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Subject[PATCH 1/5] f2fs: obsolete ALLOC_NID_LIST list
Date
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>
---
fs/f2fs/debug.c | 8 ++---
fs/f2fs/f2fs.h | 15 +++++----
fs/f2fs/node.c | 97 ++++++++++++++++++++++++++----------------------------
fs/f2fs/node.h | 15 ++-------
fs/f2fs/shrinker.c | 2 +-
5 files changed, 64 insertions(+), 73 deletions(-)

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 00c1d4a9f356..14095fbb4039 100644
--- 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 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
}

/* 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 c95069435b47..3440551289d2 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -688,10 +688,13 @@ 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 {
@@ -714,8 +717,8 @@ 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 275ad3f35579..d087b45b3f72 100644
--- 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 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
}

/* 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--;
}
@@ -2641,16 +2640,15 @@ 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);
@@ -2742,16 +2740,15 @@ 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 bb53e9955ff2..e91b08b4a51a 100644
--- 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 5c60fc28ec75..0b5664a1a6cc 100644
--- 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;
}
--
2.13.1.388.g69e6b9b4f4a9
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