From 1fbffa0aa45560889e29a74c4c6ff16d526de700 Mon Sep 17 00:00:00 2001
From: Jeff Darcy <jdarcy@redhat.com>
Date: Tue, 4 Mar 2014 16:53:33 +0000
Subject: api: add glfs_get_volfile

From the API-header description:

> Sometimes it's useful e.g. for scripts to see the volfile, so that
> they can parse it and find subvolumes to do things like split-brain
> resolution or custom layouts.  The API here was specifically intended
> to make access e.g. from Python as simple as possible.
>
> Note that the volume must be started (not necessarily mounted) for
> this to work.

Change-Id: If3f55ee9611cdf4b77aa53659f0af0d21957817d
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-on: http://review.gluster.org/7183
Reviewed-by: Anand Avati <avati@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
---
 api/src/glfs-mgmt.c |  4 ++++
 api/src/glfs.c      | 20 ++++++++++++++++++++
 api/src/glfs.h      | 30 ++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+)

(limited to 'api/src')

diff --git a/api/src/glfs-mgmt.c b/api/src/glfs-mgmt.c
index afb351da03a..7f62fa259af 100644
--- a/api/src/glfs-mgmt.c
+++ b/api/src/glfs-mgmt.c
@@ -207,6 +207,8 @@ glusterfs_oldvolfile_update (struct glfs *fs, char *volfile, ssize_t size)
 {
 	int ret = -1;
 
+        pthread_mutex_lock (&fs->mutex);
+
 	fs->oldvollen = size;
 	if (!fs->oldvolfile) {
 		fs->oldvolfile = GF_CALLOC (1, size+1, glfs_mt_volfile_t);
@@ -222,6 +224,8 @@ glusterfs_oldvolfile_update (struct glfs *fs, char *volfile, ssize_t size)
 		ret = 0;
 	}
 
+        pthread_mutex_unlock (&fs->mutex);
+
 	return ret;
 }
 
diff --git a/api/src/glfs.c b/api/src/glfs.c
index ea10fb55c65..9e9a55ccb65 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -680,3 +680,23 @@ glfs_fini (struct glfs *fs)
 
         return ret;
 }
+
+ssize_t
+glfs_get_volfile (struct glfs *fs, void *buf, size_t len)
+{
+        ssize_t         res;
+
+        glfs_lock(fs);
+        if (len >= fs->oldvollen) {
+                gf_log ("glfs", GF_LOG_TRACE, "copying %lu to %p", len, buf);
+                memcpy(buf,fs->oldvolfile,len);
+                res = len;
+        }
+        else {
+                res = len - fs->oldvollen;
+                gf_log ("glfs", GF_LOG_TRACE, "buffer is %ld too short", -res);
+        }
+        glfs_unlock(fs);
+
+        return res;
+}
diff --git a/api/src/glfs.h b/api/src/glfs.h
index 20fb18c9ecf..af6b4899037 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -252,6 +252,36 @@ int glfs_init (glfs_t *fs) __THROW;
 
 int glfs_fini (glfs_t *fs) __THROW;
 
+/*
+  SYNOPSIS
+
+      glfs_getvol: Get the volfile associated with a 'virtual mount'
+
+  DESCRIPTION
+
+      Sometimes it's useful e.g. for scripts to see the volfile, so that they
+      can parse it and find subvolumes to do things like split-brain resolution
+      or custom layouts.  The API here was specifically intended to make access
+      e.g. from Python as simple as possible.
+
+      Note that the volume must be started (not necessarily mounted) for this
+      to work.
+
+  PARAMETERS
+
+      @fs:  The 'virtual mount' object for which a volfile is desired
+      @buf: Pointer to a place for the volfile length to be stored
+      @len: Length of @buf
+
+  RETURN VALUES
+
+      >0: filled N bytes of buffer
+       0: no volfile available
+      <0: volfile length exceeds @len by N bytes (@buf unchanged)
+*/
+
+ssize_t glfs_get_volfile (glfs_t *fs, void *buf, size_t len) __THROW;
+
 /*
  * FILE OPERATION
  *
-- 
cgit