read-only: read-only/worm translator should be in brick graph by default

Problem:
read-only/worm translator is not loaded by default in brick graph because of which
when read-only option is set through volume set volume still remains writable
untill the bricks are restarted as the translator does not have an inmemory flag
to decide whether the read-only/worm option is turned or not.

Solution:
read-only/worm should be loaded by default in brick graph and the read-only/worm
option can be toggled through volume set command. read-only/worm translator now'
has an in-memory flag to decide whether the volume is read-only or not and based
on that either reject the fop or proceed.

Change-Id: Ic79328698f6a72c50433cff15ecadb1a92acc643
BUG: 1134822
Signed-off-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-on: http://review.gluster.org/8571
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 64 insertions, 4 deletions

diff --git a/xlators/features/read-only/src/worm.c b/xlators/features/read-only/src/worm.c
index 16c3eb3daed..f62ffa3f6f3 100644
--- a/xlators/features/read-only/src/worm.c
+++ b/xlators/features/read-only/src/worm.c
@@ -15,6 +15,21 @@
 #include "xlator.h"
 #include "defaults.h"
 #include "read-only-common.h"
+#include "read-only-mem-types.h"
+#include "read-only.h"
+
+int32_t
+mem_acct_init (xlator_t *this)
+{
+        int     ret = -1;
+
+        ret = xlator_mem_acct_init (this, gf_read_only_mt_end + 1);
+        if (ret)
+                gf_log (this->name, GF_LOG_ERROR, "Memory accounting "
+                        "initialization failed.");
+
+        return ret;
+}
 
 static int32_t
 worm_open_cbk (call_frame_t *frame, void *cookie, xlator_t *this, int32_t op_ret,
@@ -28,9 +43,10 @@ int32_t
 worm_open (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
            fd_t *fd, dict_t *xdata)
 {
-        if ((((flags & O_ACCMODE) == O_WRONLY) ||
+        if (is_readonly_or_worm_enabled (this) &&
+            ((((flags & O_ACCMODE) == O_WRONLY) ||
               ((flags & O_ACCMODE) == O_RDWR)) &&
-              !(flags & O_APPEND)) {
+              !(flags & O_APPEND))) {
                 STACK_UNWIND_STRICT (open, frame, -1, EROFS, NULL, NULL);
                 return 0;
         }
@@ -43,6 +59,9 @@ worm_open (call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
 int32_t
 init (xlator_t *this)
 {
+        int                     ret     = -1;
+        read_only_priv_t       *priv    = NULL;
+
         if (!this->children || this->children->next) {
                 gf_log (this->name, GF_LOG_ERROR,
                         "translator not configured with exactly one child");
@@ -54,13 +73,49 @@ init (xlator_t *this)
                         "dangling volume. check volfile ");
         }
 
-        return 0;
+        priv = GF_CALLOC (1, sizeof (*priv), gf_read_only_mt_priv_t);
+        if (!priv)
+                goto out;
+
+        GF_OPTION_INIT ("worm", priv->readonly_or_worm_enabled, bool, out);
+
+        this->private = priv;
+        ret = 0;
+out:
+        return ret;
 }
 
+int
+reconfigure (xlator_t *this, dict_t *options)
+{
+        read_only_priv_t  *priv                     = NULL;
+        int                ret                      = -1;
+        gf_boolean_t       readonly_or_worm_enabled = _gf_false;
+
+        priv = this->private;
+        GF_ASSERT (priv);
+
+        GF_OPTION_RECONF ("worm", readonly_or_worm_enabled, options, bool, out);
+
+        priv->readonly_or_worm_enabled = readonly_or_worm_enabled;
+        ret = 0;
+out:
+        gf_log (this->name, GF_LOG_DEBUG, "returning %d", ret);
+        return ret;
+}
 
 void
 fini (xlator_t *this)
 {
+        read_only_priv_t         *priv    = NULL;
+
+        priv = this->private;
+        if (!priv)
+                return;
+
+        this->private = NULL;
+        GF_FREE (priv);
+
         return;
 }
 
@@ -84,6 +139,11 @@ struct xlator_fops fops = {
 struct xlator_cbks cbks;
 
 struct volume_options options[] = {
-        { .key = {NULL} },
+        { .key  = {"worm"},
+          .type = GF_OPTION_TYPE_BOOL,
+          .default_value = "off",
+          .description = "When \"on\", makes a volume get write once read many "
+                         " feature. It is turned \"off\" by default."
+        },
 };