performance/readdir-ahead: limit cache size

This patch introduces a new option called "rda-cache-limit", which is
the maximum value the entire readdir-ahead cache can grow into. Since,
readdir-ahead holds a reference to inode through dentries, this patch
also accounts memory stored by various xlators in inode contexts.

Change-Id: I84cc0ca812f35e0f9041f8cc71effae53a9e7f99
BUG: 1356960
Signed-off-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-on: http://review.gluster.org/16137
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Poornima G <pgurusid@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

3 files changed, 41 insertions, 0 deletions

diff --git a/libglusterfs/src/inode.c b/libglusterfs/src/inode.c
index 6e4c2f11bc..841f0b63f1 100644
--- a/libglusterfs/src/inode.c
+++ b/libglusterfs/src/inode.c
@@ -2504,3 +2504,35 @@ out:
 
         return;
 }
+
+size_t
+inode_ctx_size (inode_t *inode)
+{
+        int       i    = 0;
+        size_t    size = 0;
+        xlator_t *xl   = NULL, *old_THIS = NULL;
+
+        if (!inode)
+                goto out;
+
+        LOCK (&inode->lock);
+        {
+                for (i = 0; i < inode->table->ctxcount; i++) {
+                        if (!inode->_ctx[i].xl_key)
+                                continue;
+
+                        xl = (xlator_t *)(long)inode->_ctx[i].xl_key;
+                        old_THIS = THIS;
+                        THIS = xl;
+
+                        if (xl->cbks->ictxsize)
+                                size += xl->cbks->ictxsize (xl, inode);
+
+                        THIS = old_THIS;
+                }
+        }
+        UNLOCK (&inode->lock);
+
+out:
+        return size;
+}
diff --git a/libglusterfs/src/inode.h b/libglusterfs/src/inode.h
index 114aeae78b..5289b15bca 100644
--- a/libglusterfs/src/inode.h
+++ b/libglusterfs/src/inode.h
@@ -279,4 +279,7 @@ inode_needs_lookup (inode_t *inode, xlator_t *this);
 int
 inode_has_dentry (inode_t *inode);
 
+size_t
+inode_ctx_size (inode_t *inode);
+
 #endif /* _INODE_H */
diff --git a/libglusterfs/src/xlator.h b/libglusterfs/src/xlator.h
index 70e6f0a108..b11d1a96f3 100644
--- a/libglusterfs/src/xlator.h
+++ b/libglusterfs/src/xlator.h
@@ -847,6 +847,10 @@ typedef int32_t (*cbk_client_t)(xlator_t *this, client_t *client);
 typedef void (*cbk_ictxmerge_t) (xlator_t *this, fd_t *fd,
                                  inode_t *inode, inode_t *linked_inode);
 
+typedef size_t (*cbk_inodectx_size_t)(xlator_t *this, inode_t *inode);
+
+typedef size_t (*cbk_fdctx_size_t)(xlator_t *this, fd_t *fd);
+
 struct xlator_cbks {
         cbk_forget_t             forget;
         cbk_release_t            release;
@@ -855,6 +859,8 @@ struct xlator_cbks {
         cbk_client_t             client_destroy;
         cbk_client_t             client_disconnect;
         cbk_ictxmerge_t          ictxmerge;
+        cbk_inodectx_size_t      ictxsize;
+        cbk_fdctx_size_t         fdctxsize;
 };
 
 typedef int32_t (*dumpop_priv_t) (xlator_t *this);