Linux kernel source tree
Go to file
Johannes Thumshirn cebae292e0 btrfs: zoned: allocate dummy checksums for zoned NODATASUM writes
Shin'ichiro reported that when he's running fstests' test-case
btrfs/167 on emulated zoned devices, he's seeing the following NULL
pointer dereference in 'btrfs_zone_finish_endio()':

  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
  CPU: 4 PID: 2332440 Comm: kworker/u80:15 Tainted: G        W          6.10.0-rc2-kts+ #4
  Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]

  RSP: 0018:ffff88867f107a90 EFLAGS: 00010206
  RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff893e5534
  RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088
  RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed1081696028
  R10: ffff88840b4b0143 R11: ffff88834dfff600 R12: ffff88840b4b0000
  R13: 0000000000020000 R14: 0000000000000000 R15: ffff888530ad5210
  FS:  0000000000000000(0000) GS:ffff888e3f800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f87223fff38 CR3: 00000007a7c6a002 CR4: 00000000007706f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? __die_body.cold+0x19/0x27
   ? die_addr+0x46/0x70
   ? exc_general_protection+0x14f/0x250
   ? asm_exc_general_protection+0x26/0x30
   ? do_raw_read_unlock+0x44/0x70
   ? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
   btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs]
   ? __pfx_lock_release+0x10/0x10
   ? do_raw_write_lock+0x90/0x260
   ? __pfx_do_raw_write_lock+0x10/0x10
   ? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs]
   ? _raw_write_unlock+0x23/0x40
   ? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs]
   ? lock_acquire+0x435/0x500
   btrfs_work_helper+0x1b1/0xa70 [btrfs]
   ? __schedule+0x10a8/0x60b0
   ? __pfx___might_resched+0x10/0x10
   process_one_work+0x862/0x1410
   ? __pfx_lock_acquire+0x10/0x10
   ? __pfx_process_one_work+0x10/0x10
   ? assign_work+0x16c/0x240
   worker_thread+0x5e6/0x1010
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x2c3/0x3a0
   ? trace_irq_enable.constprop.0+0xce/0x110
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x31/0x70
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to
trigger:

  assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815

This indicates, that we're missing the checksums list on the
ordered_extent. As btrfs/167 is doing a NOCOW write this is to be
expected.

Further analysis with drgn confirmed the assumption:

  >>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode
  >>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \
         				"vfs_inode")
  >>> print(btrfs_inode.flags)
  (u32)1

As zoned emulation mode simulates conventional zones on regular devices,
we cannot use zone-append for writing. But we're only attaching dummy
checksums if we're doing a zone-append write.

So for NOCOW zoned data writes on conventional zones, also attach a
dummy checksum.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: cbfce4c7fb ("btrfs: optimize the logical to physical mapping for zoned writes")
CC: Naohiro Aota <Naohiro.Aota@wdc.com> # 6.6+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-06-13 20:43:55 +02:00
arch powerpc fixes for 6.9 #4 2024-05-05 10:44:04 -07:00
block bio: Export bio_add_folio_nofail to modules 2024-05-07 21:31:10 +02:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression that broke iwd as well as a divide by 2024-03-25 10:48:23 -07:00
Documentation Char/Misc driver fixes for 6.9-rc7 2024-05-05 10:08:52 -07:00
drivers Reapply "drm/qxl: simplify qxl_fence_wait" 2024-05-06 13:28:59 -07:00
fs btrfs: zoned: allocate dummy checksums for zoned NODATASUM writes 2024-06-13 20:43:55 +02:00
include btrfs: add tracepoints for extent map shrinker events 2024-05-07 21:31:07 +02:00
init Rust fixes for v6.9 2024-04-27 12:11:55 -07:00
io_uring io_uring/net: restore msg_control on sendzc retry 2024-04-08 21:48:41 -06:00
ipc sysctl changes for v6.9-rc1 2024-03-18 14:59:13 -07:00
kernel Fix suspicious RCU usage in __do_softirq(). 2024-05-05 10:12:32 -07:00
lib Char/Misc driver fixes for 6.9-rc7 2024-05-05 10:08:52 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm/slub: avoid zeroing outside-object freepointer for single free 2024-05-01 17:28:56 +02:00
net Including fixes from bpf. 2024-05-02 08:51:47 -07:00
rust rust: remove params from module macro example 2024-04-25 17:34:33 +02:00
samples Tracing updates for 6.9: 2024-03-18 15:11:44 -07:00
scripts Rust fixes for v6.9 2024-04-27 12:11:55 -07:00
security security: Place security_path_post_mknod() where the original IMA call was 2024-04-03 10:21:32 -07:00
sound ALSA: hda/realtek: Fix build error without CONFIG_PM 2024-05-02 08:25:06 +02:00
tools cxl fix for v6.9-rc7 2024-05-03 16:21:05 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start() 2024-04-11 12:58:53 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap bpf-for-netdev 2024-04-26 17:36:53 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS Including fixes from bpf. 2024-05-02 08:51:47 -07:00
Makefile Linux 6.9-rc7 2024-05-05 14:06:01 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.