From: Markus Trippelsdorf <markus@trippelsdorf.de>
To: xfs@oss.sgi.com
Subject: System stuck in D state while deleting messages in mutt
Date: Mon, 19 Sep 2011 15:56:22 +0200 [thread overview]
Message-ID: <20110919135622.GA13039@x4.trippels.de> (raw)
My system just got stuck while I was trying to delete old messages in
mutt. I'm running the latest git kernel. This happened on my SSD:
# xfs_info /dev/sda
meta-data=/dev/sda isize=256 agcount=4, agsize=91571162 blks
= sectsz=4096 attr=2
data = bsize=4096 blocks=366284646, imaxpct=5
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=178849, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none
I was able to capture the following SysRq-w output:
Sep 19 15:29:59 x4 kernel: SysRq : Show Blocked State
Sep 19 15:29:59 x4 kernel: task PC stack pid father
Sep 19 15:29:59 x4 kernel: gconfd-2 D 0000000000000000 0 1513 1 0x00000000
Sep 19 15:29:59 x4 kernel: ffff8802102f9d88 0000000000000086 ffff880200000000 ffff8802102f9fd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff8802102f9fd8 ffff8802168d5740 ffff8802125015d0
Sep 19 15:29:59 x4 kernel: 00000001102f9d68 ffffffff8111ad40 0000000000000000 0000000000000000
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff8111ad40>] ? link_path_walk+0x70/0x850
Sep 19 15:29:59 x4 kernel: [<ffffffff8111aa38>] ? complete_walk+0x88/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff8150288f>] __mutex_lock_slowpath+0xef/0x180
Sep 19 15:29:59 x4 kernel: [<ffffffff8150268d>] mutex_lock+0x1d/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d0c7>] kern_path_create+0x77/0x120
Sep 19 15:29:59 x4 kernel: [<ffffffff8120ce0c>] ? strncpy_from_user+0x2c/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff811195e0>] ? getname_flags+0xe0/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff8112c138>] ? mntput+0x18/0x30
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d1b5>] user_path_create+0x45/0x70
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d5d5>] sys_mkdirat+0x25/0xd0
Sep 19 15:29:59 x4 kernel: [<ffffffff81122411>] ? sys_poll+0x71/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d693>] sys_mkdir+0x13/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff8150467b>] system_call_fastpath+0x16/0x1b
Sep 19 15:29:59 x4 kernel: mutt D 0000000000000001 0 1631 1609 0x00000000
Sep 19 15:29:59 x4 kernel: ffff8802094bfc68 0000000000000082 0000000100000000 ffff8802094bffd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff8802094bffd8 ffff880215425740 ffff8802124015d0
Sep 19 15:29:59 x4 kernel: 000000010000001c 0000000000000292 ffff8802094bfbc8 ffffffff810971cc
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff810971cc>] ? up+0x2c/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff811d708e>] ? xfs_trans_unreserve_and_mod_sb+0x22e/0x370
Sep 19 15:29:59 x4 kernel: [<ffffffff81186188>] ? xfs_buf_rele+0x48/0x150
Sep 19 15:29:59 x4 kernel: [<ffffffff811dffa1>] ? xfs_ail_push+0x1/0x80
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff811d975a>] xlog_grant_log_space+0x32a/0x630
Sep 19 15:29:59 x4 kernel: [<ffffffff8106e670>] ? try_to_wake_up+0x280/0x280
Sep 19 15:29:59 x4 kernel: [<ffffffff811dc17a>] xfs_log_reserve+0x14a/0x1b0
Sep 19 15:29:59 x4 kernel: [<ffffffff811d6b06>] xfs_trans_reserve+0x96/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff811d6989>] ? xfs_trans_alloc+0x99/0xb0
Sep 19 15:29:59 x4 kernel: [<ffffffff8119a17c>] xfs_inactive+0x39c/0x410
Sep 19 15:29:59 x4 kernel: [<ffffffff811272fb>] ? end_writeback+0x2b/0x90
Sep 19 15:29:59 x4 kernel: [<ffffffff81194d07>] xfs_fs_evict_inode+0x97/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff81127407>] evict+0xa7/0x1a0
Sep 19 15:29:59 x4 kernel: [<ffffffff81128115>] iput+0x105/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff8111db9e>] do_unlinkat+0x15e/0x1c0
Sep 19 15:29:59 x4 kernel: [<ffffffff8110fcb8>] ? vfs_write+0x118/0x150
Sep 19 15:29:59 x4 kernel: [<ffffffff8110fdc5>] ? sys_write+0x45/0x90
Sep 19 15:29:59 x4 kernel: [<ffffffff8103eaa9>] ? do_device_not_available+0x9/0x10
Sep 19 15:29:59 x4 kernel: [<ffffffff8111dc51>] sys_unlink+0x11/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff8150467b>] system_call_fastpath+0x16/0x1b
Sep 19 15:29:59 x4 kernel: zsh D 0000000000000000 0 1638 1609 0x00000000
Sep 19 15:29:59 x4 kernel: ffff8802094bdd88 0000000000000082 ffff8802094bdca8 ffff8802094bdfd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff8802094bdfd8 ffff880214c5d740 ffff88020be08000
Sep 19 15:29:59 x4 kernel: ffff8802094bdd68 ffffffff8111ad40 ffff8802094bdcd8 ffffffff8105cc50
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff8111ad40>] ? link_path_walk+0x70/0x850
Sep 19 15:29:59 x4 kernel: [<ffffffff8105cc50>] ? ptep_set_access_flags+0x30/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff810efec8>] ? do_wp_page+0x328/0x790
Sep 19 15:29:59 x4 kernel: [<ffffffff8111aa38>] ? complete_walk+0x88/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff8150288f>] __mutex_lock_slowpath+0xef/0x180
Sep 19 15:29:59 x4 kernel: [<ffffffff8150268d>] mutex_lock+0x1d/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d0c7>] kern_path_create+0x77/0x120
Sep 19 15:29:59 x4 kernel: [<ffffffff8120ce0c>] ? strncpy_from_user+0x2c/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff811195e0>] ? getname_flags+0xe0/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d1b5>] user_path_create+0x45/0x70
Sep 19 15:29:59 x4 kernel: [<ffffffff8111dd5f>] sys_symlinkat+0x3f/0xd0
Sep 19 15:29:59 x4 kernel: [<ffffffff8111de01>] sys_symlink+0x11/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff8150467b>] system_call_fastpath+0x16/0x1b
Sep 19 15:29:59 x4 kernel: zsh D 0000000000000001 0 1640 1609 0x00000000
Sep 19 15:29:59 x4 kernel: ffff880209497c08 0000000000000082 0000000000000000 ffff880209497fd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff880209497fd8 ffff880214f72ba0 ffff8802157715d0
Sep 19 15:29:59 x4 kernel: ffff880214f72be8 ffff88021fc91970 0000000000000001 ffff880214f72ba0
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff81069b46>] ? __wake_up+0x46/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff81272052>] ? put_ldisc+0x42/0x90
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff811d99d3>] xlog_grant_log_space+0x5a3/0x630
Sep 19 15:29:59 x4 kernel: [<ffffffff8120da49>] ? random32+0x39/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff8106e670>] ? try_to_wake_up+0x280/0x280
Sep 19 15:29:59 x4 kernel: [<ffffffff811dc17a>] xfs_log_reserve+0x14a/0x1b0
Sep 19 15:29:59 x4 kernel: [<ffffffff811d6b06>] xfs_trans_reserve+0x96/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff8119b449>] xfs_symlink+0x209/0x870
Sep 19 15:29:59 x4 kernel: [<ffffffff811253c0>] ? d_lookup+0x30/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff81119b34>] ? lookup_hash+0x14/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff8111d0d3>] ? kern_path_create+0x83/0x120
Sep 19 15:29:59 x4 kernel: [<ffffffff81191a74>] xfs_vn_symlink+0x54/0xc0
Sep 19 15:29:59 x4 kernel: [<ffffffff8111dccd>] vfs_symlink+0x6d/0xc0
Sep 19 15:29:59 x4 kernel: [<ffffffff8111dddb>] sys_symlinkat+0xbb/0xd0
Sep 19 15:29:59 x4 kernel: [<ffffffff8111de01>] sys_symlink+0x11/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff8150467b>] system_call_fastpath+0x16/0x1b
Sep 19 15:29:59 x4 kernel: kworker/3:1 D 0000000000000000 0 30556 2 0x00000000
Sep 19 15:29:59 x4 kernel: ffff88017b65bc80 0000000000000046 ffff880100000000 ffff88017b65bfd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff88017b65bfd8 ffff8802168ec170 ffff880216bac170
Sep 19 15:29:59 x4 kernel: 0000000100000400 0000000000000000 ffff880215447980 ffff880215447968
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff8106e67d>] ? default_wake_function+0xd/0x10
Sep 19 15:29:59 x4 kernel: [<ffffffff81120e91>] ? pollwake+0x61/0x70
Sep 19 15:29:59 x4 kernel: [<ffffffff8106e670>] ? try_to_wake_up+0x280/0x280
Sep 19 15:29:59 x4 kernel: [<ffffffff8105e2bf>] ? __wake_up_common+0x4f/0x80
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff811d99d3>] xlog_grant_log_space+0x5a3/0x630
Sep 19 15:29:59 x4 kernel: [<ffffffff8120da49>] ? random32+0x39/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff8106e670>] ? try_to_wake_up+0x280/0x280
Sep 19 15:29:59 x4 kernel: [<ffffffff811dc17a>] xfs_log_reserve+0x14a/0x1b0
Sep 19 15:29:59 x4 kernel: [<ffffffff811d6b06>] xfs_trans_reserve+0x96/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff8118cb1e>] xfs_fs_log_dummy+0x3e/0x90
Sep 19 15:29:59 x4 kernel: [<ffffffff81196804>] xfs_sync_worker+0x74/0x80
Sep 19 15:29:59 x4 kernel: [<ffffffff8108c446>] process_one_work+0x116/0x440
Sep 19 15:29:59 x4 kernel: [<ffffffff81196790>] ? xfs_sync_inode_attr+0xf0/0xf0
Sep 19 15:29:59 x4 kernel: [<ffffffff8108cd27>] worker_thread+0x167/0x300
Sep 19 15:29:59 x4 kernel: [<ffffffff8108cbc0>] ? manage_workers.isra.25+0x1f0/0x1f0
Sep 19 15:29:59 x4 kernel: [<ffffffff81091597>] kthread+0x87/0x90
Sep 19 15:29:59 x4 kernel: [<ffffffff81505834>] kernel_thread_helper+0x4/0x10
Sep 19 15:29:59 x4 kernel: [<ffffffff81091510>] ? kthread_flush_work_fn+0x10/0x10
Sep 19 15:29:59 x4 kernel: [<ffffffff81505830>] ? gs_change+0xb/0xb
Sep 19 15:29:59 x4 kernel: flush-8:16 D 0000000000000003 0 3450 2 0x00000000
Sep 19 15:29:59 x4 kernel: ffff880173e0b660 0000000000000046 ffff880173e0b580 ffff880173e0bfd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff880173e0bfd8 ffff880216baaba0 ffff880215ac2ba0
Sep 19 15:29:59 x4 kernel: ffff880173e0b590 ffffffff8108d475 ffff880173e0b5b0 ffffffff811f0d2c
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff8108d475>] ? queue_delayed_work+0x25/0x30
Sep 19 15:29:59 x4 kernel: [<ffffffff811f0d2c>] ? blk_run_queue_async+0x3c/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff811f0e4d>] ? queue_unplugged+0xfd/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff811d99d3>] xlog_grant_log_space+0x5a3/0x630
Sep 19 15:29:59 x4 kernel: [<ffffffff8120da49>] ? random32+0x39/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff8106e670>] ? try_to_wake_up+0x280/0x280
Sep 19 15:29:59 x4 kernel: [<ffffffff811dc17a>] xfs_log_reserve+0x14a/0x1b0
Sep 19 15:29:59 x4 kernel: [<ffffffff811d6b06>] xfs_trans_reserve+0x96/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff81190cf4>] xfs_iomap_write_allocate+0x204/0x310
Sep 19 15:29:59 x4 kernel: [<ffffffff81183992>] xfs_map_blocks+0x212/0x2a0
Sep 19 15:29:59 x4 kernel: [<ffffffff81184a62>] xfs_vm_writepage+0x192/0x520
Sep 19 15:29:59 x4 kernel: [<ffffffff810d89c2>] __writepage+0x12/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff810da147>] write_cache_pages+0x1e7/0x4b0
Sep 19 15:29:59 x4 kernel: [<ffffffff810d89b0>] ? free_pages_exact+0x40/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff810da44b>] generic_writepages+0x3b/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff81183749>] xfs_vm_writepages+0x49/0x60
Sep 19 15:29:59 x4 kernel: [<ffffffff810da48c>] do_writepages+0x1c/0x30
Sep 19 15:29:59 x4 kernel: [<ffffffff81133e33>] writeback_single_inode+0x113/0x3b0
Sep 19 15:29:59 x4 kernel: [<ffffffff811342b8>] writeback_sb_inodes+0x1e8/0x2a0
Sep 19 15:29:59 x4 kernel: [<ffffffff81134407>] __writeback_inodes_wb+0x97/0xd0
Sep 19 15:29:59 x4 kernel: [<ffffffff8113542b>] wb_writeback+0x32b/0x360
Sep 19 15:29:59 x4 kernel: [<ffffffff811358ff>] wb_do_writeback+0x28f/0x2a0
Sep 19 15:29:59 x4 kernel: [<ffffffff81135993>] bdi_writeback_thread+0x83/0x2b0
Sep 19 15:29:59 x4 kernel: [<ffffffff81135910>] ? wb_do_writeback+0x2a0/0x2a0
Sep 19 15:29:59 x4 kernel: [<ffffffff81091597>] kthread+0x87/0x90
Sep 19 15:29:59 x4 kernel: [<ffffffff81505834>] kernel_thread_helper+0x4/0x10
Sep 19 15:29:59 x4 kernel: [<ffffffff81091510>] ? kthread_flush_work_fn+0x10/0x10
Sep 19 15:29:59 x4 kernel: [<ffffffff81505830>] ? gs_change+0xb/0xb
Sep 19 15:29:59 x4 kernel: rm D 0000000000000000 0 17349 1460 0x00000004
Sep 19 15:29:59 x4 kernel: ffff880210031de8 0000000000000086 0000000200000000 ffff880210031fd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff880210031fd8 ffff8802168d5740 ffff880216bf0000
Sep 19 15:29:59 x4 kernel: 0000000116bf0000 ffff880216bf0000 000000000040a000 ffff8802139b8cc8
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff8111aa38>] ? complete_walk+0x88/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff8111b588>] ? path_lookupat+0x68/0x730
Sep 19 15:29:59 x4 kernel: [<ffffffff81107c5b>] ? kmem_cache_free+0x1b/0x110
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff8150288f>] __mutex_lock_slowpath+0xef/0x180
Sep 19 15:29:59 x4 kernel: [<ffffffff8150268d>] mutex_lock+0x1d/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff8111dad6>] do_unlinkat+0x96/0x1c0
Sep 19 15:29:59 x4 kernel: [<ffffffff81113fa5>] ? sys_newfstatat+0x25/0x30
Sep 19 15:29:59 x4 kernel: [<ffffffff8111dc1d>] sys_unlinkat+0x1d/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff8150467b>] system_call_fastpath+0x16/0x1b
Sep 19 15:29:59 x4 kernel: xauth D 0000000000000000 0 17360 17353 0x00000000
Sep 19 15:29:59 x4 kernel: ffff8802103d3bd8 0000000000000082 ffff880200000000 ffff8802103d3fd8
Sep 19 15:29:59 x4 kernel: 0000000000004000 ffff8802103d3fd8 ffff8802168d5740 ffff880216bf15d0
Sep 19 15:29:59 x4 kernel: 00000001103d3b48 00000001ffffffff 0000000000000000 0000003fffffffc0
Sep 19 15:29:59 x4 kernel: Call Trace:
Sep 19 15:29:59 x4 kernel: [<ffffffff810d51da>] ? zone_watermark_ok+0x1a/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff810d6f00>] ? get_page_from_freelist+0x2c0/0x570
Sep 19 15:29:59 x4 kernel: [<ffffffff8106bb0a>] schedule+0x3a/0x50
Sep 19 15:29:59 x4 kernel: [<ffffffff8150288f>] __mutex_lock_slowpath+0xef/0x180
Sep 19 15:29:59 x4 kernel: [<ffffffff8150268d>] mutex_lock+0x1d/0x40
Sep 19 15:29:59 x4 kernel: [<ffffffff8111a85f>] do_lookup+0x25f/0x370
Sep 19 15:29:59 x4 kernel: [<ffffffff810eee80>] ? __do_fault+0x1e0/0x4e0
Sep 19 15:29:59 x4 kernel: [<ffffffff8111b627>] path_lookupat+0x107/0x730
Sep 19 15:29:59 x4 kernel: [<ffffffff8111952f>] ? getname_flags+0x2f/0x210
Sep 19 15:29:59 x4 kernel: [<ffffffff8111bc7b>] do_path_lookup+0x2b/0x70
Sep 19 15:29:59 x4 kernel: [<ffffffff8111c114>] user_path_at+0x54/0xa0
Sep 19 15:29:59 x4 kernel: [<ffffffff810592f4>] ? do_page_fault+0x184/0x440
Sep 19 15:29:59 x4 kernel: [<ffffffff8112b71b>] ? mntput_no_expire+0x2b/0xe0
Sep 19 15:29:59 x4 kernel: [<ffffffff81113e22>] vfs_fstatat+0x42/0x70
Sep 19 15:29:59 x4 kernel: [<ffffffff810870a4>] ? do_sigaction+0x124/0x1e0
Sep 19 15:29:59 x4 kernel: [<ffffffff81113e66>] vfs_stat+0x16/0x20
Sep 19 15:29:59 x4 kernel: [<ffffffff81113f35>] sys_newstat+0x15/0x30
Sep 19 15:29:59 x4 kernel: [<ffffffff81087465>] ? sys_rt_sigaction+0xa5/0xc0
Sep 19 15:29:59 x4 kernel: [<ffffffff8150426f>] ? page_fault+0x1f/0x30
Sep 19 15:29:59 x4 kernel: [<ffffffff8150467b>] system_call_fastpath+0x16/0x1b
--
Markus
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next reply other threads:[~2011-09-19 13:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-19 13:56 Markus Trippelsdorf [this message]
2011-09-22 16:49 ` System stuck in D state while deleting messages in mutt Christoph Hellwig
2011-09-22 17:01 ` Markus Trippelsdorf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110919135622.GA13039@x4.trippels.de \
--to=markus@trippelsdorf.de \
--cc=xfs@oss.sgi.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.