cluster/distribute: Add support for 'min-free-inodes' on each distribute subvolume.

This change is required as increasingly large number of small files
would cause inodes to run out before they run out on available disk space.
It is highly necessary to support algorithmic checking of inodes too
just as we do for disk space.

Change-Id: I9b87405328d443825e239ee80ab664aceb50ee68
BUG: 3799
Signed-off-by: Harshavardhana <fharshav@redhat.com>
Reviewed-on: http://review.gluster.com/730
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-by: Amar Tumballi <amar@gluster.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/xlators/cluster/dht/src/dht.c b/xlators/cluster/dht/src/dht.c
index c5bb36be0..8be573f51 100644
--- a/xlators/cluster/dht/src/dht.c
+++ b/xlators/cluster/dht/src/dht.c
@@ -131,6 +131,7 @@ dht_priv_dump (xlator_t *this)
         gf_proc_dump_write("search_unhashed", "%d", conf->search_unhashed);
         gf_proc_dump_write("gen", "%d", conf->gen);
         gf_proc_dump_write("min_free_disk", "%lu", conf->min_free_disk);
+	gf_proc_dump_write("min_free_inodes", "%lu", conf->min_free_inodes);
         gf_proc_dump_write("disk_unit", "%c", conf->disk_unit);
         gf_proc_dump_write("refresh_interval", "%d", conf->refresh_interval);
         gf_proc_dump_write("unhashed_sticky_bit", "%d", conf->unhashed_sticky_bit);
@@ -139,6 +140,8 @@ dht_priv_dump (xlator_t *this)
                                    conf->du_stats->avail_percent);
                 gf_proc_dump_write("du_stats.avail_space", "%lu",
                                    conf->du_stats->avail_space);
+		gf_proc_dump_write("du_stats.avail_inodes", "%lf",
+                                   conf->du_stats->avail_inodes);
                 gf_proc_dump_write("du_stats.log", "%lu", conf->du_stats->log);
         }
         gf_proc_dump_write("last_stat_fetch", "%s", ctime(&conf->last_stat_fetch.tv_sec));
@@ -318,9 +321,10 @@ reconfigure (xlator_t *this, dict_t *options)
                 }
         }
 
-        GF_OPTION_RECONF ("min-free-disk", conf->min_free_disk, options,
+	GF_OPTION_RECONF ("min-free-disk", conf->min_free_disk, options,
                           percent_or_size, out);
-
+	GF_OPTION_RECONF ("min-free-inodes", conf->min_free_inodes, options,
+                          percent, out);
         GF_OPTION_RECONF ("directory-layout-spread", conf->dir_spread_cnt,
                           options, uint32, out);
 
@@ -376,7 +380,10 @@ init (xlator_t *this)
 
         GF_OPTION_INIT ("use-readdirp", conf->use_readdirp, bool, err);
 
-        GF_OPTION_INIT ("min-free-disk", conf->min_free_disk, percent_or_size,
+	GF_OPTION_INIT ("min-free-disk", conf->min_free_disk, percent_or_size,
+			err);
+
+        GF_OPTION_INIT ("min-free-inodes", conf->min_free_inodes, percent,
                         err);
 
         conf->dir_spread_cnt = conf->subvolume_cnt;
@@ -517,6 +524,12 @@ struct volume_options options[] = {
           .description = "Percentage/Size of disk space that must be "
                          "kept free."
         },
+	{ .key  = {"min-free-inodes"},
+          .type = GF_OPTION_TYPE_PERCENT,
+          .default_value = "5%",
+          .description = "Percentage inodes that must be "
+                         "kept free."
+        },
         { .key = {"unhashed-sticky-bit"},
           .type = GF_OPTION_TYPE_BOOL,
           .default_value = "off",