| Message ID | 20150528075332.6945fd09@synchrony.poochiereds.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/28/2015 01:53 PM, Jeff Layton wrote: > On Tue, 26 May 2015 15:20:46 +0200 > Jerome Marchand <jmarchan@redhat.com> wrote: > >> >> Commit dad2b015 added an rcu read lock around the call to xs_swapper() >> in nfs_activate()/deactivate(), which can sleep, thus raising a bug at >> each swapon and swapoff over NFS. >> I'm not sure if this is related or not, but swapoff also triggers the >> WARN_ON(sk->sk_forward_alloc) in sk_clear_memalloc(). >> >> [ 243.668067] =============================== >> [ 243.668665] [ INFO: suspicious RCU usage. ] >> [ 243.669293] 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 Not tainted >> [ 243.670301] ------------------------------- >> [ 243.670905] include/linux/rcupdate.h:570 Illegal context switch in RCU read-side critical section! >> [ 243.672163] >> other info that might help us debug this: >> >> [ 243.673025] >> rcu_scheduler_active = 1, debug_locks = 0 >> [ 243.673565] 2 locks held by swapon/1176: >> [ 243.673893] #0: (&sb->s_type->i_mutex_key#17){+.+.+.}, at: [<ffffffff812385e0>] SyS_swapon+0x2b0/0x1000 >> [ 243.674758] #1: (rcu_read_lock){......}, at: [<ffffffffa036fd75>] nfs_swap_activate+0x5/0x180 [nfs] >> [ 243.675591] >> stack backtrace: >> [ 243.675957] CPU: 0 PID: 1176 Comm: swapon Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >> [ 243.676687] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >> [ 243.677179] 0000000000000000 00000000ef88d841 ffff88003327bcd8 ffffffff818861f0 >> [ 243.677854] 0000000000000000 ffff880078e38000 ffff88003327bd08 ffffffff8110d237 >> [ 243.678514] 0000000000000000 ffffffff81c650e4 0000000000000268 ffff880078e38000 >> [ 243.679171] Call Trace: >> [ 243.679383] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >> [ 243.679811] [<ffffffff8110d237>] lockdep_rcu_suspicious+0xe7/0x120 >> [ 243.680348] [<ffffffff810df1bf>] ___might_sleep+0xaf/0x250 >> [ 243.680815] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 >> [ 243.681279] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 >> [ 243.681762] [<ffffffff811e409c>] static_key_slow_inc+0x7c/0xc0 >> [ 243.682264] [<ffffffff8171afa7>] sk_set_memalloc+0x27/0x30 >> [ 243.682736] [<ffffffffa012f824>] xs_swapper+0x54/0x60 [sunrpc] >> [ 243.683238] [<ffffffffa036fe03>] nfs_swap_activate+0x93/0x180 [nfs] >> [ 243.683760] [<ffffffffa036fd75>] ? nfs_swap_activate+0x5/0x180 [nfs] >> [ 243.684316] [<ffffffff81238e04>] SyS_swapon+0xad4/0x1000 >> [ 243.684766] [<ffffffff818911b0>] ? syscall_return+0x16/0x59 >> [ 243.685245] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >> [ 243.685743] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 >> [ 243.686439] in_atomic(): 1, irqs_disabled(): 0, pid: 1176, name: swapon >> [ 243.687053] INFO: lockdep is turned off. >> [ 243.687429] CPU: 0 PID: 1176 Comm: swapon Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >> [ 243.688313] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >> [ 243.688845] 0000000000000000 00000000ef88d841 ffff88003327bd08 ffffffff818861f0 >> [ 243.689570] 0000000000000000 ffff880078e38000 ffff88003327bd38 ffffffff810df29c >> [ 243.690353] ffff880000000001 ffffffff81c650e4 0000000000000268 0000000000000000 >> [ 243.691057] Call Trace: >> [ 243.691315] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >> [ 243.691785] [<ffffffff810df29c>] ___might_sleep+0x18c/0x250 >> [ 243.692306] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 >> [ 243.692807] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 >> [ 243.693346] [<ffffffff811e409c>] static_key_slow_inc+0x7c/0xc0 >> [ 243.693887] [<ffffffff8171afa7>] sk_set_memalloc+0x27/0x30 >> [ 243.694416] [<ffffffffa012f824>] xs_swapper+0x54/0x60 [sunrpc] >> [ 243.694959] [<ffffffffa036fe03>] nfs_swap_activate+0x93/0x180 [nfs] >> [ 243.695535] [<ffffffffa036fd75>] ? nfs_swap_activate+0x5/0x180 [nfs] >> [ 243.696193] [<ffffffff81238e04>] SyS_swapon+0xad4/0x1000 >> [ 243.696699] [<ffffffff818911b0>] ? syscall_return+0x16/0x59 >> [ 243.697299] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >> [ 243.702101] Adding 524284k swap on /mnt/swapfile512. Priority:-2 extents:1 across:524284k FS >> [ 325.151350] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 >> [ 325.152688] in_atomic(): 1, irqs_disabled(): 0, pid: 1199, name: swapoff >> [ 325.153737] INFO: lockdep is turned off. >> [ 325.154457] CPU: 1 PID: 1199 Comm: swapoff Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >> [ 325.156204] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >> [ 325.157120] 0000000000000000 00000000a7682b83 ffff88007ac3fce8 ffffffff818861f0 >> [ 325.158361] 0000000000000000 ffff880032434c00 ffff88007ac3fd18 ffffffff810df29c >> [ 325.159592] 0000000000000000 ffffffff81c650e4 0000000000000268 0000000000000000 >> [ 325.160798] Call Trace: >> [ 325.161251] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >> [ 325.162071] [<ffffffff810df29c>] ___might_sleep+0x18c/0x250 >> [ 325.163073] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 >> [ 325.163934] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 >> [ 325.164927] [<ffffffff8110a00f>] atomic_dec_and_mutex_lock+0x4f/0x70 >> [ 325.166020] [<ffffffff811e4107>] __static_key_slow_dec+0x27/0xc0 >> [ 325.166942] [<ffffffff811e41c6>] static_key_slow_dec+0x26/0x50 >> [ 325.167955] [<ffffffff8171db3f>] sk_clear_memalloc+0x2f/0x80 >> [ 325.169075] [<ffffffffa012f811>] xs_swapper+0x41/0x60 [sunrpc] >> [ 325.170241] [<ffffffffa0370447>] nfs_swap_deactivate+0x87/0x170 [nfs] >> [ 325.171276] [<ffffffffa03703c5>] ? nfs_swap_deactivate+0x5/0x170 [nfs] >> [ 325.172349] [<ffffffff81237547>] destroy_swap_extents+0x77/0x90 >> [ 325.173754] [<ffffffff8123b225>] SyS_swapoff+0x215/0x600 >> [ 325.174726] [<ffffffff81434deb>] ? trace_hardirqs_on_thunk+0x17/0x19 >> [ 325.175971] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >> [ 325.178052] ------------[ cut here ]------------ >> [ 325.178892] WARNING: CPU: 1 PID: 1199 at net/core/sock.c:364 sk_clear_memalloc+0x51/0x80() >> [ 325.180363] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iosf_mbi crct10dif_pclmul crc32_pclmul crc32c_intel ppdev ghash_clmulni_intel joydev nfsd parport_pc pcspkr virtio_console serio_raw virtio_balloon parport pvpanic i2c_piix4 acpi_cpufreq auth_rpcgss nfs_acl lockd grace sunrpc virtio_blk qxl virtio_net drm_kms_helper ttm drm virtio_pci virtio_ring virtio ata_generic pata_acpi floppy >> [ 325.192279] CPU: 1 PID: 1199 Comm: swapoff Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >> [ 325.193605] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >> [ 325.194491] 0000000000000000 00000000a7682b83 ffff88007ac3fdf8 ffffffff818861f0 >> [ 325.195692] 0000000000000000 0000000000000000 ffff88007ac3fe38 ffffffff810af5ca >> [ 325.196891] ffff88007ac3fe78 ffff88007b068000 ffff88007b484a00 ffff88007b484aa8 >> [ 325.198119] Call Trace: >> [ 325.198555] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >> [ 325.199380] [<ffffffff810af5ca>] warn_slowpath_common+0x8a/0xc0 >> [ 325.200601] [<ffffffff810af6fa>] warn_slowpath_null+0x1a/0x20 >> [ 325.201536] [<ffffffff8171db61>] sk_clear_memalloc+0x51/0x80 >> [ 325.202468] [<ffffffffa012f811>] xs_swapper+0x41/0x60 [sunrpc] >> [ 325.203398] [<ffffffffa0370447>] nfs_swap_deactivate+0x87/0x170 [nfs] >> [ 325.204426] [<ffffffffa03703c5>] ? nfs_swap_deactivate+0x5/0x170 [nfs] >> [ 325.205456] [<ffffffff81237547>] destroy_swap_extents+0x77/0x90 >> [ 325.206406] [<ffffffff8123b225>] SyS_swapoff+0x215/0x600 >> [ 325.207287] [<ffffffff81434deb>] ? trace_hardirqs_on_thunk+0x17/0x19 >> [ 325.208300] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >> [ 325.209248] ---[ end trace 13f1014b56e5e711 ]--- >> > > Jerome, > > Can you test the attached patch and let me know if this fixes the > problem? If so, then I'll send it on "officially" to Trond. > > Thanks, > It doesn't build: xprt_put() is not exported. Jerome
On Thu, May 28, 2015 at 10:20 AM, Jerome Marchand <jmarchan@redhat.com> wrote: > On 05/28/2015 01:53 PM, Jeff Layton wrote: >> On Tue, 26 May 2015 15:20:46 +0200 >> Jerome Marchand <jmarchan@redhat.com> wrote: >> >>> >>> Commit dad2b015 added an rcu read lock around the call to xs_swapper() >>> in nfs_activate()/deactivate(), which can sleep, thus raising a bug at >>> each swapon and swapoff over NFS. >>> I'm not sure if this is related or not, but swapoff also triggers the >>> WARN_ON(sk->sk_forward_alloc) in sk_clear_memalloc(). >>> >>> [ 243.668067] =============================== >>> [ 243.668665] [ INFO: suspicious RCU usage. ] >>> [ 243.669293] 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 Not tainted >>> [ 243.670301] ------------------------------- >>> [ 243.670905] include/linux/rcupdate.h:570 Illegal context switch in RCU read-side critical section! >>> [ 243.672163] >>> other info that might help us debug this: >>> >>> [ 243.673025] >>> rcu_scheduler_active = 1, debug_locks = 0 >>> [ 243.673565] 2 locks held by swapon/1176: >>> [ 243.673893] #0: (&sb->s_type->i_mutex_key#17){+.+.+.}, at: [<ffffffff812385e0>] SyS_swapon+0x2b0/0x1000 >>> [ 243.674758] #1: (rcu_read_lock){......}, at: [<ffffffffa036fd75>] nfs_swap_activate+0x5/0x180 [nfs] >>> [ 243.675591] >>> stack backtrace: >>> [ 243.675957] CPU: 0 PID: 1176 Comm: swapon Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >>> [ 243.676687] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >>> [ 243.677179] 0000000000000000 00000000ef88d841 ffff88003327bcd8 ffffffff818861f0 >>> [ 243.677854] 0000000000000000 ffff880078e38000 ffff88003327bd08 ffffffff8110d237 >>> [ 243.678514] 0000000000000000 ffffffff81c650e4 0000000000000268 ffff880078e38000 >>> [ 243.679171] Call Trace: >>> [ 243.679383] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >>> [ 243.679811] [<ffffffff8110d237>] lockdep_rcu_suspicious+0xe7/0x120 >>> [ 243.680348] [<ffffffff810df1bf>] ___might_sleep+0xaf/0x250 >>> [ 243.680815] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 >>> [ 243.681279] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 >>> [ 243.681762] [<ffffffff811e409c>] static_key_slow_inc+0x7c/0xc0 >>> [ 243.682264] [<ffffffff8171afa7>] sk_set_memalloc+0x27/0x30 >>> [ 243.682736] [<ffffffffa012f824>] xs_swapper+0x54/0x60 [sunrpc] >>> [ 243.683238] [<ffffffffa036fe03>] nfs_swap_activate+0x93/0x180 [nfs] >>> [ 243.683760] [<ffffffffa036fd75>] ? nfs_swap_activate+0x5/0x180 [nfs] >>> [ 243.684316] [<ffffffff81238e04>] SyS_swapon+0xad4/0x1000 >>> [ 243.684766] [<ffffffff818911b0>] ? syscall_return+0x16/0x59 >>> [ 243.685245] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >>> [ 243.685743] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 >>> [ 243.686439] in_atomic(): 1, irqs_disabled(): 0, pid: 1176, name: swapon >>> [ 243.687053] INFO: lockdep is turned off. >>> [ 243.687429] CPU: 0 PID: 1176 Comm: swapon Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >>> [ 243.688313] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >>> [ 243.688845] 0000000000000000 00000000ef88d841 ffff88003327bd08 ffffffff818861f0 >>> [ 243.689570] 0000000000000000 ffff880078e38000 ffff88003327bd38 ffffffff810df29c >>> [ 243.690353] ffff880000000001 ffffffff81c650e4 0000000000000268 0000000000000000 >>> [ 243.691057] Call Trace: >>> [ 243.691315] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >>> [ 243.691785] [<ffffffff810df29c>] ___might_sleep+0x18c/0x250 >>> [ 243.692306] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 >>> [ 243.692807] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 >>> [ 243.693346] [<ffffffff811e409c>] static_key_slow_inc+0x7c/0xc0 >>> [ 243.693887] [<ffffffff8171afa7>] sk_set_memalloc+0x27/0x30 >>> [ 243.694416] [<ffffffffa012f824>] xs_swapper+0x54/0x60 [sunrpc] >>> [ 243.694959] [<ffffffffa036fe03>] nfs_swap_activate+0x93/0x180 [nfs] >>> [ 243.695535] [<ffffffffa036fd75>] ? nfs_swap_activate+0x5/0x180 [nfs] >>> [ 243.696193] [<ffffffff81238e04>] SyS_swapon+0xad4/0x1000 >>> [ 243.696699] [<ffffffff818911b0>] ? syscall_return+0x16/0x59 >>> [ 243.697299] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >>> [ 243.702101] Adding 524284k swap on /mnt/swapfile512. Priority:-2 extents:1 across:524284k FS >>> [ 325.151350] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 >>> [ 325.152688] in_atomic(): 1, irqs_disabled(): 0, pid: 1199, name: swapoff >>> [ 325.153737] INFO: lockdep is turned off. >>> [ 325.154457] CPU: 1 PID: 1199 Comm: swapoff Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >>> [ 325.156204] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >>> [ 325.157120] 0000000000000000 00000000a7682b83 ffff88007ac3fce8 ffffffff818861f0 >>> [ 325.158361] 0000000000000000 ffff880032434c00 ffff88007ac3fd18 ffffffff810df29c >>> [ 325.159592] 0000000000000000 ffffffff81c650e4 0000000000000268 0000000000000000 >>> [ 325.160798] Call Trace: >>> [ 325.161251] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >>> [ 325.162071] [<ffffffff810df29c>] ___might_sleep+0x18c/0x250 >>> [ 325.163073] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 >>> [ 325.163934] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 >>> [ 325.164927] [<ffffffff8110a00f>] atomic_dec_and_mutex_lock+0x4f/0x70 >>> [ 325.166020] [<ffffffff811e4107>] __static_key_slow_dec+0x27/0xc0 >>> [ 325.166942] [<ffffffff811e41c6>] static_key_slow_dec+0x26/0x50 >>> [ 325.167955] [<ffffffff8171db3f>] sk_clear_memalloc+0x2f/0x80 >>> [ 325.169075] [<ffffffffa012f811>] xs_swapper+0x41/0x60 [sunrpc] >>> [ 325.170241] [<ffffffffa0370447>] nfs_swap_deactivate+0x87/0x170 [nfs] >>> [ 325.171276] [<ffffffffa03703c5>] ? nfs_swap_deactivate+0x5/0x170 [nfs] >>> [ 325.172349] [<ffffffff81237547>] destroy_swap_extents+0x77/0x90 >>> [ 325.173754] [<ffffffff8123b225>] SyS_swapoff+0x215/0x600 >>> [ 325.174726] [<ffffffff81434deb>] ? trace_hardirqs_on_thunk+0x17/0x19 >>> [ 325.175971] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >>> [ 325.178052] ------------[ cut here ]------------ >>> [ 325.178892] WARNING: CPU: 1 PID: 1199 at net/core/sock.c:364 sk_clear_memalloc+0x51/0x80() >>> [ 325.180363] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iosf_mbi crct10dif_pclmul crc32_pclmul crc32c_intel ppdev ghash_clmulni_intel joydev nfsd parport_pc pcspkr virtio_console serio_raw virtio_balloon parport pvpanic i2c_piix4 acpi_cpufreq auth_rpcgss nfs_acl lockd grace sunrpc virtio_blk qxl virtio_net drm_kms_helper ttm drm virtio_pci virtio_ring virtio ata_generic pata_acpi floppy >>> [ 325.192279] CPU: 1 PID: 1199 Comm: swapoff Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 >>> [ 325.193605] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >>> [ 325.194491] 0000000000000000 00000000a7682b83 ffff88007ac3fdf8 ffffffff818861f0 >>> [ 325.195692] 0000000000000000 0000000000000000 ffff88007ac3fe38 ffffffff810af5ca >>> [ 325.196891] ffff88007ac3fe78 ffff88007b068000 ffff88007b484a00 ffff88007b484aa8 >>> [ 325.198119] Call Trace: >>> [ 325.198555] [<ffffffff818861f0>] dump_stack+0x4c/0x65 >>> [ 325.199380] [<ffffffff810af5ca>] warn_slowpath_common+0x8a/0xc0 >>> [ 325.200601] [<ffffffff810af6fa>] warn_slowpath_null+0x1a/0x20 >>> [ 325.201536] [<ffffffff8171db61>] sk_clear_memalloc+0x51/0x80 >>> [ 325.202468] [<ffffffffa012f811>] xs_swapper+0x41/0x60 [sunrpc] >>> [ 325.203398] [<ffffffffa0370447>] nfs_swap_deactivate+0x87/0x170 [nfs] >>> [ 325.204426] [<ffffffffa03703c5>] ? nfs_swap_deactivate+0x5/0x170 [nfs] >>> [ 325.205456] [<ffffffff81237547>] destroy_swap_extents+0x77/0x90 >>> [ 325.206406] [<ffffffff8123b225>] SyS_swapoff+0x215/0x600 >>> [ 325.207287] [<ffffffff81434deb>] ? trace_hardirqs_on_thunk+0x17/0x19 >>> [ 325.208300] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 >>> [ 325.209248] ---[ end trace 13f1014b56e5e711 ]--- >>> >> >> Jerome, >> >> Can you test the attached patch and let me know if this fixes the >> problem? If so, then I'll send it on "officially" to Trond. >> >> Thanks, >> > > It doesn't build: xprt_put() is not exported. > Jeff, could you please change xs_swapper to take a struct rpc_clnt argument. There is absolutely no reason for it to be taking a struct rpc_xprt. Thanks Trond -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 28 May 2015 10:56:14 -0400 Trond Myklebust <trond.myklebust@primarydata.com> wrote: > On Thu, May 28, 2015 at 10:20 AM, Jerome Marchand <jmarchan@redhat.com> wrote: > > On 05/28/2015 01:53 PM, Jeff Layton wrote: > >> On Tue, 26 May 2015 15:20:46 +0200 > >> Jerome Marchand <jmarchan@redhat.com> wrote: > >> > >>> > >>> Commit dad2b015 added an rcu read lock around the call to xs_swapper() > >>> in nfs_activate()/deactivate(), which can sleep, thus raising a bug at > >>> each swapon and swapoff over NFS. > >>> I'm not sure if this is related or not, but swapoff also triggers the > >>> WARN_ON(sk->sk_forward_alloc) in sk_clear_memalloc(). > >>> > >>> [ 243.668067] =============================== > >>> [ 243.668665] [ INFO: suspicious RCU usage. ] > >>> [ 243.669293] 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 Not tainted > >>> [ 243.670301] ------------------------------- > >>> [ 243.670905] include/linux/rcupdate.h:570 Illegal context switch in RCU read-side critical section! > >>> [ 243.672163] > >>> other info that might help us debug this: > >>> > >>> [ 243.673025] > >>> rcu_scheduler_active = 1, debug_locks = 0 > >>> [ 243.673565] 2 locks held by swapon/1176: > >>> [ 243.673893] #0: (&sb->s_type->i_mutex_key#17){+.+.+.}, at: [<ffffffff812385e0>] SyS_swapon+0x2b0/0x1000 > >>> [ 243.674758] #1: (rcu_read_lock){......}, at: [<ffffffffa036fd75>] nfs_swap_activate+0x5/0x180 [nfs] > >>> [ 243.675591] > >>> stack backtrace: > >>> [ 243.675957] CPU: 0 PID: 1176 Comm: swapon Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 > >>> [ 243.676687] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > >>> [ 243.677179] 0000000000000000 00000000ef88d841 ffff88003327bcd8 ffffffff818861f0 > >>> [ 243.677854] 0000000000000000 ffff880078e38000 ffff88003327bd08 ffffffff8110d237 > >>> [ 243.678514] 0000000000000000 ffffffff81c650e4 0000000000000268 ffff880078e38000 > >>> [ 243.679171] Call Trace: > >>> [ 243.679383] [<ffffffff818861f0>] dump_stack+0x4c/0x65 > >>> [ 243.679811] [<ffffffff8110d237>] lockdep_rcu_suspicious+0xe7/0x120 > >>> [ 243.680348] [<ffffffff810df1bf>] ___might_sleep+0xaf/0x250 > >>> [ 243.680815] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 > >>> [ 243.681279] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 > >>> [ 243.681762] [<ffffffff811e409c>] static_key_slow_inc+0x7c/0xc0 > >>> [ 243.682264] [<ffffffff8171afa7>] sk_set_memalloc+0x27/0x30 > >>> [ 243.682736] [<ffffffffa012f824>] xs_swapper+0x54/0x60 [sunrpc] > >>> [ 243.683238] [<ffffffffa036fe03>] nfs_swap_activate+0x93/0x180 [nfs] > >>> [ 243.683760] [<ffffffffa036fd75>] ? nfs_swap_activate+0x5/0x180 [nfs] > >>> [ 243.684316] [<ffffffff81238e04>] SyS_swapon+0xad4/0x1000 > >>> [ 243.684766] [<ffffffff818911b0>] ? syscall_return+0x16/0x59 > >>> [ 243.685245] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 > >>> [ 243.685743] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 > >>> [ 243.686439] in_atomic(): 1, irqs_disabled(): 0, pid: 1176, name: swapon > >>> [ 243.687053] INFO: lockdep is turned off. > >>> [ 243.687429] CPU: 0 PID: 1176 Comm: swapon Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 > >>> [ 243.688313] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > >>> [ 243.688845] 0000000000000000 00000000ef88d841 ffff88003327bd08 ffffffff818861f0 > >>> [ 243.689570] 0000000000000000 ffff880078e38000 ffff88003327bd38 ffffffff810df29c > >>> [ 243.690353] ffff880000000001 ffffffff81c650e4 0000000000000268 0000000000000000 > >>> [ 243.691057] Call Trace: > >>> [ 243.691315] [<ffffffff818861f0>] dump_stack+0x4c/0x65 > >>> [ 243.691785] [<ffffffff810df29c>] ___might_sleep+0x18c/0x250 > >>> [ 243.692306] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 > >>> [ 243.692807] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 > >>> [ 243.693346] [<ffffffff811e409c>] static_key_slow_inc+0x7c/0xc0 > >>> [ 243.693887] [<ffffffff8171afa7>] sk_set_memalloc+0x27/0x30 > >>> [ 243.694416] [<ffffffffa012f824>] xs_swapper+0x54/0x60 [sunrpc] > >>> [ 243.694959] [<ffffffffa036fe03>] nfs_swap_activate+0x93/0x180 [nfs] > >>> [ 243.695535] [<ffffffffa036fd75>] ? nfs_swap_activate+0x5/0x180 [nfs] > >>> [ 243.696193] [<ffffffff81238e04>] SyS_swapon+0xad4/0x1000 > >>> [ 243.696699] [<ffffffff818911b0>] ? syscall_return+0x16/0x59 > >>> [ 243.697299] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 > >>> [ 243.702101] Adding 524284k swap on /mnt/swapfile512. Priority:-2 extents:1 across:524284k FS > >>> [ 325.151350] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616 > >>> [ 325.152688] in_atomic(): 1, irqs_disabled(): 0, pid: 1199, name: swapoff > >>> [ 325.153737] INFO: lockdep is turned off. > >>> [ 325.154457] CPU: 1 PID: 1199 Comm: swapoff Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 > >>> [ 325.156204] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > >>> [ 325.157120] 0000000000000000 00000000a7682b83 ffff88007ac3fce8 ffffffff818861f0 > >>> [ 325.158361] 0000000000000000 ffff880032434c00 ffff88007ac3fd18 ffffffff810df29c > >>> [ 325.159592] 0000000000000000 ffffffff81c650e4 0000000000000268 0000000000000000 > >>> [ 325.160798] Call Trace: > >>> [ 325.161251] [<ffffffff818861f0>] dump_stack+0x4c/0x65 > >>> [ 325.162071] [<ffffffff810df29c>] ___might_sleep+0x18c/0x250 > >>> [ 325.163073] [<ffffffff810df3ad>] __might_sleep+0x4d/0x90 > >>> [ 325.163934] [<ffffffff8188bc17>] mutex_lock_nested+0x47/0x430 > >>> [ 325.164927] [<ffffffff8110a00f>] atomic_dec_and_mutex_lock+0x4f/0x70 > >>> [ 325.166020] [<ffffffff811e4107>] __static_key_slow_dec+0x27/0xc0 > >>> [ 325.166942] [<ffffffff811e41c6>] static_key_slow_dec+0x26/0x50 > >>> [ 325.167955] [<ffffffff8171db3f>] sk_clear_memalloc+0x2f/0x80 > >>> [ 325.169075] [<ffffffffa012f811>] xs_swapper+0x41/0x60 [sunrpc] > >>> [ 325.170241] [<ffffffffa0370447>] nfs_swap_deactivate+0x87/0x170 [nfs] > >>> [ 325.171276] [<ffffffffa03703c5>] ? nfs_swap_deactivate+0x5/0x170 [nfs] > >>> [ 325.172349] [<ffffffff81237547>] destroy_swap_extents+0x77/0x90 > >>> [ 325.173754] [<ffffffff8123b225>] SyS_swapoff+0x215/0x600 > >>> [ 325.174726] [<ffffffff81434deb>] ? trace_hardirqs_on_thunk+0x17/0x19 > >>> [ 325.175971] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 > >>> [ 325.178052] ------------[ cut here ]------------ > >>> [ 325.178892] WARNING: CPU: 1 PID: 1199 at net/core/sock.c:364 sk_clear_memalloc+0x51/0x80() > >>> [ 325.180363] Modules linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iosf_mbi crct10dif_pclmul crc32_pclmul crc32c_intel ppdev ghash_clmulni_intel joydev nfsd parport_pc pcspkr virtio_console serio_raw virtio_balloon parport pvpanic i2c_piix4 acpi_cpufreq auth_rpcgss nfs_acl lockd grace sunrpc virtio_blk qxl virtio_net drm_kms_helper ttm drm virtio_pci virtio_ring virtio ata_generic pata_acpi floppy > >>> [ 325.192279] CPU: 1 PID: 1199 Comm: swapoff Not tainted 4.1.0-rc1-lock_stat-dbg-next-20150430+ #235 > >>> [ 325.193605] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > >>> [ 325.194491] 0000000000000000 00000000a7682b83 ffff88007ac3fdf8 ffffffff818861f0 > >>> [ 325.195692] 0000000000000000 0000000000000000 ffff88007ac3fe38 ffffffff810af5ca > >>> [ 325.196891] ffff88007ac3fe78 ffff88007b068000 ffff88007b484a00 ffff88007b484aa8 > >>> [ 325.198119] Call Trace: > >>> [ 325.198555] [<ffffffff818861f0>] dump_stack+0x4c/0x65 > >>> [ 325.199380] [<ffffffff810af5ca>] warn_slowpath_common+0x8a/0xc0 > >>> [ 325.200601] [<ffffffff810af6fa>] warn_slowpath_null+0x1a/0x20 > >>> [ 325.201536] [<ffffffff8171db61>] sk_clear_memalloc+0x51/0x80 > >>> [ 325.202468] [<ffffffffa012f811>] xs_swapper+0x41/0x60 [sunrpc] > >>> [ 325.203398] [<ffffffffa0370447>] nfs_swap_deactivate+0x87/0x170 [nfs] > >>> [ 325.204426] [<ffffffffa03703c5>] ? nfs_swap_deactivate+0x5/0x170 [nfs] > >>> [ 325.205456] [<ffffffff81237547>] destroy_swap_extents+0x77/0x90 > >>> [ 325.206406] [<ffffffff8123b225>] SyS_swapoff+0x215/0x600 > >>> [ 325.207287] [<ffffffff81434deb>] ? trace_hardirqs_on_thunk+0x17/0x19 > >>> [ 325.208300] [<ffffffff81890f6e>] system_call_fastpath+0x12/0x76 > >>> [ 325.209248] ---[ end trace 13f1014b56e5e711 ]--- > >>> > >> > >> Jerome, > >> > >> Can you test the attached patch and let me know if this fixes the > >> problem? If so, then I'll send it on "officially" to Trond. > >> > >> Thanks, > >> > > > > It doesn't build: xprt_put() is not exported. > > > > Jeff, could you please change xs_swapper to take a struct rpc_clnt > argument. There is absolutely no reason for it to be taking a struct > rpc_xprt. > Yes. I agree that it's currently a bit of a layering violation. I'll also take a crack at fixing up the refcounting and maybe see if we can also handle migration events sanely.
From 527e41205915d605f68c356a636dfc12b7545b7b Mon Sep 17 00:00:00 2001 From: Jeff Layton <jeff.layton@primarydata.com> Date: Thu, 28 May 2015 07:39:39 -0400 Subject: [PATCH] nfs: don't hold rcu_read_lock over xs_swapper call Jerome reported seeing a WARN_ON pop up when enabling a swapfile on NFS. The xs_swapper call can sleep so we do not want to hold the rcu_read_lock when calling it. Fix this by taking a reference to the xprt in the critical section, calling xs_swapper outside it and then putting that reference. Reported-by: Jerome Marchand <jmarchan@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> --- fs/nfs/file.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 8b8d83a526ce..3ee08460c4cf 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -561,12 +561,18 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, { int ret; struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); + struct rpc_xprt *xprt; *span = sis->pages; rcu_read_lock(); - ret = xs_swapper(rcu_dereference(clnt->cl_xprt), 1); + xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); rcu_read_unlock(); + if (!xprt) + return -EINVAL; + + ret = xs_swapper(xprt, 1); + xprt_put(xprt); return ret; } @@ -574,10 +580,16 @@ static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, static void nfs_swap_deactivate(struct file *file) { struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); + struct rpc_xprt *xprt; rcu_read_lock(); - xs_swapper(rcu_dereference(clnt->cl_xprt), 0); + xprt = xprt_get(rcu_dereference(clnt->cl_xprt)); rcu_read_unlock(); + if (!xprt) + return; + + xs_swapper(xprt, 0); + xprt_put(xprt); } #endif -- 2.4.1