/* * Ceph string constants */ #include #include const char *ceph_entity_type_name(int type) { switch (type) { case CEPH_ENTITY_TYPE_MDS: return "mds"; case CEPH_ENTITY_TYPE_OSD: return "osd"; case CEPH_ENTITY_TYPE_MON: return "mon"; case CEPH_ENTITY_TYPE_CLIENT: return "client"; case CEPH_ENTITY_TYPE_AUTH: return "auth"; default: return "unknown"; } } EXPORT_SYMBOL(ceph_entity_type_name); const char *ceph_osd_op_name(int op) { switch (op) { #define GENERATE_CASE(op, opcode, str) case CEPH_OSD_OP_##op: return (str); __CEPH_FORALL_OSD_OPS(GENERATE_CASE) #undef GENERATE_CASE default: return "???"; } } const char *ceph_osd_watch_op_name(int o) { switch (o) { case CEPH_OSD_WATCH_OP_UNWATCH: return "unwatch"; case CEPH_OSD_WATCH_OP_WATCH: return "watch"; case CEPH_OSD_WATCH_OP_RECONNECT: return "reconnect"; case CEPH_OSD_WATCH_OP_PING: return "ping"; default: return "???"; } } const char *ceph_osd_state_name(int s) { switch (s) { case CEPH_OSD_EXISTS: return "exists"; case CEPH_OSD_UP: return "up"; case CEPH_OSD_AUTOOUT: return "autoout"; case CEPH_OSD_NEW: return "new"; default: return "???"; } } ption> net-next plumbingsTobias Klauser
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /drivers/usb/dwc3/dwc3-st.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'drivers/usb/dwc3/dwc3-st.c')