From: Sage Weil <sage@redhat.com>
Date: Fri, 6 Oct 2017 20:29:15 +0000 (-0500)
Subject: os/filestore: make 0-length zero avoid touching object length
X-Git-Tag: v12.2.3~190^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=45d70b1329a8c635d2ac0ea5ec171cbea0f6ce02;p=ceph.git

os/filestore: make 0-length zero avoid touching object length

Fixes: http://tracker.ceph.com/issues/21712
Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit 979b7c9cd2e4919b8c7d5ed2418019310959f4bf)
---

diff --git a/src/os/filestore/FileStore.cc b/src/os/filestore/FileStore.cc
index caac76ec4140..8b596a723616 100644
--- a/src/os/filestore/FileStore.cc
+++ b/src/os/filestore/FileStore.cc
@@ -3578,8 +3578,8 @@ int FileStore::_zero(const coll_t& cid, const ghobject_t& oid, uint64_t offset,
     if (ret < 0) {
       ret = -errno;
     } else {
-      // ensure we extent file size, if needed
-      if (offset + len > (uint64_t)st.st_size) {
+      // ensure we extend file size, if needed
+      if (len > 0 && offset + len > (uint64_t)st.st_size) {
 	ret = ::ftruncate(**fd, offset + len);
 	if (ret < 0) {
 	  ret = -errno;