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  1. 24 Oct, 2023 1 commit
  3. 23 Oct, 2023 3 commits
    • Linus Torvalds's avatar
      Merge tag 'for-6.6-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux · e017769f
      Linus Torvalds authored 
      Pull btrfs fix from David Sterba:
 "One more fix for a problem with snapshot of a newly created subvolume
  that can lead to inconsistent data under some circumstances. Kernel
  6.5 added a performance optimization to skip transaction commit for
  subvolume creation but this could end up with newer data on disk but
  not linked to other structures.

  The fix itself is an added condition, the rest of the patch is a
  parameter added to several functions"

* tag 'for-6.6-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix unwritten extent buffer after snapshotting a new subvolume
      e017769f
    • Linus Torvalds's avatar
      Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost · 7c145640
      Linus Torvalds authored 
      Pull virtio fixes from Michael Tsirkin:
 "A collection of small fixes that look like worth having in this
  release"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_pci: fix the common cfg map size
  virtio-crypto: handle config changed by work queue
  vhost: Allow null msg.size on VHOST_IOTLB_INVALIDATE
  vdpa/mlx5: Fix firmware error on creation of 1k VQs
  virtio_balloon: Fix endless deflation and inflation on arm64
  vdpa/mlx5: Fix double release of debugfs entry
  virtio-mmio: fix memory leak of vm_dev
  vdpa_sim_blk: Fix the potential leak of mgmt_dev
  tools/virtio: Add dma sync api for virtio test
      7c145640
    • Filipe Manana's avatar
      btrfs: fix unwritten extent buffer after snapshotting a new subvolume · eb96e221
      Filipe Manana authored 
      When creating a snapshot of a subvolume that was created in the current
transaction, we can end up not persisting a dirty extent buffer that is
referenced by the snapshot, resulting in IO errors due to checksum failures
when trying to read the extent buffer later from disk. A sequence of steps
that leads to this is the following:

1) At ioctl.c:create_subvol() we allocate an extent buffer, with logical
   address 36007936, for the leaf/root of a new subvolume that has an ID
   of 291. We mark the extent buffer as dirty, and at this point the
   subvolume tree has a single node/leaf which is also its root (level 0);

2) We no longer commit the transaction used to create the subvolume at
   create_subvol(). We used to, but that was recently removed in
   commit 1b53e51a ("btrfs: don't commit transaction for every subvol
   create");

3) The transaction used to create the subvolume has an ID of 33, so the
   extent buffer 36007936 has a generation of 33;

4) Several updates happen to subvolume 291 during transaction 33, several
   files created and its tree height changes from 0 to 1, so we end up with
   a new root at level 1 and the extent buffer 36007936 is now a leaf of
   that new root node, which is extent buffer 36048896.

   The commit root remains as 36007936, since we are still at transaction
   33;

5) Creation of a snapshot of subvolume 291, with an ID of 292, starts at
   ioctl.c:create_snapshot(). This triggers a commit of transaction 33 and
   we end up at transaction.c:create_pending_snapshot(), in the critical
   section of a transaction commit.

   There we COW the root of subvolume 291, which is extent buffer 36048896.
   The COW operation returns extent buffer 36048896, since there's no need
   to COW because the extent buffer was created in this transaction and it
   was not written yet.

   The we call btrfs_copy_root() against the root node 36048896. During
   this operation we allocate a new extent buffer to turn into the root
   node of the snapshot, copy the contents of the root node 36048896 into
   this snapshot root extent buffer, set the owner to 292 (the ID of the
   snapshot), etc, and then we call btrfs_inc_ref(). This will create a
   delayed reference for each leaf pointed by the root node with a
   reference root of 292 - this includes a reference for the leaf
   36007936.

   After that we set the bit BTRFS_ROOT_FORCE_COW in the root's state.

   Then we call btrfs_insert_dir_item(), to create the directory entry in
   in the tree of subvolume 291 that points to the snapshot. This ends up
   needing to modify leaf 36007936 to insert the respective directory
   items. Because the bit BTRFS_ROOT_FORCE_COW is set for the root's state,
   we need to COW the leaf. We end up at btrfs_force_cow_block() and then
   at update_ref_for_cow().

   At update_ref_for_cow() we call btrfs_block_can_be_shared() which
   returns false, despite the fact the leaf 36007936 is shared - the
   subvolume's root and the snapshot's root point to that leaf. The
   reason that it incorrectly returns false is because the commit root
   of the subvolume is extent buffer 36007936 - it was the initial root
   of the subvolume when we created it. So btrfs_block_can_be_shared()
   which has the following logic:

   int btrfs_block_can_be_shared(struct btrfs_root *root,
                                 struct extent_buffer *buf)
   {
       if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
           buf != root->node && buf != root->commit_root &&
           (btrfs_header_generation(buf) <=
            btrfs_root_last_snapshot(&root->root_item) ||
            btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
               return 1;

       return 0;
   }

   Returns false (0) since 'buf' (extent buffer 36007936) matches the
   root's commit root.

   As a result, at update_ref_for_cow(), we don't check for the number
   of references for extent buffer 36007936, we just assume it's not
   shared and therefore that it has only 1 reference, so we set the local
   variable 'refs' to 1.

   Later on, in the final if-else statement at update_ref_for_cow():

   static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
                                          struct btrfs_root *root,
                                          struct extent_buffer *buf,
                                          struct extent_buffer *cow,
                                          int *last_ref)
   {
      (...)
      if (refs > 1) {
          (...)
      } else {
          (...)
          btrfs_clear_buffer_dirty(trans, buf);
          *last_ref = 1;
      }
   }

   So we mark the extent buffer 36007936 as not dirty, and as a result
   we don't write it to disk later in the transaction commit, despite the
   fact that the snapshot's root points to it.

   Attempting to access the leaf or dumping the tree for example shows
   that the extent buffer was not written:

   $ btrfs inspect-internal dump-tree -t 292 /dev/sdb
   btrfs-progs v6.2.2
   file tree key (292 ROOT_ITEM 33)
   node 36110336 level 1 items 2 free space 119 generation 33 owner 292
   node 36110336 flags 0x1(WRITTEN) backref revision 1
   checksum stored a8103e3e
   checksum calced a8103e3e
   fs uuid 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79
   chunk uuid e8c9c885-78f4-4d31-85fe-89e5f5fd4a07
           key (256 INODE_ITEM 0) block 36007936 gen 33
           key (257 EXTENT_DATA 0) block 36052992 gen 33
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   total bytes 107374182400
   bytes used 38572032
   uuid 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79

   The respective on disk region is full of zeroes as the device was
   trimmed at mkfs time.

   Obviously 'btrfs check' also detects and complains about this:

   $ btrfs check /dev/sdb
   Opening filesystem to check...
   Checking filesystem on /dev/sdb
   UUID: 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79
   generation: 33 (33)
   [1/7] checking root items
   [2/7] checking extents
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   bad tree block 36007936, bytenr mismatch, want=36007936, have=0
   owner ref check failed [36007936 4096]
   ERROR: errors found in extent allocation tree or chunk allocation
   [3/7] checking free space tree
   [4/7] checking fs roots
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
   bad tree block 36007936, bytenr mismatch, want=36007936, have=0
   The following tree block(s) is corrupted in tree 292:
        tree block bytenr: 36110336, level: 1, node key: (256, 1, 0)
   root 292 root dir 256 not found
   ERROR: errors found in fs roots
   found 38572032 bytes used, error(s) found
   total csum bytes: 16048
   total tree bytes: 1265664
   total fs tree bytes: 1118208
   total extent tree bytes: 65536
   btree space waste bytes: 562598
   file data blocks allocated: 65978368
    referenced 36569088

Fix this by updating btrfs_block_can_be_shared() to consider that an
extent buffer may be shared if it matches the commit root and if its
generation matches the current transaction's generation.

This can be reproduced with the following script:

   $ cat test.sh
   #!/bin/bash

   MNT=/mnt/sdi
   DEV=/dev/sdi

   # Use a filesystem with a 64K node size so that we have the same node
   # size on every machine regardless of its page size (on x86_64 default
   # node size is 16K due to the 4K page size, while on PPC it's 64K by
   # default). This way we can make sure we are able to create a btree for
   # the subvolume with a height of 2.
   mkfs.btrfs -f -n 64K $DEV
   mount $DEV $MNT

   btrfs subvolume create $MNT/subvol

   # Create a few empty files on the subvolume, this bumps its btree
   # height to 2 (root node at level 1 and 2 leaves).
   for ((i = 1; i <= 300; i++)); do
       echo -n > $MNT/subvol/file_$i
   done

   btrfs subvolume snapshot -r $MNT/subvol $MNT/subvol/snap

   umount $DEV

   btrfs check $DEV

Running it on a 6.5 kernel (or any 6.6-rc kernel at the moment):

   $ ./test.sh
   Create subvolume '/mnt/sdi/subvol'
   Create a readonly snapshot of '/mnt/sdi/subvol' in '/mnt/sdi/subvol/snap'
   Opening filesystem to check...
   Checking filesystem on /dev/sdi
   UUID: bbdde2ff-7d02-45ca-8a73-3c36f23755a1
   [1/7] checking root items
   [2/7] checking extents
   parent transid verify failed on 30539776 wanted 7 found 5
   parent transid verify failed on 30539776 wanted 7 found 5
   parent transid verify failed on 30539776 wanted 7 found 5
   Ignoring transid failure
   owner ref check failed [30539776 65536]
   ERROR: errors found in extent allocation tree or chunk allocation
   [3/7] checking free space tree
   [4/7] checking fs roots
   parent transid verify failed on 30539776 wanted 7 found 5
   Ignoring transid failure
   Wrong key of child node/leaf, wanted: (256, 1, 0), have: (2, 132, 0)
   Wrong generation of child node/leaf, wanted: 5, have: 7
   root 257 root dir 256 not found
   ERROR: errors found in fs roots
   found 917504 bytes used, error(s) found
   total csum bytes: 0
   total tree bytes: 851968
   total fs tree bytes: 393216
   total extent tree bytes: 65536
   btree space waste bytes: 736550
   file data blocks allocated: 0
    referenced 0

A test case for fstests will follow soon.

Fixes: 1b53e51a ("btrfs: don't commit transaction for every subvol create")
CC: stable@vger.kernel.org # 6.5+
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>
      eb96e221
  5. 22 Oct, 2023 4 commits
    • Linus Torvalds's avatar
      Linux 6.6-rc7 · 05d3ef8b
      Linus Torvalds authored
      05d3ef8b
    • Linus Torvalds's avatar
      Merge tag 'phy-fixes-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy · fe3cfe86
      Linus Torvalds authored 
      Pull phy fixes from Vinod Koul:

 - mapphone-mdm6600 runtime pm & pinctrl handling fixes

 - Qualcomm qmp usb pcs register fixes, qmp pcie register size warning
   fix, m31 fixes for wrong pointer in PTR_ERR and dropping wrong vreg
   check, qmp combo fix for 8550 power config register

 - realtek usb fix for debugfs_create_dir() and kconfig dependency

* tag 'phy-fixes-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy:
  phy: realtek: Realtek PHYs should depend on ARCH_REALTEK
  phy: qualcomm: Fix typos in comments
  phy: qcom-qmp-combo: initialize PCS_USB registers
  phy: qcom-qmp-combo: Square out 8550 POWER_STATE_CONFIG1
  phy: qcom: m31: Remove unwanted qphy->vreg is NULL check
  phy: realtek: usb: Drop unnecessary error check for debugfs_create_dir()
  phy: qcom: phy-qcom-m31: change m31_ipq5332_regs to static
  phy: qcom: phy-qcom-m31: fix wrong pointer pass to PTR_ERR()
  dt-bindings: phy: qcom,ipq8074-qmp-pcie: fix warning regarding reg size
  phy: qcom-qmp-usb: split PCS_USB init table for sc8280xp and sa8775p
  phy: qcom-qmp-usb: initialize PCS_USB registers
  phy: mapphone-mdm6600: Fix pinctrl_pm handling for sleep pins
  phy: mapphone-mdm6600: Fix runtime PM for remove
  phy: mapphone-mdm6600: Fix runtime disable on probe
      fe3cfe86
    • Linus Torvalds's avatar
      Merge tag 'efi-fixes-for-v6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi · 70e65afc
      Linus Torvalds authored 
      Pull EFI fixes from Ard Biesheuvel:
 "The boot_params pointer fix uses a somewhat ugly extern struct
  declaration but this will be cleaned up the next cycle.

   - don't try to print warnings to the console when it is no longer
     available

   - fix theoretical memory leak in SSDT override handling

   - make sure that the boot_params global variable is set before the
     KASLR code attempts to hash it for 'randomness'

   - avoid soft lockups in the memory acceptance code"

* tag 'efi-fixes-for-v6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi/unaccepted: Fix soft lockups caused by parallel memory acceptance
  x86/boot: efistub: Assign global boot_params variable
  efi: fix memory leak in krealloc failure handling
  x86/efistub: Don't try to print after ExitBootService()
      70e65afc
    • Linus Torvalds's avatar
      Merge tag 'powerpc-6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 1acfd2bd
      Linus Torvalds authored 
      Pull powerpc fixes from Michael Ellerman:

 - Fix stale propagated yield_cpu in qspinlocks leading to lockups

 - Fix broken hugepages on some configs due to ARCH_FORCE_MAX_ORDER

 - Fix a spurious warning when copros are in use at exit time

Thanks to Nicholas Piggin, Christophe Leroy, Nysal Jan K.A Sachin Sant,
and Shrikanth Hegde.

* tag 'powerpc-6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/qspinlock: Fix stale propagated yield_cpu
  powerpc/64s/radix: Don't warn on copros in radix__tlb_flush()
  powerpc/mm: Allow ARCH_FORCE_MAX_ORDER up to 12
      1acfd2bd
  7. 21 Oct, 2023 10 commits
  9. 20 Oct, 2023 22 commits
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