is advertised
      f81664f7
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 9bdeaca1
      Linus Torvalds authored 
      Pull powerpc fix from Michael Ellerman:
 "Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set.

  Thanks to Murilo Opsfelder Araujo, and Erhard F"

* tag 'powerpc-5.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set
      9bdeaca1
    • Linus Torvalds's avatar
      Merge tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · f40a33f5
      Linus Torvalds authored 
      Pull tracing fixes from Steven Rostedt:

 - Fix sorting on old "cpu" value in histograms

 - Fix return value of __setup() boot parameter handlers

* tag 'trace-v5.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix return value of __setup handlers
  tracing/histogram: Fix sorting on old "cpu" value
      f40a33f5
  5. 05 Mar, 2022 13 commits
  7. 04 Mar, 2022 11 commits
    • Linus Torvalds's avatar
      Merge tag 'riscv-for-linus-5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux · 07ebd38a
      Linus Torvalds authored 
      Pull RISC-V fixes from Palmer Dabbelt:

 - Fixes for a handful of KASAN-related crashes.

 - A fix to avoid a crash during boot for SPARSEMEM &&
   !SPARSEMEM_VMEMMAP configurations.

 - A fix to stop reporting some incorrect errors under DEBUG_VIRTUAL.

 - A fix for the K210's device tree to properly populate the interrupt
   map, so hart1 will get interrupts again.

* tag 'riscv-for-linus-5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: dts: k210: fix broken IRQs on hart1
  riscv: Fix kasan pud population
  riscv: Move high_memory initialization to setup_bootmem
  riscv: Fix config KASAN && DEBUG_VIRTUAL
  riscv: Fix DEBUG_VIRTUAL false warnings
  riscv: Fix config KASAN && SPARSEMEM && !SPARSE_VMEMMAP
  riscv: Fix is_linear_mapping with recent move of KASAN region
      07ebd38a
    • Linus Torvalds's avatar
      Merge tag 'iommu-fixes-v5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu · 3f509f59
      Linus Torvalds authored 
      Pull iommu fixes from Joerg Roedel:

 - Fix a double list_add() in Intel VT-d code

 - Add missing put_device() in Tegra SMMU driver

 - Two AMD IOMMU fixes:
     - Memory leak in IO page-table freeing code
     - Add missing recovery from event-log overflow

* tag 'iommu-fixes-v5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find
  iommu/vt-d: Fix double list_add when enabling VMD in scalable mode
  iommu/amd: Fix I/O page table memory leak
  iommu/amd: Recover from event log overflow
      3f509f59
    • Linus Torvalds's avatar
      Merge tag 'thermal-5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · a4ffdb61
      Linus Torvalds authored 
      Pull thermal control fix from Rafael Wysocki:
 "Fix NULL pointer dereference in the thermal netlink interface (Nicolas
  Cavallari)"

* tag 'thermal-5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: core: Fix TZ_GET_TRIP NULL pointer dereference
      a4ffdb61
    • Linus Torvalds's avatar
      Merge tag 'sound-5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound · 8d670948
      Linus Torvalds authored 
      Pull sound fixes from Takashi Iwai:
 "Hopefully the last PR for 5.17, including just a few small changes:
  an additional fix for ASoC ops boundary check and other minor
  device-specific fixes"

* tag 'sound-5.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: intel_hdmi: Fix reference to PCM buffer address
  ASoC: cs4265: Fix the duplicated control name
  ASoC: ops: Shift tested values in snd_soc_put_volsw() by +min
      8d670948
    • Linus Torvalds's avatar
      Merge tag 'drm-fixes-2022-03-04' of git://anongit.freedesktop.org/drm/drm · c4fc118a
      Linus Torvalds authored 
      Pull drm fixes from Dave Airlie:
 "Things are quieting down as expected, just a small set of fixes, i915,
  exynos, amdgpu, vrr, bridge and hdlcd. Nothing scary at all.

  i915:
   - Fix GuC SLPC unset command
   - Fix misidentification of some Apple MacBook Pro laptops as Jasper Lake

  amdgpu:
   - Suspend regression fix

  exynos:
   - irq handling fixes
   - Fix two regressions to TE-gpio handling

  arm/hdlcd:
   - Select DRM_GEM_CMEA_HELPER for HDLCD

  bridge:
   - ti-sn65dsi86: Properly undo autosuspend

  vrr:
   - Fix potential NULL-pointer deref"

* tag 'drm-fixes-2022-03-04' of git://anongit.freedesktop.org/drm/drm:
  drm/amdgpu: fix suspend/resume hang regression
  drm/vrr: Set VRR capable prop only if it is attached to connector
  drm/arm: arm hdlcd select DRM_GEM_CMA_HELPER
  drm/bridge: ti-sn65dsi86: Properly undo autosuspend
  drm/i915: s/JSP2/ICP2/ PCH
  drm/i915/guc/slpc: Correct the param count for unset param
  drm/exynos: Search for TE-gpio in DSI panel's node
  drm/exynos: Don't fail if no TE-gpio is defined for DSI driver
  drm/exynos: gsc: Use platform_get_irq() to get the interrupt
  drm/exynos/fimc: Use platform_get_irq() to get the interrupt
  drm/exynos/exynos_drm_fimd: Use platform_get_irq_byname() to get the interrupt
  drm/exynos: mixer: Use platform_get_irq() to get the interrupt
  drm/exynos/exynos7_drm_decon: Use platform_get_irq_byname() to get the interrupt
      c4fc118a
    • Linus Torvalds's avatar
      Merge tag 'pinctrl-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl · 0b7344a6
      Linus Torvalds authored 
      Pull pin control fixes from Linus Walleij:
 "These two fixes should fix the issues seen on the OrangePi, first we
  needed the correct offset when calling pinctrl_gpio_direction(), and
  fixing that made a lockdep issue explode in our face. Both now fixed"

* tag 'pinctrl-v5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: sunxi: Use unique lockdep classes for IRQs
  pinctrl-sunxi: sunxi_pinctrl_gpio_direction_in/output: use correct offset
      0b7344a6
    • Randy Dunlap's avatar
      tracing: Fix return value of __setup handlers · 1d02b444
      Randy Dunlap authored 
      __setup() handlers should generally return 1 to indicate that the
boot options have been handled.

Using invalid option values causes the entire kernel boot option
string to be reported as Unknown and added to init's environment
strings, polluting it.

  Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
    kprobe_event=p,syscall_any,$arg1 trace_options=quiet
    trace_clock=jiffies", will be passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6
     kprobe_event=p,syscall_any,$arg1
     trace_options=quiet
     trace_clock=jiffies

Return 1 from the __setup() handlers so that init's environment is not
polluted with kernel boot options.

Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org

Cc: stable@vger.kernel.org
Fixes: 7bcfaf54 ("tracing: Add trace_options kernel command line parameter")
Fixes: e1e232ca ("tracing: Add trace_clock=<clock> kernel parameter")
Fixes: 970988e1 ("tracing/kprobe: Add kprobe_event= boot parameter")
Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Reported-by: default avatarIgor Zhbanov <i.zhbanov@omprussia.ru>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
      1d02b444
    • Daniel Borkmann's avatar
      mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls · 0708a0af
      Daniel Borkmann authored 
      syzkaller was recently triggering an oversized kvmalloc() warning via
xdp_umem_create().

The triggered warning was added back in 7661809d ("mm: don't allow
oversized kvmalloc() calls"). The rationale for the warning for huge
kvmalloc sizes was as a reaction to a security bug where the size was
more than UINT_MAX but not everything was prepared to handle unsigned
long sizes.

Anyway, the AF_XDP related call trace from this syzkaller report was:

  kvmalloc include/linux/mm.h:806 [inline]
  kvmalloc_array include/linux/mm.h:824 [inline]
  kvcalloc include/linux/mm.h:829 [inline]
  xdp_umem_pin_pages net/xdp/xdp_umem.c:102 [inline]
  xdp_umem_reg net/xdp/xdp_umem.c:219 [inline]
  xdp_umem_create+0x6a5/0xf00 net/xdp/xdp_umem.c:252
  xsk_setsockopt+0x604/0x790 net/xdp/xsk.c:1068
  __sys_setsockopt+0x1fd/0x4e0 net/socket.c:2176
  __do_sys_setsockopt net/socket.c:2187 [inline]
  __se_sys_setsockopt net/socket.c:2184 [inline]
  __x64_sys_setsockopt+0xb5/0x150 net/socket.c:2184
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Björn mentioned that requests for >2GB allocation can still be valid:

  The structure that is being allocated is the page-pinning accounting.
  AF_XDP has an internal limit of U32_MAX pages, which is *a lot*, but
  still fewer than what memcg allows (PAGE_COUNTER_MAX is a LONG_MAX/
  PAGE_SIZE on 64 bit systems). [...]

  I could just change from U32_MAX to INT_MAX, but as I stated earlier
  that has a hacky feeling to it. [...] From my perspective, the code
  isn't broken, with the memcg limits in consideration. [...]

Linus says:

  [...] Pretty much every time this has come up, the kernel warning has
  shown that yes, the code was broken and there really wasn't a reason
  for doing allocations that big.

  Of course, some people would be perfectly fine with the allocation
  failing, they just don't want the warning. I didn't want __GFP_NOWARN
  to shut it up originally because I wanted people to see all those
  cases, but these days I think we can just say "yeah, people can shut
  it up explicitly by saying 'go ahead and fail this allocation, don't
  warn about it'".

  So enough time has passed that by now I'd certainly be ok with [it].

Thus allow call-sites to silence such userspace triggered splats if the
allocation requests have __GFP_NOWARN. For xdp_umem_pin_pages()'s call
to kvcalloc() this is already the case, so nothing else needed there.

Fixes: 7661809d ("mm: don't allow oversized kvmalloc() calls")
Reported-by: syzbot+11421fbbff99b989670e@syzkaller.appspotmail.com
Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+11421fbbff99b989670e@syzkaller.appspotmail.com
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Link: https://lore.kernel.org/bpf/CAJ+HfNhyfsT5cS_U9EC213ducHs9k9zNxX9+abqC0kTrPbQ0gg@mail.gmail.com
Link: https://lore.kernel.org/bpf/20211201202905.b9892171e3f5b9a60f9da251@linux-foundation.orgReviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Ackd-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0708a0af
    • Filipe Manana's avatar
      btrfs: fallback to blocking mode when doing async dio over multiple extents · ca93e44b
      Filipe Manana authored 
      Some users recently reported that MariaDB was getting a read corruption
when using io_uring on top of btrfs. This started to happen in 5.16,
after commit 51bd9563 ("btrfs: fix deadlock due to page faults
during direct IO reads and writes"). That changed btrfs to use the new
iomap flag IOMAP_DIO_PARTIAL and to disable page faults before calling
iomap_dio_rw(). This was necessary to fix deadlocks when the iovector
corresponds to a memory mapped file region. That type of scenario is
exercised by test case generic/647 from fstests.

For this MariaDB scenario, we attempt to read 16K from file offset X
using IOCB_NOWAIT and io_uring. In that range we have 4 extents, each
with a size of 4K, and what happens is the following:

1) btrfs_direct_read() disables page faults and calls iomap_dio_rw();

2) iomap creates a struct iomap_dio object, its reference count is
   initialized to 1 and its ->size field is initialized to 0;

3) iomap calls btrfs_dio_iomap_begin() with file offset X, which finds
   the first 4K extent, and setups an iomap for this extent consisting
   of a single page;

4) At iomap_dio_bio_iter(), we are able to access the first page of the
   buffer (struct iov_iter) with bio_iov_iter_get_pages() without
   triggering a page fault;

5) iomap submits a bio for this 4K extent
   (iomap_dio_submit_bio() -> btrfs_submit_direct()) and increments
   the refcount on the struct iomap_dio object to 2; The ->size field
   of the struct iomap_dio object is incremented to 4K;

6) iomap calls btrfs_iomap_begin() again, this time with a file
   offset of X + 4K. There we setup an iomap for the next extent
   that also has a size of 4K;

7) Then at iomap_dio_bio_iter() we call bio_iov_iter_get_pages(),
   which tries to access the next page (2nd page) of the buffer.
   This triggers a page fault and returns -EFAULT;

8) At __iomap_dio_rw() we see the -EFAULT, but we reset the error
   to 0 because we passed the flag IOMAP_DIO_PARTIAL to iomap and
   the struct iomap_dio object has a ->size value of 4K (we submitted
   a bio for an extent already). The 'wait_for_completion' variable
   is not set to true, because our iocb has IOCB_NOWAIT set;

9) At the bottom of __iomap_dio_rw(), we decrement the reference count
   of the struct iomap_dio object from 2 to 1. Because we were not
   the only ones holding a reference on it and 'wait_for_completion' is
   set to false, -EIOCBQUEUED is returned to btrfs_direct_read(), which
   just returns it up the callchain, up to io_uring;

10) The bio submitted for the first extent (step 5) completes and its
    bio endio function, iomap_dio_bio_end_io(), decrements the last
    reference on the struct iomap_dio object, resulting in calling
    iomap_dio_complete_work() -> iomap_dio_complete().

11) At iomap_dio_complete() we adjust the iocb->ki_pos from X to X + 4K
    and return 4K (the amount of io done) to iomap_dio_complete_work();

12) iomap_dio_complete_work() calls the iocb completion callback,
    iocb->ki_complete() with a second argument value of 4K (total io
    done) and the iocb with the adjust ki_pos of X + 4K. This results
    in completing the read request for io_uring, leaving it with a
    result of 4K bytes read, and only the first page of the buffer
    filled in, while the remaining 3 pages, corresponding to the other
    3 extents, were not filled;

13) For the application, the result is unexpected because if we ask
    to read N bytes, it expects to get N bytes read as long as those
    N bytes don't cross the EOF (i_size).

MariaDB reports this as an error, as it's not expecting a short read,
since it knows it's asking for read operations fully within the i_size
boundary. This is typical in many applications, but it may also be
questionable if they should react to such short reads by issuing more
read calls to get the remaining data. Nevertheless, the short read
happened due to a change in btrfs regarding how it deals with page
faults while in the middle of a read operation, and there's no reason
why btrfs can't have the previous behaviour of returning the whole data
that was requested by the application.

The problem can also be triggered with the following simple program:

  /* Get O_DIRECT */
  #ifndef _GNU_SOURCE
  #define _GNU_SOURCE
  #endif

  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <string.h>
  #include <liburing.h>

  int main(int argc, char *argv[])
  {
      char *foo_path;
      struct io_uring ring;
      struct io_uring_sqe *sqe;
      struct io_uring_cqe *cqe;
      struct iovec iovec;
      int fd;
      long pagesize;
      void *write_buf;
      void *read_buf;
      ssize_t ret;
      int i;

      if (argc != 2) {
          fprintf(stderr, "Use: %s <directory>\n", argv[0]);
          return 1;
      }

      foo_path = malloc(strlen(argv[1]) + 5);
      if (!foo_path) {
          fprintf(stderr, "Failed to allocate memory for file path\n");
          return 1;
      }
      strcpy(foo_path, argv[1]);
      strcat(foo_path, "/foo");

      /*
       * Create file foo with 2 extents, each with a size matching
       * the page size. Then allocate a buffer to read both extents
       * with io_uring, using O_DIRECT and IOCB_NOWAIT. Before doing
       * the read with io_uring, access the first page of the buffer
       * to fault it in, so that during the read we only trigger a
       * page fault when accessing the second page of the buffer.
       */
       fd = open(foo_path, O_CREAT | O_TRUNC | O_WRONLY |
                O_DIRECT, 0666);
       if (fd == -1) {
           fprintf(stderr,
                   "Failed to create file 'foo': %s (errno %d)",
                   strerror(errno), errno);
           return 1;
       }

       pagesize = sysconf(_SC_PAGE_SIZE);
       ret = posix_memalign(&write_buf, pagesize, 2 * pagesize);
       if (ret) {
           fprintf(stderr, "Failed to allocate write buffer\n");
           return 1;
       }

       memset(write_buf, 0xab, pagesize);
       memset(write_buf + pagesize, 0xcd, pagesize);

       /* Create 2 extents, each with a size matching page size. */
       for (i = 0; i < 2; i++) {
           ret = pwrite(fd, write_buf + i * pagesize, pagesize,
                        i * pagesize);
           if (ret != pagesize) {
               fprintf(stderr,
                     "Failed to write to file, ret = %ld errno %d (%s)\n",
                      ret, errno, strerror(errno));
               return 1;
           }
           ret = fsync(fd);
           if (ret != 0) {
               fprintf(stderr, "Failed to fsync file\n");
               return 1;
           }
       }

       close(fd);
       fd = open(foo_path, O_RDONLY | O_DIRECT);
       if (fd == -1) {
           fprintf(stderr,
                   "Failed to open file 'foo': %s (errno %d)",
                   strerror(errno), errno);
           return 1;
       }

       ret = posix_memalign(&read_buf, pagesize, 2 * pagesize);
       if (ret) {
           fprintf(stderr, "Failed to allocate read buffer\n");
           return 1;
       }

       /*
        * Fault in only the first page of the read buffer.
        * We want to trigger a page fault for the 2nd page of the
        * read buffer during the read operation with io_uring
        * (O_DIRECT and IOCB_NOWAIT).
        */
       memset(read_buf, 0, 1);

       ret = io_uring_queue_init(1, &ring, 0);
       if (ret != 0) {
           fprintf(stderr, "Failed to create io_uring queue\n");
           return 1;
       }

       sqe = io_uring_get_sqe(&ring);
       if (!sqe) {
           fprintf(stderr, "Failed to get io_uring sqe\n");
           return 1;
       }

       iovec.iov_base = read_buf;
       iovec.iov_len = 2 * pagesize;
       io_uring_prep_readv(sqe, fd, &iovec, 1, 0);

       ret = io_uring_submit_and_wait(&ring, 1);
       if (ret != 1) {
           fprintf(stderr,
                   "Failed at io_uring_submit_and_wait()\n");
           return 1;
       }

       ret = io_uring_wait_cqe(&ring, &cqe);
       if (ret < 0) {
           fprintf(stderr, "Failed at io_uring_wait_cqe()\n");
           return 1;
       }

       printf("io_uring read result for file foo:\n\n");
       printf("  cqe->res == %d (expected %d)\n", cqe->res, 2 * pagesize);
       printf("  memcmp(read_buf, write_buf) == %d (expected 0)\n",
              memcmp(read_buf, write_buf, 2 * pagesize));

       io_uring_cqe_seen(&ring, cqe);
       io_uring_queue_exit(&ring);

       return 0;
  }

When running it on an unpatched kernel:

  $ gcc io_uring_test.c -luring
  $ mkfs.btrfs -f /dev/sda
  $ mount /dev/sda /mnt/sda
  $ ./a.out /mnt/sda
  io_uring read result for file foo:

    cqe->res == 4096 (expected 8192)
    memcmp(read_buf, write_buf) == -205 (expected 0)

After this patch, the read always returns 8192 bytes, with the buffer
filled with the correct data. Although that reproducer always triggers
the bug in my test vms, it's possible that it will not be so reliable
on other environments, as that can happen if the bio for the first
extent completes and decrements the reference on the struct iomap_dio
object before we do the atomic_dec_and_test() on the reference at
__iomap_dio_rw().

Fix this in btrfs by having btrfs_dio_iomap_begin() return -EAGAIN
whenever we try to satisfy a non blocking IO request (IOMAP_NOWAIT flag
set) over a range that spans multiple extents (or a mix of extents and
holes). This avoids returning success to the caller when we only did
partial IO, which is not optimal for writes and for reads it's actually
incorrect, as the caller doesn't expect to get less bytes read than it has
requested (unless EOF is crossed), as previously mentioned. This is also
the type of behaviour that xfs follows (xfs_direct_write_iomap_begin()),
even though it doesn't use IOMAP_DIO_PARTIAL.

A test case for fstests will follow soon.

Link: https://lore.kernel.org/linux-btrfs/CABVffEM0eEWho+206m470rtM0d9J8ue85TtR-A_oVTuGLWFicA@mail.gmail.com/
Link: https://lore.kernel.org/linux-btrfs/CAHF2GV6U32gmqSjLe=XKgfcZAmLCiH26cJ2OnHGp5x=VAH4OHQ@mail.gmail.com/
CC: stable@vger.kernel.org # 5.16+
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>
      ca93e44b
    • Niklas Cassel's avatar
      riscv: dts: k210: fix broken IRQs on hart1 · 74583f1b
      Niklas Cassel authored 
      Commit 67d96729 ("riscv: Update Canaan Kendryte K210 device tree")
incorrectly removed two entries from the PLIC interrupt-controller node's
interrupts-extended property.

The PLIC driver cannot know the mapping between hart contexts and hart ids,
so this information has to be provided by device tree, as specified by the
PLIC device tree binding.

The PLIC driver uses the interrupts-extended property, and initializes the
hart context registers in the exact same order as provided by the
interrupts-extended property.

In other words, if we don't specify the S-mode interrupts, the PLIC driver
will simply initialize the hart0 S-mode hart context with the hart1 M-mode
configuration. It is therefore essential to specify the S-mode IRQs even
though the system itself will only ever be running in M-mode.

Re-add the S-mode interrupts, so that we get working IRQs on hart1 again.

Cc: <stable@vger.kernel.org>
Fixes: 67d96729 ("riscv: Update Canaan Kendryte K210 device tree")
Signed-off-by: default avatarNiklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
      74583f1b
    • Dave Airlie's avatar
      Merge tag 'drm-misc-fixes-2022-03-03' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes · 8fdb1967
      Dave Airlie authored 
       * drm/arm: Select DRM_GEM_CMEA_HELPER for HDLCD
 * drm/bridge: ti-sn65dsi86: Properly undo autosuspend
 * drm/vrr: Fix potential NULL-pointer deref
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>

From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/YiCTGZ8IVCw0ilKK@linux-uq9g
      8fdb1967
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