linux/include
Eric Biggers 2fb48d88e7 blk-crypto: use dynamic lock class for blk_crypto_profile::lock
When a device-mapper device is passing through the inline encryption
support of an underlying device, calls to blk_crypto_evict_key() take
the blk_crypto_profile::lock of the device-mapper device, then take the
blk_crypto_profile::lock of the underlying device (nested).  This isn't
a real deadlock, but it causes a lockdep report because there is only
one lock class for all instances of this lock.

Lockdep subclasses don't really work here because the hierarchy of block
devices is dynamic and could have more than 2 levels.

Instead, register a dynamic lock class for each blk_crypto_profile, and
associate that with the lock.

This avoids false-positive lockdep reports like the following:

    ============================================
    WARNING: possible recursive locking detected
    6.4.0-rc5 #2 Not tainted
    --------------------------------------------
    fscryptctl/1421 is trying to acquire lock:
    ffffff80829ca418 (&profile->lock){++++}-{3:3}, at: __blk_crypto_evict_key+0x44/0x1c0

                   but task is already holding lock:
    ffffff8086b68ca8 (&profile->lock){++++}-{3:3}, at: __blk_crypto_evict_key+0xc8/0x1c0

                   other info that might help us debug this:
     Possible unsafe locking scenario:

           CPU0
           ----
      lock(&profile->lock);
      lock(&profile->lock);

                    *** DEADLOCK ***

     May be due to missing lock nesting notation

Fixes: 1b26283970 ("block: Keyslot Manager for Inline Encryption")
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230610061139.212085-1-ebiggers@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-05 16:36:12 -06:00
..
acpi hardening updates for v6.5-rc1 2023-06-27 21:24:18 -07:00
asm-generic Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
clocksource
crypto This update includes the following changes: 2023-06-30 21:27:13 -07:00
drm
dt-bindings Another set of clk driver updates and fixes for the merge window. The 2023-07-04 11:07:45 -07:00
keys
kunit
kvm Common KVM changes for 6.5: 2023-07-01 07:07:55 -04:00
linux blk-crypto: use dynamic lock class for blk_crypto_profile::lock 2023-07-05 16:36:12 -06:00
math-emu
media
memory
misc
net v6.5 merge window RDMA pull request 2023-06-29 21:01:17 -07:00
pcmcia
ras
rdma rdma: fix INFINIBAND_USER_ACCESS dependency 2023-07-03 16:55:04 -07:00
rv
scsi SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
soc ARM: SoC drivers for 6.5 2023-06-29 15:22:19 -07:00
sound
target SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
trace NFS client updates for Linux 6.5 2023-07-01 14:38:25 -07:00
uapi firewire updates for 6.5-rc1 2023-07-04 11:02:34 -07:00
ufs SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
vdso
video sticon/parisc: Fix STI console on 64-bit only machines 2023-06-30 17:14:14 +02:00
xen