Disable brick daemon from incorrect brick directory

Summary:
Currently the bricks can open any mount directory from the given volume. This patch adds a provision to prevent
bricks from opening brick directories that aren't created for them. This will help with operating gluster on large
scale.

We add a new xattr GF_XATTR_BRICK_NAME to the brick directory. When we start a brick daemon, we make sure the path on
disk matches with the config provided. For backward compatibility, we ignore if there is no value for
GF_XATTR_BRICK_NAME and set the current brick daemon's path as value.

We ignore GF_XATTR_BRICK_NAME during healing and reset GF_XATTR_BRICK_NAME on brick replace.

Test Plan: Run fb-smoke

Reviewers: jdarcy, sshreyas

Reviewed By: sshreyas

Differential Revision: https://phabricator.intern.facebook.com/D5448921

Porting note: disabled some checks to deal with the snapshot case

Change-Id: I98e62033dfd07f30ad3b99ac003ce94c8d935e5f
Signed-off-by: Jeff Darcy <jdarcy@fb.com>
Reviewed-on: https://review.gluster.org/18275
Reviewed-by: Jeff Darcy <jeff@pl.atyp.us>
Tested-by: Jeff Darcy <jeff@pl.atyp.us>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-ops.c b/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
index 97fb5605715..9fb60cc0802 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
@@ -1610,6 +1610,24 @@ glusterd_op_stage_start_volume (dict_t *dict, char **op_errstr,
                         goto out;
                 }
 
+                /* check GF_XATTR_BRICK_PATH is set to brick path */
+                ret = gf_compare_or_fix_xattr_brick_path (brickinfo->path);
+
+                if (ret != 0) {
+                        gf_log (this->name, GF_LOG_ERROR, "Error comparing %s "
+                                "on %s", GF_XATTR_BRICK_PATH, brickinfo->path);
+                        if (strstr (brickinfo->path, "/snaps/")) {
+                                /*
+                                 * This is "naturally" going to be wrong on
+                                 * snap bricks, but that's OK.
+                                 */
+                                ret = 0;
+                        } else {
+                                ret = -1;
+                                goto out;
+                        }
+                }
+
                 /* A bricks mount dir is required only by snapshots which were
                  * introduced in gluster-3.6.0
                  */