Luis Chamberlain c7b333600a blktrace: break out of blktrace setup on concurrent calls ... [ Upstream commit 1b0b283648 ] We use one blktrace per request_queue, that means one per the entire disk. So we cannot run one blktrace on say /dev/vda and then /dev/vda1, or just two calls on /dev/vda. We check for concurrent setup only at the very end of the blktrace setup though. If we try to run two concurrent blktraces on the same block device the second one will fail, and the first one seems to go on. However when one tries to kill the first one one will see things like this: The kernel will show these: ``` debugfs: File 'dropped' in directory 'nvme1n1' already present! debugfs: File 'msg' in directory 'nvme1n1' already present! debugfs: File 'trace0' in directory 'nvme1n1' already present! `` And userspace just sees this error message for the second call: ``` blktrace /dev/nvme1n1 BLKTRACESETUP(2) /dev/nvme1n1 failed: 5/Input/output error ``` The first userspace process #1 will also claim that the files were taken underneath their nose as well. The files are taken away form the first process given that when the second blktrace fails, it will follow up with a BLKTRACESTOP and BLKTRACETEARDOWN. This means that even if go-happy process #1 is waiting for blktrace data, we *have* been asked to take teardown the blktrace. This can easily be reproduced with break-blktrace [0] run_0005.sh test. Just break out early if we know we're already going to fail, this will prevent trying to create the files all over again, which we know still exist. [0] https://github.com/mcgrof/break-blktrace Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-06-30 23:17:15 -04:00
..
bpf	cpumap: Avoid warning when CONFIG_DEBUG_PER_CPU_MAPS is enabled	2020-05-02 17:25:53 +02:00
cgroup	Revert "cgroup: Add memory barriers to plug cgroup_rstat_updated() race window"	2020-06-07 13:17:53 +02:00
configs	kconfig: tinyconfig: remove stale stack protector fixups	2018-06-15 07:15:28 +09:00
debug	kgdb: Prevent infinite recursive entries to the debugger	2020-06-22 09:05:11 +02:00
dma	dma-debug: add a schedule point in debug_dma_dump_mappings()	2020-01-04 19:12:43 +01:00
events	perf: Add cond_resched() to task_function_call()	2020-06-22 09:05:08 +02:00
gcov	kernel/gcov/fs.c: gcov_seq_next() should increase position index	2020-04-29 16:31:12 +02:00
irq	genirq/irqdomain: Check pointer in irq_domain_alloc_irqs_hierarchy()	2020-04-17 10:48:41 +02:00
livepatch	livepatch: Nullify obj->mod in klp_module_coming()'s error path	2019-10-07 18:57:10 +02:00
locking	locktorture: Print ratio of acquisitions, not failures	2020-04-23 10:30:23 +02:00
power	PM: hibernate: Freeze kernel threads in software_resume()	2020-05-06 08:13:28 +02:00
printk	printk: fix exclusive_console replaying	2020-02-11 04:33:51 -08:00
rcu	rcu: Avoid data-race in rcu_gp_fqs_check_wake()	2020-02-11 04:33:55 -08:00
sched	sched/core: Fix PI boosting between RT and DEADLINE tasks	2020-06-30 23:17:13 -04:00
time	clocksource: Prevent double add_timer_on() for watchdog_timer	2020-02-11 04:34:18 -08:00
trace	blktrace: break out of blktrace setup on concurrent calls	2020-06-30 23:17:15 -04:00
.gitignore
acct.c	acct_on(): don't mess with freeze protection	2019-05-31 06:46:05 -07:00
async.c
audit.c	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:05:13 +02:00
audit.h	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:05:13 +02:00
audit_fsnotify.c
audit_tree.c	audit: Embed key into chunk	2019-12-13 08:51:11 +01:00
audit_watch.c	audit_get_nd(): don't unlock parent too early	2019-12-13 08:51:02 +01:00
auditfilter.c	audit: fix a net reference leak in audit_list_rules_send()	2020-06-22 09:05:13 +02:00
auditsc.c	audit: print empty EXECVE args	2019-12-01 09:17:17 +01:00
backtracetest.c
bounds.c	kbuild: fix kernel/bounds.c 'W=1' warning	2018-11-13 11:08:47 -08:00
capability.c	LSM: generalize flag passing to security_capable	2020-01-23 08:21:29 +01:00
compat.c	make 'user_access_begin()' do 'access_ok()'	2020-06-22 09:04:58 +02:00
configs.c
context_tracking.c
cpu.c	sched/core: Fix illegal RCU from offline CPUs	2020-06-22 09:05:14 +02:00
cpu_pm.c	kernel/cpu_pm: Fix uninitted local in cpu_pm	2020-06-22 09:05:28 +02:00
crash_core.c	kernel/crash_core.c: print timestamp using time64_t	2018-08-22 10:52:47 -07:00
crash_dump.c
cred.c	memcg: account security cred as well to kmemcg	2020-01-09 10:19:00 +01:00
delayacct.c
dma.c
elfcore.c	kernel/elfcore.c: include proper prototypes	2019-10-11 18:21:23 +02:00
exec_domain.c
exit.c	exit: Move preemption fixup up, move blocking operations down	2020-06-22 09:05:14 +02:00
extable.c
fail_function.c	bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe	2018-06-21 12:33:19 +02:00
fork.c	fork,memcg: alloc_thread_stack_node needs to set tsk->stack	2020-01-27 14:50:58 +01:00
freezer.c	PM / reboot: Eliminate race between reboot and suspend	2018-08-06 12:35:20 +02:00
futex.c	futex: Unbreak futex hashing	2020-03-25 08:06:14 +01:00
groups.c
hung_task.c	kernel: hung_task.c: disable on suspend	2019-04-20 09:16:02 +02:00
iomem.c
irq_work.c	irq_work: Do not raise an IPI when queueing work on the local CPU	2019-05-31 06:46:19 -07:00
jump_label.c	jump_label: move 'asm goto' support test to Kconfig	2019-06-04 08:02:34 +02:00
kallsyms.c	kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol	2019-09-21 07:17:02 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt	kconfig: include kernel/Kconfig.preempt from init/Kconfig	2018-08-02 08:06:54 +09:00
kcov.c	kernel/kcov.c: mark write_comp_data() as notrace	2019-02-12 19:47:20 +01:00
kexec.c	kexec: add call to LSM hook in original kexec_load syscall	2018-07-16 12:31:57 -07:00
kexec_core.c	kexec: Allocate decrypted control pages for kdump if SME is enabled	2019-11-24 08:20:29 +01:00
kexec_file.c	treewide: Use array_size() in vzalloc()	2018-06-12 16:19:22 -07:00
kexec_internal.h
kmod.c	kmod: make request_module() return an error when autoloading is disabled	2020-04-17 10:48:52 +02:00
kprobes.c	kretprobe: Prevent triggering kretprobe from within kprobe_flush_task	2020-06-25 15:33:10 +02:00
ksysfs.c
kthread.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-08-13 11:25:07 -07:00
latencytop.c
Makefile	y2038: futex: Move compat implementation into futex.c	2019-12-01 09:17:38 +01:00
memremap.c	mm/memory_hotplug: shrink zones when offlining memory	2020-01-29 16:43:27 +01:00
module-internal.h	modsign: log module name in the event of an error	2018-07-02 11:36:17 +02:00
module.c	module: avoid setting info->name early in case we can fall back to info->mod->name	2020-02-24 08:34:49 +01:00
module_signing.c	modsign: log module name in the event of an error	2018-07-02 11:36:17 +02:00
notifier.c	x86/mm: split vmalloc_sync_all()	2020-03-25 08:06:13 +01:00
nsproxy.c
padata.c	padata: purge get_cpu and reorder_via_wq from padata_do_serial	2020-05-27 17:37:36 +02:00
panic.c	kernel/panic.c: do not append newline to the stack protector panic string	2019-12-01 09:17:10 +01:00
params.c
pid.c	Fix failure path in alloc_pid()	2019-01-13 09:51:06 +01:00
pid_namespace.c	signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig	2019-07-26 09:14:01 +02:00
profile.c
ptrace.c	ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()	2020-01-23 08:21:29 +01:00
range.c
reboot.c	PM / reboot: Eliminate race between reboot and suspend	2018-08-06 12:35:20 +02:00
relay.c	kernel/relay.c: handle alloc_percpu returning NULL in relay_open	2020-06-07 13:17:54 +02:00
resource.c	resource: fix locking in find_next_iomem_res()	2019-09-16 08:22:20 +02:00
rseq.c	rseq: uapi: Declare rseq_cs field as union, update includes	2018-07-10 22:18:52 +02:00
seccomp.c	LSM: generalize flag passing to security_capable	2020-01-23 08:21:29 +01:00
signal.c	signal: Extend exec_id to 64bits	2020-04-17 10:48:47 +02:00
smp.c	cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM	2019-02-12 19:47:25 +01:00
smpboot.c	smpboot: Remove cpumask from the API	2018-07-03 09:20:44 +02:00
smpboot.h
softirq.c	nohz: Fix missing tick reprogram when interrupting an inline softirq	2018-08-03 15:52:10 +02:00
stacktrace.c
stop_machine.c	Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-08-13 11:25:07 -07:00
sys.c	kernel/sys.c: prctl: fix false positive in validate_prctl_map()	2019-06-15 11:54:01 +02:00
sys_ni.c	Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2018-06-10 10:17:09 -07:00
sysctl.c	kernel: sysctl: make drop_caches write-only	2020-01-04 19:13:17 +01:00
sysctl_binary.c
task_work.c
taskstats.c	taskstats: fix data-race	2020-01-09 10:18:59 +01:00
test_kprobes.c	kprobes: Remove jprobe API implementation	2018-06-21 12:33:05 +02:00
torture.c	torture: Keep old-school dmesg format	2018-06-25 11:30:10 -07:00
tracepoint.c	tracepoint: Fix tracepoint array element size mismatch	2018-10-17 15:35:29 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c	coredump: fix crash when umh is disabled	2020-05-14 07:57:21 +02:00
up.c
user-return-notifier.c
user.c	userns: use irqsave variant of refcount_dec_and_lock()	2018-08-22 10:52:47 -07:00
user_namespace.c	userns: also map extents in the reverse map to kernel IDs	2018-11-13 11:09:00 -08:00
utsname.c
utsname_sysctl.c	sys: don't hold uts_sem while accessing userspace memory	2018-08-11 02:05:53 -05:00
watchdog.c	watchdog/softlockup: Enforce that timestamp is valid on boot	2020-02-24 08:34:49 +01:00
watchdog_hld.c	watchdog: Mark watchdog touch functions as notrace	2018-08-30 12:56:40 +02:00
workqueue.c	workqueue: don't use wq_select_unbound_cpu() for bound works	2020-03-18 07:14:20 +01:00
workqueue_internal.h