sysfs related lockdep trace in current tree.
From: Dave Jones
Date: Thu Nov 07 2013 - 21:29:53 EST
Haven't seen this before today, so I'm guessing it's related to the sysfs
changes that just got merged?
Dave
[ 853.451912] ======================================================
[ 853.451934] [ INFO: possible circular locking dependency detected ]
[ 853.451959] 3.12.0+ #113 Not tainted
[ 853.451975] -------------------------------------------------------
[ 853.451999] trinity-child3/13563 is trying to acquire lock:
[ 853.452022] (&of->mutex){+.+.+.}, at: [<ffffffff8123a6ef>] sysfs_bin_mmap+0x4f/0x120
[ 853.452063]
but task is already holding lock:
[ 853.452087] (&mm->mmap_sem){++++++}, at: [<ffffffff8116b37f>] vm_mmap_pgoff+0x6f/0xc0
[ 853.452125]
which lock already depends on the new lock.
[ 853.452156]
the existing dependency chain (in reverse order) is:
[ 853.452184]
-> #3 (&mm->mmap_sem){++++++}:
[ 853.452212] [<ffffffff810cb243>] lock_acquire+0x93/0x200
[ 853.452239] [<ffffffff811757a4>] might_fault+0x84/0xb0
[ 853.452265] [<ffffffff812f9a75>] scsi_cmd_ioctl+0x295/0x470
[ 853.452293] [<ffffffff812f9c92>] scsi_cmd_blk_ioctl+0x42/0x50
[ 853.452320] [<ffffffff81503951>] cdrom_ioctl+0x41/0x1050
[ 853.452347] [<ffffffff814d6b0f>] sr_block_ioctl+0x6f/0xd0
[ 853.452372] [<ffffffff812f5934>] blkdev_ioctl+0x234/0x840
[ 853.452398] [<ffffffff811f5b87>] block_ioctl+0x47/0x50
[ 853.452423] [<ffffffff811caea5>] do_vfs_ioctl+0x305/0x530
[ 853.452449] [<ffffffff811cb151>] SyS_ioctl+0x81/0xa0
[ 853.452473] [<ffffffff8172db64>] tracesys+0xdd/0xe2
[ 853.453341]
-> #2 (sr_mutex){+.+.+.}:
[ 853.455048] [<ffffffff810cb243>] lock_acquire+0x93/0x200
[ 853.455918] [<ffffffff8171ebbc>] mutex_lock_nested+0x7c/0x420
[ 853.456779] [<ffffffff814d7194>] sr_block_open+0x24/0x130
[ 853.457637] [<ffffffff811f6951>] __blkdev_get+0xd1/0x4c0
[ 853.458480] [<ffffffff811f6f25>] blkdev_get+0x1e5/0x380
[ 853.459316] [<ffffffff811f717a>] blkdev_open+0x6a/0x90
[ 853.460138] [<ffffffff811b49fb>] do_dentry_open+0x24b/0x300
[ 853.460963] [<ffffffff811b4af0>] finish_open+0x40/0x50
[ 853.461788] [<ffffffff811c6cfc>] do_last+0x5cc/0x1230
[ 853.462606] [<ffffffff811c7a1e>] path_openat+0xbe/0x6a0
[ 853.463412] [<ffffffff811c873a>] do_filp_open+0x3a/0x90
[ 853.464212] [<ffffffff811b5f6e>] do_sys_open+0x12e/0x210
[ 853.464980] [<ffffffff811b606e>] SyS_open+0x1e/0x20
[ 853.465770] [<ffffffff8172db64>] tracesys+0xdd/0xe2
[ 853.466563]
-> #1 (&bdev->bd_mutex){+.+.+.}:
[ 853.468123] [<ffffffff810cb243>] lock_acquire+0x93/0x200
[ 853.468917] [<ffffffff8171ebbc>] mutex_lock_nested+0x7c/0x420
[ 853.469716] [<ffffffff8112d9ff>] sysfs_blk_trace_attr_show+0x5f/0x1f0
[ 853.470524] [<ffffffff814a92c0>] dev_attr_show+0x20/0x60
[ 853.471322] [<ffffffff8123af98>] sysfs_seq_show+0xc8/0x160
[ 853.472095] [<ffffffff811de66c>] seq_read+0x16c/0x450
[ 853.472841] [<ffffffff811b6a81>] vfs_read+0xa1/0x170
[ 853.473583] [<ffffffff811b75ec>] SyS_read+0x4c/0xa0
[ 853.474318] [<ffffffff8172db64>] tracesys+0xdd/0xe2
[ 853.475052]
-> #0 (&of->mutex){+.+.+.}:
[ 853.476494] [<ffffffff810ca7ca>] __lock_acquire+0x191a/0x1be0
[ 853.477221] [<ffffffff810cb243>] lock_acquire+0x93/0x200
[ 853.477953] [<ffffffff8171ebbc>] mutex_lock_nested+0x7c/0x420
[ 853.478716] [<ffffffff8123a6ef>] sysfs_bin_mmap+0x4f/0x120
[ 853.479444] [<ffffffff81180438>] mmap_region+0x3e8/0x5d0
[ 853.480153] [<ffffffff81180980>] do_mmap_pgoff+0x360/0x3f0
[ 853.480859] [<ffffffff8116b3a0>] vm_mmap_pgoff+0x90/0xc0
[ 853.481548] [<ffffffff8117eec5>] SyS_mmap_pgoff+0x1d5/0x270
[ 853.482232] [<ffffffff81008042>] SyS_mmap+0x22/0x30
[ 853.482933] [<ffffffff8172db64>] tracesys+0xdd/0xe2
[ 853.483634]
other info that might help us debug this:
[ 853.485660] Chain exists of:
&of->mutex --> sr_mutex --> &mm->mmap_sem
[ 853.487610] Possible unsafe locking scenario:
[ 853.488951] CPU0 CPU1
[ 853.489638] ---- ----
[ 853.490271] lock(&mm->mmap_sem);
[ 853.490901] lock(sr_mutex);
[ 853.491558] lock(&mm->mmap_sem);
[ 853.492240] lock(&of->mutex);
[ 853.492907]
*** DEADLOCK ***
[ 853.494769] 1 lock held by trinity-child3/13563:
[ 853.495449] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8116b37f>] vm_mmap_pgoff+0x6f/0xc0
[ 853.496131]
stack backtrace:
[ 853.497393] CPU: 3 PID: 13563 Comm: trinity-child3 Not tainted 3.12.0+ #113
[ 853.498807] ffffffff82501cb0 ffff8800a10d9ba8 ffffffff8171a8e8 ffffffff82529260
[ 853.499514] ffff8800a10d9be8 ffffffff81716dae ffff8800a10d9c40 ffff880233544720
[ 853.500223] ffff880233544020 0000000000000000 ffff8802335446e8 ffff880233544720
[ 853.500929] Call Trace:
[ 853.501622] [<ffffffff8171a8e8>] dump_stack+0x4e/0x82
[ 853.502321] [<ffffffff81716dae>] print_circular_bug+0x200/0x20f
[ 853.503109] [<ffffffff810ca7ca>] __lock_acquire+0x191a/0x1be0
[ 853.503881] [<ffffffff810cb243>] lock_acquire+0x93/0x200
[ 853.504653] [<ffffffff8123a6ef>] ? sysfs_bin_mmap+0x4f/0x120
[ 853.505423] [<ffffffff8123a6ef>] ? sysfs_bin_mmap+0x4f/0x120
[ 853.506193] [<ffffffff8171ebbc>] mutex_lock_nested+0x7c/0x420
[ 853.506956] [<ffffffff8123a6ef>] ? sysfs_bin_mmap+0x4f/0x120
[ 853.507722] [<ffffffff8123a6ef>] ? sysfs_bin_mmap+0x4f/0x120
[ 853.508484] [<ffffffff8123a6ef>] sysfs_bin_mmap+0x4f/0x120
[ 853.509243] [<ffffffff81180438>] mmap_region+0x3e8/0x5d0
[ 853.509983] [<ffffffff81180980>] do_mmap_pgoff+0x360/0x3f0
[ 853.510723] [<ffffffff8116b3a0>] vm_mmap_pgoff+0x90/0xc0
[ 853.511486] [<ffffffff8117eec5>] SyS_mmap_pgoff+0x1d5/0x270
[ 853.512257] [<ffffffff81010b05>] ? syscall_trace_enter+0x145/0x2a0
[ 853.513027] [<ffffffff81008042>] SyS_mmap+0x22/0x30
[ 853.513795] [<ffffffff8172db64>] tracesys+0xdd/0xe2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/