This patch adds to account free nids for each NAT blocks, and while
scanning all free nid bitmap, do check count and skip lookuping in
full NAT block.
Signed-off-by: Chao Yu <[email protected]>
---
fs/f2fs/debug.c | 1 +
fs/f2fs/f2fs.h | 2 ++
fs/f2fs/node.c | 34 ++++++++++++++++++++++++++++------
3 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index a77df377e2e8..ee2d0a485fc3 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -196,6 +196,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE;
si->base_mem += NM_I(sbi)->nat_blocks / 8;
+ si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
get_cache:
si->cache_mem = 0;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7e2924981eeb..c0b33719dfa9 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -557,6 +557,8 @@ struct f2fs_nm_info {
struct mutex build_lock; /* lock for build free nids */
unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
unsigned char *nat_block_bitmap;
+ unsigned short *free_nid_count; /* free nid count of NAT block */
+ spinlock_t free_nid_lock; /* protect updating of nid count */
/* for checkpoint */
char *nat_bitmap; /* NAT bitmap pointer */
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 94967171dee8..1a759d45b7e4 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1823,7 +1823,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
kmem_cache_free(free_nid_slab, i);
}
-void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
+void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
+ bool set, bool build)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
@@ -1836,6 +1837,13 @@ void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
else
clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
+
+ spin_lock(&nm_i->free_nid_lock);
+ if (set)
+ nm_i->free_nid_count[nat_ofs]++;
+ else if (!build)
+ nm_i->free_nid_count[nat_ofs]--;
+ spin_unlock(&nm_i->free_nid_lock);
}
static void scan_nat_page(struct f2fs_sb_info *sbi,
@@ -1847,6 +1855,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
int i;
+ if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
+ return;
+
set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
i = start_nid % NAT_ENTRY_PER_BLOCK;
@@ -1861,7 +1872,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
if (blk_addr == NULL_ADDR)
freed = add_free_nid(sbi, start_nid, true);
- update_free_nid_bitmap(sbi, start_nid, freed);
+ update_free_nid_bitmap(sbi, start_nid, freed, true);
}
}
@@ -1877,6 +1888,8 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
for (i = 0; i < nm_i->nat_blocks; i++) {
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++) {
nid_t nid;
@@ -2081,7 +2094,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
__insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
nm_i->available_nids--;
- update_free_nid_bitmap(sbi, *nid, false);
+ update_free_nid_bitmap(sbi, *nid, false, false);
spin_unlock(&nm_i->nid_list_lock);
return true;
@@ -2137,7 +2150,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
nm_i->available_nids++;
- update_free_nid_bitmap(sbi, nid, true);
+ update_free_nid_bitmap(sbi, nid, true, false);
spin_unlock(&nm_i->nid_list_lock);
@@ -2467,11 +2480,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
add_free_nid(sbi, nid, false);
spin_lock(&NM_I(sbi)->nid_list_lock);
NM_I(sbi)->available_nids++;
- update_free_nid_bitmap(sbi, nid, true);
+ update_free_nid_bitmap(sbi, nid, true, false);
spin_unlock(&NM_I(sbi)->nid_list_lock);
} else {
spin_lock(&NM_I(sbi)->nid_list_lock);
- update_free_nid_bitmap(sbi, nid, false);
+ update_free_nid_bitmap(sbi, nid, false, false);
spin_unlock(&NM_I(sbi)->nid_list_lock);
}
}
@@ -2651,6 +2664,14 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
GFP_KERNEL);
if (!nm_i->nat_block_bitmap)
return -ENOMEM;
+
+ nm_i->free_nid_count = f2fs_kvzalloc(nm_i->nat_blocks *
+ sizeof(unsigned short), GFP_KERNEL);
+ if (!nm_i->free_nid_count)
+ return -ENOMEM;
+
+ spin_lock_init(&nm_i->free_nid_lock);
+
return 0;
}
@@ -2730,6 +2751,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
kvfree(nm_i->nat_block_bitmap);
kvfree(nm_i->free_nid_bitmap);
+ kvfree(nm_i->free_nid_count);
kfree(nm_i->nat_bitmap);
kfree(nm_i->nat_bits);
--
2.8.2.295.g3f1c1d0
On 3/1/2017 17:09, Chao Yu wrote:
> This patch adds to account free nids for each NAT blocks, and while
> scanning all free nid bitmap, do check count and skip lookuping in
> full NAT block.
>
> Signed-off-by: Chao Yu <[email protected]>
> ---
> fs/f2fs/debug.c | 1 +
> fs/f2fs/f2fs.h | 2 ++
> fs/f2fs/node.c | 34 ++++++++++++++++++++++++++++------
> 3 files changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> index a77df377e2e8..ee2d0a485fc3 100644
> --- a/fs/f2fs/debug.c
> +++ b/fs/f2fs/debug.c
> @@ -196,6 +196,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
> si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
> si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE;
> si->base_mem += NM_I(sbi)->nat_blocks / 8;
> + si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
>
> get_cache:
> si->cache_mem = 0;
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 7e2924981eeb..c0b33719dfa9 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -557,6 +557,8 @@ struct f2fs_nm_info {
> struct mutex build_lock; /* lock for build free nids */
> unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
> unsigned char *nat_block_bitmap;
> + unsigned short *free_nid_count; /* free nid count of NAT block */
> + spinlock_t free_nid_lock; /* protect updating of nid count */
>
Sorry for my reply so late.
Is the free_nid_lock needed here?
The free_nid_count should be protected as free_nid_bitmap,
but there isn't any lock for free_nid_bitmap.
How about atomic?
The free node ids management seems a little complex now.
thanks,
Kinglong Mee
> /* for checkpoint */
> char *nat_bitmap; /* NAT bitmap pointer */
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 94967171dee8..1a759d45b7e4 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1823,7 +1823,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
> kmem_cache_free(free_nid_slab, i);
> }
>
> -void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
> +void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
> + bool set, bool build)
> {
> struct f2fs_nm_info *nm_i = NM_I(sbi);
> unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> @@ -1836,6 +1837,13 @@ void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
> set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> else
> clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> +
> + spin_lock(&nm_i->free_nid_lock);
> + if (set)
> + nm_i->free_nid_count[nat_ofs]++;
> + else if (!build)
> + nm_i->free_nid_count[nat_ofs]--;
> + spin_unlock(&nm_i->free_nid_lock);
> }
>
> static void scan_nat_page(struct f2fs_sb_info *sbi,
> @@ -1847,6 +1855,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
> unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
> int i;
>
> + if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
> + return;
> +
> set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
>
> i = start_nid % NAT_ENTRY_PER_BLOCK;
> @@ -1861,7 +1872,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
> f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
> if (blk_addr == NULL_ADDR)
> freed = add_free_nid(sbi, start_nid, true);
> - update_free_nid_bitmap(sbi, start_nid, freed);
> + update_free_nid_bitmap(sbi, start_nid, freed, true);
> }
> }
>
> @@ -1877,6 +1888,8 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
> for (i = 0; i < nm_i->nat_blocks; i++) {
> 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++) {
> nid_t nid;
>
> @@ -2081,7 +2094,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
> __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
> nm_i->available_nids--;
>
> - update_free_nid_bitmap(sbi, *nid, false);
> + update_free_nid_bitmap(sbi, *nid, false, false);
>
> spin_unlock(&nm_i->nid_list_lock);
> return true;
> @@ -2137,7 +2150,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
>
> nm_i->available_nids++;
>
> - update_free_nid_bitmap(sbi, nid, true);
> + update_free_nid_bitmap(sbi, nid, true, false);
>
> spin_unlock(&nm_i->nid_list_lock);
>
> @@ -2467,11 +2480,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
> add_free_nid(sbi, nid, false);
> spin_lock(&NM_I(sbi)->nid_list_lock);
> NM_I(sbi)->available_nids++;
> - update_free_nid_bitmap(sbi, nid, true);
> + update_free_nid_bitmap(sbi, nid, true, false);
> spin_unlock(&NM_I(sbi)->nid_list_lock);
> } else {
> spin_lock(&NM_I(sbi)->nid_list_lock);
> - update_free_nid_bitmap(sbi, nid, false);
> + update_free_nid_bitmap(sbi, nid, false, false);
> spin_unlock(&NM_I(sbi)->nid_list_lock);
> }
> }
> @@ -2651,6 +2664,14 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
> GFP_KERNEL);
> if (!nm_i->nat_block_bitmap)
> return -ENOMEM;
> +
> + nm_i->free_nid_count = f2fs_kvzalloc(nm_i->nat_blocks *
> + sizeof(unsigned short), GFP_KERNEL);
> + if (!nm_i->free_nid_count)
> + return -ENOMEM;
> +
> + spin_lock_init(&nm_i->free_nid_lock);
> +
> return 0;
> }
>
> @@ -2730,6 +2751,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
>
> kvfree(nm_i->nat_block_bitmap);
> kvfree(nm_i->free_nid_bitmap);
> + kvfree(nm_i->free_nid_count);
>
> kfree(nm_i->nat_bitmap);
> kfree(nm_i->nat_bits);
>
On 03/10, Kinglong Mee wrote:
> On 3/1/2017 17:09, Chao Yu wrote:
> > This patch adds to account free nids for each NAT blocks, and while
> > scanning all free nid bitmap, do check count and skip lookuping in
> > full NAT block.
> >
> > Signed-off-by: Chao Yu <[email protected]>
> > ---
> > fs/f2fs/debug.c | 1 +
> > fs/f2fs/f2fs.h | 2 ++
> > fs/f2fs/node.c | 34 ++++++++++++++++++++++++++++------
> > 3 files changed, 31 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
> > index a77df377e2e8..ee2d0a485fc3 100644
> > --- a/fs/f2fs/debug.c
> > +++ b/fs/f2fs/debug.c
> > @@ -196,6 +196,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
> > si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
> > si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE;
> > si->base_mem += NM_I(sbi)->nat_blocks / 8;
> > + si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
> >
> > get_cache:
> > si->cache_mem = 0;
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 7e2924981eeb..c0b33719dfa9 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -557,6 +557,8 @@ struct f2fs_nm_info {
> > struct mutex build_lock; /* lock for build free nids */
> > unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
> > unsigned char *nat_block_bitmap;
> > + unsigned short *free_nid_count; /* free nid count of NAT block */
> > + spinlock_t free_nid_lock; /* protect updating of nid count */
> >
>
> Sorry for my reply so late.
>
> Is the free_nid_lock needed here?
> The free_nid_count should be protected as free_nid_bitmap,
> but there isn't any lock for free_nid_bitmap.
update_free_nid_bitmap() is covered by nid_list_lock except scan_nat_page.
But, it seems build_free_nids() can cover the exception. So, at a glance,
we don't need free_nid_lock.
Chao, could you check the whole lock coverage again?
> How about atomic?
IMO, atomic array would not be a proper way.
Thanks,
> The free node ids management seems a little complex now.
>
> thanks,
> Kinglong Mee
>
> > /* for checkpoint */
> > char *nat_bitmap; /* NAT bitmap pointer */
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index 94967171dee8..1a759d45b7e4 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1823,7 +1823,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
> > kmem_cache_free(free_nid_slab, i);
> > }
> >
> > -void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
> > +void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
> > + bool set, bool build)
> > {
> > struct f2fs_nm_info *nm_i = NM_I(sbi);
> > unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> > @@ -1836,6 +1837,13 @@ void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
> > set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> > else
> > clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> > +
> > + spin_lock(&nm_i->free_nid_lock);
> > + if (set)
> > + nm_i->free_nid_count[nat_ofs]++;
> > + else if (!build)
> > + nm_i->free_nid_count[nat_ofs]--;
> > + spin_unlock(&nm_i->free_nid_lock);
> > }
> >
> > static void scan_nat_page(struct f2fs_sb_info *sbi,
> > @@ -1847,6 +1855,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
> > unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
> > int i;
> >
> > + if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
> > + return;
> > +
> > set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
> >
> > i = start_nid % NAT_ENTRY_PER_BLOCK;
> > @@ -1861,7 +1872,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
> > f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
> > if (blk_addr == NULL_ADDR)
> > freed = add_free_nid(sbi, start_nid, true);
> > - update_free_nid_bitmap(sbi, start_nid, freed);
> > + update_free_nid_bitmap(sbi, start_nid, freed, true);
> > }
> > }
> >
> > @@ -1877,6 +1888,8 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
> > for (i = 0; i < nm_i->nat_blocks; i++) {
> > 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++) {
> > nid_t nid;
> >
> > @@ -2081,7 +2094,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
> > __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
> > nm_i->available_nids--;
> >
> > - update_free_nid_bitmap(sbi, *nid, false);
> > + update_free_nid_bitmap(sbi, *nid, false, false);
> >
> > spin_unlock(&nm_i->nid_list_lock);
> > return true;
> > @@ -2137,7 +2150,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
> >
> > nm_i->available_nids++;
> >
> > - update_free_nid_bitmap(sbi, nid, true);
> > + update_free_nid_bitmap(sbi, nid, true, false);
> >
> > spin_unlock(&nm_i->nid_list_lock);
> >
> > @@ -2467,11 +2480,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
> > add_free_nid(sbi, nid, false);
> > spin_lock(&NM_I(sbi)->nid_list_lock);
> > NM_I(sbi)->available_nids++;
> > - update_free_nid_bitmap(sbi, nid, true);
> > + update_free_nid_bitmap(sbi, nid, true, false);
> > spin_unlock(&NM_I(sbi)->nid_list_lock);
> > } else {
> > spin_lock(&NM_I(sbi)->nid_list_lock);
> > - update_free_nid_bitmap(sbi, nid, false);
> > + update_free_nid_bitmap(sbi, nid, false, false);
> > spin_unlock(&NM_I(sbi)->nid_list_lock);
> > }
> > }
> > @@ -2651,6 +2664,14 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
> > GFP_KERNEL);
> > if (!nm_i->nat_block_bitmap)
> > return -ENOMEM;
> > +
> > + nm_i->free_nid_count = f2fs_kvzalloc(nm_i->nat_blocks *
> > + sizeof(unsigned short), GFP_KERNEL);
> > + if (!nm_i->free_nid_count)
> > + return -ENOMEM;
> > +
> > + spin_lock_init(&nm_i->free_nid_lock);
> > +
> > return 0;
> > }
> >
> > @@ -2730,6 +2751,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
> >
> > kvfree(nm_i->nat_block_bitmap);
> > kvfree(nm_i->free_nid_bitmap);
> > + kvfree(nm_i->free_nid_count);
> >
> > kfree(nm_i->nat_bitmap);
> > kfree(nm_i->nat_bits);
> >
On 2017/3/11 2:40, Jaegeuk Kim wrote:
> On 03/10, Kinglong Mee wrote:
>> On 3/1/2017 17:09, Chao Yu wrote:
>>> This patch adds to account free nids for each NAT blocks, and while
>>> scanning all free nid bitmap, do check count and skip lookuping in
>>> full NAT block.
>>>
>>> Signed-off-by: Chao Yu <[email protected]>
>>> ---
>>> fs/f2fs/debug.c | 1 +
>>> fs/f2fs/f2fs.h | 2 ++
>>> fs/f2fs/node.c | 34 ++++++++++++++++++++++++++++------
>>> 3 files changed, 31 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
>>> index a77df377e2e8..ee2d0a485fc3 100644
>>> --- a/fs/f2fs/debug.c
>>> +++ b/fs/f2fs/debug.c
>>> @@ -196,6 +196,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
>>> si->base_mem += (NM_I(sbi)->nat_bits_blocks << F2FS_BLKSIZE_BITS);
>>> si->base_mem += NM_I(sbi)->nat_blocks * NAT_ENTRY_BITMAP_SIZE;
>>> si->base_mem += NM_I(sbi)->nat_blocks / 8;
>>> + si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
>>>
>>> get_cache:
>>> si->cache_mem = 0;
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 7e2924981eeb..c0b33719dfa9 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -557,6 +557,8 @@ struct f2fs_nm_info {
>>> struct mutex build_lock; /* lock for build free nids */
>>> unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
>>> unsigned char *nat_block_bitmap;
>>> + unsigned short *free_nid_count; /* free nid count of NAT block */
>>> + spinlock_t free_nid_lock; /* protect updating of nid count */
>>>
>>
>> Sorry for my reply so late.
>>
>> Is the free_nid_lock needed here?
>> The free_nid_count should be protected as free_nid_bitmap,
>> but there isn't any lock for free_nid_bitmap.
>
> update_free_nid_bitmap() is covered by nid_list_lock except scan_nat_page.
> But, it seems build_free_nids() can cover the exception. So, at a glance,
> we don't need free_nid_lock.
>
> Chao, could you check the whole lock coverage again?
- alloc_nid
- scan_nat_page
- update_free_nid_bitmap (nid in NAT block)
- update_free_nid_bitmap (nid in journal)
There is still a race condition in between alloc_nid and scan_nat_page, how
about use nid_list_lock to cover update_free_nid_bitmap in scan_nat_page as well?
Could you check the following patch?
Thanks,
>
>> How about atomic?
>
> IMO, atomic array would not be a proper way.
>
> Thanks,
>
>> The free node ids management seems a little complex now.
>>
>> thanks,
>> Kinglong Mee
>>
>>> /* for checkpoint */
>>> char *nat_bitmap; /* NAT bitmap pointer */
>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>>> index 94967171dee8..1a759d45b7e4 100644
>>> --- a/fs/f2fs/node.c
>>> +++ b/fs/f2fs/node.c
>>> @@ -1823,7 +1823,8 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
>>> kmem_cache_free(free_nid_slab, i);
>>> }
>>>
>>> -void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
>>> +void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
>>> + bool set, bool build)
>>> {
>>> struct f2fs_nm_info *nm_i = NM_I(sbi);
>>> unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
>>> @@ -1836,6 +1837,13 @@ void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, bool set)
>>> set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
>>> else
>>> clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
>>> +
>>> + spin_lock(&nm_i->free_nid_lock);
>>> + if (set)
>>> + nm_i->free_nid_count[nat_ofs]++;
>>> + else if (!build)
>>> + nm_i->free_nid_count[nat_ofs]--;
>>> + spin_unlock(&nm_i->free_nid_lock);
>>> }
>>>
>>> static void scan_nat_page(struct f2fs_sb_info *sbi,
>>> @@ -1847,6 +1855,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
>>> unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
>>> int i;
>>>
>>> + if (test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
>>> + return;
>>> +
>>> set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
>>>
>>> i = start_nid % NAT_ENTRY_PER_BLOCK;
>>> @@ -1861,7 +1872,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
>>> f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
>>> if (blk_addr == NULL_ADDR)
>>> freed = add_free_nid(sbi, start_nid, true);
>>> - update_free_nid_bitmap(sbi, start_nid, freed);
>>> + update_free_nid_bitmap(sbi, start_nid, freed, true);
>>> }
>>> }
>>>
>>> @@ -1877,6 +1888,8 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
>>> for (i = 0; i < nm_i->nat_blocks; i++) {
>>> 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++) {
>>> nid_t nid;
>>>
>>> @@ -2081,7 +2094,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
>>> __insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
>>> nm_i->available_nids--;
>>>
>>> - update_free_nid_bitmap(sbi, *nid, false);
>>> + update_free_nid_bitmap(sbi, *nid, false, false);
>>>
>>> spin_unlock(&nm_i->nid_list_lock);
>>> return true;
>>> @@ -2137,7 +2150,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
>>>
>>> nm_i->available_nids++;
>>>
>>> - update_free_nid_bitmap(sbi, nid, true);
>>> + update_free_nid_bitmap(sbi, nid, true, false);
>>>
>>> spin_unlock(&nm_i->nid_list_lock);
>>>
>>> @@ -2467,11 +2480,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
>>> add_free_nid(sbi, nid, false);
>>> spin_lock(&NM_I(sbi)->nid_list_lock);
>>> NM_I(sbi)->available_nids++;
>>> - update_free_nid_bitmap(sbi, nid, true);
>>> + update_free_nid_bitmap(sbi, nid, true, false);
>>> spin_unlock(&NM_I(sbi)->nid_list_lock);
>>> } else {
>>> spin_lock(&NM_I(sbi)->nid_list_lock);
>>> - update_free_nid_bitmap(sbi, nid, false);
>>> + update_free_nid_bitmap(sbi, nid, false, false);
>>> spin_unlock(&NM_I(sbi)->nid_list_lock);
>>> }
>>> }
>>> @@ -2651,6 +2664,14 @@ int init_free_nid_cache(struct f2fs_sb_info *sbi)
>>> GFP_KERNEL);
>>> if (!nm_i->nat_block_bitmap)
>>> return -ENOMEM;
>>> +
>>> + nm_i->free_nid_count = f2fs_kvzalloc(nm_i->nat_blocks *
>>> + sizeof(unsigned short), GFP_KERNEL);
>>> + if (!nm_i->free_nid_count)
>>> + return -ENOMEM;
>>> +
>>> + spin_lock_init(&nm_i->free_nid_lock);
>>> +
>>> return 0;
>>> }
>>>
>>> @@ -2730,6 +2751,7 @@ void destroy_node_manager(struct f2fs_sb_info *sbi)
>>>
>>> kvfree(nm_i->nat_block_bitmap);
>>> kvfree(nm_i->free_nid_bitmap);
>>> + kvfree(nm_i->free_nid_count);
>>>
>>> kfree(nm_i->nat_bitmap);
>>> kfree(nm_i->nat_bits);
>>>
>
> .
>