Re: [PATCH v4] f2fs: obsolete free nid list approach
From: Jaegeuk Kim
Date: Fri Dec 01 2017 - 02:36:46 EST
Hi Chao,
This is really hard to review and risky a lot to apply it shortly. Do we have a
strong reason we have to do this? The original design goal was to minimize
allocation delay which is almost zero for now. Of course, I agreed that there'd
be some trade-off though, we don't have a critical issue with this, FWIW.
Can we expect to see some speed gains with this? How much?
Thanks,
On 11/30, Chao Yu wrote:
> Previously, we use free nid list to manage free nid entry, so during nid
> allocation, we can just pick up one entry from list header, which has
> quite low overhead.
>
> But sadly, during initialization of free nid list, we should do lookup
> combining with lots of different inner caches, including NAT page cache,
> nat entry cache, curseg journal cache and free nid bitmap, so flow became
> quite complicated.
>
> In this patch, we choose to obsolete old free nid management approach,
> instead, we use existing free nid bitmap which has the same functionality
> to manage free nid, in order to make free nid management codes more easy
> to maintain.
>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> v4: clean up codes.
> fs/f2fs/checkpoint.c | 1 -
> fs/f2fs/debug.c | 7 +-
> fs/f2fs/f2fs.h | 9 +-
> fs/f2fs/inode.c | 2 +
> fs/f2fs/node.c | 487 +++++++++++++++++----------------------------------
> fs/f2fs/node.h | 22 ---
> fs/f2fs/segment.c | 5 -
> fs/f2fs/shrinker.c | 14 --
> 8 files changed, 164 insertions(+), 383 deletions(-)
>
> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
> index d1f160ae4959..885525a0d981 100644
> --- a/fs/f2fs/checkpoint.c
> +++ b/fs/f2fs/checkpoint.c
> @@ -1024,7 +1024,6 @@ static void __prepare_cp_block(struct f2fs_sb_info *sbi)
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> nid_t last_nid = nm_i->next_scan_nid;
>
> - next_free_nid(sbi, &last_nid);
> ckpt->valid_block_count = cpu_to_le64(valid_user_blocks(sbi));
> ckpt->valid_node_count = cpu_to_le32(valid_node_count(sbi));
> ckpt->valid_inode_count = cpu_to_le32(valid_inode_count(sbi));
> diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> index a66107b5cfff..413e031b10c4 100644
> --- a/fs/f2fs/debug.c
> +++ b/fs/f2fs/debug.c
> @@ -100,9 +100,8 @@ static void update_general_status(struct f2fs_sb_info *sbi)
> si->dirty_nats = NM_I(sbi)->dirty_nat_cnt;
> si->sits = MAIN_SEGS(sbi);
> si->dirty_sits = SIT_I(sbi)->dirty_sentries;
> - si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
> + si->free_nids = NM_I(sbi)->available_free_nids;
> si->avail_nids = NM_I(sbi)->available_nids;
> - si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
> si->bg_gc = sbi->bg_gc;
> si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
> * 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
> @@ -233,10 +232,6 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
> atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
> }
>
> - /* free nids */
> - si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID] +
> - NM_I(sbi)->nid_cnt[PREALLOC_NID]) *
> - sizeof(struct free_nid);
> si->cache_mem += NM_I(sbi)->nat_cnt * sizeof(struct nat_entry);
> si->cache_mem += NM_I(sbi)->dirty_nat_cnt *
> sizeof(struct nat_entry_set);
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index d92eba66263c..f08e0feb38c1 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -723,14 +723,13 @@ struct f2fs_nm_info {
> unsigned int nat_blocks; /* # of nat blocks */
>
> /* free node ids management */
> - struct radix_tree_root free_nid_root;/* root of the free_nid cache */
> - struct list_head free_nid_list; /* list for free nids excluding preallocated nids */
> - unsigned int nid_cnt[MAX_NID_STATE]; /* the number of free node id */
> - spinlock_t nid_list_lock; /* protect nid lists ops */
> + spinlock_t free_nid_lock; /* protect nid lists ops */
> struct mutex build_lock; /* lock for build free nids */
> unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
> + unsigned char (*prealloc_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
> unsigned char *nat_block_bitmap;
> unsigned short *free_nid_count; /* free nid count of NAT block */
> + unsigned int available_free_nids; /* available free nid count in bitmaps */
>
> /* for checkpoint */
> char *nat_bitmap; /* NAT bitmap pointer */
> @@ -2622,11 +2621,9 @@ int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
> struct writeback_control *wbc, bool atomic);
> int sync_node_pages(struct f2fs_sb_info *sbi, struct writeback_control *wbc,
> bool do_balance, enum iostat_type io_type);
> -void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount);
> bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid);
> void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid);
> void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid);
> -int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink);
> void recover_inline_xattr(struct inode *inode, struct page *page);
> int recover_xattr_data(struct inode *inode, struct page *page);
> int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page);
> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> index 9684d53563f1..82f543e5c35b 100644
> --- a/fs/f2fs/inode.c
> +++ b/fs/f2fs/inode.c
> @@ -559,7 +559,9 @@ void f2fs_evict_inode(struct inode *inode)
> add_ino_entry(sbi, inode->i_ino, UPDATE_INO);
> }
> if (is_inode_flag_set(inode, FI_FREE_NID)) {
> + f2fs_lock_op(sbi);
> alloc_nid_failed(sbi, inode->i_ino);
> + f2fs_unlock_op(sbi);
> clear_inode_flag(inode, FI_FREE_NID);
> } else {
> f2fs_bug_on(sbi, err &&
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 80c37a094631..d2c9dcb0cbf8 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -23,10 +23,7 @@
> #include "trace.h"
> #include <trace/events/f2fs.h>
>
> -#define on_build_free_nids(nmi) mutex_is_locked(&(nm_i)->build_lock)
> -
> static struct kmem_cache *nat_entry_slab;
> -static struct kmem_cache *free_nid_slab;
> static struct kmem_cache *nat_entry_set_slab;
>
> bool available_free_memory(struct f2fs_sb_info *sbi, int type)
> @@ -43,13 +40,9 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
> avail_ram = val.totalram - val.totalhigh;
>
> /*
> - * give 25%, 25%, 50%, 50%, 50% memory for each components respectively
> + * give 25%, 50%, 50%, 50% memory for each components respectively
> */
> - if (type == FREE_NIDS) {
> - mem_size = (nm_i->nid_cnt[FREE_NID] *
> - sizeof(struct free_nid)) >> PAGE_SHIFT;
> - res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
> - } else if (type == NAT_ENTRIES) {
> + if (type == NAT_ENTRIES) {
> mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >>
> PAGE_SHIFT;
> res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
> @@ -1774,259 +1767,171 @@ const struct address_space_operations f2fs_node_aops = {
> #endif
> };
>
> -static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
> - nid_t n)
> -{
> - return radix_tree_lookup(&nm_i->free_nid_root, n);
> -}
> -
> -static int __insert_free_nid(struct f2fs_sb_info *sbi,
> - struct free_nid *i, enum nid_state state)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> -
> - int err = radix_tree_insert(&nm_i->free_nid_root, i->nid, i);
> - if (err)
> - return err;
> -
> - f2fs_bug_on(sbi, state != i->state);
> - nm_i->nid_cnt[state]++;
> - if (state == FREE_NID)
> - list_add_tail(&i->list, &nm_i->free_nid_list);
> - return 0;
> -}
> -
> -static void __remove_free_nid(struct f2fs_sb_info *sbi,
> - struct free_nid *i, enum nid_state state)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> -
> - f2fs_bug_on(sbi, state != i->state);
> - nm_i->nid_cnt[state]--;
> - if (state == FREE_NID)
> - list_del(&i->list);
> - radix_tree_delete(&nm_i->free_nid_root, i->nid);
> -}
> -
> -static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i,
> - enum nid_state org_state, enum nid_state dst_state)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> -
> - f2fs_bug_on(sbi, org_state != i->state);
> - i->state = dst_state;
> - nm_i->nid_cnt[org_state]--;
> - nm_i->nid_cnt[dst_state]++;
> -
> - switch (dst_state) {
> - case PREALLOC_NID:
> - list_del(&i->list);
> - break;
> - case FREE_NID:
> - list_add_tail(&i->list, &nm_i->free_nid_list);
> - break;
> - default:
> - BUG_ON(1);
> - }
> -}
> -
> -static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
> - bool set, bool build)
> +static bool update_free_nid_bitmap(struct f2fs_sb_info *sbi,
> + nid_t nid, bool set)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> unsigned int nid_ofs = nid - START_NID(nid);
>
> if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
> - return;
> + return false;
>
> if (set) {
> if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
> - return;
> + return false;
> __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> nm_i->free_nid_count[nat_ofs]++;
> + nm_i->available_free_nids++;
> } else {
> if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
> - return;
> + return false;
> __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> - if (!build)
> - nm_i->free_nid_count[nat_ofs]--;
> + nm_i->free_nid_count[nat_ofs]--;
> + nm_i->available_free_nids--;
> + }
> + return true;
> +}
> +
> +static void update_prealloc_nid_bitmap(struct f2fs_sb_info *sbi,
> + nid_t nid, bool set)
> +{
> + struct f2fs_nm_info *nm_i = NM_I(sbi);
> + unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> + unsigned int nid_ofs = nid - START_NID(nid);
> +
> + if (set) {
> + f2fs_bug_on(sbi, test_bit_le(nid_ofs,
> + nm_i->prealloc_nid_bitmap[nat_ofs]));
> + __set_bit_le(nid_ofs, nm_i->prealloc_nid_bitmap[nat_ofs]);
> + } else {
> + f2fs_bug_on(sbi, !test_bit_le(nid_ofs,
> + nm_i->prealloc_nid_bitmap[nat_ofs]));
> + __clear_bit_le(nid_ofs, nm_i->prealloc_nid_bitmap[nat_ofs]);
> }
> }
>
> /* return if the nid is recognized as free */
> -static bool add_free_nid(struct f2fs_sb_info *sbi,
> - nid_t nid, bool build, bool update)
> +static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i, *e;
> struct nat_entry *ne;
> - int err = -EINVAL;
> - bool ret = false;
> + unsigned int nat_ofs, nid_ofs;
>
> /* 0 nid should not be used */
> if (unlikely(nid == 0))
> return false;
>
> - i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
> - i->nid = nid;
> - i->state = FREE_NID;
> -
> - radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
> -
> - spin_lock(&nm_i->nid_list_lock);
> + ne = __lookup_nat_cache(nm_i, nid);
> + if (ne && (!get_nat_flag(ne, IS_CHECKPOINTED) ||
> + nat_get_blkaddr(ne) != NULL_ADDR))
> + return false;
>
> - if (build) {
> - /*
> - * Thread A Thread B
> - * - f2fs_create
> - * - f2fs_new_inode
> - * - alloc_nid
> - * - __insert_nid_to_list(PREALLOC_NID)
> - * - f2fs_balance_fs_bg
> - * - build_free_nids
> - * - __build_free_nids
> - * - scan_nat_page
> - * - add_free_nid
> - * - __lookup_nat_cache
> - * - f2fs_add_link
> - * - init_inode_metadata
> - * - new_inode_page
> - * - new_node_page
> - * - set_node_addr
> - * - alloc_nid_done
> - * - __remove_nid_from_list(PREALLOC_NID)
> - * - __insert_nid_to_list(FREE_NID)
> - */
> - ne = __lookup_nat_cache(nm_i, nid);
> - if (ne && (!get_nat_flag(ne, IS_CHECKPOINTED) ||
> - nat_get_blkaddr(ne) != NULL_ADDR))
> - goto err_out;
> -
> - e = __lookup_free_nid_list(nm_i, nid);
> - if (e) {
> - if (e->state == FREE_NID)
> - ret = true;
> - goto err_out;
> - }
> - }
> - ret = true;
> - err = __insert_free_nid(sbi, i, FREE_NID);
> -err_out:
> - if (update) {
> - update_free_nid_bitmap(sbi, nid, ret, build);
> - if (!build)
> - nm_i->available_nids++;
> - }
> - spin_unlock(&nm_i->nid_list_lock);
> - radix_tree_preload_end();
> + nat_ofs = NAT_BLOCK_OFFSET(nid);
> + nid_ofs = nid - START_NID(nid);
> + if (test_bit_le(nid_ofs, nm_i->prealloc_nid_bitmap[nat_ofs]))
> + return false;
>
> - if (err)
> - kmem_cache_free(free_nid_slab, i);
> - return ret;
> + update_free_nid_bitmap(sbi, nid, true);
> + return true;
> }
>
> -static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
> +static void scan_curseg_cache(struct f2fs_sb_info *sbi, nid_t start_nid,
> + nid_t end_nid)
> {
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i;
> - bool need_free = false;
> + struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
> + struct f2fs_journal *journal = curseg->journal;
> + int i;
>
> - spin_lock(&nm_i->nid_list_lock);
> - i = __lookup_free_nid_list(nm_i, nid);
> - if (i && i->state == FREE_NID) {
> - __remove_free_nid(sbi, i, FREE_NID);
> - need_free = true;
> - }
> - spin_unlock(&nm_i->nid_list_lock);
> + down_read(&curseg->journal_rwsem);
> + for (i = 0; i < nats_in_cursum(journal); i++) {
> + block_t addr;
> + nid_t nid = le32_to_cpu(nid_in_journal(journal, i));
> +
> + if (nid < start_nid || nid >= end_nid)
> + continue;
> +
> + addr = le32_to_cpu(nat_in_journal(journal, i).block_addr);
> +
> + f2fs_bug_on(sbi, addr == NEW_ADDR);
>
> - if (need_free)
> - kmem_cache_free(free_nid_slab, i);
> + spin_lock(&NM_I(sbi)->free_nid_lock);
> + if (addr == NULL_ADDR)
> + add_free_nid(sbi, nid);
> + else
> + update_free_nid_bitmap(sbi, nid, false);
> + spin_unlock(&NM_I(sbi)->free_nid_lock);
> + }
> + up_read(&curseg->journal_rwsem);
> }
>
> -static void scan_nat_page(struct f2fs_sb_info *sbi,
> - struct page *nat_page, nid_t start_nid)
> +static void scan_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct f2fs_nat_block *nat_blk = page_address(nat_page);
> + struct page *page;
> + struct f2fs_nat_block *nat_blk;
> block_t blk_addr;
> - unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
> + unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> + nid_t start_nid = nid;
> int i;
>
> + if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
> + return;
> +
> + page = get_current_nat_page(sbi, nid);
> + nat_blk = page_address(page);
> +
> __set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
>
> - i = start_nid % NAT_ENTRY_PER_BLOCK;
> + i = nid % NAT_ENTRY_PER_BLOCK;
>
> - for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
> - if (unlikely(start_nid >= nm_i->max_nid))
> + for (; i < NAT_ENTRY_PER_BLOCK; i++, nid++) {
> + if (unlikely(nid >= nm_i->max_nid))
> break;
>
> blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
> f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
> if (blk_addr == NULL_ADDR) {
> - add_free_nid(sbi, start_nid, true, true);
> - } else {
> - spin_lock(&NM_I(sbi)->nid_list_lock);
> - update_free_nid_bitmap(sbi, start_nid, false, true);
> - spin_unlock(&NM_I(sbi)->nid_list_lock);
> + spin_lock(&nm_i->free_nid_lock);
> + add_free_nid(sbi, nid);
> + spin_unlock(&nm_i->free_nid_lock);
> }
> }
> -}
> -
> -static void scan_curseg_cache(struct f2fs_sb_info *sbi)
> -{
> - struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
> - struct f2fs_journal *journal = curseg->journal;
> - int i;
>
> - down_read(&curseg->journal_rwsem);
> - for (i = 0; i < nats_in_cursum(journal); i++) {
> - block_t addr;
> - nid_t nid;
> + f2fs_put_page(page, 1);
>
> - addr = le32_to_cpu(nat_in_journal(journal, i).block_addr);
> - nid = le32_to_cpu(nid_in_journal(journal, i));
> - if (addr == NULL_ADDR)
> - add_free_nid(sbi, nid, true, false);
> - else
> - remove_free_nid(sbi, nid);
> - }
> - up_read(&curseg->journal_rwsem);
> + /* find free nids from current sum_pages */
> + scan_curseg_cache(sbi, start_nid, start_nid + NAT_ENTRY_PER_BLOCK);
> }
>
> -static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
> +static nid_t lookup_free_nid_bitmap(struct f2fs_sb_info *sbi)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - unsigned int i, idx;
> - nid_t nid;
> -
> - down_read(&nm_i->nat_tree_lock);
> + unsigned int i;
> + nid_t nid = 0;
>
> for (i = 0; i < nm_i->nat_blocks; i++) {
> + unsigned int idx = 0;
> +
> if (!test_bit_le(i, nm_i->nat_block_bitmap))
> continue;
> if (!nm_i->free_nid_count[i])
> continue;
> - for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) {
> - idx = find_next_bit_le(nm_i->free_nid_bitmap[i],
> - NAT_ENTRY_PER_BLOCK, idx);
> - if (idx >= NAT_ENTRY_PER_BLOCK)
> - break;
>
> - nid = i * NAT_ENTRY_PER_BLOCK + idx;
> - add_free_nid(sbi, nid, true, false);
> + idx = find_next_bit_le(nm_i->free_nid_bitmap[i],
> + NAT_ENTRY_PER_BLOCK, idx);
> + if (idx >= NAT_ENTRY_PER_BLOCK)
> + continue;
>
> - if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS)
> - goto out;
> - }
> + nid = i * NAT_ENTRY_PER_BLOCK + idx;
> + break;
> }
> -out:
> - scan_curseg_cache(sbi);
>
> - up_read(&nm_i->nat_tree_lock);
> + f2fs_bug_on(sbi, !nid);
> + return nid;
> }
>
> -static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
> +static void __build_free_nids(struct f2fs_sb_info *sbi, bool mount)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> int i = 0;
> @@ -2036,59 +1941,36 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
> nid = 0;
>
> /* Enough entries */
> - if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
> - return;
> -
> - if (!sync && !available_free_memory(sbi, FREE_NIDS))
> + if (!mount && nm_i->available_free_nids >= NAT_ENTRY_PER_BLOCK)
> return;
>
> - if (!mount) {
> - /* try to find free nids in free_nid_bitmap */
> - scan_free_nid_bits(sbi);
> -
> - if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
> - return;
> - }
> -
> /* readahead nat pages to be scanned */
> ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES,
> META_NAT, true);
>
> down_read(&nm_i->nat_tree_lock);
>
> - while (1) {
> - if (!test_bit_le(NAT_BLOCK_OFFSET(nid),
> - nm_i->nat_block_bitmap)) {
> - struct page *page = get_current_nat_page(sbi, nid);
> -
> - scan_nat_page(sbi, page, nid);
> - f2fs_put_page(page, 1);
> - }
> + do {
> + scan_nat_page(sbi, nid);
>
> nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
> if (unlikely(nid >= nm_i->max_nid))
> nid = 0;
> -
> - if (++i >= FREE_NID_PAGES)
> - break;
> - }
> + } while (++i < FREE_NID_PAGES);
>
> /* go to the next free nat pages to find free nids abundantly */
> nm_i->next_scan_nid = nid;
>
> - /* find free nids from current sum_pages */
> - scan_curseg_cache(sbi);
> -
> up_read(&nm_i->nat_tree_lock);
>
> ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nm_i->next_scan_nid),
> nm_i->ra_nid_pages, META_NAT, false);
> }
>
> -void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
> +void build_free_nids(struct f2fs_sb_info *sbi, bool mount)
> {
> mutex_lock(&NM_I(sbi)->build_lock);
> - __build_free_nids(sbi, sync, mount);
> + __build_free_nids(sbi, mount);
> mutex_unlock(&NM_I(sbi)->build_lock);
> }
>
> @@ -2100,7 +1982,6 @@ void build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
> bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i = NULL;
> retry:
> #ifdef CONFIG_F2FS_FAULT_INJECTION
> if (time_to_inject(sbi, FAULT_ALLOC_NID)) {
> @@ -2108,32 +1989,34 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
> return false;
> }
> #endif
> - spin_lock(&nm_i->nid_list_lock);
> +
> + spin_lock(&nm_i->free_nid_lock);
>
> if (unlikely(nm_i->available_nids == 0)) {
> - spin_unlock(&nm_i->nid_list_lock);
> + spin_unlock(&nm_i->free_nid_lock);
> return false;
> }
>
> /* We should not use stale free nids created by build_free_nids */
> - if (nm_i->nid_cnt[FREE_NID] && !on_build_free_nids(nm_i)) {
> - f2fs_bug_on(sbi, list_empty(&nm_i->free_nid_list));
> - i = list_first_entry(&nm_i->free_nid_list,
> - struct free_nid, list);
> - *nid = i->nid;
> + if (nm_i->available_free_nids && mutex_trylock(&nm_i->build_lock)) {
> + bool updated;
> +
> + *nid = lookup_free_nid_bitmap(sbi);
>
> - __move_free_nid(sbi, i, FREE_NID, PREALLOC_NID);
> + updated = update_free_nid_bitmap(sbi, *nid, false);
> + f2fs_bug_on(sbi, !updated);
> nm_i->available_nids--;
>
> - update_free_nid_bitmap(sbi, *nid, false, false);
> + update_prealloc_nid_bitmap(sbi, *nid, true);
>
> - spin_unlock(&nm_i->nid_list_lock);
> + spin_unlock(&nm_i->free_nid_lock);
> + mutex_unlock(&nm_i->build_lock);
> return true;
> }
> - spin_unlock(&nm_i->nid_list_lock);
> + spin_unlock(&nm_i->free_nid_lock);
>
> /* Let's scan nat pages and its caches to get free nids */
> - build_free_nids(sbi, true, false);
> + build_free_nids(sbi, false);
> goto retry;
> }
>
> @@ -2143,15 +2026,10 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
> void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i;
> -
> - spin_lock(&nm_i->nid_list_lock);
> - i = __lookup_free_nid_list(nm_i, nid);
> - f2fs_bug_on(sbi, !i);
> - __remove_free_nid(sbi, i, PREALLOC_NID);
> - spin_unlock(&nm_i->nid_list_lock);
>
> - kmem_cache_free(free_nid_slab, i);
> + spin_lock(&nm_i->free_nid_lock);
> + update_prealloc_nid_bitmap(sbi, nid, false);
> + spin_unlock(&nm_i->free_nid_lock);
> }
>
> /*
> @@ -2160,59 +2038,21 @@ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
> void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i;
> - bool need_free = false;
>
> if (!nid)
> return;
>
> - spin_lock(&nm_i->nid_list_lock);
> - i = __lookup_free_nid_list(nm_i, nid);
> - f2fs_bug_on(sbi, !i);
> -
> - if (!available_free_memory(sbi, FREE_NIDS)) {
> - __remove_free_nid(sbi, i, PREALLOC_NID);
> - need_free = true;
> - } else {
> - __move_free_nid(sbi, i, PREALLOC_NID, FREE_NID);
> - }
> -
> - nm_i->available_nids++;
> -
> - update_free_nid_bitmap(sbi, nid, true, false);
> -
> - spin_unlock(&nm_i->nid_list_lock);
> -
> - if (need_free)
> - kmem_cache_free(free_nid_slab, i);
> -}
> -
> -int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i, *next;
> - int nr = nr_shrink;
> -
> - if (nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
> - return 0;
> -
> - if (!mutex_trylock(&nm_i->build_lock))
> - return 0;
> + mutex_lock(&nm_i->build_lock);
> + down_read(&nm_i->nat_tree_lock);
> + spin_lock(&nm_i->free_nid_lock);
>
> - spin_lock(&nm_i->nid_list_lock);
> - list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
> - if (nr_shrink <= 0 ||
> - nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
> - break;
> + update_prealloc_nid_bitmap(sbi, nid, false);
>
> - __remove_free_nid(sbi, i, FREE_NID);
> - kmem_cache_free(free_nid_slab, i);
> - nr_shrink--;
> - }
> - spin_unlock(&nm_i->nid_list_lock);
> + if (add_free_nid(sbi, nid))
> + nm_i->available_nids++;
> + spin_unlock(&nm_i->free_nid_lock);
> + up_read(&nm_i->nat_tree_lock);
> mutex_unlock(&nm_i->build_lock);
> -
> - return nr - nr_shrink;
> }
>
> void recover_inline_xattr(struct inode *inode, struct page *page)
> @@ -2303,7 +2143,10 @@ int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
> }
>
> /* Should not use this inode from free nid list */
> - remove_free_nid(sbi, ino);
> + spin_lock(&NM_I(sbi)->free_nid_lock);
> + update_free_nid_bitmap(sbi, ino, false);
> + NM_I(sbi)->available_nids--;
> + spin_unlock(&NM_I(sbi)->free_nid_lock);
>
> if (!PageUptodate(ipage))
> SetPageUptodate(ipage);
> @@ -2408,9 +2251,9 @@ static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
> */
> if (!get_nat_flag(ne, IS_DIRTY) &&
> le32_to_cpu(raw_ne.block_addr) == NULL_ADDR) {
> - spin_lock(&nm_i->nid_list_lock);
> + spin_lock(&nm_i->free_nid_lock);
> nm_i->available_nids--;
> - spin_unlock(&nm_i->nid_list_lock);
> + spin_unlock(&nm_i->free_nid_lock);
> }
>
> __set_nat_cache_dirty(nm_i, ne);
> @@ -2519,11 +2362,14 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
> nat_reset_flag(ne);
> __clear_nat_cache_dirty(NM_I(sbi), set, ne);
> if (nat_get_blkaddr(ne) == NULL_ADDR) {
> - add_free_nid(sbi, nid, false, true);
> + spin_lock(&NM_I(sbi)->free_nid_lock);
> + add_free_nid(sbi, nid);
> + NM_I(sbi)->available_nids++;
> + spin_unlock(&NM_I(sbi)->free_nid_lock);
> } else {
> - spin_lock(&NM_I(sbi)->nid_list_lock);
> - update_free_nid_bitmap(sbi, nid, false, false);
> - spin_unlock(&NM_I(sbi)->nid_list_lock);
> + spin_lock(&NM_I(sbi)->free_nid_lock);
> + update_free_nid_bitmap(sbi, nid, false);
> + spin_unlock(&NM_I(sbi)->free_nid_lock);
> }
> }
>
> @@ -2647,10 +2493,10 @@ static inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
> nid = i * NAT_ENTRY_PER_BLOCK;
> last_nid = nid + NAT_ENTRY_PER_BLOCK;
>
> - spin_lock(&NM_I(sbi)->nid_list_lock);
> + spin_lock(&NM_I(sbi)->free_nid_lock);
> for (; nid < last_nid; nid++)
> - update_free_nid_bitmap(sbi, nid, true, true);
> - spin_unlock(&NM_I(sbi)->nid_list_lock);
> + update_free_nid_bitmap(sbi, nid, true);
> + spin_unlock(&NM_I(sbi)->free_nid_lock);
> }
>
> for (i = 0; i < nm_i->nat_blocks; i++) {
> @@ -2660,6 +2506,8 @@ static inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
>
> __set_bit_le(i, nm_i->nat_block_bitmap);
> }
> +
> + scan_curseg_cache(sbi, 0, nm_i->max_nid);
> }
>
> static int init_node_manager(struct f2fs_sb_info *sbi)
> @@ -2680,21 +2528,18 @@ static int init_node_manager(struct f2fs_sb_info *sbi)
> /* not used nids: 0, node, meta, (and root counted as valid node) */
> nm_i->available_nids = nm_i->max_nid - sbi->total_valid_node_count -
> sbi->nquota_files - F2FS_RESERVED_NODE_NUM;
> - nm_i->nid_cnt[FREE_NID] = 0;
> - nm_i->nid_cnt[PREALLOC_NID] = 0;
> + nm_i->available_free_nids = 0;
> nm_i->nat_cnt = 0;
> nm_i->ram_thresh = DEF_RAM_THRESHOLD;
> nm_i->ra_nid_pages = DEF_RA_NID_PAGES;
> nm_i->dirty_nats_ratio = DEF_DIRTY_NAT_RATIO_THRESHOLD;
>
> - 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_NOIO);
> INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);
> INIT_LIST_HEAD(&nm_i->nat_entries);
>
> mutex_init(&nm_i->build_lock);
> - spin_lock_init(&nm_i->nid_list_lock);
> + spin_lock_init(&nm_i->free_nid_lock);
> init_rwsem(&nm_i->nat_tree_lock);
>
> nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
> @@ -2731,6 +2576,11 @@ static int init_free_nid_cache(struct f2fs_sb_info *sbi)
> if (!nm_i->free_nid_bitmap)
> return -ENOMEM;
>
> + nm_i->prealloc_nid_bitmap = f2fs_kvzalloc(sbi, nm_i->nat_blocks *
> + NAT_ENTRY_BITMAP_SIZE, GFP_KERNEL);
> + if (!nm_i->prealloc_nid_bitmap)
> + return -ENOMEM;
> +
> nm_i->nat_block_bitmap = f2fs_kvzalloc(sbi, nm_i->nat_blocks / 8,
> GFP_KERNEL);
> if (!nm_i->nat_block_bitmap)
> @@ -2763,14 +2613,13 @@ int build_node_manager(struct f2fs_sb_info *sbi)
> /* load free nid status from nat_bits table */
> load_free_nid_bitmap(sbi);
>
> - build_free_nids(sbi, true, true);
> + build_free_nids(sbi, true);
> return 0;
> }
>
> void destroy_node_manager(struct f2fs_sb_info *sbi)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *i, *next_i;
> struct nat_entry *natvec[NATVEC_SIZE];
> struct nat_entry_set *setvec[SETVEC_SIZE];
> nid_t nid = 0;
> @@ -2779,19 +2628,6 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
> if (!nm_i)
> return;
>
> - /* destroy free nid list */
> - spin_lock(&nm_i->nid_list_lock);
> - list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
> - __remove_free_nid(sbi, i, FREE_NID);
> - spin_unlock(&nm_i->nid_list_lock);
> - kmem_cache_free(free_nid_slab, i);
> - spin_lock(&nm_i->nid_list_lock);
> - }
> - f2fs_bug_on(sbi, nm_i->nid_cnt[FREE_NID]);
> - f2fs_bug_on(sbi, nm_i->nid_cnt[PREALLOC_NID]);
> - f2fs_bug_on(sbi, !list_empty(&nm_i->free_nid_list));
> - spin_unlock(&nm_i->nid_list_lock);
> -
> /* destroy nat cache */
> down_write(&nm_i->nat_tree_lock);
> while ((found = __gang_lookup_nat_cache(nm_i,
> @@ -2822,6 +2658,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
>
> kvfree(nm_i->nat_block_bitmap);
> kvfree(nm_i->free_nid_bitmap);
> + kvfree(nm_i->prealloc_nid_bitmap);
> kvfree(nm_i->free_nid_count);
>
> kfree(nm_i->nat_bitmap);
> @@ -2840,19 +2677,12 @@ int __init create_node_manager_caches(void)
> if (!nat_entry_slab)
> goto fail;
>
> - free_nid_slab = f2fs_kmem_cache_create("free_nid",
> - sizeof(struct free_nid));
> - if (!free_nid_slab)
> - goto destroy_nat_entry;
> -
> nat_entry_set_slab = f2fs_kmem_cache_create("nat_entry_set",
> sizeof(struct nat_entry_set));
> if (!nat_entry_set_slab)
> - goto destroy_free_nid;
> + goto destroy_nat_entry;
> return 0;
>
> -destroy_free_nid:
> - kmem_cache_destroy(free_nid_slab);
> destroy_nat_entry:
> kmem_cache_destroy(nat_entry_slab);
> fail:
> @@ -2862,6 +2692,5 @@ int __init create_node_manager_caches(void)
> void destroy_node_manager_caches(void)
> {
> kmem_cache_destroy(nat_entry_set_slab);
> - kmem_cache_destroy(free_nid_slab);
> kmem_cache_destroy(nat_entry_slab);
> }
> diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
> index 0ee3e5ff49a3..d5cf8af70c90 100644
> --- a/fs/f2fs/node.h
> +++ b/fs/f2fs/node.h
> @@ -135,7 +135,6 @@ static inline bool excess_cached_nats(struct f2fs_sb_info *sbi)
> }
>
> enum mem_type {
> - FREE_NIDS, /* indicates the free nid list */
> NAT_ENTRIES, /* indicates the cached nat entry */
> DIRTY_DENTS, /* indicates dirty dentry pages */
> INO_ENTRIES, /* indicates inode entries */
> @@ -151,27 +150,6 @@ struct nat_entry_set {
> unsigned int entry_cnt; /* the # of nat entries in set */
> };
>
> -struct free_nid {
> - struct list_head list; /* for free node id list */
> - nid_t nid; /* node id */
> - int state; /* in use or not: FREE_NID or PREALLOC_NID */
> -};
> -
> -static inline void next_free_nid(struct f2fs_sb_info *sbi, nid_t *nid)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct free_nid *fnid;
> -
> - spin_lock(&nm_i->nid_list_lock);
> - if (nm_i->nid_cnt[FREE_NID] <= 0) {
> - spin_unlock(&nm_i->nid_list_lock);
> - return;
> - }
> - fnid = list_first_entry(&nm_i->free_nid_list, struct free_nid, list);
> - *nid = fnid->nid;
> - spin_unlock(&nm_i->nid_list_lock);
> -}
> -
> /*
> * inline functions
> */
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 176a2b97e6d3..c9a0563907aa 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -482,11 +482,6 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
> if (!available_free_memory(sbi, NAT_ENTRIES))
> try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
>
> - if (!available_free_memory(sbi, FREE_NIDS))
> - try_to_free_nids(sbi, MAX_FREE_NIDS);
> - else
> - build_free_nids(sbi, false, false);
> -
> if (!is_idle(sbi) && !excess_dirty_nats(sbi))
> return;
>
> diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
> index 0b5664a1a6cc..7123bcb3cb62 100644
> --- a/fs/f2fs/shrinker.c
> +++ b/fs/f2fs/shrinker.c
> @@ -26,13 +26,6 @@ static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
> return count > 0 ? count : 0;
> }
>
> -static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
> -{
> - long count = NM_I(sbi)->nid_cnt[FREE_NID] - MAX_FREE_NIDS;
> -
> - return count > 0 ? count : 0;
> -}
> -
> static unsigned long __count_extent_cache(struct f2fs_sb_info *sbi)
> {
> return atomic_read(&sbi->total_zombie_tree) +
> @@ -64,9 +57,6 @@ unsigned long f2fs_shrink_count(struct shrinker *shrink,
> /* shrink clean nat cache entries */
> count += __count_nat_entries(sbi);
>
> - /* count free nids cache entries */
> - count += __count_free_nids(sbi);
> -
> spin_lock(&f2fs_list_lock);
> p = p->next;
> mutex_unlock(&sbi->umount_mutex);
> @@ -111,10 +101,6 @@ unsigned long f2fs_shrink_scan(struct shrinker *shrink,
> if (freed < nr)
> freed += try_to_free_nats(sbi, nr - freed);
>
> - /* shrink free nids cache entries */
> - if (freed < nr)
> - freed += try_to_free_nids(sbi, nr - freed);
> -
> spin_lock(&f2fs_list_lock);
> p = p->next;
> list_move_tail(&sbi->s_list, &f2fs_list);
> --
> 2.15.0.55.gc2ece9dc4de6