client: don't use special faked-up inode for /..

The CEPH_INO_DOTDOT thing is quite strange. Under most OS (Linux
included), the parent of the root is itself. IOW, at the root, '.' and
'..' refer to the same inode.

Change the ceph client to do the same, as this allows users to get
valid stat info for '..', as well as elimnating some special-casing.

Also in several places, we're checking dn_set.empty as an indicator
of being the root. While that is true for the root, it's also true
for unlinked directories.

This patch has treats them the same. An unlinked directory will
be reparented to itself, effectively acting as a root of its own.

Signed-off-by: Jeff Layton <jlayton@redhat.com>

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 2df632fc0e088d66ee3b8acd32e577cc76bf54de..4af0fe0f8aa94dbd2a70293657fc632e971880a0 100644 (file)
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -5910,7 +5910,7 @@ int Client::_lookup(Inode *dir, const string& dname, int mask,
 
   if (dname == "..") {
     if (dir->dn_set.empty())
-      r = -ENOENT;
+      *target = dir;
     else
       *target = dir->get_first_parent()->dir->parent_inode; //dirs can't be hard-linked
     goto done;
@@ -7239,16 +7239,14 @@ int Client::readdir_r_cb(dir_result_t *d, add_dirent_cb_t cb, void *p)
   if (dirp->offset == 1) {
     ldout(cct, 15) << " including .." << dendl;
     uint64_t next_off = 2;
-    if (!diri->dn_set.empty()) {
-      InodeRef& in = diri->get_first_parent()->inode;
-      fill_stat(in, &st);
-      fill_dirent(&de, "..", S_IFDIR, st.st_ino, next_off);
-    } else {
-      /* must be at the root (no parent),
-       * so we add the dotdot with a special inode (3) */
-      fill_dirent(&de, "..", S_IFDIR, CEPH_INO_DOTDOT, next_off);
-    }
+    InodeRef in;
+    if (diri->dn_set.empty())
+      in = diri;
+    else
+      in = diri->get_first_parent()->inode;
 
+    fill_stat(in, &st);
+    fill_dirent(&de, "..", S_IFDIR, st.st_ino, next_off);
 
     client_lock.Unlock();
     int r = cb(p, &de, &st, -1, next_off);
@@ -9684,13 +9682,6 @@ int Client::ll_getattr(Inode *in, struct stat *attr, int uid, int gid)
   tout(cct) << "ll_getattr" << std::endl;
   tout(cct) << vino.ino.val << std::endl;
 
-  /* special case for dotdot (..) */
-  if (vino.ino.val == CEPH_INO_DOTDOT) {
-    attr->st_mode = S_IFDIR | 0755;
-    attr->st_nlink = 2;
-    return 0;
-  }
-
   int res;
   if (vino.snapid < CEPH_NOSNAP)
     res = 0;

diff --git a/src/include/ceph_fs.h b/src/include/ceph_fs.h
index 772e475ccc919ae10366bb96b175716110506987..1610aaf17cc2cd63cbc8dba62d5d4d760623a392 100644 (file)
--- a/src/include/ceph_fs.h
+++ b/src/include/ceph_fs.h
@@ -28,7 +28,6 @@
 
 #define CEPH_INO_ROOT   1
 #define CEPH_INO_CEPH   2       /* hidden .ceph dir */
-#define CEPH_INO_DOTDOT 3      /* used by ceph fuse for parent (..) */
 #define CEPH_INO_LOST_AND_FOUND 4      /* reserved ino for use in recovery */
 
 /* arbitrary limit on max # of monitors (cluster of 3 is typical) */