protocol/client: Added lk_ctx info in fdctx dump

- Added a brief explanation as to why we can't use gf_log
  when in statedump.

- Removed gf_log messages from client_priv_dump since
  it can cause a 'deadlock' - See statedump.c for explanation

- Added try-lock based accessors for fd_lk_list for dump purposes.

Change-Id: I1d755a4ef2c568acf22fb8c4ab0a33a4f5fd07b4
BUG: 789858
Signed-off-by: Krishnan Parthasarathi <kp@gluster.com>
Reviewed-on: http://review.gluster.com/2882
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Vijay Bellur <vijay@gluster.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/libglusterfs/src/fd-lk.c b/libglusterfs/src/fd-lk.c
index 8df43bb602f..4e10d649ee9 100644
--- a/libglusterfs/src/fd-lk.c
+++ b/libglusterfs/src/fd-lk.c
@@ -129,6 +129,27 @@ fd_lk_ctx_ref (fd_lk_ctx_t *lk_ctx)
 }
 
 fd_lk_ctx_t *
+fd_lk_ctx_try_ref (fd_lk_ctx_t *lk_ctx)
+{
+        int         ret         = -1;
+        fd_lk_ctx_t *new_lk_ctx = NULL;
+
+        if (!lk_ctx) {
+                goto out;
+        }
+
+        ret = TRY_LOCK (&lk_ctx->lock);
+        if (ret)
+                goto out;
+
+        new_lk_ctx = _fd_lk_ctx_ref (lk_ctx);
+        UNLOCK (&lk_ctx->lock);
+
+out:
+        return new_lk_ctx;
+}
+
+fd_lk_ctx_t *
 fd_lk_ctx_create ()
 {
         fd_lk_ctx_t *fd_lk_ctx = NULL;