On Tue, 2009-10-20 at 18:49 +0200, Fredrik Andersson wrote: > I found the following post to the ext4 list. This seems to fit my > experienced problems pretty exactly. > > http://osdir.com/ml/linux-ext4/2009-08/msg00184.html > > Is it the same problem? > The link you provided about is related to a race between restart a transaction from truncate, and the other process is doing something like block allocation to the same file. Do you have another threads allocating blocks while you are truncating? > /Fredrik > > On Mon, Oct 19, 2009 at 11:49 AM, Fredrik Andersson <nablaman@xxxxxxxxx> wrote: > > Hi, here is the data for this process: > > > > 5958816.744013] drdbmake D ffff88021e4c7800 0 27019 13796 > > [5958816.744013] ffff8801d1bcda88 0000000000000082 ffff8801f4ce9bf0 > > ffff8801678b1380 > > [5958816.744013] 0000000000010e80 000000000000c748 ffff8800404963c0 > > ffffffff81526360 > > [5958816.744013] ffff880040496730 00000000f4ce9bf0 000000025819cebe > > 0000000000000282 > > [5958816.744013] Call Trace: > > [5958816.744013] [<ffffffff813a9639>] schedule+0x9/0x20 > > [5958816.744013] [<ffffffff81177ea5>] start_this_handle+0x365/0x5d0 > > [5958816.744013] [<ffffffff8105b900>] ? autoremove_wake_function+0x0/ > > 0x40 > > [5958816.744013] [<ffffffff811781ce>] jbd2_journal_restart+0xbe/0x150 > > [5958816.744013] [<ffffffff8116243d>] ext4_ext_truncate+0x6dd/0xa20 > > [5958816.744013] [<ffffffff81095b3b>] ? find_get_pages+0x3b/0xf0 > > [5958816.744013] [<ffffffff81150a78>] ext4_truncate+0x198/0x680 > > [5958816.744013] [<ffffffff810ac984>] ? unmap_mapping_range+0x74/0x280 > > [5958816.744013] [<ffffffff811772c0>] ? jbd2_journal_stop+0x1e0/0x360 > > [5958816.744013] [<ffffffff810acd25>] vmtruncate+0xa5/0x110 > > [5958816.744013] [<ffffffff810dda10>] inode_setattr+0x30/0x180 > > [5958816.744013] [<ffffffff8114d073>] ext4_setattr+0x173/0x310 > > [5958816.744013] [<ffffffff810ddc79>] notify_change+0x119/0x330 > > [5958816.744013] [<ffffffff810c6df3>] do_truncate+0x63/0x90 > > [5958816.744013] [<ffffffff810d0cc3>] ? get_write_access+0x23/0x60 > > [5958816.744013] [<ffffffff810c70cb>] sys_truncate+0x17b/0x180 > > [5958816.744013] [<ffffffff8100bfab>] system_call_fastpath+0x16/0x1b > > > > Don't know if this has anything to do with it, but I also noticed > > that another process of mine, > > which is working just fine, is executing a suspicious looking function > > called raid0_unplug. > > It operates on the same raid0/ext4 filesystem as the hung process. I > > include the calltrace for it here too: > > > > [5958816.744013] nodeserv D ffff880167bd7ca8 0 17900 13796 > > [5958816.744013] ffff880167bd7bf8 0000000000000082 ffff88002800a588 > > ffff88021e5b56e0 > > [5958816.744013] 0000000000010e80 000000000000c748 ffff880100664020 > > ffffffff81526360 > > [5958816.744013] ffff880100664390 000000008119bd17 000000026327bfa9 > > 0000000000000002 > > [5958816.744013] Call Trace: > > [5958816.744013] [<ffffffffa0039291>] ? raid0_unplug+0x51/0x70 [raid0] > > [5958816.744013] [<ffffffff813a9639>] schedule+0x9/0x20 > > [5958816.744013] [<ffffffff813a9687>] io_schedule+0x37/0x50 > > [5958816.744013] [<ffffffff81095e35>] sync_page+0x35/0x60 > > [5958816.744013] [<ffffffff81095e69>] sync_page_killable+0x9/0x50 > > [5958816.744013] [<ffffffff813a99d2>] __wait_on_bit_lock+0x52/0xb0 > > [5958816.744013] [<ffffffff81095e60>] ? sync_page_killable+0x0/0x50 > > [5958816.744013] [<ffffffff81095d74>] __lock_page_killable+0x64/0x70 > > [5958816.744013] [<ffffffff8105b940>] ? wake_bit_function+0x0/0x40 > > [5958816.744013] [<ffffffff81095c0b>] ? find_get_page+0x1b/0xb0 > > [5958816.744013] [<ffffffff81097908>] generic_file_aio_read+0x3b8/0x6b0 > > [5958816.744013] [<ffffffff810c7dc1>] do_sync_read+0xf1/0x140 > > [5958816.744013] [<ffffffff8106a5e8>] ? do_futex+0xb8/0xb20 > > [5958816.744013] [<ffffffff813ab78f>] ? _spin_unlock_irqrestore+0x2f/0x40 > > [5958816.744013] [<ffffffff8105b900>] ? autoremove_wake_function+0x0/0x40 > > [5958816.744013] [<ffffffff8105bc73>] ? add_wait_queue+0x43/0x60 > > [5958816.744013] [<ffffffff81062a6c>] ? getnstimeofday+0x5c/0xf0 > > [5958816.744013] [<ffffffff810c85b8>] vfs_read+0xc8/0x170 > > [5958816.744013] [<ffffffff810c86fa>] sys_pread64+0x9a/0xa0 > > [5958816.744013] [<ffffffff8100bfab>] system_call_fastpath+0x16/0x1b > > This stack seems to me this thread is doing IO but never come back. > > Hope this makes sense to anyone, and please let me know if there is > > more info I can provide. > > > > /Fredrik > > > > On Sun, Oct 18, 2009 at 5:57 PM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote: > >> > >> Fredrik Andersson wrote: > >>> > >>> Hi, I'd like to report what I'm fairly certain is an ext4 bug. I hope > >>> this is the right place to do so. > >>> > >>> My program creates a big file (around 30 GB) with posix_fallocate (to > >>> utilize extents), fills it with data and uses ftruncate to crop it to > >>> its final size (usually somewhere between 20 and 25 GB). > >>> The problem is that in around 5% of the cases, the program locks up > >>> completely in a syscall. The process can thus not be killed even with > >>> kill -9, and a reboot is all that will do. > >> > >> does echo w > /proc/sysrq-trigger (this does sleeping processes; or use echo t for all processes) show you where the stuck threads are? > >> > >> -Eric > >> > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
