Messages in this thread | | | Date | Fri, 28 Oct 2011 13:49:23 +0800 | From | Wanlong Gao <> | Subject | Re: [possible deadlock][3.1.0-g138c4ae] possible circular locking dependency detected |
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On 10/28/2011 01:44 PM, Bob Liu wrote:
> On Fri, Oct 28, 2011 at 11:42 AM, Wanlong Gao <gaowanlong@cn.fujitsu.com> wrote: >> Hi folks: >> >> My dmesg said that: >> >> ====================================================== >> [ INFO: possible circular locking dependency detected ] >> 3.1.0-138c4ae #2 >> ------------------------------------------------------- >> hugemmap05/18198 is trying to acquire lock: >> (&mm->mmap_sem){++++++}, at: [<ffffffff8114d85c>] might_fault+0x5c/0xb0 >> >> but task is already holding lock: >> (&sb->s_type->i_mutex_key#21){+.+.+.}, at: [<ffffffff811a10f6>] vfs_readdir+0x86/0xe0 >> >> which lock already depends on the new lock. >> >> >> the existing dependency chain (in reverse order) is: >> >> -> #1 (&sb->s_type->i_mutex_key#21){+.+.+.}: >> [<ffffffff810afd34>] validate_chain+0x704/0x860 >> [<ffffffff810b018c>] __lock_acquire+0x2fc/0x500 >> [<ffffffff810b0b01>] lock_acquire+0xb1/0x1a0 >> [<ffffffff815464f2>] __mutex_lock_common+0x62/0x420 >> [<ffffffff81546a1a>] mutex_lock_nested+0x4a/0x60 >> [<ffffffff8120b4ba>] hugetlbfs_file_mmap+0xaa/0x160 >> [<ffffffff81158071>] mmap_region+0x3e1/0x590 >> [<ffffffff81158584>] do_mmap_pgoff+0x364/0x3b0 >> [<ffffffff811587d9>] sys_mmap_pgoff+0x209/0x240 >> [<ffffffff8101aac9>] sys_mmap+0x29/0x30 >> [<ffffffff81551542>] system_call_fastpath+0x16/0x1b >> >> -> #0 (&mm->mmap_sem){++++++}: >> [<ffffffff810af607>] check_prev_add+0x537/0x560 >> [<ffffffff810afd34>] validate_chain+0x704/0x860 >> [<ffffffff810b018c>] __lock_acquire+0x2fc/0x500 >> [<ffffffff810b0b01>] lock_acquire+0xb1/0x1a0 >> [<ffffffff8114d889>] might_fault+0x89/0xb0 >> [<ffffffff811a0f2e>] filldir+0x7e/0xe0 >> [<ffffffff811b445e>] dcache_readdir+0x5e/0x230 >> [<ffffffff811a1130>] vfs_readdir+0xc0/0xe0 >> [<ffffffff811a12c9>] sys_getdents+0x89/0x100 >> [<ffffffff81551542>] system_call_fastpath+0x16/0x1b >> >> other info that might help us debug this: >> >> Possible unsafe locking scenario: >> >> CPU0 CPU1 >> ---- ---- >> lock(&sb->s_type->i_mutex_key); >> lock(&mm->mmap_sem); >> lock(&sb->s_type->i_mutex_key); >> lock(&mm->mmap_sem); >> >> *** DEADLOCK *** >> >> 1 lock held by hugemmap05/18198: >> #0: (&sb->s_type->i_mutex_key#21){+.+.+.}, at: [<ffffffff811a10f6>] vfs_readdir+0x86/0xe0 >> >> stack backtrace: >> Pid: 18198, comm: hugemmap05 Not tainted 3.1.0-138c4ae #2 >> Call Trace: >> [<ffffffff810ad469>] print_circular_bug+0x109/0x110 >> [<ffffffff810af607>] check_prev_add+0x537/0x560 >> [<ffffffff8114e112>] ? do_anonymous_page+0xf2/0x2d0 >> [<ffffffff810afd34>] validate_chain+0x704/0x860 >> [<ffffffff810b018c>] __lock_acquire+0x2fc/0x500 >> [<ffffffff810b0b01>] lock_acquire+0xb1/0x1a0 >> [<ffffffff8114d85c>] ? might_fault+0x5c/0xb0 >> [<ffffffff8114d889>] might_fault+0x89/0xb0 >> [<ffffffff8114d85c>] ? might_fault+0x5c/0xb0 >> [<ffffffff81546763>] ? __mutex_lock_common+0x2d3/0x420 >> [<ffffffff811a10f6>] ? vfs_readdir+0x86/0xe0 >> [<ffffffff811a0f2e>] filldir+0x7e/0xe0 >> [<ffffffff811b445e>] dcache_readdir+0x5e/0x230 >> [<ffffffff811a0eb0>] ? filldir64+0xf0/0xf0 >> [<ffffffff811a0eb0>] ? filldir64+0xf0/0xf0 >> [<ffffffff811a0eb0>] ? filldir64+0xf0/0xf0 >> [<ffffffff811a1130>] vfs_readdir+0xc0/0xe0 >> [<ffffffff8118e9be>] ? fget+0xee/0x220 >> [<ffffffff8118e8d0>] ? fget_raw+0x220/0x220 >> [<ffffffff811a12c9>] sys_getdents+0x89/0x100 >> [<ffffffff81551542>] system_call_fastpath+0x16/0x1b >> > > Please try this patch "lockdep: Add helper function for dir vs file > i_mutex annotation" by josh. > http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdiff;h=e096d0c7e2e4e5893792db865dd065ac73cf1f00 >
Oh, it looks like can fix this bug, but I also can't reproduce it whether with or without this patch.
Thanks -Wanlong Gao
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