Re: [f2fs-dev] [PATCH] f2fs: cover update_free_nid_bitmap with free_list_lock

From: Jaegeuk Kim
Date: Mon Mar 13 2017 - 15:57:57 EST


On 03/13, Kinglong Mee wrote:
> On 3/13/2017 20:10, Chao Yu wrote:
> > free_nid_bitmap and free_nid_count in update_free_nid_bitmap should be
> > updated atomically, use free_list_lock cover them to avoid race in
>
> nid_list_lock?

Think so.
I merged a modified one in dev-test and started to test it.

Thanks,

>
> Reviewed-by: Kinglong Mee <kinglongmee@xxxxxxxxx>
>
> > concurrent scenario.
> >
> > Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> > ---
> > fs/f2fs/f2fs.h | 1 -
> > fs/f2fs/node.c | 27 +++++++++++----------------
> > 2 files changed, 11 insertions(+), 17 deletions(-)
> >
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 843ce39502bc..d905e53ba524 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -561,7 +561,6 @@ struct f2fs_nm_info {
> > 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 11df8ab32478..3bfffd744f87 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -1815,7 +1815,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
> > }
> >
> > static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
> > - bool set, bool build, bool locked)
> > + bool set, bool build)
> > {
> > struct f2fs_nm_info *nm_i = NM_I(sbi);
> > unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> > @@ -1829,14 +1829,10 @@ static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
> > else
> > __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
> >
> > - if (!locked)
> > - 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]--;
> > - if (!locked)
> > - spin_unlock(&nm_i->free_nid_lock);
> > }
> >
> > static void scan_nat_page(struct f2fs_sb_info *sbi,
> > @@ -1865,7 +1861,9 @@ 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, true, false);
> > + spin_lock(&NM_I(sbi)->nid_list_lock);
> > + update_free_nid_bitmap(sbi, start_nid, freed, true);
> > + spin_unlock(&NM_I(sbi)->nid_list_lock);
> > }
> > }
> >
> > @@ -2020,7 +2018,7 @@ 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, false, false);
> > + update_free_nid_bitmap(sbi, *nid, false, false);
> >
> > spin_unlock(&nm_i->nid_list_lock);
> > return true;
> > @@ -2076,7 +2074,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
> >
> > nm_i->available_nids++;
> >
> > - update_free_nid_bitmap(sbi, nid, true, false, false);
> > + update_free_nid_bitmap(sbi, nid, true, false);
> >
> > spin_unlock(&nm_i->nid_list_lock);
> >
> > @@ -2406,11 +2404,11 @@ 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, false, false);
> > + 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, false, false);
> > + update_free_nid_bitmap(sbi, nid, false, false);
> > spin_unlock(&NM_I(sbi)->nid_list_lock);
> > }
> > }
> > @@ -2535,10 +2533,10 @@ inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
> > nid = i * NAT_ENTRY_PER_BLOCK;
> > last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
> >
> > - spin_lock(&nm_i->free_nid_lock);
> > + spin_lock(&NM_I(sbi)->nid_list_lock);
> > for (; nid < last_nid; nid++)
> > - update_free_nid_bitmap(sbi, nid, true, true, true);
> > - spin_unlock(&nm_i->free_nid_lock);
> > + update_free_nid_bitmap(sbi, nid, true, true);
> > + spin_unlock(&NM_I(sbi)->nid_list_lock);
> > }
> >
> > for (i = 0; i < nm_i->nat_blocks; i++) {
> > @@ -2629,9 +2627,6 @@ static int init_free_nid_cache(struct f2fs_sb_info *sbi)
> > sizeof(unsigned short), GFP_KERNEL);
> > if (!nm_i->free_nid_count)
> > return -ENOMEM;
> > -
> > - spin_lock_init(&nm_i->free_nid_lock);
> > -
> > return 0;
> > }
> >
> >