features/shard: Fix size update for writes at hole region

Change-Id: Iceccef8f3f466c7ffb9991f8eb248b81e7b80efb
BUG: 1256580
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/12020
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

3 files changed, 45 insertions, 2 deletions

diff --git a/tests/bugs/shard/bug-1256580.t b/tests/bugs/shard/bug-1256580.t
new file mode 100644
index 00000000000..93762c115ce
--- /dev/null
+++ b/tests/bugs/shard/bug-1256580.t
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+
+cleanup
+
+TEST glusterd
+TEST pidof glusterd
+TEST $CLI volume create $V0 $H0:$B0/${V0}{0,1}
+TEST $CLI volume set $V0 features.shard on
+TEST $CLI volume set $V0 performance.strict-write-ordering on
+TEST $CLI volume start $V0
+
+TEST glusterfs --volfile-id=$V0 --volfile-server=$H0 $M0
+
+TEST mkdir $M0/dir
+TEST touch $M0/dir/file
+
+# Create "file" with holes.
+TEST truncate -s 6M $M0/dir/file
+EXPECT '6291456' stat -c %s $M0/dir/file
+
+# Perform writes that do not cross the 6M boundary
+TEST dd if=/dev/zero of=$M0/dir/file bs=1024 seek=3072 count=2048 conv=notrunc
+
+# Ensure that the file size is 6M (as opposed to 8M that would appear in the
+# presence of this bug).
+EXPECT '6291456' stat -c %s $M0/dir/file
+
+#Extend the write beyond EOF such that it again creates a hole of 1M size
+TEST dd if=/dev/zero of=$M0/dir/file bs=1024 seek=7168 count=2048 conv=notrunc
+
+# Ensure that the file size is not greater than 9M.
+EXPECT '9437184' stat -c %s $M0/dir/file
+cleanup
diff --git a/xlators/features/shard/src/shard.c b/xlators/features/shard/src/shard.c
index ba1579f1170..2c893cc1101 100644
--- a/xlators/features/shard/src/shard.c
+++ b/xlators/features/shard/src/shard.c
@@ -2929,6 +2929,13 @@ shard_writev_do_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                         SHARD_STACK_UNWIND (writev, frame, local->written_size,
                                             local->op_errno, NULL, NULL, NULL);
                 } else {
+                        if (local->is_write_extending)
+                                local->delta_size = (local->offset +
+                                                     local->total_size) -
+                                                    local->prebuf.ia_size;
+                        else
+                                local->delta_size = 0;
+                        local->hole_size = 0;
                         if (xdata)
                                 local->xattr_rsp = dict_ref (xdata);
                         shard_update_file_size (frame, this, local->fd, NULL,
@@ -3102,8 +3109,8 @@ shard_post_lookup_writev_handler (call_frame_t *frame, xlator_t *this)
         /* At this point, calculate the size of the hole if it is going to be
          * created as part of this write.
          */
-        if (local->offset > local->prebuf.ia_size)
-                local->hole_size = local->offset - local->prebuf.ia_size;
+        if (local->offset + local->total_size > local->prebuf.ia_size)
+                local->is_write_extending = _gf_true;
 
         if (local->create_count)
                 shard_common_resume_mknod (frame, this,
diff --git a/xlators/features/shard/src/shard.h b/xlators/features/shard/src/shard.h
index 61255cd4936..ca57c033167 100644
--- a/xlators/features/shard/src/shard.h
+++ b/xlators/features/shard/src/shard.h
@@ -180,6 +180,7 @@ typedef struct shard_local {
         struct iobuf *iobuf;
         gf_dirent_t entries_head;
         gf_boolean_t list_inited;
+        gf_boolean_t is_write_extending;
         shard_post_fop_handler_t handler;
         shard_post_lookup_shards_fop_handler_t pls_fop_handler;
         shard_post_resolve_fop_handler_t post_res_handler;