Re: [PATCH 2/5 v2] f2fs: introduce f2fs_gc_control to consolidate f2fs_gc parameters

From: Jaegeuk Kim
Date: Thu May 12 2022 - 16:51:19 EST


No functional change.

- remove checkpoint=disable check for f2fs_write_checkpoint
- get sec_freed all the time

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---

Change log from v1:
- clean up more

fs/f2fs/f2fs.h | 11 +++++-
fs/f2fs/file.c | 30 ++++++++++++---
fs/f2fs/gc.c | 74 ++++++++++++++++++++-----------------
fs/f2fs/segment.c | 8 +++-
fs/f2fs/super.c | 8 +++-
include/trace/events/f2fs.h | 18 ++++-----
6 files changed, 98 insertions(+), 51 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 0699d7460d5d..9920b2d6af8f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1265,6 +1265,14 @@ struct atgc_management {
unsigned long long age_threshold; /* age threshold */
};

+struct f2fs_gc_control {
+ unsigned int victim_segno; /* target victim segment number */
+ int init_gc_type; /* FG_GC or BG_GC */
+ bool no_bg_gc; /* check the space and stop bg_gc */
+ bool should_migrate_blocks; /* should migrate blocks */
+ bool err_gc_skipped; /* return EAGAIN if GC skipped */
+};
+
/* For s_flag in struct f2fs_sb_info */
enum {
SBI_IS_DIRTY, /* dirty flag for checkpoint */
@@ -3761,8 +3769,7 @@ extern const struct iomap_ops f2fs_iomap_ops;
int f2fs_start_gc_thread(struct f2fs_sb_info *sbi);
void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi);
block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode);
-int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, bool background, bool force,
- unsigned int segno);
+int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control);
void f2fs_build_gc_manager(struct f2fs_sb_info *sbi);
int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count);
int __init f2fs_create_garbage_collection_cache(void);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 6da8a663de7b..d0547bef0851 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1647,6 +1647,10 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE,
.m_may_create = true };
+ struct f2fs_gc_control gc_control = { .victim_segno = NULL_SEGNO,
+ .init_gc_type = FG_GC,
+ .should_migrate_blocks = false,
+ .err_gc_skipped = true };
pgoff_t pg_start, pg_end;
loff_t new_size = i_size_read(inode);
loff_t off_end;
@@ -1684,7 +1688,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
if (has_not_enough_free_secs(sbi, 0,
GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
f2fs_down_write(&sbi->gc_lock);
- err = f2fs_gc(sbi, true, false, false, NULL_SEGNO);
+ err = f2fs_gc(sbi, &gc_control);
if (err && err != -ENODATA)
goto out_err;
}
@@ -2344,6 +2348,9 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct f2fs_gc_control gc_control = { .victim_segno = NULL_SEGNO,
+ .no_bg_gc = false,
+ .should_migrate_blocks = false };
__u32 sync;
int ret;

@@ -2369,7 +2376,9 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
f2fs_down_write(&sbi->gc_lock);
}

- ret = f2fs_gc(sbi, sync, true, false, NULL_SEGNO);
+ gc_control.init_gc_type = sync ? FG_GC : BG_GC;
+ gc_control.err_gc_skipped = sync;
+ ret = f2fs_gc(sbi, &gc_control);
out:
mnt_drop_write_file(filp);
return ret;
@@ -2378,6 +2387,11 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
static int __f2fs_ioc_gc_range(struct file *filp, struct f2fs_gc_range *range)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
+ struct f2fs_gc_control gc_control = {
+ .init_gc_type = range->sync ? FG_GC : BG_GC,
+ .no_bg_gc = false,
+ .should_migrate_blocks = false,
+ .err_gc_skipped = range->sync };
u64 end;
int ret;

@@ -2405,8 +2419,8 @@ static int __f2fs_ioc_gc_range(struct file *filp, struct f2fs_gc_range *range)
f2fs_down_write(&sbi->gc_lock);
}

- ret = f2fs_gc(sbi, range->sync, true, false,
- GET_SEGNO(sbi, range->start));
+ gc_control.victim_segno = GET_SEGNO(sbi, range->start);
+ ret = f2fs_gc(sbi, &gc_control);
if (ret) {
if (ret == -EBUSY)
ret = -EAGAIN;
@@ -2820,6 +2834,10 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
unsigned int start_segno = 0, end_segno = 0;
unsigned int dev_start_segno = 0, dev_end_segno = 0;
struct f2fs_flush_device range;
+ struct f2fs_gc_control gc_control = {
+ .init_gc_type = FG_GC,
+ .should_migrate_blocks = true,
+ .err_gc_skipped = true };
int ret;

if (!capable(CAP_SYS_ADMIN))
@@ -2863,7 +2881,9 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
sm->last_victim[GC_CB] = end_segno + 1;
sm->last_victim[GC_GREEDY] = end_segno + 1;
sm->last_victim[ALLOC_NEXT] = end_segno + 1;
- ret = f2fs_gc(sbi, true, true, true, start_segno);
+
+ gc_control.victim_segno = start_segno;
+ ret = f2fs_gc(sbi, &gc_control);
if (ret == -EAGAIN)
ret = 0;
else if (ret < 0)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index ba8e93e517be..f3d58d154240 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -35,6 +35,9 @@ static int gc_thread_func(void *data)
wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
unsigned int wait_ms;
+ struct f2fs_gc_control gc_control = {
+ .victim_segno = NULL_SEGNO,
+ .should_migrate_blocks = false };

wait_ms = gc_th->min_sleep_time;

@@ -141,8 +144,12 @@ static int gc_thread_func(void *data)
if (foreground)
sync_mode = false;

+ gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
+ gc_control.no_bg_gc = foreground;
+ gc_control.err_gc_skipped = sync_mode;
+
/* if return value is not zero, no victim was selected */
- if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
+ if (f2fs_gc(sbi, &gc_control))
wait_ms = gc_th->no_gc_sleep_time;

if (foreground)
@@ -1740,21 +1747,20 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
return seg_freed;
}

-int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
- bool background, bool force, unsigned int segno)
+int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
{
- int gc_type = sync ? FG_GC : BG_GC;
+ int gc_type = gc_control->init_gc_type;
+ unsigned int segno = gc_control->victim_segno;
int sec_freed = 0, seg_freed = 0, total_freed = 0;
int ret = 0;
struct cp_control cpc;
- unsigned int init_segno = segno;
struct gc_inode_list gc_list = {
.ilist = LIST_HEAD_INIT(gc_list.ilist),
.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
};
unsigned int skipped_round = 0, round = 0;

- trace_f2fs_gc_begin(sbi->sb, sync, background,
+ trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
get_pages(sbi, F2FS_DIRTY_NODES),
get_pages(sbi, F2FS_DIRTY_DENTS),
get_pages(sbi, F2FS_DIRTY_IMETA),
@@ -1781,8 +1787,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
* threshold, we can make them free by checkpoint. Then, we
* secure free segments which doesn't need fggc any more.
*/
- if (prefree_segments(sbi) &&
- !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
+ if (prefree_segments(sbi)) {
ret = f2fs_write_checkpoint(sbi, &cpc);
if (ret)
goto stop;
@@ -1792,7 +1797,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
}

/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
- if (gc_type == BG_GC && !background) {
+ if (gc_type == BG_GC && gc_control->no_bg_gc) {
ret = -EINVAL;
goto stop;
}
@@ -1808,45 +1813,48 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
goto stop;
}

- seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
- if (gc_type == FG_GC &&
- seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
- sec_freed++;
+ seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
+ gc_control->should_migrate_blocks);
total_freed += seg_freed;

- if (gc_type == FG_GC) {
- if (sbi->skipped_gc_rwsem)
- skipped_round++;
- round++;
- }
+ if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
+ sec_freed++;

if (gc_type == FG_GC)
sbi->cur_victim_sec = NULL_SEGNO;

- if (sync)
+ if (gc_control->init_gc_type == FG_GC)
goto stop;

- if (!has_not_enough_free_secs(sbi, sec_freed, 0))
+ if (!has_not_enough_free_secs(sbi,
+ (gc_type == FG_GC) ? sec_freed : 0, 0))
goto stop;

- if (skipped_round <= MAX_SKIP_GC_COUNT || skipped_round * 2 < round) {
-
- /* Write checkpoint to reclaim prefree segments */
- if (free_sections(sbi) < NR_CURSEG_PERSIST_TYPE &&
- prefree_segments(sbi) &&
- !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
+ /* FG_GC stops GC by skip_count */
+ if (gc_type == FG_GC) {
+ if (sbi->skipped_gc_rwsem)
+ skipped_round++;
+ round++;
+ if (skipped_round > MAX_SKIP_GC_COUNT &&
+ skipped_round * 2 >= round) {
ret = f2fs_write_checkpoint(sbi, &cpc);
- if (ret)
- goto stop;
+ goto stop;
}
- segno = NULL_SEGNO;
- goto gc_more;
}
- if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
+
+ /* Write checkpoint to reclaim prefree segments */
+ if (free_sections(sbi) < NR_CURSEG_PERSIST_TYPE &&
+ prefree_segments(sbi)) {
ret = f2fs_write_checkpoint(sbi, &cpc);
+ if (ret)
+ goto stop;
+ }
+ segno = NULL_SEGNO;
+ goto gc_more;
+
stop:
SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
- SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
+ SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;

if (gc_type == FG_GC)
f2fs_unpin_all_sections(sbi, true);
@@ -1864,7 +1872,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,

put_gc_inode(&gc_list);

- if (sync && !ret)
+ if (gc_control->err_gc_skipped && !ret)
ret = sec_freed ? 0 : -EAGAIN;
return ret;
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 47934995e2ca..8b4f2b1d2cca 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -399,8 +399,14 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
io_schedule();
finish_wait(&sbi->gc_thread->fggc_wq, &wait);
} else {
+ struct f2fs_gc_control gc_control = {
+ .victim_segno = NULL_SEGNO,
+ .init_gc_type = BG_GC,
+ .no_bg_gc = true,
+ .should_migrate_blocks = false,
+ .err_gc_skipped = false };
f2fs_down_write(&sbi->gc_lock);
- f2fs_gc(sbi, false, false, false, NULL_SEGNO);
+ f2fs_gc(sbi, &gc_control);
}
}
}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8c81dd324297..a28c27eed6d0 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2076,8 +2076,14 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
sbi->gc_mode = GC_URGENT_HIGH;

while (!f2fs_time_over(sbi, DISABLE_TIME)) {
+ struct f2fs_gc_control gc_control = {
+ .victim_segno = NULL_SEGNO,
+ .init_gc_type = FG_GC,
+ .should_migrate_blocks = false,
+ .err_gc_skipped = true };
+
f2fs_down_write(&sbi->gc_lock);
- err = f2fs_gc(sbi, true, false, false, NULL_SEGNO);
+ err = f2fs_gc(sbi, &gc_control);
if (err == -ENODATA) {
err = 0;
break;
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 7e915dbf3674..54ec9e543f09 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -644,19 +644,19 @@ TRACE_EVENT(f2fs_background_gc,

TRACE_EVENT(f2fs_gc_begin,

- TP_PROTO(struct super_block *sb, bool sync, bool background,
+ TP_PROTO(struct super_block *sb, int gc_type, bool no_bg_gc,
long long dirty_nodes, long long dirty_dents,
long long dirty_imeta, unsigned int free_sec,
unsigned int free_seg, int reserved_seg,
unsigned int prefree_seg),

- TP_ARGS(sb, sync, background, dirty_nodes, dirty_dents, dirty_imeta,
+ TP_ARGS(sb, gc_type, no_bg_gc, dirty_nodes, dirty_dents, dirty_imeta,
free_sec, free_seg, reserved_seg, prefree_seg),

TP_STRUCT__entry(
__field(dev_t, dev)
- __field(bool, sync)
- __field(bool, background)
+ __field(int, gc_type)
+ __field(bool, no_bg_gc)
__field(long long, dirty_nodes)
__field(long long, dirty_dents)
__field(long long, dirty_imeta)
@@ -668,8 +668,8 @@ TRACE_EVENT(f2fs_gc_begin,

TP_fast_assign(
__entry->dev = sb->s_dev;
- __entry->sync = sync;
- __entry->background = background;
+ __entry->gc_type = gc_type;
+ __entry->no_bg_gc = no_bg_gc;
__entry->dirty_nodes = dirty_nodes;
__entry->dirty_dents = dirty_dents;
__entry->dirty_imeta = dirty_imeta;
@@ -679,12 +679,12 @@ TRACE_EVENT(f2fs_gc_begin,
__entry->prefree_seg = prefree_seg;
),

- TP_printk("dev = (%d,%d), sync = %d, background = %d, nodes = %lld, "
+ TP_printk("dev = (%d,%d), gc_type = %s, no_background_GC = %d, nodes = %lld, "
"dents = %lld, imeta = %lld, free_sec:%u, free_seg:%u, "
"rsv_seg:%d, prefree_seg:%u",
show_dev(__entry->dev),
- __entry->sync,
- __entry->background,
+ show_gc_type(__entry->gc_type),
+ (__entry->gc_type == BG_GC) ? __entry->no_bg_gc : -1,
__entry->dirty_nodes,
__entry->dirty_dents,
__entry->dirty_imeta,
--
2.36.0.550.gb090851708-goog