From: Yan, Zheng <zyan@redhat.com>
Date: Fri, 15 Apr 2016 12:15:14 +0000 (+0800)
Subject: mds: disallow 'open truncate' non-regular inode
X-Git-Tag: v0.94.8~18^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=2633ec3934ad8f7629c55b4345f426cacfb7b140;p=ceph.git

mds: disallow 'open truncate' non-regular inode

Signed-off-by: Yan, Zheng <zyan@redhat.com>
(cherry picked from commit 0e4b6f2332bb4822cf324587a94144f1c98e4b97)

Conflicts:
	src/mds/Server.cc (hammer has cur->inode.inline_version - in master
	this has been changed to cur->inode.inline_data.version)
---

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 3b1426958c3..da9ad31de9b 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -2732,9 +2732,13 @@ void Server::handle_client_open(MDRequestRef& mdr)
     return;
   }
 
-  // can only open non-regular inode with mode FILE_MODE_PIN, at least for now.
-  if (!cur->inode.is_file())
+  if (!cur->inode.is_file()) {
+    // can only open non-regular inode with mode FILE_MODE_PIN, at least for now.
     cmode = CEPH_FILE_MODE_PIN;
+    // the inode is symlink and client wants to follow it, ignore the O_TRUNC flag.
+    if (cur->inode.is_symlink() && !(flags & O_NOFOLLOW))
+      flags &= ~O_TRUNC;
+  }
 
   dout(10) << "open flags = " << flags
 	   << ", filemode = " << cmode
@@ -2753,6 +2757,13 @@ void Server::handle_client_open(MDRequestRef& mdr)
     return;
   }
 
+  if ((flags & O_TRUNC) && !cur->inode.is_file()) {
+    dout(7) << "specified O_TRUNC on !(file|symlink) " << *cur << dendl;
+    // we should return -EISDIR for directory, return -EINVAL for other non-regular
+    respond_to_request(mdr, cur->inode.is_dir() ? EISDIR : -EINVAL);
+    return;
+  }
+
   if (cur->inode.inline_version != CEPH_INLINE_NONE &&
       !mdr->session->connection->has_feature(CEPH_FEATURE_MDS_INLINE_DATA)) {
     dout(7) << "old client cannot open inline data file " << *cur << dendl;