osd/PrimaryLogPG: allow trimmed read for OP_CHECKSUM

Normal reads support trimmed read length, and so shall checksums!

This fixes occasionally failure of rados/thrash test scripts, e.g.:
(1) create object using WriteOp with random generated length
(2) normal writes might accompany with TruncOp of randomized chosen truncate_size
(3) for ReadOp, pick a random 'length' to read, and do checksum simultaneously
    for the same range ([0, 'length']) to read too.

Since the 'length' for reading is randomized chosen, it might
exceed the current object size, and hence causing an EOVERFLOW error.

Related issues:
http://qa-proxy.ceph.com/teuthology/xxg-2017-09-22_01:52:47-rados-wip-object-logic-size-distro-basic-smithi/1657337
http://qa-proxy.ceph.com/teuthology/xxg-2017-09-22_14:14:19-rados-wip-object-logic-size-distro-basic-smithi/1658015

Fix the above problems by keeping pace with normal reads.

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>

diff --git a/src/osd/PrimaryLogPG.cc b/src/osd/PrimaryLogPG.cc
index 6179d63a14c5326eb6ea3af50ba489e8cee8fe97..facbbd20c754fd89f6011c863ac391fb4e0f9a72 100644 (file)
--- a/src/osd/PrimaryLogPG.cc
+++ b/src/osd/PrimaryLogPG.cc
@@ -4410,8 +4410,21 @@ int PrimaryLogPG::do_checksum(OpContext *ctx, OSDOp& osd_op,
   if (op.checksum.offset == 0 && op.checksum.length == 0) {
     // zeroed offset+length implies checksum whole object
     op.checksum.length = oi.size;
-  } else if (op.checksum.offset + op.checksum.length > oi.size) {
-    return -EOVERFLOW;
+  } else if (op.checksum.offset >= oi.size) {
+    // read size was trimmed to zero, do nothing
+    // see PrimaryLogPG::do_read
+    return 0;
+  } else if (op.extent.offset + op.extent.length > oi.size) {
+    op.extent.length = oi.size - op.extent.offset;
+    if (op.checksum.chunk_size > 0 &&
+        op.checksum.length % op.checksum.chunk_size != 0) {
+      dout(10) << __func__ << ": length (trimmed to 0x"
+               << std::hex << op.checksum.length
+               << ") not aligned to chunk size 0x"
+               << op.checksum.chunk_size << std::dec
+               << dendl;
+      return -EINVAL;
+    }
   }
 
   Checksummer::CSumType csum_type;