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, 27 insertions, 18 deletions

diff --git a/xlators/cluster/afr/src/afr-inode-read.c b/xlators/cluster/afr/src/afr-inode-read.c
index 25d576d0261..77acf0b25b9 100644
--- a/xlators/cluster/afr/src/afr-inode-read.c
+++ b/xlators/cluster/afr/src/afr-inode-read.c
@@ -35,6 +35,7 @@
 #include "common-utils.h"
 #include "compat-errno.h"
 #include "compat.h"
+#include "quota-common-utils.h"
 
 #include "afr-transaction.h"
 
@@ -50,15 +51,16 @@
 int
 afr_handle_quota_size (call_frame_t *frame, xlator_t *this)
 {
-        unsigned char *readable = NULL;
-        afr_local_t *local = NULL;
-        afr_private_t *priv = NULL;
+        unsigned char *readable   = NULL;
+        afr_local_t *local        = NULL;
+        afr_private_t *priv       = NULL;
         struct afr_reply *replies = NULL;
-        int i = 0;
-        uint64_t size = 0;
-        uint64_t max_size = 0;
-        int readable_cnt = 0;
-        int read_subvol = -1;
+        int i                     = 0;
+        int ret                   = 0;
+        quota_meta_t size         = {0, };
+        quota_meta_t max_size     = {0, };
+        int readable_cnt          = 0;
+        int read_subvol           = -1;
 
         local = frame->local;
         priv = this->private;
@@ -77,22 +79,29 @@ afr_handle_quota_size (call_frame_t *frame, xlator_t *this)
                         continue;
                 if (!replies[i].xdata)
                         continue;
-                if (dict_get_uint64 (replies[i].xdata, QUOTA_SIZE_KEY, &size))
+                ret = quota_dict_get_meta (replies[i].xdata, QUOTA_SIZE_KEY,
+                                           &size);
+                if (ret == -1)
                         continue;
-                size = ntoh64 (size);
                 if (read_subvol == -1)
                         read_subvol = i;
-                if (size > max_size) {
+                if (size.size > max_size.size ||
+                    (size.file_count + size.dir_count) >
+                    (max_size.file_count + max_size.dir_count))
                         read_subvol = i;
-                        max_size = size;
-                }
+
+                if (size.size > max_size.size)
+                        max_size.size = size.size;
+                if (size.file_count > max_size.file_count)
+                        max_size.file_count = size.file_count;
+                if (size.dir_count > max_size.dir_count)
+                        max_size.dir_count = size.dir_count;
         }
 
-        if (!max_size)
+        if (max_size.size == 0 && max_size.file_count == 0 &&
+            max_size.dir_count == 0)
                 return read_subvol;
 
-        max_size = hton64 (max_size);
-
         for (i = 0; i < priv->child_count; i++) {
                 if (!replies[i].valid || replies[i].op_ret == -1)
                         continue;
@@ -100,8 +109,8 @@ afr_handle_quota_size (call_frame_t *frame, xlator_t *this)
                         continue;
                 if (!replies[i].xdata)
                         continue;
-                if (dict_set_uint64 (replies[i].xdata, QUOTA_SIZE_KEY, max_size))
-                        continue;
+                quota_dict_set_meta (replies[i].xdata, QUOTA_SIZE_KEY,
+                                     &max_size, IA_IFDIR);
         }
 
         return read_subvol;