From d2f5890f8451412ff21fd480fedc41eafc755d07 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@inktank.com>
Date: Fri, 7 Dec 2012 01:16:53 -0800
Subject: [PATCH] client, libcephfs: add method to get the pool name for an
 open file

Signed-off-by: Sage Weil <sage@inktank.com>
---
 src/client/Client.cc           |  8 ++++++++
 src/client/Client.h            |  1 +
 src/include/cephfs/libcephfs.h | 14 ++++++++++++++
 src/libcephfs.cc               | 19 +++++++++++++++++++
 src/test/libcephfs/test.cc     |  6 ++++++
 5 files changed, 48 insertions(+)

diff --git a/src/client/Client.cc b/src/client/Client.cc
index ac23877ebc077..58d4292333f9c 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -7251,6 +7251,14 @@ int Client::describe_layout(int fd, ceph_file_layout *lp)
 
 // expose osdmap
 
+string Client::get_pool_name(int64_t pool)
+{
+  Mutex::Locker lock(client_lock);
+  if (!osdmap->have_pg_pool(pool))
+    return string();
+  return osdmap->get_pool_name(pool);
+}
+
 int Client::get_pool_replication(int64_t pool)
 {
   Mutex::Locker lock(client_lock);
diff --git a/src/client/Client.h b/src/client/Client.h
index 125e194a9f4ab..b1d943f42e53d 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -654,6 +654,7 @@ public:
   // expose osdmap 
   int get_local_osd();
   int get_pool_replication(int64_t pool);
+  string get_pool_name(int64_t pool);
 
   int enumerate_layout(int fd, vector<ObjectExtent>& result,
 		       loff_t length, loff_t offset);
diff --git a/src/include/cephfs/libcephfs.h b/src/include/cephfs/libcephfs.h
index adeea248dd2e3..7e5afb9b98508 100644
--- a/src/include/cephfs/libcephfs.h
+++ b/src/include/cephfs/libcephfs.h
@@ -841,6 +841,20 @@ int ceph_get_file_stripe_unit(struct ceph_mount_info *cmount, int fh);
  */
 int ceph_get_file_pool(struct ceph_mount_info *cmount, int fh);
 
+/**
+ * Get the name of the pool a file is stored in,
+ *
+ * Write the name of the file's pool to the buffer.  If buflen is 0, return
+ * a suggested length for the buffer.
+ *
+ * @param cmount the ceph mount handle to use.
+ * @param fh the open file descriptor referring to the file
+ * @param buf buffer to store the name in
+ * @param buflen size of the buffer
+ * @returns length in bytes of the pool name
+ */
+int ceph_get_file_pool_name(struct ceph_mount_info *cmount, int fh, char *buf, size_t buflen);
+
 /**
  * Get the file replication information.
  * @param cmount the ceph mount handle to use.
diff --git a/src/libcephfs.cc b/src/libcephfs.cc
index d085f846265b8..55bcfed1ff713 100644
--- a/src/libcephfs.cc
+++ b/src/libcephfs.cc
@@ -705,6 +705,25 @@ extern "C" int ceph_get_file_pool(struct ceph_mount_info *cmount, int fh)
   return l.fl_pg_pool;
 }
 
+extern "C" int ceph_get_file_pool_name(struct ceph_mount_info *cmount, int fh, char *buf, size_t len)
+{
+  struct ceph_file_layout l;
+  int r;
+
+  if (!cmount->is_mounted())
+    return -ENOTCONN;
+  r = cmount->get_client()->describe_layout(fh, &l);
+  if (r < 0)
+    return r;
+  string name = cmount->get_client()->get_pool_name(l.fl_pg_pool);
+  if (len == 0)
+    return name.length();
+  if (name.length() > len)
+    return -ERANGE;
+  strncpy(buf, name.c_str(), len);
+  return name.length();
+}
+
 extern "C" int ceph_get_file_replication(struct ceph_mount_info *cmount, int fh)
 {
   struct ceph_file_layout l;
diff --git a/src/test/libcephfs/test.cc b/src/test/libcephfs/test.cc
index b2d22f9acebb2..f576fefd16447 100644
--- a/src/test/libcephfs/test.cc
+++ b/src/test/libcephfs/test.cc
@@ -160,6 +160,10 @@ TEST(LibCephFS, OpenLayout) {
   sprintf(test_layout_file, "test_layout_%d_b", getpid());
   int fd = ceph_open_layout(cmount, test_layout_file, O_CREAT, 0666, (1<<20), 7, (1<<20), NULL);
   ASSERT_GT(fd, 0);
+  char poolname[80];
+  ASSERT_LT(0, ceph_get_file_pool_name(cmount, fd, poolname, sizeof(poolname)));
+  ASSERT_EQ(4, ceph_get_file_pool_name(cmount, fd, poolname, 0));
+  ASSERT_EQ(0, strcmp("data", poolname));
   ceph_close(cmount, fd);
 
   /* invalid layout */
@@ -171,6 +175,8 @@ TEST(LibCephFS, OpenLayout) {
   sprintf(test_layout_file, "test_layout_%d_d", getpid());
   fd = ceph_open_layout(cmount, test_layout_file, O_CREAT, 0666, (1<<20), 7, (1<<20), "data");
   ASSERT_GT(fd, 0);
+  ASSERT_EQ(4, ceph_get_file_pool_name(cmount, fd, poolname, sizeof(poolname)));
+  ASSERT_EQ(0, strcmp("data", poolname));
   ceph_close(cmount, fd);
 
   /* with metadata pool (invalid) */
-- 
2.39.5