LU-5324 lfsck: invalidly memory access in lfsck_del_target

[fs/lustre-release.git] / lustre / fld / fld_internal.h

diff --git a/lustre/fld/fld_internal.h b/lustre/fld/fld_internal.h
index aab457b..ae8dce1 100644 (file)
--- a/lustre/fld/fld_internal.h
+++ b/lustre/fld/fld_internal.h
@@ -35,6 +35,24 @@
  *
  * lustre/fld/fld_internal.h
  *
+ * Subsystem Description:
+ * FLD is FID Location Database, which stores where (IE, on which MDT)
+ * FIDs are located.
+ * The database is basically a record file, each record consists of a FID
+ * sequence range, MDT/OST index, and flags. The FLD for the whole FS
+ * is only stored on the sequence controller(MDT0) right now, but each target
+ * also has its local FLD, which only stores the local sequence.
+ *
+ * The FLD subsystem usually has two tasks:
+ * 1. maintain the database, i.e. when the sequence controller allocates
+ * new sequence ranges to some nodes, it will call the FLD API to insert the
+ * location information <sequence_range, node_index> in FLDB.
+ *
+ * 2. Handle requests from other nodes, i.e. if client needs to know where
+ * the FID is located, if it can not find the information in the local cache,
+ * it will send a FLD lookup RPC to the FLD service, and the FLD service will
+ * look up the FLDB entry and return the location information to client.
+ *
  * Author: Yury Umanets <umka@clusterfs.com>
  * Author: Tom WangDi <wangdi@clusterfs.com>
  */
@@ -68,11 +86,11 @@ struct lu_fld_hash {
 };
 
 struct fld_cache_entry {
-        cfs_list_t               fce_lru;
-        cfs_list_t               fce_list;
-        /**
-         * fld cache entries are sorted on range->lsr_start field. */
-        struct lu_seq_range      fce_range;
+       struct list_head        fce_lru;
+       struct list_head        fce_list;
+       /**
+        * fld cache entries are sorted on range->lsr_start field. */
+       struct lu_seq_range     fce_range;
 };
 
 struct fld_cache {
@@ -96,11 +114,11 @@ struct fld_cache {
 
         /**
          * LRU list fld entries. */
-        cfs_list_t               fci_lru;
+       struct list_head        fci_lru;
 
         /**
          * sorted fld entries. */
-        cfs_list_t               fci_entries_head;
+       struct list_head        fci_entries_head;
 
         /**
          * Cache statistics. */
@@ -132,10 +150,10 @@ extern struct lu_fld_hash fld_hash[];
 
 #ifdef __KERNEL__
 
-# ifdef LPROCFS
+#ifdef LPROCFS
 extern struct proc_dir_entry *fld_type_proc_dir;
-extern struct lprocfs_vars fld_client_proc_list[];
-# endif
+extern struct lprocfs_seq_vars fld_client_proc_list[];
+#endif
 
 # ifdef HAVE_SERVER_SUPPORT
 struct fld_thread_info {
@@ -148,7 +166,7 @@ extern struct lu_context_key fld_thread_key;
 
 struct dt_device;
 int fld_index_init(const struct lu_env *env, struct lu_server_fld *fld,
-                  struct dt_device *dt);
+                  struct dt_device *dt, int type);
 
 void fld_index_fini(const struct lu_env *env, struct lu_server_fld *fld);
 
@@ -170,10 +188,10 @@ void fld_server_mod_exit(void);
 
 int fld_server_read(const struct lu_env *env, struct lu_server_fld *fld,
                    struct lu_seq_range *range, void *data, int data_len);
-# ifdef LPROCFS
+#ifdef LPROCFS
 extern const struct file_operations fld_proc_seq_fops;
-extern struct lprocfs_vars fld_server_proc_list[];
-# endif
+extern struct lprocfs_seq_vars fld_server_proc_list[];
+#endif
 
 # endif /* HAVE_SERVER_SUPPORT */