From: Igor Fedotov <ifedotov@suse.com>
Date: Thu, 15 Jul 2021 12:10:14 +0000 (+0300)
Subject: os/bluestore: fix improper offset calculation when repairing.
X-Git-Tag: v17.1.0~784^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=ca4b6675fc3fd2f4cadad58044c97c5bb23d5938;p=ceph.git

os/bluestore: fix improper offset calculation when repairing.

While repairing misreferenced blobs BlueStore could improperly calculate
an offset within a blob being fixed. This could happen when single
physical extent has been replaced by multiple ones - the following
pextent (if any in the current blob) would be treated with the improper offset within the blob. Offset calculation didn't account for each of that new pextents but the last one only.

Fixes: https://tracker.ceph.com/issues/51682

Signed-off-by: Igor Fedotov <ifedotov@suse.com>
---

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 5368993ff0d2..ef63279bbf48 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -8547,7 +8547,9 @@ int BlueStore::_fsck_on_open(BlueStore::FSCKDepth depth, bool repair)
 	  pext_to_release.reserve(pextents.size());
 	  // rewriting all valid pextents
 	  for (auto e = pextents.begin(); e != pextents.end();
-	         b_off += e->length, e++) {
+	         e++) {
+	    auto b_off_cur = b_off;
+	    b_off += e->length;
 	    if (!e->is_valid()) {
 	      continue;
 	    }
@@ -8585,7 +8587,7 @@ int BlueStore::_fsck_on_open(BlueStore::FSCKDepth depth, bool repair)
 	    e = pextents.erase(e);
     	    e = pextents.insert(e, exts.begin(), exts.end());
 	    b->get_blob().map_bl(
-	      b_off, bl,
+	      b_off_cur, bl,
 	      [&](uint64_t offset, bufferlist& t) {
 		int r = bdev->write(offset, t, false);
 		ceph_assert(r == 0);