From 5c9e418436f3445d7cc4f3ba2964f231a4b33f17 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 13 Dec 2016 18:54:59 +0800 Subject: [PATCH] f2fs: don't cache nat entry if out of memory If we run out of memory, in cache_nat_entry, it's better to avoid loop for allocating memory to cache nat entry, so in low memory scenario, for read path of node block, I expect this can avoid unneeded latency. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index b9078fd..03a1f90 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -245,12 +245,24 @@ 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) +static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid, + bool no_fail) { struct nat_entry *new; - new = f2fs_kmem_cache_alloc(nat_entry_slab, GFP_NOFS); - f2fs_radix_tree_insert(&nm_i->nat_root, nid, 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); @@ -267,8 +279,9 @@ static void cache_nat_entry(struct f2fs_sb_info *sbi, nid_t nid, e = __lookup_nat_cache(nm_i, nid); if (!e) { - e = grab_nat_entry(nm_i, nid); - node_info_from_raw_nat(&e->ni, ne); + e = grab_nat_entry(nm_i, nid, false); + if (e) + node_info_from_raw_nat(&e->ni, ne); } else { f2fs_bug_on(sbi, nat_get_ino(e) != le32_to_cpu(ne->ino) || nat_get_blkaddr(e) != @@ -286,7 +299,7 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni, 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); + e = grab_nat_entry(nm_i, ni->nid, true); copy_node_info(&e->ni, ni); f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR); } else if (new_blkaddr == NEW_ADDR) { @@ -2152,7 +2165,7 @@ 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); + ne = grab_nat_entry(nm_i, nid, true); node_info_from_raw_nat(&ne->ni, &raw_ne); } -- 2.7.4