linux-stable.git/drivers/md/md-bitmap.c, branch v6.14

md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime

2025-01-24T18:03:32+00:00

After commit ec6bb299c7c3 ("md/md-bitmap: add 'sync_size' into struct
md_bitmap_stats"), following panic is reported:

Oops: general protection fault, probably for non-canonical address
RIP: 0010:bitmap_get_stats+0x2b/0xa0
Call Trace:
 
 md_seq_show+0x2d2/0x5b0
 seq_read_iter+0x2b9/0x470
 seq_read+0x12f/0x180
 proc_reg_read+0x57/0xb0
 vfs_read+0xf6/0x380
 ksys_read+0x6c/0xf0
 do_syscall_64+0x82/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Root cause is that bitmap_get_stats() can be called at anytime if mddev
is still there, even if bitmap is destroyed, or not fully initialized.
Deferenceing bitmap in this case can crash the kernel. Meanwhile, the
above commit start to deferencing bitmap->storage, make the problem
easier to trigger.

Fix the problem by protecting bitmap_get_stats() with bitmap_info.mutex.

Cc: stable@vger.kernel.org # v6.12+
Fixes: 32a7627cf3a3 ("[PATCH] md: optimised resync using Bitmap based intent logging")
Reported-and-tested-by: Harshit Mogalapalli 
Closes: https://lore.kernel.org/linux-raid/ca3a91a2-50ae-4f68-b317-abd9889f3907@oracle.com/T/#m6e5086c95201135e4941fe38f9efa76daf9666c5
Signed-off-by: Yu Kuai 
Link: https://lore.kernel.org/r/20250124092055.4050195-1-yukuai1@huaweicloud.com
Signed-off-by: Song Liu

md/md-bitmap: remove the last parameter for bimtap_ops->endwrite()

2025-01-13T16:56:10+00:00

For the case that IO failed for one rdev, the bit will be mark as NEEDED
in following cases:

1) If badblocks is set and rdev is not faulty;
2) If rdev is faulty;

Case 1) is useless because synchronize data to badblocks make no sense.
Case 2) can be replaced with mddev->degraded.

Also remove R1BIO_Degraded, R10BIO_Degraded and STRIPE_DEGRADED since
case 2) no longer use them.

Signed-off-by: Yu Kuai 
Link: https://lore.kernel.org/r/20250109015145.158868-3-yukuai1@huaweicloud.com
Signed-off-by: Song Liu

md/md-bitmap: factor behind write counters out from bitmap_{start/end}write()

2025-01-13T16:56:10+00:00

behind_write is only used in raid1, prepare to refactor
bitmap_{start/end}write(), there are no functional changes.

Signed-off-by: Yu Kuai 
Reviewed-by: Xiao Ni 
Link: https://lore.kernel.org/r/20250109015145.158868-2-yukuai1@huaweicloud.com
Signed-off-by: Song Liu

md: Replace deprecated kmap_atomic() with kmap_local_page()

2025-01-13T15:36:29+00:00

kmap_atomic() is deprecated and should be replaced with kmap_local_page()
[1][2]. kmap_local_page() is faster in kernels with HIGHMEM enabled, can
take page faults, and allows preemption.

According to [2], this is safe as long as the code between kmap_atomic()
and kunmap_atomic() does not implicitly depend on disabling page faults or
preemption. It appears to me that none of the call sites in this patch
depend on disabling page faults or preemption; they are all mapping a page
to simply extract some information from it or print some debug info.

[1] https://lwn.net/Articles/836144/
[2] https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings

Signed-off-by: David Reaver 
Link: https://lore.kernel.org/r/20250108192131.46843-1-me@davidreaver.com
Signed-off-by: Song Liu

md/md-bitmap: Add missing destroy_work_on_stack()

2024-11-06T05:06:51+00:00

This commit add missed destroy_work_on_stack() operations for
unplug_work.work in bitmap_unplug_async().

Fixes: a022325ab970 ("md/md-bitmap: add a new helper to unplug bitmap asynchrously")
Cc: stable@vger.kernel.org
Signed-off-by: Yuan Can 
Reviewed-by: Yu Kuai 
Link: https://lore.kernel.org/r/20241105130105.127336-1-yuancan@huawei.com
Signed-off-by: Song Liu

Merge tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux

2024-09-16T11:33:06+00:00

Pull block updates from Jens Axboe:

 - MD changes via Song:
      - md-bitmap refactoring (Yu Kuai)
      - raid5 performance optimization (Artur Paszkiewicz)
      - Other small fixes (Yu Kuai, Chen Ni)
      - Add a sysfs entry 'new_level' (Xiao Ni)
      - Improve information reported in /proc/mdstat (Mateusz Kusiak)

 - NVMe changes via Keith:
      - Asynchronous namespace scanning (Stuart)
      - TCP TLS updates (Hannes)
      - RDMA queue controller validation (Niklas)
      - Align field names to the spec (Anuj)
      - Metadata support validation (Puranjay)
      - A syntax cleanup (Shen)
      - Fix a Kconfig linking error (Arnd)
      - New queue-depth quirk (Keith)

 - Add missing unplug trace event (Keith)

 - blk-iocost fixes (Colin, Konstantin)

 - t10-pi modular removal and fixes (Alexey)

 - Fix for potential BLKSECDISCARD overflow (Alexey)

 - bio splitting cleanups and fixes (Christoph)

 - Deal with folios rather than rather than pages, speeding up how the
   block layer handles bigger IOs (Kundan)

 - Use spinlocks rather than bit spinlocks in zram (Sebastian, Mike)

 - Reduce zoned device overhead in ublk (Ming)

 - Add and use sendpages_ok() for drbd and nvme-tcp (Ofir)

 - Fix regression in partition error pointer checking (Riyan)

 - Add support for write zeroes and rotational status in nbd (Wouter)

 - Add Yu Kuai as new BFQ maintainer. The scheduler has been
   unmaintained for quite a while.

 - Various sets of fixes for BFQ (Yu Kuai)

 - Misc fixes and cleanups (Alvaro, Christophe, Li, Md Haris, Mikhail,
   Yang)

* tag 'for-6.12/block-20240913' of git://git.kernel.dk/linux: (120 commits)
  nvme-pci: qdepth 1 quirk
  block: fix potential invalid pointer dereference in blk_add_partition
  blk_iocost: make read-only static array vrate_adj_pct const
  block: unpin user pages belonging to a folio at once
  mm: release number of pages of a folio
  block: introduce folio awareness and add a bigger size from folio
  block: Added folio-ized version of bio_add_hw_page()
  block, bfq: factor out a helper to split bfqq in bfq_init_rq()
  block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
  block, bfq: remove local variable 'split' in bfq_init_rq()
  block, bfq: remove bfq_log_bfqg()
  block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
  block, bfq: fix procress reference leakage for bfqq in merge chain
  block, bfq: fix uaf for accessing waker_bfqq after splitting
  blk-throttle: support prioritized processing of metadata
  blk-throttle: remove last_low_overflow_time
  drbd: Add NULL check for net_conf to prevent dereference in state validation
  nvme-tcp: fix link failure for TCP auth
  blk-mq: add missing unplug trace event
  mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
  ...

fs: drop GFP_NOFAIL mode from alloc_page_buffers

2024-08-30T12:54:03+00:00

There is only one called of alloc_page_buffers and it doesn't require
__GFP_NOFAIL so drop this allocation mode.

Signed-off-by: Michal Hocko 
Link: https://lore.kernel.org/r/20240829130640.1397970-1-mhocko@kernel.org
Acked-by: Song Liu 
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

md/md-bitmap: make in memory structure internal

2024-08-27T19:43:16+00:00

Now that struct bitmap_page and bitmap is not used externally anymore,
move them from md-bitmap.h to md-bitmap.c (expect that dm-raid is still
using define marco 'COUNTER_MAX').

Also fix some checkpatch warnings.

Signed-off-by: Yu Kuai 
Link: https://lore.kernel.org/r/20240826074452.1490072-43-yukuai1@huaweicloud.com
Signed-off-by: Song Liu

md/md-bitmap: merge md_bitmap_enabled() into bitmap_operations

2024-08-27T19:43:16+00:00

So that the implementation won't be exposed, and it'll be possible
to invent a new bitmap by replacing bitmap_operations.

Signed-off-by: Yu Kuai 
Link: https://lore.kernel.org/r/20240826074452.1490072-42-yukuai1@huaweicloud.com
Signed-off-by: Song Liu

md/md-bitmap: merge md_bitmap_wait_behind_writes() into bitmap_operations

2024-08-27T19:43:16+00:00

So that the implementation won't be exposed, and it'll be possible
to invent a new bitmap by replacing bitmap_operations.

Signed-off-by: Yu Kuai 
Link: https://lore.kernel.org/r/20240826074452.1490072-41-yukuai1@huaweicloud.com
Signed-off-by: Song Liu