f2fs: introduce a radix_tree for the free_nid list

This patch introduces a radix tree for the list of free_nids, which enhances
the performance on free nid management.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c56e67b468dafcfa18a6a2179934aaf4067038fa..11fd8bec670bf2e25cb7ac5ab570dbfde7574c78 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -247,6 +247,7 @@ struct f2fs_nm_info {
        struct list_head dirty_nat_entries; /* cached nat entry list (dirty) */
 
        /* free node ids management */
+       struct radix_tree_root free_nid_root;/* root of the free_nid cache */
        struct list_head free_nid_list; /* a list for free nids */
        spinlock_t free_nid_list_lock;  /* protect free nid list */
        unsigned int fcnt;              /* the number of free node id */

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 431bcb42cdd02aa5e6c869592ef1cb36999a8a05..1f9cf2148816cbd2cb460f089fcaaa579b79e349 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1269,21 +1269,17 @@ const struct address_space_operations f2fs_node_aops = {
        .releasepage    = f2fs_release_node_page,
 };
 
-static struct free_nid *__lookup_free_nid_list(nid_t n, struct list_head *head)
+static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
+                                               nid_t n)
 {
-       struct list_head *this;
-       struct free_nid *i;
-       list_for_each(this, head) {
-               i = list_entry(this, struct free_nid, list);
-               if (i->nid == n)
-                       return i;
-       }
-       return NULL;
+       return radix_tree_lookup(&nm_i->free_nid_root, n);
 }
 
-static void __del_from_free_nid_list(struct free_nid *i)
+static void __del_from_free_nid_list(struct f2fs_nm_info *nm_i,
+                                               struct free_nid *i)
 {
        list_del(&i->list);
+       radix_tree_delete(&nm_i->free_nid_root, i->nid);
        kmem_cache_free(free_nid_slab, i);
 }
 
@@ -1304,7 +1300,8 @@ static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid, bool build)
                /* do not add allocated nids */
                read_lock(&nm_i->nat_tree_lock);
                ne = __lookup_nat_cache(nm_i, nid);
-               if (ne && nat_get_blkaddr(ne) != NULL_ADDR)
+               if (ne &&
+                       (!ne->checkpointed || nat_get_blkaddr(ne) != NULL_ADDR))
                        allocated = true;
                read_unlock(&nm_i->nat_tree_lock);
                if (allocated)
@@ -1316,7 +1313,7 @@ static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid, bool build)
        i->state = NID_NEW;
 
        spin_lock(&nm_i->free_nid_list_lock);
-       if (__lookup_free_nid_list(nid, &nm_i->free_nid_list)) {
+       if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {
                spin_unlock(&nm_i->free_nid_list_lock);
                kmem_cache_free(free_nid_slab, i);
                return 0;
@@ -1331,9 +1328,9 @@ static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
 {
        struct free_nid *i;
        spin_lock(&nm_i->free_nid_list_lock);
-       i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+       i = __lookup_free_nid_list(nm_i, nid);
        if (i && i->state == NID_NEW) {
-               __del_from_free_nid_list(i);
+               __del_from_free_nid_list(nm_i, i);
                nm_i->fcnt--;
        }
        spin_unlock(&nm_i->free_nid_list_lock);
@@ -1457,9 +1454,9 @@ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
        struct free_nid *i;
 
        spin_lock(&nm_i->free_nid_list_lock);
-       i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+       i = __lookup_free_nid_list(nm_i, nid);
        f2fs_bug_on(!i || i->state != NID_ALLOC);
-       __del_from_free_nid_list(i);
+       __del_from_free_nid_list(nm_i, i);
        spin_unlock(&nm_i->free_nid_list_lock);
 }
 
@@ -1475,10 +1472,10 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
                return;
 
        spin_lock(&nm_i->free_nid_list_lock);
-       i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
+       i = __lookup_free_nid_list(nm_i, nid);
        f2fs_bug_on(!i || i->state != NID_ALLOC);
        if (nm_i->fcnt > 2 * MAX_FREE_NIDS) {
-               __del_from_free_nid_list(i);
+               __del_from_free_nid_list(nm_i, i);
        } else {
                i->state = NID_NEW;
                nm_i->fcnt++;
@@ -1812,6 +1809,7 @@ static int init_node_manager(struct f2fs_sb_info *sbi)
        nm_i->fcnt = 0;
        nm_i->nat_cnt = 0;
 
+       INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
        INIT_LIST_HEAD(&nm_i->free_nid_list);
        INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC);
        INIT_LIST_HEAD(&nm_i->nat_entries);
@@ -1865,7 +1863,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
        spin_lock(&nm_i->free_nid_list_lock);
        list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
                f2fs_bug_on(i->state == NID_ALLOC);
-               __del_from_free_nid_list(i);
+               __del_from_free_nid_list(nm_i, i);
                nm_i->fcnt--;
        }
        f2fs_bug_on(nm_i->fcnt);