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Josef Bacik 96a40c3fa3 btrfs: tree-checker: do not error out if extent ref hash doesn't match
commit 1119a72e22 upstream.

The tree checker checks the extent ref hash at read and write time to
make sure we do not corrupt the file system.  Generally extent
references go inline, but if we have enough of them we need to make an
item, which looks like

key.objectid	= <bytenr>
key.type	= <BTRFS_EXTENT_DATA_REF_KEY|BTRFS_TREE_BLOCK_REF_KEY>
key.offset	= hash(tree, owner, offset)

However if key.offset collide with an unrelated extent reference we'll
simply key.offset++ until we get something that doesn't collide.
Obviously this doesn't match at tree checker time, and thus we error
while writing out the transaction.  This is relatively easy to
reproduce, simply do something like the following

  xfs_io -f -c "pwrite 0 1M" file
  offset=2

  for i in {0..10000}
  do
	  xfs_io -c "reflink file 0 ${offset}M 1M" file
	  offset=$(( offset + 2 ))
  done

  xfs_io -c "reflink file 0 17999258914816 1M" file
  xfs_io -c "reflink file 0 35998517829632 1M" file
  xfs_io -c "reflink file 0 53752752058368 1M" file

  btrfs filesystem sync

And the sync will error out because we'll abort the transaction.  The
magic values above are used because they generate hash collisions with
the first file in the main subvol.

The fix for this is to remove the hash value check from tree checker, as
we have no idea which offset ours should belong to.

Reported-by: Tuomas Lähdekorpi <tuomas.lahdekorpi@gmail.com>
Fixes: 0785a9aacf ("btrfs: tree-checker: Add EXTENT_DATA_REF check")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10 13:37:01 +02:00
arch MIPS: ralink: export rt_sysc_membase for rt2880_wdt.c 2021-06-03 08:59:16 +02:00
block blk-mq: Swap two calls in blk_mq_exit_queue() 2021-05-19 10:08:30 +02:00
certs certs: Fix blacklist flag type confusion 2021-03-04 10:26:29 +01:00
crypto crypto: rng - fix crypto_rng_reset() refcounting when !CRYPTO_STATS 2021-05-11 14:04:15 +02:00
Documentation Documentation: seccomp: Fix user notification documentation 2021-06-03 08:59:03 +02:00
drivers usb: core: reduce power-on-good delay time of root hub 2021-06-03 08:59:16 +02:00
fs btrfs: tree-checker: do not error out if extent ref hash doesn't match 2021-06-10 13:37:01 +02:00
include net: sched: fix tx action rescheduling issue during deactivation 2021-06-03 08:59:13 +02:00
init init/Kconfig: make COMPILE_TEST depend on HAS_IOMEM 2021-04-10 13:34:32 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel bpf: No need to simulate speculative domain for immediates 2021-05-28 13:10:26 +02:00
lib lib: stackdepot: turn depot_lock spinlock to raw_spinlock 2021-05-22 11:38:30 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/hugetlb: fix F_SEAL_FUTURE_WRITE 2021-05-19 10:08:29 +02:00
net neighbour: Prevent Race condition in neighbour subsytem 2021-06-03 08:59:16 +02:00
samples samples/bpf: Fix broken tracex1 due to kprobe argument change 2021-05-19 10:08:23 +02:00
scripts scripts: switch explicitly to Python 3 2021-05-22 11:38:30 +02:00
security security: commoncap: fix -Wstringop-overread warning 2021-05-11 14:04:16 +02:00
sound Revert "Revert "ALSA: usx2y: Fix potential NULL pointer dereference"" 2021-06-03 08:59:16 +02:00
tools perf jevents: Fix getting maximum number of fds 2021-06-03 08:59:08 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: Initialize VCPU mdcr_el2 before loading it 2021-05-22 11:38:30 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.124 2021-06-03 08:59:17 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.