On 2017/11/7 17:47, Yunlei He wrote:
> This path separate nat_entry mem alloc from nat_tree_lock,
> which will benefit in some low mem case.
>
> Signed-off-by: Yunlei He <[email protected]>
> ---
> fs/f2fs/node.c | 56 +++++++++++++++++++++++++++++++++++++++-----------------
> 1 file changed, 39 insertions(+), 17 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index fef5c68..c6aea33 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -257,22 +257,15 @@ static struct nat_entry *grab_nat_entry(struct
> f2fs_nm_info *nm_i, nid_t nid,
>
> 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;
> }
>
> @@ -282,17 +275,32 @@ static void cache_nat_entry(struct f2fs_sb_info *sbi,
> nid_t nid,
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> struct nat_entry *e;
>
> +#ifdef CONFIG_F2FS_CHECK_FS
> + down_read(&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 (unlikely(e)) {
> 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_blkaddr(e) != le32_to_cpu(ne->block_addr) ||
> nat_get_version(e) != ne->version);
> + up_read(&nm_i->nat_tree_lock);
> + return;
> + }
> + up_read(&nm_i->nat_tree_lock);
> +#endif
> + e = grab_nat_entry(nm_i, nid, false);
if (!e)
return;
Thanks,
> + down_write(&nm_i->nat_tree_lock);
> + if (!e)
> + goto out;
> +
> + if (!radix_tree_insert(&nm_i->nat_root, nid, e)) {
> + list_add_tail(&e->list, &nm_i->nat_entries);
> + nm_i->nat_cnt++;
> + node_info_from_raw_nat(&e->ni, ne);
> + } else {
> + kmem_cache_free(nat_entry_slab, e);
> }
> +out:
> + up_write(&nm_i->nat_tree_lock);
> }
>
> static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
> @@ -300,11 +308,21 @@ 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 = grab_nat_entry(nm_i, ni->nid, true);
>
> +retry:
> 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 = new;
> + if (radix_tree_insert(&nm_i->nat_root, ni->nid, e)) {
> + up_write(&nm_i->nat_tree_lock);
> + cond_resched();
> + goto retry;
> + }
> +
> + list_add_tail(&e->list, &nm_i->nat_entries);
> + nm_i->nat_cnt++;
> copy_node_info(&e->ni, ni);
> f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
> } else if (new_blkaddr == NEW_ADDR) {
> @@ -315,6 +333,9 @@ 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);
> + kmem_cache_free(nat_entry_slab, new);
> + } else {
> + kmem_cache_free(nat_entry_slab, new);
> }
>
> /* sanity check */
> @@ -424,9 +445,7 @@ 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);
> }
>
> /*
> @@ -2375,6 +2394,9 @@ 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);
> + f2fs_radix_tree_insert(&nm_i->nat_root, nid, ne);
> + list_add_tail(&ne->list, &nm_i->nat_entries);
> + nm_i->nat_cnt++;
> node_info_from_raw_nat(&ne->ni, &raw_ne);
> }
>
>
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