posix: Add option to disable nftw() based deletes when purging the landfill directory

Summary:
- We may have found an issue where certain directories were being moved into .landfill and then being quickly purged via nftw().
- We would like to have an emergency option to disable these purges.

> Reviewed-on: https://review.gluster.org/18253
> Reviewed-by: Shreyas Siravara <sshreyas@fb.com>

Fixes #371

Change-Id: I90b54c535930c1ca2925a928728199b6b80eadd9
Signed-off-by: Amar Tumballi <amarts@redhat.com>

4 files changed, 53 insertions, 8 deletions

diff --git a/xlators/storage/posix/src/posix-common.c b/xlators/storage/posix/src/posix-common.c
index 1b2bb609fb0..fa2655ed8c0 100644
--- a/xlators/storage/posix/src/posix-common.c
+++ b/xlators/storage/posix/src/posix-common.c
@@ -382,6 +382,20 @@ posix_reconfigure (xlator_t *this, dict_t *options)
 
         GF_OPTION_RECONF ("shared-brick-count", priv->shared_brick_count,
                           options, int32, out);
+
+        GF_OPTION_RECONF ("disable-landfill-purge",
+                          priv->disable_landfill_purge,
+                          options, bool, out);
+        if (priv->disable_landfill_purge) {
+                gf_log (this->name, GF_LOG_WARNING,
+                        "Janitor WILL NOT purge the landfill directory. "
+                        "Your landfill directory"
+                        " may fill up this brick.");
+        } else {
+                gf_msg_debug (this->name, 0, "Janitor will purge the landfill "
+                              "directory, which is default behavior");
+        }
+
         GF_OPTION_RECONF ("force-create-mode", force_create_mode,
                           options, int32, out);
         priv->force_create_mode = force_create_mode;
@@ -1064,6 +1078,16 @@ posix_init (xlator_t *this)
 
         GF_OPTION_INIT ("batch-fsync-delay-usec", _private->batch_fsync_delay_usec,
                         uint32, out);
+
+        GF_OPTION_INIT ("disable-landfill-purge",
+                        _private->disable_landfill_purge, bool, out);
+        if (_private->disable_landfill_purge) {
+                gf_msg (this->name, GF_LOG_WARNING, 0, 0,
+                        "Janitor WILL NOT purge the landfill directory. "
+                        "Your landfill directory"
+                        " may fill up this brick.");
+        }
+
         GF_OPTION_INIT ("force-create-mode", force_create, int32, out);
         _private->force_create_mode = force_create;
 
@@ -1288,6 +1312,15 @@ struct volume_options options[] = {
           " Useful for displaying the proper usable size through statvfs() "
           "call (df command)",
         },
+        {
+          .key = {"disable-landfill-purge"},
+          .type = GF_OPTION_TYPE_BOOL,
+          .default_value = "off",
+          .description = "Disable glusterfs/landfill purges. "
+          "WARNING: This can fill up a brick.",
+          .op_version = {GD_OP_VERSION_4_0_0},
+          .tags = {"diagnosis"},
+        },
         { .key  = {"force-create-mode"},
           .type = GF_OPTION_TYPE_INT,
           .min = 0000,
diff --git a/xlators/storage/posix/src/posix-entry-ops.c b/xlators/storage/posix/src/posix-entry-ops.c
index e7658e46543..9d336ee5f60 100644
--- a/xlators/storage/posix/src/posix-entry-ops.c
+++ b/xlators/storage/posix/src/posix-entry-ops.c
@@ -1281,6 +1281,8 @@ posix_rmdir (call_frame_t *frame, xlator_t *this,
                 } else {
                         (void) snprintf (tmp_path, sizeof(tmp_path), "%s/%s",
                                          priv->trash_path, gfid_str);
+                        gf_msg_debug (this->name, 0,
+                                      "Moving %s to %s", real_path, tmp_path);
                         op_ret = sys_rename (real_path, tmp_path);
                         pthread_cond_signal (&priv->janitor_cond);
                 }
diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index 8f550f9fe0d..525f65f7eba 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -1414,15 +1414,22 @@ posix_janitor_thread_proc (void *data)
 
                 time (&now);
                 if ((now - priv->last_landfill_check) > priv->janitor_sleep_duration) {
-                        gf_msg_trace (this->name, 0,
-                                      "janitor cleaning out %s",
-                                      priv->trash_path);
-
-                        nftw (priv->trash_path,
-                              janitor_walker,
-                              32,
-                              FTW_DEPTH | FTW_PHYS);
+                        if (priv->disable_landfill_purge) {
+                                gf_msg_debug (this->name, 0,
+                                              "Janitor would have "
+                                              "cleaned out %s, but purge"
+                                              "is disabled.",
+                                              priv->trash_path);
+                        } else {
+                                gf_msg_trace (this->name, 0,
+                                              "janitor cleaning out %s",
+                                              priv->trash_path);
 
+                                nftw (priv->trash_path,
+                                      janitor_walker,
+                                      32,
+                                      FTW_DEPTH | FTW_PHYS);
+                        }
                         priv->last_landfill_check = now;
                 }
 
diff --git a/xlators/storage/posix/src/posix.h b/xlators/storage/posix/src/posix.h
index afb4b4413f6..f9ab3ec9e75 100644
--- a/xlators/storage/posix/src/posix.h
+++ b/xlators/storage/posix/src/posix.h
@@ -233,6 +233,9 @@ struct posix_private {
            same backend. Very much usable in brick-splitting feature. */
         int32_t shared_brick_count;
 
+        /* This option is used for either to call a landfill_purge or not */
+        gf_boolean_t disable_landfill_purge;
+
         /*Option to set mode bit permission that will always be set on
           file/directory. */
         mode_t          force_create_mode;