f2fs: obsolete ALLOC_NID_LIST list

As Fan Li reported, there is no user traversing nid_list[ALLOC_NID_LIST]
which is used for tracking preallocated nids. Let's drop it, and only
track preallocated nids in free_nid_root radix-tree.

Reported-by: Fan Li <fanofcode.li@samsung.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 00c1d4a..14095fb 100644 (file)
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -98,9 +98,9 @@ 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_LIST];
+       si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
        si->avail_nids = NM_I(sbi)->available_nids;
-       si->alloc_nids = NM_I(sbi)->nid_cnt[ALLOC_NID_LIST];
+       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)
@@ -233,8 +233,8 @@ get_cache:
        }
 
        /* free nids */
-       si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID_LIST] +
-                               NM_I(sbi)->nid_cnt[ALLOC_NID_LIST]) *
+       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 *

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 91edbf9..67944f2 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -666,10 +666,13 @@ static inline void __try_update_largest_extent(struct inode *inode,
        }
 }
 
-enum nid_list {
-       FREE_NID_LIST,
-       ALLOC_NID_LIST,
-       MAX_NID_LIST,
+/*
+ * For free nid management
+ */
+enum nid_state {
+       FREE_NID,               /* newly added to free nid list */
+       PREALLOC_NID,           /* it is preallocated */
+       MAX_NID_STATE,
 };
 
 struct f2fs_nm_info {
@@ -692,8 +695,8 @@ struct f2fs_nm_info {
 
        /* free node ids management */
        struct radix_tree_root free_nid_root;/* root of the free_nid cache */
-       struct list_head nid_list[MAX_NID_LIST];/* lists for free nids */
-       unsigned int nid_cnt[MAX_NID_LIST];     /* the number of free node id */
+       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 */
        struct mutex build_lock;        /* lock for build free nids */
        unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 33dd47f..d187aa4 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -46,7 +46,7 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
         * give 25%, 25%, 50%, 50%, 50% memory for each components respectively
         */
        if (type == FREE_NIDS) {
-               mem_size = (nm_i->nid_cnt[FREE_NID_LIST] *
+               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) {
@@ -1757,8 +1757,8 @@ static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
        return radix_tree_lookup(&nm_i->free_nid_root, n);
 }
 
-static int __insert_nid_to_list(struct f2fs_sb_info *sbi,
-                       struct free_nid *i, enum nid_list list, bool new)
+static int __insert_free_nid(struct f2fs_sb_info *sbi,
+                       struct free_nid *i, enum nid_state state, bool new)
 {
        struct f2fs_nm_info *nm_i = NM_I(sbi);
 
@@ -1768,22 +1768,22 @@ static int __insert_nid_to_list(struct f2fs_sb_info *sbi,
                        return err;
        }
 
-       f2fs_bug_on(sbi, list == FREE_NID_LIST ? i->state != NID_NEW :
-                                               i->state != NID_ALLOC);
-       nm_i->nid_cnt[list]++;
-       list_add_tail(&i->list, &nm_i->nid_list[list]);
+       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_nid_from_list(struct f2fs_sb_info *sbi,
-                       struct free_nid *i, enum nid_list list, bool reuse)
+static void __remove_free_nid(struct f2fs_sb_info *sbi,
+                       struct free_nid *i, enum nid_state state, bool reuse)
 {
        struct f2fs_nm_info *nm_i = NM_I(sbi);
 
-       f2fs_bug_on(sbi, list == FREE_NID_LIST ? i->state != NID_NEW :
-                                               i->state != NID_ALLOC);
-       nm_i->nid_cnt[list]--;
-       list_del(&i->list);
+       f2fs_bug_on(sbi, state != i->state);
+       nm_i->nid_cnt[state]--;
+       if (state == FREE_NID)
+               list_del(&i->list);
        if (!reuse)
                radix_tree_delete(&nm_i->free_nid_root, i->nid);
 }
@@ -1803,7 +1803,7 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
 
        i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
        i->nid = nid;
-       i->state = NID_NEW;
+       i->state = FREE_NID;
 
        if (radix_tree_preload(GFP_NOFS))
                goto err;
@@ -1816,7 +1816,7 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
                 *  - f2fs_create
                 *   - f2fs_new_inode
                 *    - alloc_nid
-                *     - __insert_nid_to_list(ALLOC_NID_LIST)
+                *     - __insert_nid_to_list(PREALLOC_NID)
                 *                     - f2fs_balance_fs_bg
                 *                      - build_free_nids
                 *                       - __build_free_nids
@@ -1829,8 +1829,8 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
                 *     - new_node_page
                 *      - set_node_addr
                 *  - alloc_nid_done
-                *   - __remove_nid_from_list(ALLOC_NID_LIST)
-                *                         - __insert_nid_to_list(FREE_NID_LIST)
+                *   - __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) ||
@@ -1839,13 +1839,13 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
 
                e = __lookup_free_nid_list(nm_i, nid);
                if (e) {
-                       if (e->state == NID_NEW)
+                       if (e->state == FREE_NID)
                                ret = true;
                        goto err_out;
                }
        }
        ret = true;
-       err = __insert_nid_to_list(sbi, i, FREE_NID_LIST, true);
+       err = __insert_free_nid(sbi, i, FREE_NID, true);
 err_out:
        spin_unlock(&nm_i->nid_list_lock);
        radix_tree_preload_end();
@@ -1863,8 +1863,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
 
        spin_lock(&nm_i->nid_list_lock);
        i = __lookup_free_nid_list(nm_i, nid);
-       if (i && i->state == NID_NEW) {
-               __remove_nid_from_list(sbi, i, FREE_NID_LIST, false);
+       if (i && i->state == FREE_NID) {
+               __remove_free_nid(sbi, i, FREE_NID, false);
                need_free = true;
        }
        spin_unlock(&nm_i->nid_list_lock);
@@ -1949,7 +1949,7 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
                        nid = i * NAT_ENTRY_PER_BLOCK + idx;
                        add_free_nid(sbi, nid, true);
 
-                       if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
+                       if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS)
                                goto out;
                }
        }
@@ -1982,7 +1982,7 @@ 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_LIST] >= NAT_ENTRY_PER_BLOCK)
+       if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
                return;
 
        if (!sync && !available_free_memory(sbi, FREE_NIDS))
@@ -1992,7 +1992,7 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
                /* try to find free nids in free_nid_bitmap */
                scan_free_nid_bits(sbi);
 
-               if (nm_i->nid_cnt[FREE_NID_LIST])
+               if (nm_i->nid_cnt[FREE_NID])
                        return;
        }
 
@@ -2069,15 +2069,15 @@ retry:
        }
 
        /* We should not use stale free nids created by build_free_nids */
-       if (nm_i->nid_cnt[FREE_NID_LIST] && !on_build_free_nids(nm_i)) {
-               f2fs_bug_on(sbi, list_empty(&nm_i->nid_list[FREE_NID_LIST]));
-               i = list_first_entry(&nm_i->nid_list[FREE_NID_LIST],
+       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;
 
-               __remove_nid_from_list(sbi, i, FREE_NID_LIST, true);
-               i->state = NID_ALLOC;
-               __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
+               __remove_free_nid(sbi, i, FREE_NID, true);
+               i->state = PREALLOC_NID;
+               __insert_free_nid(sbi, i, PREALLOC_NID, false);
                nm_i->available_nids--;
 
                update_free_nid_bitmap(sbi, *nid, false, false);
@@ -2103,7 +2103,7 @@ void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
        spin_lock(&nm_i->nid_list_lock);
        i = __lookup_free_nid_list(nm_i, nid);
        f2fs_bug_on(sbi, !i);
-       __remove_nid_from_list(sbi, i, ALLOC_NID_LIST, false);
+       __remove_free_nid(sbi, i, PREALLOC_NID, false);
        spin_unlock(&nm_i->nid_list_lock);
 
        kmem_cache_free(free_nid_slab, i);
@@ -2126,12 +2126,12 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
        f2fs_bug_on(sbi, !i);
 
        if (!available_free_memory(sbi, FREE_NIDS)) {
-               __remove_nid_from_list(sbi, i, ALLOC_NID_LIST, false);
+               __remove_free_nid(sbi, i, PREALLOC_NID, false);
                need_free = true;
        } else {
-               __remove_nid_from_list(sbi, i, ALLOC_NID_LIST, true);
-               i->state = NID_NEW;
-               __insert_nid_to_list(sbi, i, FREE_NID_LIST, false);
+               __remove_free_nid(sbi, i, PREALLOC_NID, true);
+               i->state = FREE_NID;
+               __insert_free_nid(sbi, i, FREE_NID, false);
        }
 
        nm_i->available_nids++;
@@ -2150,20 +2150,19 @@ int try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
        struct free_nid *i, *next;
        int nr = nr_shrink;
 
-       if (nm_i->nid_cnt[FREE_NID_LIST] <= MAX_FREE_NIDS)
+       if (nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
                return 0;
 
        if (!mutex_trylock(&nm_i->build_lock))
                return 0;
 
        spin_lock(&nm_i->nid_list_lock);
-       list_for_each_entry_safe(i, next, &nm_i->nid_list[FREE_NID_LIST],
-                                                                       list) {
+       list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
                if (nr_shrink <= 0 ||
-                               nm_i->nid_cnt[FREE_NID_LIST] <= MAX_FREE_NIDS)
+                               nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
                        break;
 
-               __remove_nid_from_list(sbi, i, FREE_NID_LIST, false);
+               __remove_free_nid(sbi, i, FREE_NID, false);
                kmem_cache_free(free_nid_slab, i);
                nr_shrink--;
        }
@@ -2635,16 +2634,15 @@ 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 -
                                                        F2FS_RESERVED_NODE_NUM;
-       nm_i->nid_cnt[FREE_NID_LIST] = 0;
-       nm_i->nid_cnt[ALLOC_NID_LIST] = 0;
+       nm_i->nid_cnt[FREE_NID] = 0;
+       nm_i->nid_cnt[PREALLOC_NID] = 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->nid_list[FREE_NID_LIST]);
-       INIT_LIST_HEAD(&nm_i->nid_list[ALLOC_NID_LIST]);
+       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);
@@ -2736,16 +2734,15 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
 
        /* destroy free nid list */
        spin_lock(&nm_i->nid_list_lock);
-       list_for_each_entry_safe(i, next_i, &nm_i->nid_list[FREE_NID_LIST],
-                                                                       list) {
-               __remove_nid_from_list(sbi, i, FREE_NID_LIST, false);
+       list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
+               __remove_free_nid(sbi, i, FREE_NID, false);
                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_LIST]);
-       f2fs_bug_on(sbi, nm_i->nid_cnt[ALLOC_NID_LIST]);
-       f2fs_bug_on(sbi, !list_empty(&nm_i->nid_list[ALLOC_NID_LIST]));
+       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 */

diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index bb53e99..e91b08b 100644 (file)
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -150,18 +150,10 @@ struct nat_entry_set {
        unsigned int entry_cnt;         /* the # of nat entries in set */
 };
 
-/*
- * For free nid mangement
- */
-enum nid_state {
-       NID_NEW,        /* newly added to free nid list */
-       NID_ALLOC       /* it is allocated */
-};
-
 struct free_nid {
        struct list_head list;  /* for free node id list */
        nid_t nid;              /* node id */
-       int state;              /* in use or not: NID_NEW or NID_ALLOC */
+       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)
@@ -170,12 +162,11 @@ static inline void next_free_nid(struct f2fs_sb_info *sbi, nid_t *nid)
        struct free_nid *fnid;
 
        spin_lock(&nm_i->nid_list_lock);
-       if (nm_i->nid_cnt[FREE_NID_LIST] <= 0) {
+       if (nm_i->nid_cnt[FREE_NID] <= 0) {
                spin_unlock(&nm_i->nid_list_lock);
                return;
        }
-       fnid = list_first_entry(&nm_i->nid_list[FREE_NID_LIST],
-                                               struct free_nid, list);
+       fnid = list_first_entry(&nm_i->free_nid_list, struct free_nid, list);
        *nid = fnid->nid;
        spin_unlock(&nm_i->nid_list_lock);
 }

diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index 5c60fc2..0b5664a 100644 (file)
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -28,7 +28,7 @@ static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
 
 static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
 {
-       long count = NM_I(sbi)->nid_cnt[FREE_NID_LIST] - MAX_FREE_NIDS;
+       long count = NM_I(sbi)->nid_cnt[FREE_NID] - MAX_FREE_NIDS;
 
        return count > 0 ? count : 0;
 }