From: Alexey Sheplyakov <asheplyakov@mirantis.com>
Date: Fri, 12 Feb 2016 17:56:02 +0000 (+0300)
Subject: FileJournal::_open: return the correct error code
X-Git-Tag: v11.0.0~526^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=7469ef3cba436299692fabef91afaf6f6d6d56c2;p=ceph.git

FileJournal::_open: return the correct error code

.. and print a more helpful error message. Unlike most of IO routines
(open, creat, write*, read, close) io_setup does NOT set the errno,
instead it returns the negated error code. Also -EAGAIN indicates
the limit of available events has been exceeded.

Signed-off-by: Alexey Sheplyakov <asheplyakov@mirantis.com>
---

diff --git a/src/os/filestore/FileJournal.cc b/src/os/filestore/FileJournal.cc
index 7763c6f95f4d..ed93598a5e63 100644
--- a/src/os/filestore/FileJournal.cc
+++ b/src/os/filestore/FileJournal.cc
@@ -103,9 +103,16 @@ int FileJournal::_open(bool forwrite, bool create)
     aio_ctx = 0;
     ret = io_setup(128, &aio_ctx);
     if (ret < 0) {
-      ret = errno;
-      derr << "FileJournal::_open: unable to setup io_context " << cpp_strerror(ret) << dendl;
-      ret = -ret;
+      switch (ret) {
+	// Contrary to naive expectations -EAGIAN means ...
+	case -EAGAIN:
+	  derr << "FileJournal::_open: user's limit of aio events exceeded. "
+	       << "Try increasing /proc/sys/fs/aio-max-nr" << dendl;
+	  break;
+	default:
+	  derr << "FileJournal::_open: unable to setup io_context " << cpp_strerror(-ret) << dendl;
+	  break;
+      }
       goto out_fd;
     }
   }