Description of problem:

"INFO: possible recursive locking detected", with stacktrace.

Version-Release number of selected component (if applicable):

kernel-2.6.18-1.2693.fc6

$ uname -a
Linux sawfish.linpro.no 2.6.18-1.2693.fc6 #1 SMP Fri Sep 22 18:03:54 EDT 2006
i686 i686 i386 GNU/Linux

How reproducible:

Seems to be triggered by 'cryptsetup luksOpen foo bar".

Steps to Reproduce:
1.  Create and initialize an encypted device
2.  cryptsetup luksOpen /dev/disk0/encryptedhome home-aes
3   <type password to cryptsetup>

Actual results:

The command succeeds, and the volume can be mounted, but the following message
is printed to the console and dmesg:


=============================================
[ INFO: possible recursive locking detected ]
2.6.18-1.2693.fc6 #1
---------------------------------------------
cryptsetup/2573 is trying to acquire lock:
 (&md->io_lock){----}, at: [<f88d648e>] dm_request+0x18/0xea [dm_mod]

but task is already holding lock:
 (&md->io_lock){----}, at: [<f88d648e>] dm_request+0x18/0xea [dm_mod]

other info that might help us debug this:
1 lock held by cryptsetup/2573:
 #0:  (&md->io_lock){----}, at: [<f88d648e>] dm_request+0x18/0xea [dm_mod]

stack backtrace:
 [<c04051ed>] show_trace_log_lvl+0x58/0x16a
 [<c04057fa>] show_trace+0xd/0x10
 [<c0405913>] dump_stack+0x19/0x1b
 [<c043b641>] __lock_acquire+0x778/0x99c
 [<c043bdd6>] lock_acquire+0x4b/0x6d
 [<c0438de8>] down_read+0x2d/0x40
 [<f88d648e>] dm_request+0x18/0xea [dm_mod]
 [<c04dcd49>] generic_make_request+0x28c/0x29c
 [<f8de4829>] crypt_map+0x236/0x2e9 [dm_crypt]
 [<f88d53d5>] __map_bio+0x4a/0xef [dm_mod]
 [<f88d5d27>] __split_bio+0x159/0x3a1 [dm_mod]
 [<f88d6552>] dm_request+0xdc/0xea [dm_mod]
 [<c04dcd49>] generic_make_request+0x28c/0x29c
 [<c04deb49>] submit_bio+0xbf/0xc6
 [<c04931cb>] dio_bio_submit+0x4f/0x61
 [<c04940b7>] __blockdev_direct_IO+0x9e6/0xd5b
 [<c047a833>] blkdev_direct_IO+0x30/0x35
 [<c04573c3>] generic_file_direct_IO+0x88/0xe0
 [<c0457640>] __generic_file_aio_read+0xf2/0x1e8
 [<c045864b>] generic_file_read+0x87/0x9b
 [<c0473534>] vfs_read+0xa9/0x155
 [<c04739c4>] sys_read+0x3b/0x60
 [<c0403fb7>] syscall_call+0x7/0xb
DWARF2 unwinder stuck at syscall_call+0x7/0xb
Leftover inexact backtrace:
 [<c04057fa>] show_trace+0xd/0x10
 [<c0405913>] dump_stack+0x19/0x1b
 [<c043b641>] __lock_acquire+0x778/0x99c
 [<c043bdd6>] lock_acquire+0x4b/0x6d
 [<c0438de8>] down_read+0x2d/0x40
 [<f88d648e>] dm_request+0x18/0xea [dm_mod]
 [<c04dcd49>] generic_make_request+0x28c/0x29c
 [<f8de4829>] crypt_map+0x236/0x2e9 [dm_crypt]
 [<f88d53d5>] __map_bio+0x4a/0xef [dm_mod]
 [<f88d5d27>] __split_bio+0x159/0x3a1 [dm_mod]
 [<f88d6552>] dm_request+0xdc/0xea [dm_mod]
 [<c04dcd49>] generic_make_request+0x28c/0x29c
 [<c04deb49>] submit_bio+0xbf/0xc6
 [<c04931cb>] dio_bio_submit+0x4f/0x61
 [<c04940b7>] __blockdev_direct_IO+0x9e6/0xd5b
 [<c047a833>] blkdev_direct_IO+0x30/0x35
 [<c04573c3>] generic_file_direct_IO+0x88/0xe0
 [<c0457640>] __generic_file_aio_read+0xf2/0x1e8
 [<c045864b>] generic_file_read+0x87/0x9b
 [<c0473534>] vfs_read+0xa9/0x155
 [<c04739c4>] sys_read+0x3b/0x60
 [<c0403fb7>] syscall_call+0x7/0xb


Expected results:

No stack trace. :)

Additional info:

Seems to happen consistently.  System is a Dell Latitude X1 laptop running
updated FC6T3.