Re: [f2fs-dev] [PATCH v2] f2fs: kill heap-based allocation

From: Jaegeuk Kim
Date: Tue Feb 20 2024 - 20:57:23 EST


On 02/21, Chao Yu wrote:
> On 2024/2/21 4:51, Jaegeuk Kim wrote:
> > No one uses this feature. Let's kill it.
> >
> > Reviewed-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> > ---
> >
> > Change log from v1:
> > - keep mount options but give warnings instead
> >
> > Documentation/filesystems/f2fs.rst | 4 +--
> > fs/f2fs/gc.c | 5 ++-
> > fs/f2fs/segment.c | 54 ++++--------------------------
> > fs/f2fs/segment.h | 10 ------
> > fs/f2fs/super.c | 9 +----
> > 5 files changed, 11 insertions(+), 71 deletions(-)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> > index 9ac5083dae8e..c30a800604fd 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -126,9 +126,7 @@ norecovery Disable the roll-forward recovery routine, mounted read-
> > discard/nodiscard Enable/disable real-time discard in f2fs, if discard is
> > enabled, f2fs will issue discard/TRIM commands when a
> > segment is cleaned.
> > -no_heap Disable heap-style segment allocation which finds free
> > - segments for data from the beginning of main area, while
> > - for node from the end of main area.
> > +no_heap Deprecated.
>
> heap/no_heap Deprecated
>
> Otherwise, it looks good to me.
>
> Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
>
> BTW, do we need to kill heap-based allocation in mkfs.f2fs as well?

I was about to work on it after kernel change tho. Can you write one? :)

>
> Thanks,
>
> > nouser_xattr Disable Extended User Attributes. Note: xattr is enabled
> > by default if CONFIG_F2FS_FS_XATTR is selected.
> > noacl Disable POSIX Access Control List. Note: acl is enabled
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index 501b93b45b6c..a089a938355b 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -280,12 +280,11 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
> > p->max_search > sbi->max_victim_search)
> > p->max_search = sbi->max_victim_search;
> > - /* let's select beginning hot/small space first in no_heap mode*/
> > + /* let's select beginning hot/small space first. */
> > if (f2fs_need_rand_seg(sbi))
> > p->offset = get_random_u32_below(MAIN_SECS(sbi) *
> > SEGS_PER_SEC(sbi));
> > - else if (test_opt(sbi, NOHEAP) &&
> > - (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
> > + else if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
> > p->offset = 0;
> > else
> > p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index 94c4f7b16c19..09af17af4e7a 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -2634,16 +2634,14 @@ static int is_next_segment_free(struct f2fs_sb_info *sbi,
> > * This function should be returned with success, otherwise BUG
> > */
> > static void get_new_segment(struct f2fs_sb_info *sbi,
> > - unsigned int *newseg, bool new_sec, int dir)
> > + unsigned int *newseg, bool new_sec)
> > {
> > struct free_segmap_info *free_i = FREE_I(sbi);
> > unsigned int segno, secno, zoneno;
> > unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
> > unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg);
> > unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
> > - unsigned int left_start = hint;
> > bool init = true;
> > - int go_left = 0;
> > int i;
> > spin_lock(&free_i->segmap_lock);
> > @@ -2657,30 +2655,10 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> > find_other_zone:
> > secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
> > if (secno >= MAIN_SECS(sbi)) {
> > - if (dir == ALLOC_RIGHT) {
> > - secno = find_first_zero_bit(free_i->free_secmap,
> > + secno = find_first_zero_bit(free_i->free_secmap,
> > MAIN_SECS(sbi));
> > - f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> > - } else {
> > - go_left = 1;
> > - left_start = hint - 1;
> > - }
> > - }
> > - if (go_left == 0)
> > - goto skip_left;
> > -
> > - while (test_bit(left_start, free_i->free_secmap)) {
> > - if (left_start > 0) {
> > - left_start--;
> > - continue;
> > - }
> > - left_start = find_first_zero_bit(free_i->free_secmap,
> > - MAIN_SECS(sbi));
> > - f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
> > - break;
> > + f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
> > }
> > - secno = left_start;
> > -skip_left:
> > segno = GET_SEG_FROM_SEC(sbi, secno);
> > zoneno = GET_ZONE_FROM_SEC(sbi, secno);
> > @@ -2691,21 +2669,13 @@ static void get_new_segment(struct f2fs_sb_info *sbi,
> > goto got_it;
> > if (zoneno == old_zoneno)
> > goto got_it;
> > - if (dir == ALLOC_LEFT) {
> > - if (!go_left && zoneno + 1 >= total_zones)
> > - goto got_it;
> > - if (go_left && zoneno == 0)
> > - goto got_it;
> > - }
> > for (i = 0; i < NR_CURSEG_TYPE; i++)
> > if (CURSEG_I(sbi, i)->zone == zoneno)
> > break;
> > if (i < NR_CURSEG_TYPE) {
> > /* zone is in user, try another */
> > - if (go_left)
> > - hint = zoneno * sbi->secs_per_zone - 1;
> > - else if (zoneno + 1 >= total_zones)
> > + if (zoneno + 1 >= total_zones)
> > hint = 0;
> > else
> > hint = (zoneno + 1) * sbi->secs_per_zone;
> > @@ -2763,8 +2733,7 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
> > if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)))
> > return 0;
> > - if (test_opt(sbi, NOHEAP) &&
> > - (seg_type == CURSEG_HOT_DATA || IS_NODESEG(seg_type)))
> > + if (seg_type == CURSEG_HOT_DATA || IS_NODESEG(seg_type))
> > return 0;
> > if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
> > @@ -2784,21 +2753,12 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
> > static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
> > {
> > struct curseg_info *curseg = CURSEG_I(sbi, type);
> > - unsigned short seg_type = curseg->seg_type;
> > unsigned int segno = curseg->segno;
> > - int dir = ALLOC_LEFT;
> > if (curseg->inited)
> > - write_sum_page(sbi, curseg->sum_blk,
> > - GET_SUM_BLOCK(sbi, segno));
> > - if (seg_type == CURSEG_WARM_DATA || seg_type == CURSEG_COLD_DATA)
> > - dir = ALLOC_RIGHT;
> > -
> > - if (test_opt(sbi, NOHEAP))
> > - dir = ALLOC_RIGHT;
> > -
> > + write_sum_page(sbi, curseg->sum_blk, GET_SUM_BLOCK(sbi, segno));
> > segno = __get_next_segno(sbi, type);
> > - get_new_segment(sbi, &segno, new_sec, dir);
> > + get_new_segment(sbi, &segno, new_sec);
> > curseg->next_segno = segno;
> > reset_curseg(sbi, type, 1);
> > curseg->alloc_type = LFS;
> > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> > index 6fadfb634aac..0f1a5210c163 100644
> > --- a/fs/f2fs/segment.h
> > +++ b/fs/f2fs/segment.h
> > @@ -131,16 +131,6 @@ static inline void sanity_check_seg_type(struct f2fs_sb_info *sbi,
> > #define SECTOR_TO_BLOCK(sectors) \
> > ((sectors) >> F2FS_LOG_SECTORS_PER_BLOCK)
> > -/*
> > - * indicate a block allocation direction: RIGHT and LEFT.
> > - * RIGHT means allocating new sections towards the end of volume.
> > - * LEFT means the opposite direction.
> > - */
> > -enum {
> > - ALLOC_RIGHT = 0,
> > - ALLOC_LEFT
> > -};
> > -
> > /*
> > * In the victim_sel_policy->alloc_mode, there are three block allocation modes.
> > * LFS writes data sequentially with cleaning operations.
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 5aaf44c4698b..916e82e9c307 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -733,10 +733,8 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> > clear_opt(sbi, DISCARD);
> > break;
> > case Opt_noheap:
> > - set_opt(sbi, NOHEAP);
> > - break;
> > case Opt_heap:
> > - clear_opt(sbi, NOHEAP);
> > + f2fs_warn(sbi, "heap/no_heap options were deprecated");
> > break;
> > #ifdef CONFIG_F2FS_FS_XATTR
> > case Opt_user_xattr:
> > @@ -1962,10 +1960,6 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> > } else {
> > seq_puts(seq, ",nodiscard");
> > }
> > - if (test_opt(sbi, NOHEAP))
> > - seq_puts(seq, ",no_heap");
> > - else
> > - seq_puts(seq, ",heap");
> > #ifdef CONFIG_F2FS_FS_XATTR
> > if (test_opt(sbi, XATTR_USER))
> > seq_puts(seq, ",user_xattr");
> > @@ -2142,7 +2136,6 @@ static void default_options(struct f2fs_sb_info *sbi, bool remount)
> > set_opt(sbi, INLINE_XATTR);
> > set_opt(sbi, INLINE_DATA);
> > set_opt(sbi, INLINE_DENTRY);
> > - set_opt(sbi, NOHEAP);
> > set_opt(sbi, MERGE_CHECKPOINT);
> > F2FS_OPTION(sbi).unusable_cap = 0;
> > sbi->sb->s_flags |= SB_LAZYTIME;