From 633ee407b9d15a75ac9740ba9d3338815e1fcb95 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Tue, 21 Mar 2017 13:44:28 +0100 Subject: [PATCH] libceph: force GFP_NOIO for socket allocations sock_alloc_inode() allocates socket+inode and socket_wq with GFP_KERNEL, which is not allowed on the writeback path: Workqueue: ceph-msgr con_work [libceph] ffff8810871cb018 0000000000000046 0000000000000000 ffff881085d40000 0000000000012b00 ffff881025cad428 ffff8810871cbfd8 0000000000012b00 ffff880102fc1000 ffff881085d40000 ffff8810871cb038 ffff8810871cb148 Call Trace: [] schedule+0x29/0x70 [] schedule_timeout+0x1bd/0x200 [] ? ttwu_do_wakeup+0x2c/0x120 [] ? ttwu_do_activate.constprop.135+0x66/0x70 [] wait_for_completion+0xbf/0x180 [] ? try_to_wake_up+0x390/0x390 [] flush_work+0x165/0x250 [] ? worker_detach_from_pool+0xd0/0xd0 [] xlog_cil_force_lsn+0x81/0x200 [xfs] [] ? __slab_free+0xee/0x234 [] _xfs_log_force_lsn+0x4d/0x2c0 [xfs] [] ? lookup_page_cgroup_used+0xe/0x30 [] ? xfs_reclaim_inode+0xa3/0x330 [xfs] [] xfs_log_force_lsn+0x3f/0xf0 [xfs] [] ? xfs_reclaim_inode+0xa3/0x330 [xfs] [] xfs_iunpin_wait+0xc6/0x1a0 [xfs] [] ? wake_atomic_t_function+0x40/0x40 [] xfs_reclaim_inode+0xa3/0x330 [xfs] [] xfs_reclaim_inodes_ag+0x257/0x3d0 [xfs] [] xfs_reclaim_inodes_nr+0x33/0x40 [xfs] [] xfs_fs_free_cached_objects+0x15/0x20 [xfs] [] super_cache_scan+0x178/0x180 [] shrink_slab_node+0x14e/0x340 [] ? mem_cgroup_iter+0x16b/0x450 [] shrink_slab+0x100/0x140 [] do_try_to_free_pages+0x335/0x490 [] try_to_free_pages+0xb9/0x1f0 [] ? __alloc_pages_direct_compact+0x69/0x1be [] __alloc_pages_nodemask+0x69a/0xb40 [] alloc_pages_current+0x9e/0x110 [] new_slab+0x2c5/0x390 [] __slab_alloc+0x33b/0x459 [] ? sock_alloc_inode+0x2d/0xd0 [] ? inet_sendmsg+0x71/0xc0 [] ? sock_alloc_inode+0x2d/0xd0 [] kmem_cache_alloc+0x1a2/0x1b0 [] sock_alloc_inode+0x2d/0xd0 [] alloc_inode+0x26/0xa0 [] new_inode_pseudo+0x1a/0x70 [] sock_alloc+0x1e/0x80 [] __sock_create+0x95/0x220 [] sock_create_kern+0x24/0x30 [] con_work+0xef9/0x2050 [libceph] [] ? rbd_img_request_submit+0x4c/0x60 [rbd] [] process_one_work+0x159/0x4f0 [] worker_thread+0x11b/0x530 [] ? create_worker+0x1d0/0x1d0 [] kthread+0xc9/0xe0 [] ? flush_kthread_worker+0x90/0x90 [] ret_from_fork+0x58/0x90 [] ? flush_kthread_worker+0x90/0x90 Use memalloc_noio_{save,restore}() to temporarily force GFP_NOIO here. Cc: stable@vger.kernel.org # 3.10+, needs backporting Link: http://tracker.ceph.com/issues/19309 Reported-by: Sergey Jerusalimov Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton --- net/ceph/messenger.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 38dcf1e..f76bb33 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -469,11 +470,16 @@ static int ceph_tcp_connect(struct ceph_connection *con) { struct sockaddr_storage *paddr = &con->peer_addr.in_addr; struct socket *sock; + unsigned int noio_flag; int ret; BUG_ON(con->sock); + + /* sock_create_kern() allocates with GFP_KERNEL */ + noio_flag = memalloc_noio_save(); ret = sock_create_kern(read_pnet(&con->msgr->net), paddr->ss_family, SOCK_STREAM, IPPROTO_TCP, &sock); + memalloc_noio_restore(noio_flag); if (ret) return ret; sock->sk->sk_allocation = GFP_NOFS; -- 2.7.4