Quota/marker : Support for inode quota

Currently, the only way to retrieve the number of files/objects in a
directory or volume is to do a crawl of the entire directory/volume.
This is expensive and is not scalable.

The new mechanism proposes to store count of objects/files as part of
an extended attribute of a directory. Each directory's extended
attribute value will indicate the number of files/objects present
in a tree with the directory being considered as the root of the tree.

Currently file usage is accounted in marker by doing multiple FOPs
like setting and getting xattrs. Doing this with STACK WIND and
UNWIND can be harder to debug as involves multiple callbacks.
In this code we are replacing current mechanism with syncop approach
as syncop code is much simpler to follow and help us implement inode
quota in an organized way.

Change-Id: Ibf366fbe07037284e89a241ddaff7750fc8771b4
BUG: 1188636
Signed-off-by: vmallika <vmallika@redhat.com>
Signed-off-by: Sachin Pandit <spandit@redhat.com>
Reviewed-on: http://review.gluster.org/9567
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/libglusterfs/src/syncop.c b/libglusterfs/src/syncop.c
index e3321cf6ddb..e241e2c1ee0 100644
--- a/libglusterfs/src/syncop.c
+++ b/libglusterfs/src/syncop.c
@@ -2537,3 +2537,39 @@ syncop_inodelk (xlator_t *subvol, const char *volume, loc_t *loc, int32_t cmd,
 
         return args.op_ret;
 }
+
+int32_t
+syncop_xattrop_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                    int32_t op_ret, int32_t op_errno, dict_t *dict,
+                    dict_t *xdata)
+{
+        struct syncargs *args = NULL;
+
+        args = cookie;
+
+        args->op_ret   = op_ret;
+        args->op_errno = op_errno;
+
+        if (xdata)
+                args->xdata = dict_ref (xdata);
+
+        __wake (args);
+
+        return 0;
+
+}
+
+int
+syncop_xattrop (xlator_t *subvol, loc_t *loc, gf_xattrop_flags_t flags,
+                dict_t *dict, dict_t *xdata)
+{
+        struct syncargs args = {0, };
+
+        SYNCOP (subvol, (&args), syncop_xattrop_cbk, subvol->fops->xattrop,
+                loc, flags, dict, xdata);
+
+        if (args.op_ret < 0)
+                return -args.op_errno;
+
+        return args.op_ret;
+}