From 5b1bfebacac649e6f5051316e4075309caf93901 Mon Sep 17 00:00:00 2001
From: Barak Sason Rofman <bsasonro@redhat.com>
Date: Tue, 21 Apr 2020 19:13:41 +0300
Subject: [PATCH 364/367] dht - fixing rebalance failures for files with holes

Rebalance process handling of files which contains holes casued
rebalance to fail with "No space left on device" errors.
This patch modifies the code-flow in such a way that files with holes
will be rebalanced correctly.

backport of https://review.gluster.org/#/c/glusterfs/+/24357/
>fixes: #1187
>Change-Id: I89bc3d4ea7f074db7213d759c49307f379543932
>Signed-off-by: Barak Sason Rofman <bsasonro@redhat.com>

BUG: 1823703
Change-Id: I89bc3d4ea7f074db7213d759c49307f379543932
Signed-off-by: Barak Sason Rofman <bsasonro@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/198579
Tested-by: RHGS Build Bot <nigelb@redhat.com>
Reviewed-by: Sunil Kumar Heggodu Gopala Acharya <sheggodu@redhat.com>
---
 xlators/cluster/dht/src/dht-rebalance.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c
index f4c62b8..7d9df02 100644
--- a/xlators/cluster/dht/src/dht-rebalance.c
+++ b/xlators/cluster/dht/src/dht-rebalance.c
@@ -650,7 +650,7 @@ out:
 static int
 __dht_rebalance_create_dst_file(xlator_t *this, xlator_t *to, xlator_t *from,
                                 loc_t *loc, struct iatt *stbuf, fd_t **dst_fd,
-                                int *fop_errno)
+                                int *fop_errno, int file_has_holes)
 {
     int ret = -1;
     int ret2 = -1;
@@ -819,7 +819,7 @@ __dht_rebalance_create_dst_file(xlator_t *this, xlator_t *to, xlator_t *from,
 
     /* No need to bother about 0 byte size files */
     if (stbuf->ia_size > 0) {
-        if (conf->use_fallocate) {
+        if (conf->use_fallocate && !file_has_holes) {
             ret = syncop_fallocate(to, fd, 0, 0, stbuf->ia_size, NULL, NULL);
             if (ret < 0) {
                 if (ret == -EOPNOTSUPP || ret == -EINVAL || ret == -ENOSYS) {
@@ -846,9 +846,7 @@ __dht_rebalance_create_dst_file(xlator_t *this, xlator_t *to, xlator_t *from,
                     goto out;
                 }
             }
-        }
-
-        if (!conf->use_fallocate) {
+        } else {
             ret = syncop_ftruncate(to, fd, stbuf->ia_size, NULL, NULL, NULL,
                                    NULL);
             if (ret < 0) {
@@ -1728,9 +1726,13 @@ dht_migrate_file(xlator_t *this, loc_t *loc, xlator_t *from, xlator_t *to,
         goto out;
     }
 
+    /* Try to preserve 'holes' while migrating data */
+    if (stbuf.ia_size > (stbuf.ia_blocks * GF_DISK_SECTOR_SIZE))
+        file_has_holes = 1;
+
     /* create the destination, with required modes/xattr */
     ret = __dht_rebalance_create_dst_file(this, to, from, loc, &stbuf, &dst_fd,
-                                          fop_errno);
+                                          fop_errno, file_has_holes);
     if (ret) {
         gf_msg(this->name, GF_LOG_ERROR, 0, 0,
                "Create dst failed"
@@ -1774,8 +1776,8 @@ dht_migrate_file(xlator_t *this, loc_t *loc, xlator_t *from, xlator_t *to,
          * destination. We need to do update this only post migration
          * as in case of failure the linkto needs to point to the source
          * subvol */
-        ret = __dht_rebalance_create_dst_file(this, to, from, loc, &stbuf,
-                                              &dst_fd, fop_errno);
+        ret = __dht_rebalance_create_dst_file(
+            this, to, from, loc, &stbuf, &dst_fd, fop_errno, file_has_holes);
         if (ret) {
             gf_log(this->name, GF_LOG_ERROR,
                    "Create dst failed"
@@ -1862,9 +1864,6 @@ dht_migrate_file(xlator_t *this, loc_t *loc, xlator_t *from, xlator_t *to,
             ret = 0;
         goto out;
     }
-    /* Try to preserve 'holes' while migrating data */
-    if (stbuf.ia_size > (stbuf.ia_blocks * GF_DISK_SECTOR_SIZE))
-        file_has_holes = 1;
 
     ret = __dht_rebalance_migrate_data(this, defrag, from, to, src_fd, dst_fd,
                                        stbuf.ia_size, file_has_holes,
-- 
1.8.3.1