[patch 4/5] blktrace: disable kill option

[patch 4/5] blktrace: disable kill option

[Edward Shishkin]

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Fixup for 513950.

Problem:
'blktrace -d <device> -k' does not kill a running
backgound trace. Executing 'blktrace -d <device> -k'
for the second time results in "BLKTRACETEARDOWN:
Invalid argument" message and then each run of
blktrace on that machine prints the following output:
BLKTRACESETUP: No such file or directory.

The bug:
The option -k results in clobbering information
about running trace by kernel (blk_trace_remove),
while resources (files open in debugfs by the running
background blktrace) are not released.

Solution:
. Disable non-working "kill" option;
. Update documentation, advise to send SIGINT signal
  via kill(1) to the running background blktrace for
  its correct termination.

Signed-off-by: Edward Shishkin <edward@redhat.com>
---
 blktrace.c     |   14 +++++++++++++-
 doc/blktrace.8 |   24 ++++--------------------
 2 files changed, 17 insertions(+), 21 deletions(-)

--- blktrace.orig/blktrace.c
+++ blktrace/blktrace.c
@@ -64,6 +64,7 @@
 
 #define DEBUGFS_TYPE		(0x64626720)
 #define TRACE_NET_PORT		(8462)
+#define KILL_OPT_ENABLED        (0)
 
 enum {
 	Net_none = 0,
@@ -326,7 +327,12 @@ static int *cl_fds;
 static int (*handle_pfds)(struct tracer *, int, int);
 static int (*handle_list)(struct tracer_devpath_head *, struct list_head *);
 
+#if KILL_OPT_ENABLED
 #define S_OPTS	"d:a:A:r:o:kw:vVb:n:D:lh:p:sI:"
+#else
+#define S_OPTS	"d:a:A:r:o:w:vVb:n:D:lh:p:sI:"
+#endif /* KILL_OPT_ENABLED */
+
 static struct option l_opts[] = {
 	{
 		.name = "dev",
@@ -364,12 +370,14 @@ static struct option l_opts[] = {
 		.flag = NULL,
 		.val = 'o'
 	},
+#if KILL_OPT_ENABLED
 	{
 		.name = "kill",
 		.has_arg = no_argument,
 		.flag = NULL,
 		.val = 'k'
 	},
+#endif /* KILL_OPT_ENABLED */
 	{
 		.name = "stopwatch",
 		.has_arg = required_argument,
@@ -442,7 +450,9 @@ static char usage_str[] = \
 	"\t-r Path to mounted debugfs, defaults to /sys/kernel/debug\n" \
 	"\t-o File(s) to send output to\n" \
 	"\t-D Directory to prepend to output file names\n" \
-	"\t-k Kill a running trace\n" \
+#if KILL_OPT_ENABLED
+        "\t-k Kill a running trace\n" \
+#endif /* KILL_OPT_ENABLED */
 	"\t-w Stop after defined time, in seconds\n" \
 	"\t-a Only trace specified actions. See documentation\n" \
 	"\t-A Give trace mask as a single value. See documentation\n" \
@@ -2065,9 +2075,11 @@ static int handle_args(int argc, char *a
 		case 'o':
 			output_name = optarg;
 			break;
+#if KILL_OPT_ENABLED
 		case 'k':
 			kill_running_trace = 1;
 			break;
+#endif /* KILL_OPT_ENABLED */
 		case 'w':
 			stop_watch = atoi(optarg);
 			if (stop_watch <= 0) {
--- blktrace.orig/doc/blktrace.8
+++ blktrace/doc/blktrace.8
@@ -66,19 +66,10 @@ blktrace may also be run concurrently wi
 .TP 2
 \- 
 The default behaviour for blktrace is to run forever until explicitly
-killed by the user (via a control-C, or kill utility invocation).
-There are two ways to modify this:
-
-.TP 5
-  1. 
-You may utilise the blktrace utility itself to kill
-a running trace -- via the \fB\-k\fR option.
-
-.TP 5
-  2.
-You can specify a run-time duration for blktrace via the
-\fB\-w\fR option -- then blktrace will run for the specified number
-of seconds, and then halt.
+killed by the user (via a control-C, or sending SIGINT signal to the
+process via invocation the kill (1) utility). Also you can specify a
+run-time duration for blktrace via the \fB\-w\fR option -- then
+blktrace will run for the specified number of seconds, and then halt.
 
 
 .SH OPTIONS
@@ -119,13 +110,6 @@ Adds \fIdev\fR as a device to trace  
 Adds the devices found in \fIfile\fR as devices to trace
 .RE
 
-\-k 
-.br
-\-\-kill 
-.RS
-Kill on-going trace  
-.RE
-
 \-n \fInum\-sub\fR 
 .br
 \-\-num\-sub=\fInum-sub\fR    

Re: [patch 4/5] blktrace: disable kill option

[Jens Axboe]

On Tue, Dec 15 2009, Edward Shishkin wrote:
>

> Fixup for 513950.
> 
> Problem:
> 'blktrace -d <device> -k' does not kill a running
> backgound trace. Executing 'blktrace -d <device> -k'
> for the second time results in "BLKTRACETEARDOWN:
> Invalid argument" message and then each run of
> blktrace on that machine prints the following output:
> BLKTRACESETUP: No such file or directory.
> 
> The bug:
> The option -k results in clobbering information
> about running trace by kernel (blk_trace_remove),
> while resources (files open in debugfs by the running
> background blktrace) are not released.
> 
> Solution:
> . Disable non-working "kill" option;
> . Update documentation, advise to send SIGINT signal
>   via kill(1) to the running background blktrace for
>   its correct termination.

Patch does not compile:

gcc -o blktrace.o -c -Wall -O2 -g -W -D_GNU_SOURCE -D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITSd blktrace.c
blktrace.c:446: error: stray ?#? in program
blktrace.c:453: error: expected ?,? or ?;? before ?if?
blktrace.c:454: error: stray ?#? in program
make: *** [blktrace.o] Error 1


        "\t-D Directory to prepend to output file names\n" \
#if KILL_OPT_ENABLED
        "\t-k Kill a running trace\n" \
#endif /* KILL_OPT_ENABLED */
        "\t-w Stop after defined time, in seconds\n" \


-- 
Jens Axboe

Re: [patch 4/5] blktrace: disable kill option

[Edward Shishkin]

Jens Axboe wrote:
> On Tue, Dec 15 2009, Edward Shishkin wrote:
>   
>
>   
>> Fixup for 513950.
>>
>> Problem:
>> 'blktrace -d <device> -k' does not kill a running
>> backgound trace. Executing 'blktrace -d <device> -k'
>> for the second time results in "BLKTRACETEARDOWN:
>> Invalid argument" message and then each run of
>> blktrace on that machine prints the following output:
>> BLKTRACESETUP: No such file or directory.
>>
>> The bug:
>> The option -k results in clobbering information
>> about running trace by kernel (blk_trace_remove),
>> while resources (files open in debugfs by the running
>> background blktrace) are not released.
>>
>> Solution:
>> . Disable non-working "kill" option;
>> . Update documentation, advise to send SIGINT signal
>>   via kill(1) to the running background blktrace for
>>   its correct termination.
>>     
>
> Patch does not compile:
>
> gcc -o blktrace.o -c -Wall -O2 -g -W -D_GNU_SOURCE -D_LARGEFILE_SOURCE
> -D_FILE_OFFSET_BITSd blktrace.c
> blktrace.c:446: error: stray ?#? in program
> blktrace.c:453: error: expected ?,? or ?;? before ?if?
> blktrace.c:454: error: stray ?#? in program
> make: *** [blktrace.o] Error 1
>
>
>         "\t-D Directory to prepend to output file names\n" \
> #if KILL_OPT_ENABLED
>         "\t-k Kill a running trace\n" \
> #endif /* KILL_OPT_ENABLED */
>         "\t-w Stop after defined time, in seconds\n" \
>   
oops, sorry: wrong stuff.
I'll resend the correct one.

Edward.