osd/PrimaryLogPG: fix the extent length error of the sync read

The extent.length of the sync read is changed to 0, when
the read is failed. This makes the retry of the read with
a offset of 0 to read the total object.
Let the extent.length as it is, if the return code is -EAGAIN,
which will make the read try again later with the correct
extent.length.

Fixes: https://tracker.ceph.com/issues/37680
Signed-off-by: Xiaofei Cui <cuixiaofei@sangfor.com.cn>

diff --git a/src/osd/PrimaryLogPG.cc b/src/osd/PrimaryLogPG.cc
index 56806e1d9b8a21a3fcc1c8a7849ec4ee443c175e..f08dcb69574f914437791a47a2e5d925df799227 100644 (file)
--- a/src/osd/PrimaryLogPG.cc
+++ b/src/osd/PrimaryLogPG.cc
@@ -5518,7 +5518,12 @@ int PrimaryLogPG::do_read(OpContext *ctx, OSDOp& osd_op) {
     }
     if (r >= 0)
       op.extent.length = r;
-    else {
+    else if (r == -EAGAIN) {
+      // EAGAIN should not change the length of extent or count the read op.
+      dout(10) << " read got " << r << " / " << op.extent.length
+              << " bytes from obj " << soid << ". try again." << dendl;
+      return -EAGAIN;
+    } else {
       result = r;
       op.extent.length = 0;
     }