f2fs: separate nat entry mem alloc from nat_tree_lock

This patch splits memory allocation part in nat_entry to avoid lock contention.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 59 insertions, 39 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 9abfdbb5aae5..fe1fc662af2a 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -138,6 +138,44 @@ static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
         return dst_page;
 }
 
+static struct nat_entry *__alloc_nat_entry(nid_t nid, bool no_fail)
+{
+        struct nat_entry *new;
+
+        if (no_fail)
+                new = f2fs_kmem_cache_alloc(nat_entry_slab,
+                                                GFP_NOFS | __GFP_ZERO);
+        else
+                new = kmem_cache_alloc(nat_entry_slab,
+                                                GFP_NOFS | __GFP_ZERO);
+        if (new) {
+                nat_set_nid(new, nid);
+                nat_reset_flag(new);
+        }
+        return new;
+}
+
+static void __free_nat_entry(struct nat_entry *e)
+{
+        kmem_cache_free(nat_entry_slab, e);
+}
+
+/* must be locked by nat_tree_lock */
+static struct nat_entry *__init_nat_entry(struct f2fs_nm_info *nm_i,
+        struct nat_entry *ne, struct f2fs_nat_entry *raw_ne, bool no_fail)
+{
+        if (no_fail)
+                f2fs_radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne);
+        else if (radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne))
+                return NULL;
+
+        if (raw_ne)
+                node_info_from_raw_nat(&ne->ni, raw_ne);
+        list_add_tail(&ne->list, &nm_i->nat_entries);
+        nm_i->nat_cnt++;
+        return ne;
+}
+
 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
 {
         return radix_tree_lookup(&nm_i->nat_root, n);
@@ -154,7 +192,7 @@ static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
         list_del(&e->list);
         radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
         nm_i->nat_cnt--;
-        kmem_cache_free(nat_entry_slab, e);
+        __free_nat_entry(e);
 }
 
 static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i,
@@ -250,49 +288,29 @@ bool need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
         return need_update;
 }
 
-static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
-                                                                bool no_fail)
-{
-        struct nat_entry *new;
-
-        if (no_fail) {
-                new = f2fs_kmem_cache_alloc(nat_entry_slab, GFP_NOFS);
-                f2fs_radix_tree_insert(&nm_i->nat_root, nid, new);
-        } else {
-                new = kmem_cache_alloc(nat_entry_slab, GFP_NOFS);
-                if (!new)
-                        return NULL;
-                if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
-                        kmem_cache_free(nat_entry_slab, new);
-                        return NULL;
-                }
-        }
-
-        memset(new, 0, sizeof(struct nat_entry));
-        nat_set_nid(new, nid);
-        nat_reset_flag(new);
-        list_add_tail(&new->list, &nm_i->nat_entries);
-        nm_i->nat_cnt++;
-        return new;
-}
-
+/* must be locked by nat_tree_lock */
 static void cache_nat_entry(struct f2fs_sb_info *sbi, nid_t nid,
                                                 struct f2fs_nat_entry *ne)
 {
         struct f2fs_nm_info *nm_i = NM_I(sbi);
-        struct nat_entry *e;
+        struct nat_entry *new, *e;
 
+        new = __alloc_nat_entry(nid, false);
+        if (!new)
+                return;
+
+        down_write(&nm_i->nat_tree_lock);
         e = __lookup_nat_cache(nm_i, nid);
-        if (!e) {
-                e = grab_nat_entry(nm_i, nid, false);
-                if (e)
-                        node_info_from_raw_nat(&e->ni, ne);
-        } else {
+        if (!e)
+                e = __init_nat_entry(nm_i, new, ne, false);
+        else
                 f2fs_bug_on(sbi, nat_get_ino(e) != le32_to_cpu(ne->ino) ||
                                 nat_get_blkaddr(e) !=
                                         le32_to_cpu(ne->block_addr) ||
                                 nat_get_version(e) != ne->version);
-        }
+        up_write(&nm_i->nat_tree_lock);
+        if (e != new)
+                __free_nat_entry(new);
 }
 
 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
@@ -300,11 +318,12 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
 {
         struct f2fs_nm_info *nm_i = NM_I(sbi);
         struct nat_entry *e;
+        struct nat_entry *new = __alloc_nat_entry(ni->nid, true);
 
         down_write(&nm_i->nat_tree_lock);
         e = __lookup_nat_cache(nm_i, ni->nid);
         if (!e) {
-                e = grab_nat_entry(nm_i, ni->nid, true);
+                e = __init_nat_entry(nm_i, new, NULL, true);
                 copy_node_info(&e->ni, ni);
                 f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
         } else if (new_blkaddr == NEW_ADDR) {
@@ -316,6 +335,9 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
                 copy_node_info(&e->ni, ni);
                 f2fs_bug_on(sbi, ni->blk_addr != NULL_ADDR);
         }
+        /* let's free early to reduce memory consumption */
+        if (e != new)
+                __free_nat_entry(new);
 
         /* sanity check */
         f2fs_bug_on(sbi, nat_get_blkaddr(e) != ni->blk_addr);
@@ -424,9 +446,7 @@ void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
         f2fs_put_page(page, 1);
 cache:
         /* cache nat entry */
-        down_write(&nm_i->nat_tree_lock);
         cache_nat_entry(sbi, nid, &ne);
-        up_write(&nm_i->nat_tree_lock);
 }
 
 /*
@@ -2374,8 +2394,8 @@ static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
 
                 ne = __lookup_nat_cache(nm_i, nid);
                 if (!ne) {
-                        ne = grab_nat_entry(nm_i, nid, true);
-                        node_info_from_raw_nat(&ne->ni, &raw_ne);
+                        ne = __alloc_nat_entry(nid, true);
+                        __init_nat_entry(nm_i, ne, &raw_ne, true);
                 }
 
                 /*