Both nat_bits cache and free_nid_bitmap cache provide same functionality
as a intermediate cache between free nid cache and disk, but with
different granularity of indicating free nid range, and different
persistence policy. nat_bits cache provides better persistence ability,
and free_nid_bitmap provides better granularity.
In this patch we combine advantage of both caches, so finally policy of
the intermediate cache would be:
- init: load free nid status from nat_bits into free_nid_bitmap
- lookup: scan free_nid_bitmap before load NAT blocks
- update: update free_nid_bitmap in real-time
- persistence: udpate and persist nat_bits in checkpoint
Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/node.c | 109 +++++++++++++++++++++------------------------------------
1 file changed, 39 insertions(+), 70 deletions(-)
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 1a759d45b7e4..6c027b6833f4 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -338,9 +338,6 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
set_nat_flag(e, IS_CHECKPOINTED, false);
__set_nat_cache_dirty(nm_i, e);
- if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
- clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
-
/* update fsync_mark if its inode nat entry is still alive */
if (ni->nid != ni->ino)
e = __lookup_nat_cache(nm_i, ni->ino);
@@ -1920,58 +1917,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
up_read(&nm_i->nat_tree_lock);
}
-static int scan_nat_bits(struct f2fs_sb_info *sbi)
-{
- struct f2fs_nm_info *nm_i = NM_I(sbi);
- struct page *page;
- unsigned int i = 0;
- nid_t nid;
-
- if (!enabled_nat_bits(sbi, NULL))
- return -EAGAIN;
-
- down_read(&nm_i->nat_tree_lock);
-check_empty:
- i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
- if (i >= nm_i->nat_blocks) {
- i = 0;
- goto check_partial;
- }
-
- for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
- nid++) {
- if (unlikely(nid >= nm_i->max_nid))
- break;
- add_free_nid(sbi, nid, true);
- }
-
- if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
- goto out;
- i++;
- goto check_empty;
-
-check_partial:
- i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
- if (i >= nm_i->nat_blocks) {
- disable_nat_bits(sbi, true);
- up_read(&nm_i->nat_tree_lock);
- return -EINVAL;
- }
-
- nid = i * NAT_ENTRY_PER_BLOCK;
- page = get_current_nat_page(sbi, nid);
- scan_nat_page(sbi, page, nid);
- f2fs_put_page(page, 1);
-
- if (nm_i->nid_cnt[FREE_NID_LIST] < MAX_FREE_NIDS) {
- i++;
- goto check_partial;
- }
-out:
- up_read(&nm_i->nat_tree_lock);
- return 0;
-}
-
static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
@@ -1993,21 +1938,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
if (nm_i->nid_cnt[FREE_NID_LIST])
return;
-
- /* try to find free nids with nat_bits */
- if (!scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
- return;
- }
-
- /* find next valid candidate */
- if (enabled_nat_bits(sbi, NULL)) {
- int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
- nm_i->nat_blocks, 0);
-
- if (idx >= nm_i->nat_blocks)
- set_sbi_flag(sbi, SBI_NEED_FSCK);
- else
- nid = idx * NAT_ENTRY_PER_BLOCK;
}
/* readahead nat pages to be scanned */
@@ -2590,6 +2520,41 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
return 0;
}
+inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
+{
+ struct f2fs_nm_info *nm_i = NM_I(sbi);
+ unsigned int i = 0;
+ nid_t nid, last_nid;
+
+ for (i = 0; i < nm_i->nat_blocks; i++) {
+ i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
+ if (i >= nm_i->nat_blocks)
+ break;
+
+ set_bit_le(i, nm_i->nat_block_bitmap);
+
+ nid = i * NAT_ENTRY_PER_BLOCK;
+ last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
+
+ for (; nid < last_nid; nid++)
+ update_free_nid_bitmap(sbi, nid, true, true);
+ }
+
+ for (i = 0; i < nm_i->nat_blocks; i++) {
+ i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
+ if (i >= nm_i->nat_blocks)
+ break;
+
+ set_bit_le(i, nm_i->nat_block_bitmap);
+
+ nid = i * NAT_ENTRY_PER_BLOCK;
+ last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
+
+ for (; nid < last_nid; nid++)
+ update_free_nid_bitmap(sbi, nid, false, true);
+ }
+}
+
static int init_node_manager(struct f2fs_sb_info *sbi)
{
struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
@@ -2672,6 +2637,10 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
spin_lock_init(&nm_i->free_nid_lock);
+ /* load free nid status from nat_bits table */
+ if (enabled_nat_bits(sbi, NULL))
+ load_free_nid_bitmap(sbi);
+
return 0;
}
--
2.8.2.295.g3f1c1d0
On 3/1/2017 17:10, Chao Yu wrote:
> Both nat_bits cache and free_nid_bitmap cache provide same functionality
> as a intermediate cache between free nid cache and disk, but with
> different granularity of indicating free nid range, and different
> persistence policy. nat_bits cache provides better persistence ability,
> and free_nid_bitmap provides better granularity.
>
> In this patch we combine advantage of both caches, so finally policy of
> the intermediate cache would be:
> - init: load free nid status from nat_bits into free_nid_bitmap
> - lookup: scan free_nid_bitmap before load NAT blocks
Why not scan the full_nat_bits/empty_nat_bits before load NAT blocks here?
If after an objects shrinker, the cached free nid will be empty quickly.
thanks,
Kinglong Mee
> - update: update free_nid_bitmap in real-time
> - persistence: udpate and persist nat_bits in checkpoint
>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> fs/f2fs/node.c | 109 +++++++++++++++++++++------------------------------------
> 1 file changed, 39 insertions(+), 70 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 1a759d45b7e4..6c027b6833f4 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -338,9 +338,6 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
> set_nat_flag(e, IS_CHECKPOINTED, false);
> __set_nat_cache_dirty(nm_i, e);
>
> - if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
> - clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
> -
> /* update fsync_mark if its inode nat entry is still alive */
> if (ni->nid != ni->ino)
> e = __lookup_nat_cache(nm_i, ni->ino);
> @@ -1920,58 +1917,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
> up_read(&nm_i->nat_tree_lock);
> }
>
> -static int scan_nat_bits(struct f2fs_sb_info *sbi)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct page *page;
> - unsigned int i = 0;
> - nid_t nid;
> -
> - if (!enabled_nat_bits(sbi, NULL))
> - return -EAGAIN;
> -
> - down_read(&nm_i->nat_tree_lock);
> -check_empty:
> - i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
> - if (i >= nm_i->nat_blocks) {
> - i = 0;
> - goto check_partial;
> - }
> -
> - for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
> - nid++) {
> - if (unlikely(nid >= nm_i->max_nid))
> - break;
> - add_free_nid(sbi, nid, true);
> - }
> -
> - if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
> - goto out;
> - i++;
> - goto check_empty;
> -
> -check_partial:
> - i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
> - if (i >= nm_i->nat_blocks) {
> - disable_nat_bits(sbi, true);
> - up_read(&nm_i->nat_tree_lock);
> - return -EINVAL;
> - }
> -
> - nid = i * NAT_ENTRY_PER_BLOCK;
> - page = get_current_nat_page(sbi, nid);
> - scan_nat_page(sbi, page, nid);
> - f2fs_put_page(page, 1);
> -
> - if (nm_i->nid_cnt[FREE_NID_LIST] < MAX_FREE_NIDS) {
> - i++;
> - goto check_partial;
> - }
> -out:
> - up_read(&nm_i->nat_tree_lock);
> - return 0;
> -}
> -
> static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> @@ -1993,21 +1938,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>
> if (nm_i->nid_cnt[FREE_NID_LIST])
> return;
> -
> - /* try to find free nids with nat_bits */
> - if (!scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
> - return;
> - }
> -
> - /* find next valid candidate */
> - if (enabled_nat_bits(sbi, NULL)) {
> - int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
> - nm_i->nat_blocks, 0);
> -
> - if (idx >= nm_i->nat_blocks)
> - set_sbi_flag(sbi, SBI_NEED_FSCK);
> - else
> - nid = idx * NAT_ENTRY_PER_BLOCK;
> }
>
> /* readahead nat pages to be scanned */
> @@ -2590,6 +2520,41 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
> return 0;
> }
>
> +inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
> +{
> + struct f2fs_nm_info *nm_i = NM_I(sbi);
> + unsigned int i = 0;
> + nid_t nid, last_nid;
> +
> + for (i = 0; i < nm_i->nat_blocks; i++) {
> + i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
> + if (i >= nm_i->nat_blocks)
> + break;
> +
> + set_bit_le(i, nm_i->nat_block_bitmap);
> +
> + nid = i * NAT_ENTRY_PER_BLOCK;
> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
> +
> + for (; nid < last_nid; nid++)
> + update_free_nid_bitmap(sbi, nid, true, true);
> + }
> +
> + for (i = 0; i < nm_i->nat_blocks; i++) {
> + i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
> + if (i >= nm_i->nat_blocks)
> + break;
> +
> + set_bit_le(i, nm_i->nat_block_bitmap);
> +
> + nid = i * NAT_ENTRY_PER_BLOCK;
> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
> +
> + for (; nid < last_nid; nid++)
> + update_free_nid_bitmap(sbi, nid, false, true);
> + }
> +}
> +
> static int init_node_manager(struct f2fs_sb_info *sbi)
> {
> struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
> @@ -2672,6 +2637,10 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
>
> spin_lock_init(&nm_i->free_nid_lock);
>
> + /* load free nid status from nat_bits table */
> + if (enabled_nat_bits(sbi, NULL))
> + load_free_nid_bitmap(sbi);
> +
> return 0;
> }
>
>
On 2017/3/1 21:09, Kinglong Mee wrote:
> On 3/1/2017 17:10, Chao Yu wrote:
>> Both nat_bits cache and free_nid_bitmap cache provide same functionality
>> as a intermediate cache between free nid cache and disk, but with
>> different granularity of indicating free nid range, and different
>> persistence policy. nat_bits cache provides better persistence ability,
>> and free_nid_bitmap provides better granularity.
>>
>> In this patch we combine advantage of both caches, so finally policy of
>> the intermediate cache would be:
>> - init: load free nid status from nat_bits into free_nid_bitmap
>> - lookup: scan free_nid_bitmap before load NAT blocks
>
> Why not scan the full_nat_bits/empty_nat_bits before load NAT blocks here?
> If after an objects shrinker, the cached free nid will be empty quickly.
Since after this patch, all nids status (free or used) of
full_nat_bits/empty_nat_bits will be loaded into free_nid_bitmap, so we can just
check free_nid_bitmap instead of both cache before loading NAT blocks.
Thanks,
>
> thanks,
> Kinglong Mee
>
>> - update: update free_nid_bitmap in real-time
>> - persistence: udpate and persist nat_bits in checkpoint
>>
>> Signed-off-by: Chao Yu <[email protected]>
>> ---
>> fs/f2fs/node.c | 109 +++++++++++++++++++++------------------------------------
>> 1 file changed, 39 insertions(+), 70 deletions(-)
>>
>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>> index 1a759d45b7e4..6c027b6833f4 100644
>> --- a/fs/f2fs/node.c
>> +++ b/fs/f2fs/node.c
>> @@ -338,9 +338,6 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
>> set_nat_flag(e, IS_CHECKPOINTED, false);
>> __set_nat_cache_dirty(nm_i, e);
>>
>> - if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
>> - clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
>> -
>> /* update fsync_mark if its inode nat entry is still alive */
>> if (ni->nid != ni->ino)
>> e = __lookup_nat_cache(nm_i, ni->ino);
>> @@ -1920,58 +1917,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
>> up_read(&nm_i->nat_tree_lock);
>> }
>>
>> -static int scan_nat_bits(struct f2fs_sb_info *sbi)
>> -{
>> - struct f2fs_nm_info *nm_i = NM_I(sbi);
>> - struct page *page;
>> - unsigned int i = 0;
>> - nid_t nid;
>> -
>> - if (!enabled_nat_bits(sbi, NULL))
>> - return -EAGAIN;
>> -
>> - down_read(&nm_i->nat_tree_lock);
>> -check_empty:
>> - i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
>> - if (i >= nm_i->nat_blocks) {
>> - i = 0;
>> - goto check_partial;
>> - }
>> -
>> - for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
>> - nid++) {
>> - if (unlikely(nid >= nm_i->max_nid))
>> - break;
>> - add_free_nid(sbi, nid, true);
>> - }
>> -
>> - if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
>> - goto out;
>> - i++;
>> - goto check_empty;
>> -
>> -check_partial:
>> - i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
>> - if (i >= nm_i->nat_blocks) {
>> - disable_nat_bits(sbi, true);
>> - up_read(&nm_i->nat_tree_lock);
>> - return -EINVAL;
>> - }
>> -
>> - nid = i * NAT_ENTRY_PER_BLOCK;
>> - page = get_current_nat_page(sbi, nid);
>> - scan_nat_page(sbi, page, nid);
>> - f2fs_put_page(page, 1);
>> -
>> - if (nm_i->nid_cnt[FREE_NID_LIST] < MAX_FREE_NIDS) {
>> - i++;
>> - goto check_partial;
>> - }
>> -out:
>> - up_read(&nm_i->nat_tree_lock);
>> - return 0;
>> -}
>> -
>> static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>> {
>> struct f2fs_nm_info *nm_i = NM_I(sbi);
>> @@ -1993,21 +1938,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>>
>> if (nm_i->nid_cnt[FREE_NID_LIST])
>> return;
>> -
>> - /* try to find free nids with nat_bits */
>> - if (!scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
>> - return;
>> - }
>> -
>> - /* find next valid candidate */
>> - if (enabled_nat_bits(sbi, NULL)) {
>> - int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
>> - nm_i->nat_blocks, 0);
>> -
>> - if (idx >= nm_i->nat_blocks)
>> - set_sbi_flag(sbi, SBI_NEED_FSCK);
>> - else
>> - nid = idx * NAT_ENTRY_PER_BLOCK;
>> }
>>
>> /* readahead nat pages to be scanned */
>> @@ -2590,6 +2520,41 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
>> return 0;
>> }
>>
>> +inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
>> +{
>> + struct f2fs_nm_info *nm_i = NM_I(sbi);
>> + unsigned int i = 0;
>> + nid_t nid, last_nid;
>> +
>> + for (i = 0; i < nm_i->nat_blocks; i++) {
>> + i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
>> + if (i >= nm_i->nat_blocks)
>> + break;
>> +
>> + set_bit_le(i, nm_i->nat_block_bitmap);
>> +
>> + nid = i * NAT_ENTRY_PER_BLOCK;
>> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>> +
>> + for (; nid < last_nid; nid++)
>> + update_free_nid_bitmap(sbi, nid, true, true);
>> + }
>> +
>> + for (i = 0; i < nm_i->nat_blocks; i++) {
>> + i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
>> + if (i >= nm_i->nat_blocks)
>> + break;
>> +
>> + set_bit_le(i, nm_i->nat_block_bitmap);
>> +
>> + nid = i * NAT_ENTRY_PER_BLOCK;
>> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>> +
>> + for (; nid < last_nid; nid++)
>> + update_free_nid_bitmap(sbi, nid, false, true);
>> + }
>> +}
>> +
>> static int init_node_manager(struct f2fs_sb_info *sbi)
>> {
>> struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
>> @@ -2672,6 +2637,10 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
>>
>> spin_lock_init(&nm_i->free_nid_lock);
>>
>> + /* load free nid status from nat_bits table */
>> + if (enabled_nat_bits(sbi, NULL))
>> + load_free_nid_bitmap(sbi);
>> +
>> return 0;
>> }
>>
>>
>
> .
>
On 3/2/2017 09:35, Chao Yu wrote:
> On 2017/3/1 21:09, Kinglong Mee wrote:
>> On 3/1/2017 17:10, Chao Yu wrote:
>>> Both nat_bits cache and free_nid_bitmap cache provide same functionality
>>> as a intermediate cache between free nid cache and disk, but with
>>> different granularity of indicating free nid range, and different
>>> persistence policy. nat_bits cache provides better persistence ability,
>>> and free_nid_bitmap provides better granularity.
>>>
>>> In this patch we combine advantage of both caches, so finally policy of
>>> the intermediate cache would be:
>>> - init: load free nid status from nat_bits into free_nid_bitmap
>>> - lookup: scan free_nid_bitmap before load NAT blocks
>>
>> Why not scan the full_nat_bits/empty_nat_bits before load NAT blocks here?
>> If after an objects shrinker, the cached free nid will be empty quickly.
>
> Since after this patch, all nids status (free or used) of
> full_nat_bits/empty_nat_bits will be loaded into free_nid_bitmap, so we can just
> check free_nid_bitmap instead of both cache before loading NAT blocks.
Yes, you are right.
I forgot f2fs also updates update_free_nid_bitmap in __flush_nat_entry_set.
thanks,
Kinglong Mee
>>> - update: update free_nid_bitmap in real-time
>>> - persistence: udpate and persist nat_bits in checkpoint
>>>
>>> Signed-off-by: Chao Yu <[email protected]>
>>> ---
>>> fs/f2fs/node.c | 109 +++++++++++++++++++++------------------------------------
>>> 1 file changed, 39 insertions(+), 70 deletions(-)
>>>
>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>>> index 1a759d45b7e4..6c027b6833f4 100644
>>> --- a/fs/f2fs/node.c
>>> +++ b/fs/f2fs/node.c
>>> @@ -338,9 +338,6 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
>>> set_nat_flag(e, IS_CHECKPOINTED, false);
>>> __set_nat_cache_dirty(nm_i, e);
>>>
>>> - if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
>>> - clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
>>> -
>>> /* update fsync_mark if its inode nat entry is still alive */
>>> if (ni->nid != ni->ino)
>>> e = __lookup_nat_cache(nm_i, ni->ino);
>>> @@ -1920,58 +1917,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
>>> up_read(&nm_i->nat_tree_lock);
>>> }
>>>
>>> -static int scan_nat_bits(struct f2fs_sb_info *sbi)
>>> -{
>>> - struct f2fs_nm_info *nm_i = NM_I(sbi);
>>> - struct page *page;
>>> - unsigned int i = 0;
>>> - nid_t nid;
>>> -
>>> - if (!enabled_nat_bits(sbi, NULL))
>>> - return -EAGAIN;
>>> -
>>> - down_read(&nm_i->nat_tree_lock);
>>> -check_empty:
>>> - i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
>>> - if (i >= nm_i->nat_blocks) {
>>> - i = 0;
>>> - goto check_partial;
>>> - }
>>> -
>>> - for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
>>> - nid++) {
>>> - if (unlikely(nid >= nm_i->max_nid))
>>> - break;
>>> - add_free_nid(sbi, nid, true);
>>> - }
>>> -
>>> - if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
>>> - goto out;
>>> - i++;
>>> - goto check_empty;
>>> -
>>> -check_partial:
>>> - i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
>>> - if (i >= nm_i->nat_blocks) {
>>> - disable_nat_bits(sbi, true);
>>> - up_read(&nm_i->nat_tree_lock);
>>> - return -EINVAL;
>>> - }
>>> -
>>> - nid = i * NAT_ENTRY_PER_BLOCK;
>>> - page = get_current_nat_page(sbi, nid);
>>> - scan_nat_page(sbi, page, nid);
>>> - f2fs_put_page(page, 1);
>>> -
>>> - if (nm_i->nid_cnt[FREE_NID_LIST] < MAX_FREE_NIDS) {
>>> - i++;
>>> - goto check_partial;
>>> - }
>>> -out:
>>> - up_read(&nm_i->nat_tree_lock);
>>> - return 0;
>>> -}
>>> -
>>> static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>>> {
>>> struct f2fs_nm_info *nm_i = NM_I(sbi);
>>> @@ -1993,21 +1938,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>>>
>>> if (nm_i->nid_cnt[FREE_NID_LIST])
>>> return;
>>> -
>>> - /* try to find free nids with nat_bits */
>>> - if (!scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
>>> - return;
>>> - }
>>> -
>>> - /* find next valid candidate */
>>> - if (enabled_nat_bits(sbi, NULL)) {
>>> - int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
>>> - nm_i->nat_blocks, 0);
>>> -
>>> - if (idx >= nm_i->nat_blocks)
>>> - set_sbi_flag(sbi, SBI_NEED_FSCK);
>>> - else
>>> - nid = idx * NAT_ENTRY_PER_BLOCK;
>>> }
>>>
>>> /* readahead nat pages to be scanned */
>>> @@ -2590,6 +2520,41 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
>>> return 0;
>>> }
>>>
>>> +inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
>>> +{
>>> + struct f2fs_nm_info *nm_i = NM_I(sbi);
>>> + unsigned int i = 0;
>>> + nid_t nid, last_nid;
>>> +
>>> + for (i = 0; i < nm_i->nat_blocks; i++) {
>>> + i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
>>> + if (i >= nm_i->nat_blocks)
>>> + break;
>>> +
>>> + set_bit_le(i, nm_i->nat_block_bitmap);
>>> +
>>> + nid = i * NAT_ENTRY_PER_BLOCK;
>>> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>>> +
>>> + for (; nid < last_nid; nid++)
>>> + update_free_nid_bitmap(sbi, nid, true, true);
>>> + }
>>> +
>>> + for (i = 0; i < nm_i->nat_blocks; i++) {
>>> + i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
>>> + if (i >= nm_i->nat_blocks)
>>> + break;
>>> +
>>> + set_bit_le(i, nm_i->nat_block_bitmap);
>>> +
>>> + nid = i * NAT_ENTRY_PER_BLOCK;
>>> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>>> +
>>> + for (; nid < last_nid; nid++)
>>> + update_free_nid_bitmap(sbi, nid, false, true);
>>> + }
>>> +}
>>> +
>>> static int init_node_manager(struct f2fs_sb_info *sbi)
>>> {
>>> struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
>>> @@ -2672,6 +2637,10 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
>>>
>>> spin_lock_init(&nm_i->free_nid_lock);
>>>
>>> + /* load free nid status from nat_bits table */
>>> + if (enabled_nat_bits(sbi, NULL))
>>> + load_free_nid_bitmap(sbi);
>>> +
>>> return 0;
>>> }
>>>
>>>
>>
>> .
>>
>
>
Hi Chao,
On 03/01, Chao Yu wrote:
> Both nat_bits cache and free_nid_bitmap cache provide same functionality
> as a intermediate cache between free nid cache and disk, but with
> different granularity of indicating free nid range, and different
> persistence policy. nat_bits cache provides better persistence ability,
> and free_nid_bitmap provides better granularity.
>
> In this patch we combine advantage of both caches, so finally policy of
> the intermediate cache would be:
> - init: load free nid status from nat_bits into free_nid_bitmap
> - lookup: scan free_nid_bitmap before load NAT blocks
> - update: update free_nid_bitmap in real-time
> - persistence: udpate and persist nat_bits in checkpoint
>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> fs/f2fs/node.c | 109 +++++++++++++++++++++------------------------------------
> 1 file changed, 39 insertions(+), 70 deletions(-)
>
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 1a759d45b7e4..6c027b6833f4 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -338,9 +338,6 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
> set_nat_flag(e, IS_CHECKPOINTED, false);
> __set_nat_cache_dirty(nm_i, e);
>
> - if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
> - clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
> -
> /* update fsync_mark if its inode nat entry is still alive */
> if (ni->nid != ni->ino)
> e = __lookup_nat_cache(nm_i, ni->ino);
> @@ -1920,58 +1917,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
> up_read(&nm_i->nat_tree_lock);
> }
>
> -static int scan_nat_bits(struct f2fs_sb_info *sbi)
> -{
> - struct f2fs_nm_info *nm_i = NM_I(sbi);
> - struct page *page;
> - unsigned int i = 0;
> - nid_t nid;
> -
> - if (!enabled_nat_bits(sbi, NULL))
> - return -EAGAIN;
> -
> - down_read(&nm_i->nat_tree_lock);
> -check_empty:
> - i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
> - if (i >= nm_i->nat_blocks) {
> - i = 0;
> - goto check_partial;
> - }
> -
> - for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
> - nid++) {
> - if (unlikely(nid >= nm_i->max_nid))
> - break;
> - add_free_nid(sbi, nid, true);
> - }
> -
> - if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
> - goto out;
> - i++;
> - goto check_empty;
> -
> -check_partial:
> - i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
> - if (i >= nm_i->nat_blocks) {
> - disable_nat_bits(sbi, true);
> - up_read(&nm_i->nat_tree_lock);
> - return -EINVAL;
> - }
> -
> - nid = i * NAT_ENTRY_PER_BLOCK;
> - page = get_current_nat_page(sbi, nid);
> - scan_nat_page(sbi, page, nid);
> - f2fs_put_page(page, 1);
> -
> - if (nm_i->nid_cnt[FREE_NID_LIST] < MAX_FREE_NIDS) {
> - i++;
> - goto check_partial;
> - }
> -out:
> - up_read(&nm_i->nat_tree_lock);
> - return 0;
> -}
> -
> static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> @@ -1993,21 +1938,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>
> if (nm_i->nid_cnt[FREE_NID_LIST])
> return;
> -
> - /* try to find free nids with nat_bits */
> - if (!scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
> - return;
> - }
> -
> - /* find next valid candidate */
> - if (enabled_nat_bits(sbi, NULL)) {
> - int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
> - nm_i->nat_blocks, 0);
> -
> - if (idx >= nm_i->nat_blocks)
> - set_sbi_flag(sbi, SBI_NEED_FSCK);
> - else
> - nid = idx * NAT_ENTRY_PER_BLOCK;
> }
>
> /* readahead nat pages to be scanned */
> @@ -2590,6 +2520,41 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
> return 0;
> }
>
> +inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
> +{
> + struct f2fs_nm_info *nm_i = NM_I(sbi);
> + unsigned int i = 0;
> + nid_t nid, last_nid;
> +
> + for (i = 0; i < nm_i->nat_blocks; i++) {
> + i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
> + if (i >= nm_i->nat_blocks)
> + break;
> +
> + set_bit_le(i, nm_i->nat_block_bitmap);
> +
> + nid = i * NAT_ENTRY_PER_BLOCK;
> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
> +
> + for (; nid < last_nid; nid++)
> + update_free_nid_bitmap(sbi, nid, true, true);
> + }
> +
> + for (i = 0; i < nm_i->nat_blocks; i++) {
> + i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
> + if (i >= nm_i->nat_blocks)
> + break;
> +
> + set_bit_le(i, nm_i->nat_block_bitmap);
> +
> + nid = i * NAT_ENTRY_PER_BLOCK;
> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
> +
> + for (; nid < last_nid; nid++)
> + update_free_nid_bitmap(sbi, nid, false, true);
> + }
> +}
> +
> static int init_node_manager(struct f2fs_sb_info *sbi)
> {
> struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
> @@ -2672,6 +2637,10 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
>
> spin_lock_init(&nm_i->free_nid_lock);
>
> + /* load free nid status from nat_bits table */
> + if (enabled_nat_bits(sbi, NULL))
> + load_free_nid_bitmap(sbi);
This should be done after init_free_nid_cache() to avoid NULL pointer access.
And, it shows little bit long latency during mount, so needs to take a look at
bit ops.
Thanks,
> +
> return 0;
> }
>
> --
> 2.8.2.295.g3f1c1d0
Hi Jaegeuk,
On 2017/3/3 3:10, Jaegeuk Kim wrote:
> Hi Chao,
>
> On 03/01, Chao Yu wrote:
>> Both nat_bits cache and free_nid_bitmap cache provide same functionality
>> as a intermediate cache between free nid cache and disk, but with
>> different granularity of indicating free nid range, and different
>> persistence policy. nat_bits cache provides better persistence ability,
>> and free_nid_bitmap provides better granularity.
>>
>> In this patch we combine advantage of both caches, so finally policy of
>> the intermediate cache would be:
>> - init: load free nid status from nat_bits into free_nid_bitmap
>> - lookup: scan free_nid_bitmap before load NAT blocks
>> - update: update free_nid_bitmap in real-time
>> - persistence: udpate and persist nat_bits in checkpoint
>>
>> Signed-off-by: Chao Yu <[email protected]>
>> ---
>> fs/f2fs/node.c | 109 +++++++++++++++++++++------------------------------------
>> 1 file changed, 39 insertions(+), 70 deletions(-)
>>
>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>> index 1a759d45b7e4..6c027b6833f4 100644
>> --- a/fs/f2fs/node.c
>> +++ b/fs/f2fs/node.c
>> @@ -338,9 +338,6 @@ static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
>> set_nat_flag(e, IS_CHECKPOINTED, false);
>> __set_nat_cache_dirty(nm_i, e);
>>
>> - if (enabled_nat_bits(sbi, NULL) && new_blkaddr == NEW_ADDR)
>> - clear_bit_le(NAT_BLOCK_OFFSET(ni->nid), nm_i->empty_nat_bits);
>> -
>> /* update fsync_mark if its inode nat entry is still alive */
>> if (ni->nid != ni->ino)
>> e = __lookup_nat_cache(nm_i, ni->ino);
>> @@ -1920,58 +1917,6 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
>> up_read(&nm_i->nat_tree_lock);
>> }
>>
>> -static int scan_nat_bits(struct f2fs_sb_info *sbi)
>> -{
>> - struct f2fs_nm_info *nm_i = NM_I(sbi);
>> - struct page *page;
>> - unsigned int i = 0;
>> - nid_t nid;
>> -
>> - if (!enabled_nat_bits(sbi, NULL))
>> - return -EAGAIN;
>> -
>> - down_read(&nm_i->nat_tree_lock);
>> -check_empty:
>> - i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
>> - if (i >= nm_i->nat_blocks) {
>> - i = 0;
>> - goto check_partial;
>> - }
>> -
>> - for (nid = i * NAT_ENTRY_PER_BLOCK; nid < (i + 1) * NAT_ENTRY_PER_BLOCK;
>> - nid++) {
>> - if (unlikely(nid >= nm_i->max_nid))
>> - break;
>> - add_free_nid(sbi, nid, true);
>> - }
>> -
>> - if (nm_i->nid_cnt[FREE_NID_LIST] >= MAX_FREE_NIDS)
>> - goto out;
>> - i++;
>> - goto check_empty;
>> -
>> -check_partial:
>> - i = find_next_zero_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
>> - if (i >= nm_i->nat_blocks) {
>> - disable_nat_bits(sbi, true);
>> - up_read(&nm_i->nat_tree_lock);
>> - return -EINVAL;
>> - }
>> -
>> - nid = i * NAT_ENTRY_PER_BLOCK;
>> - page = get_current_nat_page(sbi, nid);
>> - scan_nat_page(sbi, page, nid);
>> - f2fs_put_page(page, 1);
>> -
>> - if (nm_i->nid_cnt[FREE_NID_LIST] < MAX_FREE_NIDS) {
>> - i++;
>> - goto check_partial;
>> - }
>> -out:
>> - up_read(&nm_i->nat_tree_lock);
>> - return 0;
>> -}
>> -
>> static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>> {
>> struct f2fs_nm_info *nm_i = NM_I(sbi);
>> @@ -1993,21 +1938,6 @@ static void __build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
>>
>> if (nm_i->nid_cnt[FREE_NID_LIST])
>> return;
>> -
>> - /* try to find free nids with nat_bits */
>> - if (!scan_nat_bits(sbi) && nm_i->nid_cnt[FREE_NID_LIST])
>> - return;
>> - }
>> -
>> - /* find next valid candidate */
>> - if (enabled_nat_bits(sbi, NULL)) {
>> - int idx = find_next_zero_bit_le(nm_i->full_nat_bits,
>> - nm_i->nat_blocks, 0);
>> -
>> - if (idx >= nm_i->nat_blocks)
>> - set_sbi_flag(sbi, SBI_NEED_FSCK);
>> - else
>> - nid = idx * NAT_ENTRY_PER_BLOCK;
>> }
>>
>> /* readahead nat pages to be scanned */
>> @@ -2590,6 +2520,41 @@ static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
>> return 0;
>> }
>>
>> +inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
>> +{
>> + struct f2fs_nm_info *nm_i = NM_I(sbi);
>> + unsigned int i = 0;
>> + nid_t nid, last_nid;
>> +
>> + for (i = 0; i < nm_i->nat_blocks; i++) {
>> + i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
>> + if (i >= nm_i->nat_blocks)
>> + break;
>> +
>> + set_bit_le(i, nm_i->nat_block_bitmap);
>> +
>> + nid = i * NAT_ENTRY_PER_BLOCK;
>> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>> +
>> + for (; nid < last_nid; nid++)
>> + update_free_nid_bitmap(sbi, nid, true, true);
>> + }
>> +
>> + for (i = 0; i < nm_i->nat_blocks; i++) {
>> + i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
>> + if (i >= nm_i->nat_blocks)
>> + break;
>> +
>> + set_bit_le(i, nm_i->nat_block_bitmap);
>> +
>> + nid = i * NAT_ENTRY_PER_BLOCK;
>> + last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>> +
>> + for (; nid < last_nid; nid++)
>> + update_free_nid_bitmap(sbi, nid, false, true);
>> + }
>> +}
>> +
>> static int init_node_manager(struct f2fs_sb_info *sbi)
>> {
>> struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
>> @@ -2672,6 +2637,10 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
>>
>> spin_lock_init(&nm_i->free_nid_lock);
>>
>> + /* load free nid status from nat_bits table */
>> + if (enabled_nat_bits(sbi, NULL))
>> + load_free_nid_bitmap(sbi);
>
> This should be done after init_free_nid_cache() to avoid NULL pointer access.
OK, let me move it to build_node_manager.
> And, it shows little bit long latency during mount, so needs to take a look at
> bit ops.
Could you describe your environment please?
Below optimizations may help to improve performance of free nid bitmap building:
a. use __set_bit_le instead of set_bit_le.
b. remove clear_bit_le since bitmap was built as zeroed.
Thanks,
>
> Thanks,
>
>> +
>> return 0;
>> }
>>
>> --
>> 2.8.2.295.g3f1c1d0
>
> .
>