From 9b0c88bf130fec8e90561a4ee4a538a1f8eb4b8c Mon Sep 17 00:00:00 2001
From: Sam Lang <sam.lang@inktank.com>
Date: Wed, 10 Oct 2012 10:16:53 -0500
Subject: [PATCH] client: Implement stat and correct lstat

lstat is meant to not follow symbolic links in
the given path, whereas stat does.  This adds a
stat function to Client and libcephfs and changes
the behavior of lstat to not follow symlinks.

Signed-off-by: Sam Lang <sam.lang@inktank.com>
---
 src/client/Client.cc           | 25 ++++++++++++++++++++++++-
 src/client/Client.h            |  1 +
 src/include/cephfs/libcephfs.h | 10 ++++++++++
 src/libcephfs.cc               |  6 ++++++
 src/test/libcephfs/test.cc     |  3 ++-
 5 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/client/Client.cc b/src/client/Client.cc
index a718a0cad66a6..89c5ed09961ee 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -4103,6 +4103,28 @@ int Client::setattr(const char *relpath, struct stat *attr, int mask)
   return _setattr(in, attr, mask); 
 }
 
+int Client::stat(const char *relpath, struct stat *stbuf,
+			  frag_info_t *dirstat, int mask)
+{
+  ldout(cct, 3) << "stat enter (relpath" << relpath << " mask " << mask << ")" << dendl;
+  Mutex::Locker lock(client_lock);
+  tout(cct) << "stat" << std::endl;
+  tout(cct) << relpath << std::endl;
+  filepath path(relpath);
+  Inode *in;
+  int r = path_walk(path, &in);
+  if (r < 0)
+    return r;
+  r = _getattr(in, mask);
+  if (r < 0) {
+    ldout(cct, 3) << "stat exit on error!" << dendl;
+    return r;
+  }
+  fill_stat(in, stbuf, dirstat);
+  ldout(cct, 3) << "stat exit (relpath" << relpath << " mask " << mask << ")" << dendl;
+  return r;
+}
+
 int Client::lstat(const char *relpath, struct stat *stbuf,
 			  frag_info_t *dirstat, int mask)
 {
@@ -4112,7 +4134,8 @@ int Client::lstat(const char *relpath, struct stat *stbuf,
   tout(cct) << relpath << std::endl;
   filepath path(relpath);
   Inode *in;
-  int r = path_walk(path, &in);
+  // don't follow symlinks
+  int r = path_walk(path, &in, false);
   if (r < 0)
     return r;
   r = _getattr(in, mask);
diff --git a/src/client/Client.h b/src/client/Client.h
index d4f61d6ed0afb..61bb2a9d536e0 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -583,6 +583,7 @@ public:
   int symlink(const char *existing, const char *newname);
 
   // inode stuff
+  int stat(const char *path, struct stat *stbuf, frag_info_t *dirstat=0, int mask=CEPH_STAT_CAP_INODE_ALL);
   int lstat(const char *path, struct stat *stbuf, frag_info_t *dirstat=0, int mask=CEPH_STAT_CAP_INODE_ALL);
   int lstatlite(const char *path, struct statlite *buf);
 
diff --git a/src/include/cephfs/libcephfs.h b/src/include/cephfs/libcephfs.h
index e0048b9e692b4..240fbf266d525 100644
--- a/src/include/cephfs/libcephfs.h
+++ b/src/include/cephfs/libcephfs.h
@@ -450,6 +450,16 @@ int ceph_rename(struct ceph_mount_info *cmount, const char *from, const char *to
  * @param stbuf the stat struct that will be filled in with the file's statistics.
  * @returns 0 on success or negative error code on failure.
  */
+int ceph_stat(struct ceph_mount_info *cmount, const char *path, struct stat *stbuf);
+
+/**
+ * Get a file's statistics and attributes, without following symlinks.
+ *
+ * @param cmount the ceph mount handle to use for performing the stat.
+ * @param path the file or directory to get the statistics of.
+ * @param stbuf the stat struct that will be filled in with the file's statistics.
+ * @returns 0 on success or negative error code on failure.
+ */
 int ceph_lstat(struct ceph_mount_info *cmount, const char *path, struct stat *stbuf);
 
 /**
diff --git a/src/libcephfs.cc b/src/libcephfs.cc
index 8e1020e85e070..9828a7839b9e1 100644
--- a/src/libcephfs.cc
+++ b/src/libcephfs.cc
@@ -392,6 +392,12 @@ extern "C" int ceph_symlink(struct ceph_mount_info *cmount, const char *existing
 }
 
 // inode stuff
+extern "C" int ceph_stat(struct ceph_mount_info *cmount, const char *path,
+			 struct stat *stbuf)
+{
+  return cmount->get_client()->stat(path, stbuf);
+}
+
 extern "C" int ceph_lstat(struct ceph_mount_info *cmount, const char *path,
 			  struct stat *stbuf)
 {
diff --git a/src/test/libcephfs/test.cc b/src/test/libcephfs/test.cc
index 77aa0cd59886d..aba593a57c87d 100644
--- a/src/test/libcephfs/test.cc
+++ b/src/test/libcephfs/test.cc
@@ -18,6 +18,7 @@
 #include <sys/fcntl.h>
 #include <unistd.h>
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <dirent.h>
 #include <sys/xattr.h>
 
@@ -96,7 +97,7 @@ TEST(LibCephFS, Dir_ls) {
 
   ASSERT_EQ(ceph_mkdir(cmount, foostr, 0777), 0);
   struct stat stbuf;
-  ASSERT_EQ(ceph_lstat(cmount, foostr, &stbuf), 0);
+  ASSERT_EQ(ceph_stat(cmount, foostr, &stbuf), 0);
   ASSERT_NE(S_ISDIR(stbuf.st_mode), 0);
 
   char barstr[256];
-- 
2.39.5