logging enhancements

* per translator loglevel introduced, if set, it will override process
  wide log level.
* with extended attribute 'trusted.glusterfs.<xlator-name>.set-log-level'
  with the value being '<LOGLEVEL>', one can change log level of particular
  translator.
* with extended attribute 'trusted.glusterfs.syslog' with the value
  '<BOOLEAN>', one can enable disable syslog for gluster

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 601 (Enable changing 'log-level' of GlusterFS process at runtime)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=601

3 files changed, 103 insertions, 1 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index ea5b5ae38..ac8295b96 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -2290,6 +2290,15 @@ fuse_setxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
         }
 #endif
 
+        /* Check if the command is for changing the log
+           level of process or specific xlator */
+        ret = is_gf_log_command (this, name, value);
+        if (ret >= 0) {
+                send_fuse_err (this, finh, ret);
+                GF_FREE (finh);
+                return;
+        }
+
         GET_STATE (this, finh, state);
         state->size = fsi->size;
         ret = fuse_loc_fill (&state->loc, state, finh->nodeid, 0, NULL);
@@ -2311,6 +2320,7 @@ fuse_setxattr (xlator_t *this, fuse_in_header_t *finh, void *msg)
                         "%"PRIu64": SETXATTR dict allocation failed",
                         finh->unique);
 
+                send_fuse_err (this, finh, ENOMEM);
                 free_fuse_state (state);
                 return;
         }
@@ -2749,7 +2759,6 @@ fuse_setlk (xlator_t *this, fuse_in_header_t *finh, void *msg)
         return;
 }
 
-
 static void
 fuse_init (xlator_t *this, fuse_in_header_t *finh, void *msg)
 {
@@ -3001,6 +3010,9 @@ fuse_thread_proc (void *data)
         priv->msg0_len_p = &iov_in[0].iov_len;
 
         for (;;) {
+                /* THIS has to be reset here */
+                THIS = this;
+
                 if (priv->init_recvd)
                         fuse_graph_sync (this);
 
diff --git a/xlators/mount/fuse/src/fuse-bridge.h b/xlators/mount/fuse/src/fuse-bridge.h
index 8165053e0..afefd815a 100644
--- a/xlators/mount/fuse/src/fuse-bridge.h
+++ b/xlators/mount/fuse/src/fuse-bridge.h
@@ -27,6 +27,7 @@
 #include <dirent.h>
 #include <sys/mount.h>
 #include <sys/time.h>
+#include <fnmatch.h>
 
 #ifndef _CONFIG_H
 #define _CONFIG_H
@@ -273,5 +274,6 @@ xlator_t *fuse_state_subvol (fuse_state_t *state);
 xlator_t *fuse_active_subvol (xlator_t *fuse);
 inode_t *fuse_ino_to_inode (uint64_t ino, xlator_t *fuse);
 int fuse_resolve_and_resume (fuse_state_t *state, fuse_resume_fn_t fn);
+int is_gf_log_command (xlator_t *this, const char *name, char *value);
 
 #endif /* _GF_FUSE_BRIDGE_H_ */
diff --git a/xlators/mount/fuse/src/fuse-helpers.c b/xlators/mount/fuse/src/fuse-helpers.c
index d478d014d..9a6b13514 100644
--- a/xlators/mount/fuse/src/fuse-helpers.c
+++ b/xlators/mount/fuse/src/fuse-helpers.c
@@ -298,3 +298,91 @@ gf_fuse_stat2attr (struct iatt *st, struct fuse_attr *fa)
         fa->flags      = 0;
 #endif
 }
+
+
+int
+is_gf_log_command (xlator_t *this, const char *name, char *value)
+{
+        fuse_private_t *priv        = NULL;
+        xlator_t       *trav        = NULL;
+        char            key[1024]   = {0,};
+        int             ret         = -1;
+        int             log_level   = -1;
+        gf_boolean_t    syslog_flag = 0;
+
+        priv = this->private;
+
+        if (!strcmp ("trusted.glusterfs.syslog", name)) {
+                ret = gf_string2boolean (value, &syslog_flag);
+                if (ret) {
+                        ret = EOPNOTSUPP;
+                        goto out;
+                }
+                if (syslog_flag)
+                        gf_log_enable_syslog ();
+                else
+                        gf_log_disable_syslog ();
+
+                goto out;
+        }
+
+        if (fnmatch ("trusted.glusterfs*set-log-level", name, FNM_NOESCAPE))
+                goto out;
+
+        if (!strcasecmp (value, "CRITICAL")) {
+                log_level = GF_LOG_CRITICAL;
+        } else if (!strcasecmp (value, "ERROR")) {
+                log_level = GF_LOG_ERROR;
+        } else if (!strcasecmp (value, "WARNING")) {
+                log_level = GF_LOG_WARNING;
+        } else if (!strcasecmp (value, "INFO")) {
+                log_level = GF_LOG_INFO;
+        } else if (!strcasecmp (value, "DEBUG")) {
+                log_level = GF_LOG_DEBUG;
+        } else if (!strcasecmp (value, "TRACE")) {
+                log_level = GF_LOG_TRACE;
+        } else if (!strcasecmp (value, "NONE")) {
+                log_level = GF_LOG_NONE;
+        }
+
+        if (log_level == -1) {
+                ret = EOPNOTSUPP;
+                goto out;
+        }
+
+        /* Some crude way to change the log-level of process */
+        if (!strcmp (name, "trusted.glusterfs.set-log-level")) {
+                /* */
+                gf_log ("glusterfs", gf_log_get_loglevel(),
+                        "setting log level to %d (old-value=%d)",
+                        log_level, gf_log_get_loglevel());
+                gf_log_set_loglevel (log_level);
+                ret = 0;
+                goto out;
+        }
+        if (!strcmp (name, "trusted.glusterfs.fuse.set-log-level")) {
+                /* */
+                gf_log (this->name, gf_log_get_xl_loglevel (this),
+                        "setting log level to %d (old-value=%d)",
+                        log_level, gf_log_get_xl_loglevel (this));
+                gf_log_set_xl_loglevel (this, log_level);
+                ret = 0;
+                goto out;
+        }
+
+        trav = priv->active_subvol;
+        while (trav) {
+                snprintf (key, 1024, "trusted.glusterfs.%s.set-log-level",
+                          trav->name);
+                if (fnmatch (name, key, FNM_NOESCAPE) == 0) {
+                        gf_log (trav->name, gf_log_get_xl_loglevel (trav),
+                                "setting log level to %d (old-value=%d)",
+                                log_level, gf_log_get_xl_loglevel (trav));
+                        gf_log_set_xl_loglevel (trav, log_level);
+                        ret = 0;
+                }
+                trav = trav->next;
+        }
+out:
+        return ret;
+}