Merge PR ceph#62549 into main

* refs/pull/62549/head:
	test/libcephfs: Add a new test with ceph_ll_get() API
	libcephfs: Implement ceph_ll_get() API

Reviewed-by: Dhairya Parmar <[email protected]>
Reviewed-by: Venky Shankar <[email protected]>

Author: vshankar

src/client/Client.cc

@@ -13564,6 +13564,12 @@ bool Client::_ll_forget(Inode *in, uint64_t count)
   return last;
 }
 
+void Client::ll_get(Inode *in)
+{
+  std::scoped_lock lock(client_lock);
+  _ll_get(in);
+}
+
 bool Client::ll_forget(Inode *in, uint64_t count)
 {
   std::scoped_lock lock(client_lock);

src/client/Client.h

@@ -601,6 +601,7 @@ class Client : public Dispatcher, public md_config_obs_t {
   int ll_lookupx(Inode *parent, const char *name, Inode **out,
 			struct ceph_statx *stx, unsigned want, unsigned flags,
 			const UserPerm& perms);
+  void ll_get(Inode *in);
   bool ll_forget(Inode *in, uint64_t count);
   bool ll_put(Inode *in);
   int ll_get_snap_ref(snapid_t snap);

src/include/cephfs/libcephfs.h

@@ -1994,6 +1994,7 @@ int ceph_ll_lookup_root(struct ceph_mount_info *cmount,
 int ceph_ll_lookup(struct ceph_mount_info *cmount, Inode *parent,
 		   const char *name, Inode **out, struct ceph_statx *stx,
 		   unsigned want, unsigned flags, const UserPerm *perms);
+void ceph_ll_get(struct ceph_mount_info *cmount, struct Inode *in);
 int ceph_ll_put(struct ceph_mount_info *cmount, struct Inode *in);
 int ceph_ll_forget(struct ceph_mount_info *cmount, struct Inode *in,
 		   int count);

src/libcephfs.cc

@@ -2042,6 +2042,11 @@ extern "C" int ceph_ll_lookup(struct ceph_mount_info *cmount,
 					    flags, *perms);
 }
 
+extern "C" void ceph_ll_get(class ceph_mount_info *cmount, Inode *in)
+{
+  cmount->get_client()->ll_get(in);
+}
+
 extern "C" int ceph_ll_put(class ceph_mount_info *cmount, Inode *in)
 {
   return (cmount->get_client()->ll_put(in));

src/test/libcephfs/test.cc

@@ -4100,3 +4100,51 @@ TEST(LibCephFS, SubdirLookupAfterReaddir_ll) {
   ASSERT_EQ(0, ceph_unmount(cmount));
   ceph_shutdown(cmount);
 }
+
+TEST(LibCephFS, InodeGetPut) {
+  struct ceph_mount_info *cmount;
+  ASSERT_EQ(ceph_create(&cmount, NULL), 0);
+  ASSERT_EQ(ceph_conf_read_file(cmount, NULL), 0);
+  ASSERT_EQ(0, ceph_conf_parse_env(cmount, NULL));
+  ASSERT_EQ(ceph_mount(cmount, NULL), 0);
+
+  Inode *root = NULL;
+
+  ASSERT_EQ(ceph_ll_lookup_root(cmount, &root), 0);
+  // Update reference on root
+  ceph_ll_get(cmount, root);
+
+  bool last_ref = ceph_ll_put(cmount, root);
+  // ceph_ll_put() always ignore forget on root
+  ASSERT_TRUE(last_ref);
+
+  char dir_name[128];
+  pid_t mypid = getpid();
+  sprintf(dir_name, "dir_%d", mypid);
+
+  ASSERT_EQ(ceph_mkdir(cmount, dir_name, 0777), 0);
+
+  Inode *dir_inode = NULL;
+  UserPerm *perms = ceph_mount_perms(cmount);
+  struct ceph_statx stx;
+
+  ASSERT_EQ(0, ceph_ll_lookup(cmount, root, dir_name, &dir_inode, &stx, 0, 0, perms));
+  // Update reference on directory
+  ceph_ll_get(cmount, dir_inode);
+
+  last_ref = ceph_ll_put(cmount, dir_inode);
+  ASSERT_FALSE(last_ref);
+
+  last_ref = ceph_ll_put(cmount, dir_inode);
+  ASSERT_TRUE(last_ref);
+
+  // Take another reference on directory
+  ceph_ll_get(cmount, dir_inode);
+
+  last_ref = ceph_ll_put(cmount, dir_inode);
+  ASSERT_TRUE(last_ref);
+
+  ASSERT_EQ(0, ceph_rmdir(cmount, dir_name));
+  ASSERT_EQ(0, ceph_unmount(cmount));
+  ceph_shutdown(cmount);
+}