features/quota : Introducing inode quota

==========================================================================
                             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 proposed mechanism will provide an easier alternative to determine =
= the count of files/objects in a directory or volume.                   =
=                                                                        =
= 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. =
=                                                                        =
= The count value can be accessed by performing a getxattr().            =
= Cluster translators like afr, dht and stripe will perform aggregation  =
= of count values from various bricks when getxattr() happens on the key =
= associated with file/object count.                                     =

A new interface is introduced:
------------------------------
        limit-objects  : limit the number of inodes at directory level
        list-objects   : list the directories where the limit is set
        remove-objects : remove the limit from the directory

==========================================================================

CLI COMMAND:
gluster volume quota <volname> limit-objects <path> <number> [<percent>]

* <number> is a hard-limit for number of objects limitation for path "<path>"
  If hard-limit is exceeded, creation of file/directory is no longer
permitted.

* <percent> is a soft-limit for number of objects creation for path "<path>"
  If soft-limit is exceeded, a warning is issued for each creation.

CLI COMMAND:
gluster volume quota <volname> remove-objects [path]

==========================================================================

CLI COMMAND:
gluster volume quota <volname> list-objects [path] ...

Sample output:
------------------
  Path                   Hard-limit Soft-limit   Used  Available
Soft-limit exceeded?
Hard-limit exceeded?
  ------------------------------------------------------------------------
--------------------------------------
  /dir                      10       80%          10       0
Yes
        Yes

==========================================================================

[root@snapshot-28 dir]# ls
a  b  file11  file12  file13  file14  file15  file16  file17
[root@snapshot-28 dir]# touch a1
touch: cannot touch `a1': Disk quota exceeded
* Nine files are created in directory "dir" and directory is included in
* the
count too. Hence the limit "10" is reached and further file creation
fails

==========================================================================

Note: We have also done some re-factoring in cli for volume name
validation. New function cli_validate_volname is created

==========================================================================

Change-Id: I1823497de4f790a2a20ebb1770293472ea33ee2b
BUG: 1190108
Signed-off-by: Sachin Pandit <spandit@redhat.com>
Signed-off-by: vmallika <vmallika@redhat.com>
Reviewed-on: http://review.gluster.org/9769
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 24 insertions, 3 deletions

diff --git a/xlators/features/quota/src/quotad-aggregator.c b/xlators/features/quota/src/quotad-aggregator.c
index f34bdbddd45..0abe4e6fc80 100644
--- a/xlators/features/quota/src/quotad-aggregator.c
+++ b/xlators/features/quota/src/quotad-aggregator.c
@@ -126,16 +126,29 @@ int
 quotad_aggregator_getlimit_cbk (xlator_t *this, call_frame_t *frame,
                                 void *lookup_rsp)
 {
-        gfs3_lookup_rsp            *rsp   = lookup_rsp;
+        gfs3_lookup_rsp            *rsp    = lookup_rsp;
         gf_cli_rsp                 cli_rsp = {0,};
-        dict_t                     *xdata = NULL;
-        int                         ret = -1;
+        dict_t                     *xdata  = NULL;
+        quotad_aggregator_state_t  *state  = NULL;
+        int                         ret    = -1;
+        int                         type   = 0;
 
         GF_PROTOCOL_DICT_UNSERIALIZE (frame->this, xdata,
                                       (rsp->xdata.xdata_val),
                                       (rsp->xdata.xdata_len), rsp->op_ret,
                                       rsp->op_errno, out);
 
+        if (xdata) {
+                state = frame->root->state;
+                ret = dict_get_int32 (state->xdata, "type", &type);
+                if (ret < 0)
+                        goto out;
+
+                ret = dict_set_int32 (xdata, "type", type);
+                if (ret < 0)
+                        goto out;
+        }
+
         ret = 0;
 out:
         rsp->op_ret = ret;
@@ -215,10 +228,18 @@ quotad_aggregator_getlimit (rpcsvc_request_t *req)
         }
         state = frame->root->state;
         state->xdata = dict;
+
         ret = dict_set_int32 (state->xdata, QUOTA_LIMIT_KEY, 42);
         if (ret)
                 goto err;
 
+        ret = dict_set_int32 (state->xdata, QUOTA_LIMIT_OBJECTS_KEY, 42);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "Failed to set "
+                        "QUOTA_LIMIT_OBJECTS_KEY");
+                goto err;
+        }
+
         ret = dict_set_int32 (state->xdata, QUOTA_SIZE_KEY, 42);
         if (ret)
                 goto err;