io-stats: Fix io-stat dump to dump at all levels

Previous commit to fix the bug, where io-stat-dump was overwriting
the dump file when the client and a brick was on the same host,
failed to consider the existing behaviour where io-stats can
help generate closely correlated set of stats across clients
and bricks, by triggering the dump using the same command.

This was introduced in commit:
0facb11220aea20a6573b656785922219c9650cf

Further, by limiting the first io-stat to unwind the dump request,
there is no way to trigger other io-stat xlators in the stack to
dump their stat information.

This bug hence is being fixed by this commit keeping the
following in mind,
- We need to trigger io-stat-dump for all instances in the
graph when this attr is set
- We need to write the output to different files, so that
they do not overwrite each others data
- We need to prevent this xattr from being set on the path
that is used to trigger the io-stat-dump information

Change-Id: I31ec380f0d85e10313a9d7b977da0e1ec74638a6
BUG: 1322825
Signed-off-by: Shyam <srangana@redhat.com>
Reviewed-on: http://review.gluster.org/14552
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Ravishankar N <ravishankar@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

2 files changed, 24 insertions, 13 deletions

diff --git a/xlators/debug/io-stats/src/io-stats.c b/xlators/debug/io-stats/src/io-stats.c
index 62e85bbb99b..5e82fb4c029 100644
--- a/xlators/debug/io-stats/src/io-stats.c
+++ b/xlators/debug/io-stats/src/io-stats.c
@@ -21,7 +21,8 @@
  *  d) counts of write IO block size - since process start, last interval and per fd
  *  e) counts of all FOP types passing through it
  *
- *  Usage: setfattr -n io-stats-dump /tmp/filename /mnt/gluster
+ *  Usage: setfattr -n trusted.io-stats-dump /tmp/filename /mnt/gluster
+ *      output is written to /tmp/filename.<iostats xlator instance name>
  *
  */
 
@@ -2827,15 +2828,32 @@ conditional_dump (dict_t *dict, char *key, data_t *value, void *data)
         char                 *filename = NULL;
         FILE                 *logfp = NULL;
         struct ios_dump_args args = {0};
-        int                   pid;
+        int                   pid, namelen;
         char                  dump_key[100];
+        char                 *slash_ptr = NULL;
 
         stub  = data;
         this  = stub->this;
 
-        filename = alloca (value->len + 1);
-        memset (filename, 0, value->len + 1);
+        /* Create a file name that is appended with the io-stats instance
+        name as well. This helps when there is more than a single io-stats
+        instance in the graph, or the client and server processes are running
+        on the same node */
+        /* hmmm... no check for this */
+        /* name format: <passed in path/filename>.<xlator name slashes to -> */
+        namelen = value->len + strlen (this->name) + 2; /* '.' and '\0' */
+        filename = alloca (namelen);
+        memset (filename, 0, namelen);
         memcpy (filename, data_to_str (value), value->len);
+        memcpy (filename + value->len, ".", 1);
+        memcpy (filename + value->len + 1, this->name, strlen(this->name));
+
+        /* convert any slashes to '-' so that fopen works correctly */
+        slash_ptr = strchr (filename + value->len + 1, '/');
+        while (slash_ptr) {
+                *slash_ptr = '-';
+                slash_ptr = strchr (slash_ptr, '/');
+        }
 
         pid = getpid ();
 
@@ -3018,11 +3036,6 @@ io_stats_setxattr (call_frame_t *frame, xlator_t *this,
 
         ret = dict_foreach_match (dict, match_special_xattr, NULL,
                                   conditional_dump, &stub);
-        if (ret > 0) {
-                /* Setxattr was on key 'io-stat-dump', hence dump and unwind
-                 * from here */
-                goto out;
-        }
 
         START_FOP_LATENCY (frame);
 
@@ -3031,10 +3044,6 @@ io_stats_setxattr (call_frame_t *frame, xlator_t *this,
                     FIRST_CHILD(this)->fops->setxattr,
                     loc, dict, flags, xdata);
         return 0;
-
-out:
-        STACK_UNWIND_STRICT (setxattr, frame, 0, 0, NULL);
-        return 0;
 }
 
 
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 2320bf13449..4294fa4fe36 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3746,6 +3746,8 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
 
         dict_del (dict, GFID_XATTR_KEY);
         dict_del (dict, GF_XATTR_VOL_ID_KEY);
+        /* the io-stats-dump key should not reach disk */
+        dict_del (dict, GF_XATTR_IOSTATS_DUMP_KEY);
 
         filler.real_path = real_path;
         filler.this = this;