Luis Chamberlain 1b0b283648 blktrace: break out of blktrace setup on concurrent calls ... 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>		2020-06-17 09:07:11 -06:00
..
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-06-13 16:27:13 -07:00
cgroup	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
configs	compiler: remove CONFIG_OPTIMIZE_INLINING entirely	2020-04-07 10:43:42 -07:00
debug	kernel: rename show_stack_loglvl() => show_stack()	2020-06-09 09:39:13 -07:00
dma	dma-mapping updates for 5.8, part 1	2020-06-06 11:43:23 -07:00
events	Merge branch 'akpm' (patches from Andrew)	2020-06-09 09:54:46 -07:00
gcov	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
irq	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
kcsan	kcsan: Support distinguishing volatile accesses	2020-06-11 20:04:01 +02:00
livepatch	livepatch: Make klp_apply_object_relocs static	2020-05-11 00:31:38 +02:00
locking	The X86 entry, exception and interrupt code rework	2020-06-13 10:05:47 -07:00
power	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
printk	One more printk change for 5.8	2020-06-12 12:13:36 -07:00
rcu	TTY/Serial driver updates for 5.8-rc1	2020-06-07 09:52:36 -07:00
sched	Rebase locking/kcsan to locking/urgent	2020-06-11 20:02:46 +02:00
time	The X86 entry, exception and interrupt code rework	2020-06-13 10:05:47 -07:00
trace	blktrace: break out of blktrace setup on concurrent calls	2020-06-17 09:07:11 -06:00
.gitignore	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
acct.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
async.c
audit_fsnotify.c	fsnotify: use helpers to access data by data_type	2020-03-23 18:19:06 +01:00
audit_tree.c
audit_watch.c	\n	2020-04-06 08:58:42 -07:00
audit.c	audit/stable-5.8 PR 20200601	2020-06-02 17:13:37 -07:00
audit.h	audit: fix a net reference leak in audit_list_rules_send()	2020-04-22 15:23:10 -04:00
auditfilter.c	audit: fix a net reference leak in audit_list_rules_send()	2020-04-22 15:23:10 -04:00
auditsc.c	audit: add subj creds to NETFILTER_CFG record to	2020-05-20 18:09:19 -04:00
backtracetest.c
bounds.c
capability.c
compat.c	uaccess: Selectively open read or write user access	2020-05-01 12:35:21 +10:00
configs.c	proc: convert everything to "struct proc_ops"	2020-02-04 03:05:26 +00:00
context_tracking.c	context_tracking: Ensure that the critical path cannot be instrumented	2020-06-11 15:14:36 +02:00
cpu_pm.c	kernel/cpu_pm: Fix uninitted local in cpu_pm	2020-05-15 11:44:34 -07:00
cpu.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
crash_core.c
crash_dump.c	crash_dump: Remove no longer used saved_max_pfn	2020-04-15 11:21:54 +02:00
cred.c	exec: Teach prepare_exec_creds how exec treats uids & gids	2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
extable.c	kernel/extable.c: use address-of operator on section symbols	2020-04-07 10:43:42 -07:00
fail_function.c
fork.c	mmap locking API: convert nested write lock sites	2020-06-09 09:39:14 -07:00
freezer.c
futex.c	mmap locking API: use coccinelle to convert mmap_sem rwsem call sites	2020-06-09 09:39:14 -07:00
gen_kheaders.sh	kbuild: add variables for compression tools	2020-06-06 23:42:01 +09:00
groups.c	mm: remove the pgprot argument to __vmalloc	2020-06-02 10:59:11 -07:00
hung_task.c	kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected	2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c	irq_work, smp: Allow irq_work on call_single_queue	2020-05-28 10:54:15 +02:00
jump_label.c
kallsyms.c	kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()	2020-04-07 10:43:44 -07:00
kcmp.c	kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve	2020-03-25 10:04:01 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: check kcov_softirq in kcov_remote_stop()	2020-06-10 19:14:17 -07:00
kexec_core.c
kexec_elf.c
kexec_file.c	kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED	2020-06-04 19:06:23 -07:00
kexec_internal.h
kexec.c
kheaders.c
kmod.c	kmod: make request_module() return an error when autoloading is disabled	2020-04-10 15:36:22 -07:00
kprobes.c	kernel/kprobes.c: convert to use DEFINE_SEQ_ATTRIBUTE macro	2020-06-04 19:06:26 -07:00
ksysfs.c
kthread.c	Merge branch 'akpm' (patches from Andrew)	2020-06-11 13:25:53 -07:00
latencytop.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
Makefile	Notifications over pipes + Keyring notifications	2020-06-13 09:56:21 -07:00
module_signature.c
module_signing.c
module-internal.h
module.c	module: move the set_fs hack for flush_icache_range to m68k	2020-06-08 11:05:58 -07:00
notifier.c	mm: remove vmalloc_sync_(un)mappings()	2020-06-02 10:59:12 -07:00
nsproxy.c	nsproxy: attach to namespaces via pidfds	2020-05-13 11:41:22 +02:00
padata.c	padata: add basic support for multithreaded jobs	2020-06-03 20:09:45 -07:00
panic.c	bug: Annotate WARN/BUG/stackfail as noinstr safe	2020-06-11 15:14:36 +02:00
params.c
pid_namespace.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next	2020-06-03 16:27:18 -07:00
pid.c	remove the no longer needed pid_alive() check in __task_pid_nr_ns()	2020-04-30 06:40:14 -05:00
profile.c	proc: convert everything to "struct proc_ops"	2020-02-04 03:05:26 +00:00
ptrace.c	ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()	2020-01-18 13:51:39 +01:00
range.c
reboot.c	printk: Collapse shutdown types into a single dump reason	2020-05-30 10:34:03 -07:00
relay.c	mmap locking API: convert mmap_sem comments	2020-06-09 09:39:14 -07:00
resource.c	/dev/mem: Revoke mappings when a driver claims the region	2020-05-27 11:10:05 +02:00
rseq.c
scs.c	scs: Report SCS usage in bytes rather than number of entries	2020-06-04 16:14:56 +01:00
seccomp.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
signal.c	Merge branch 'work.set_fs-exec' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-06-01 16:21:46 -07:00
smp.c	The changes in this cycle are:	2020-06-03 13:06:42 -07:00
smpboot.c
smpboot.h
softirq.c	x86/entry: Clarify irq_{enter,exit}_rcu()	2020-06-11 15:15:24 +02:00
stackleak.c
stacktrace.c
stop_machine.c	stop_machine: Make stop_cpus() static	2020-01-17 10:19:21 +01:00
sys_ni.c
sys.c	Add additional LSM hooks for SafeSetID	2020-06-14 11:39:31 -07:00
sysctl_binary.c
sysctl-test.c
sysctl.c	kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted	2020-06-08 11:05:56 -07:00
task_work.c	task_work_run: don't take ->pi_lock unconditionally	2020-03-02 14:06:33 -07:00
taskstats.c
test_kprobes.c
torture.c	CPU (hotplug) updates:	2020-03-30 18:06:39 -07:00
tracepoint.c
tsacct.c
ucount.c	ucount: Make sure ucounts in /proc/sys/user don't regress again	2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-05-15 13:48:59 -07:00
up.c	smp/up: Make smp_call_function_single() match SMP semantics	2020-02-07 15:34:12 +01:00
user_namespace.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
user-return-notifier.c
user.c	user.c: make uidhash_table static	2020-06-04 19:06:24 -07:00
utsname_sysctl.c	sysctl: pass kernel pointers to ->proc_handler	2020-04-27 02:07:40 -04:00
utsname.c	nsproxy: add struct nsset	2020-05-09 13:57:12 +02:00
watch_queue.c	Notifications over pipes + Keyring notifications	2020-06-13 09:56:21 -07:00
watchdog_hld.c
watchdog.c	kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases	2020-06-08 11:05:56 -07:00
workqueue_internal.h
workqueue.c	workqueue: use BUILD_BUG_ON() for compile time test instead of WARN_ON()	2020-06-01 11:02:42 -04:00