Filipe Manana b050f9f6dd Btrfs: fix qgroups sanity test crash or hang ... Often when running the qgroups sanity test, a crash or a hang happened. This is because the extent buffer the test uses for the root node doesn't have an header level explicitly set, making it have a random level value. This is a problem when it's not zero for the btrfs_search_slot() calls the test ends up doing, resulting in crashes or hangs such as the following: [ 6454.127192] Btrfs loaded, debug=on, assert=on, integrity-checker=on (...) [ 6454.127760] BTRFS: selftest: Running qgroup tests [ 6454.127964] BTRFS: selftest: Running test_test_no_shared_qgroup [ 6454.127966] BTRFS: selftest: Qgroup basic add [ 6480.152005] BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:5383] [ 6480.152005] Modules linked in: btrfs(+) xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc i2c_piix4 i2c_core pcspkr evbug psmouse serio_raw e1000 [last unloaded: btrfs] [ 6480.152005] irq event stamp: 188448 [ 6480.152005] hardirqs last enabled at (188447): [<ffffffff8168ef5c>] restore_args+0x0/0x30 [ 6480.152005] hardirqs last disabled at (188448): [<ffffffff81698e6a>] apic_timer_interrupt+0x6a/0x80 [ 6480.152005] softirqs last enabled at (188446): [<ffffffff810516cf>] __do_softirq+0x1cf/0x450 [ 6480.152005] softirqs last disabled at (188441): [<ffffffff81051c25>] irq_exit+0xb5/0xc0 [ 6480.152005] CPU: 0 PID: 5383 Comm: modprobe Not tainted 3.15.0-rc8-fdm-btrfs-next-33+ #4 [ 6480.152005] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 6480.152005] task: ffff8802146125a0 ti: ffff8800d0d00000 task.ti: ffff8800d0d00000 [ 6480.152005] RIP: 0010:[<ffffffff81349a63>] [<ffffffff81349a63>] __write_lock_failed+0x13/0x20 [ 6480.152005] RSP: 0018:ffff8800d0d038e8 EFLAGS: 00000287 [ 6480.152005] RAX: 0000000000000000 RBX: ffffffff8168ef5c RCX: 000005deb8525852 [ 6480.152005] RDX: 0000000000000000 RSI: 0000000000001d45 RDI: ffff8802105000b8 [ 6480.152005] RBP: ffff8800d0d038e8 R08: fffffe12710f63db R09: ffffffffa03196fb [ 6480.152005] R10: ffff8802146125a0 R11: ffff880214612e28 R12: ffff8800d0d03858 [ 6480.152005] R13: 0000000000000000 R14: ffff8800d0d00000 R15: ffff8802146125a0 [ 6480.152005] FS: 00007f14ff804700(0000) GS:ffff880215e00000(0000) knlGS:0000000000000000 [ 6480.152005] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 6480.152005] CR2: 00007fff4df0dac8 CR3: 00000000d1796000 CR4: 00000000000006f0 [ 6480.152005] Stack: [ 6480.152005] ffff8800d0d03908 ffffffff810ae967 0000000000000001 ffff8802105000b8 [ 6480.152005] ffff8800d0d03938 ffffffff8168e57e ffffffffa0319c16 0000000000000007 [ 6480.152005] ffff880210500000 ffff880210500100 ffff8800d0d039b8 ffffffffa0319c16 [ 6480.152005] Call Trace: [ 6480.152005] [<ffffffff810ae967>] do_raw_write_lock+0x47/0xa0 [ 6480.152005] [<ffffffff8168e57e>] _raw_write_lock+0x5e/0x80 [ 6480.152005] [<ffffffffa0319c16>] ? btrfs_tree_lock+0x116/0x270 [btrfs] [ 6480.152005] [<ffffffffa0319c16>] btrfs_tree_lock+0x116/0x270 [btrfs] [ 6480.152005] [<ffffffffa02b2acb>] btrfs_lock_root_node+0x3b/0x50 [btrfs] [ 6480.152005] [<ffffffffa02b81a6>] btrfs_search_slot+0x916/0xa20 [btrfs] [ 6480.152005] [<ffffffff811a727f>] ? create_object+0x23f/0x300 [ 6480.152005] [<ffffffffa02b9958>] btrfs_insert_empty_items+0x78/0xd0 [btrfs] [ 6480.152005] [<ffffffffa036041a>] insert_normal_tree_ref.constprop.4+0xa2/0x19a [btrfs] [ 6480.152005] [<ffffffffa03605c3>] test_no_shared_qgroup+0xb1/0x1ca [btrfs] [ 6480.152005] [<ffffffff8108cad6>] ? local_clock+0x16/0x30 [ 6480.152005] [<ffffffffa035ef8e>] btrfs_test_qgroups+0x1ae/0x1d7 [btrfs] [ 6480.152005] [<ffffffffa03a69d2>] ? ftrace_define_fields_btrfs_space_reservation+0xfd/0xfd [btrfs] [ 6480.152005] [<ffffffffa03a6a86>] init_btrfs_fs+0xb4/0x153 [btrfs] [ 6480.152005] [<ffffffff81000352>] do_one_initcall+0x102/0x150 [ 6480.152005] [<ffffffff8103d223>] ? set_memory_nx+0x43/0x50 [ 6480.152005] [<ffffffff81682668>] ? set_section_ro_nx+0x6d/0x74 [ 6480.152005] [<ffffffff810d91cc>] load_module+0x1cdc/0x2630 (...) Therefore initialize the extent buffer as an empty leaf (level 0). Issue easy to reproduce when btrfs is built as a module via: $ for ((i = 1; i <= 1000000; i++)); do rmmod btrfs; modprobe btrfs; done Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>		2014-06-13 09:52:24 -07:00
..
btrfs-tests.c	btrfs: prevent RCU warning when dereferencing radix tree slot	2014-06-13 09:52:22 -07:00
btrfs-tests.h	Btrfs: add sanity tests for new qgroup accounting code	2014-06-09 17:20:49 -07:00
extent-buffer-tests.c	Btrfs: add a sanity test for btrfs_split_item	2013-11-11 21:51:02 -05:00
extent-io-tests.c	Btrfs: add tests for find_lock_delalloc_range	2013-11-11 21:56:51 -05:00
free-space-tests.c	treewide: fix comments and printk msgs	2014-01-07 15:06:07 +01:00
inode-tests.c	Btrfs: add sanity tests for new qgroup accounting code	2014-06-09 17:20:49 -07:00
qgroup-tests.c	Btrfs: fix qgroups sanity test crash or hang	2014-06-13 09:52:24 -07:00