This patch makes clearer the ambiguous f2fs_gc flow as follows.
1. Remove intermediate checkpoint condition during f2fs_gc
(i.e., should_do_checkpoint() and GC_BLOCKED)
2. Remove unnecessary return values of f2fs_gc because of #1.
(i.e., GC_NODE, GC_OK, etc)
3. Simplify write_checkpoint() because of #2.
4. Clarify the main f2fs_gc flow.
o monitor how many freed sections during one iteration of do_garbage_collect().
o do GC more without checkpoints if we can't get enough free sections.
o do checkpoint once we've got enough free sections through forground GCs.
5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data
log types. See. get_ssr_segement()
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 10 ++---
fs/f2fs/f2fs.h | 3 +-
fs/f2fs/gc.c | 107 ++++++++++++++++++++-------------------------------
fs/f2fs/gc.h | 16 --------
fs/f2fs/node.c | 2 +-
fs/f2fs/recovery.c | 2 +-
fs/f2fs/segment.c | 21 +++++++++-
fs/f2fs/segment.h | 12 ++----
fs/f2fs/super.c | 4 +-
9 files changed, 72 insertions(+), 105 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 2887c19..2b6fc13 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -539,7 +539,7 @@ retry:
/*
* Freeze all the FS-operations for checkpoint.
*/
-void block_operations(struct f2fs_sb_info *sbi)
+static void block_operations(struct f2fs_sb_info *sbi)
{
int t;
struct writeback_control wbc = {
@@ -722,15 +722,13 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
/*
* We guarantee that this checkpoint procedure should not fail.
*/
-void write_checkpoint(struct f2fs_sb_info *sbi, bool blocked, bool is_umount)
+void write_checkpoint(struct f2fs_sb_info *sbi, bool is_umount)
{
struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
unsigned long long ckpt_ver;
- if (!blocked) {
- mutex_lock(&sbi->cp_mutex);
- block_operations(sbi);
- }
+ mutex_lock(&sbi->cp_mutex);
+ block_operations(sbi);
f2fs_submit_bio(sbi, DATA, true);
f2fs_submit_bio(sbi, NODE, true);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 87840bc..e7e7a29 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -969,8 +969,7 @@ int get_valid_checkpoint(struct f2fs_sb_info *);
void set_dirty_dir_page(struct inode *, struct page *);
void remove_dirty_dir_inode(struct inode *);
void sync_dirty_dir_inodes(struct f2fs_sb_info *);
-void block_operations(struct f2fs_sb_info *);
-void write_checkpoint(struct f2fs_sb_info *, bool, bool);
+void write_checkpoint(struct f2fs_sb_info *, bool);
void init_orphan_info(struct f2fs_sb_info *);
int __init create_checkpoint_caches(void);
void destroy_checkpoint_caches(void);
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 90f5e14..a2dc725 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -78,7 +78,8 @@ static int gc_thread_func(void *data)
sbi->bg_gc++;
- if (f2fs_gc(sbi) == GC_NONE)
+ /* if return value is not zero, no victim was selected */
+ if (f2fs_gc(sbi))
wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
else if (wait_ms == GC_THREAD_NOGC_SLEEP_TIME)
wait_ms = GC_THREAD_MAX_SLEEP_TIME;
@@ -359,7 +360,7 @@ static int check_valid_map(struct f2fs_sb_info *sbi,
sentry = get_seg_entry(sbi, segno);
ret = f2fs_test_bit(offset, sentry->cur_valid_map);
mutex_unlock(&sit_i->sentry_lock);
- return ret ? GC_OK : GC_NEXT;
+ return ret;
}
/*
@@ -367,7 +368,7 @@ static int check_valid_map(struct f2fs_sb_info *sbi,
* On validity, copy that node with cold status, otherwise (invalid node)
* ignore that.
*/
-static int gc_node_segment(struct f2fs_sb_info *sbi,
+static void gc_node_segment(struct f2fs_sb_info *sbi,
struct f2fs_summary *sum, unsigned int segno, int gc_type)
{
bool initial = true;
@@ -379,21 +380,12 @@ next_step:
for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
nid_t nid = le32_to_cpu(entry->nid);
struct page *node_page;
- int err;
- /*
- * It makes sure that free segments are able to write
- * all the dirty node pages before CP after this CP.
- * So let's check the space of dirty node pages.
- */
- if (should_do_checkpoint(sbi)) {
- mutex_lock(&sbi->cp_mutex);
- block_operations(sbi);
- return GC_BLOCKED;
- }
+ /* stop BG_GC if there is not enough free sections. */
+ if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
+ return;
- err = check_valid_map(sbi, segno, off);
- if (err == GC_NEXT)
+ if (check_valid_map(sbi, segno, off) == 0)
continue;
if (initial) {
@@ -423,7 +415,6 @@ next_step:
};
sync_node_pages(sbi, 0, &wbc);
}
- return GC_DONE;
}
/*
@@ -466,13 +457,13 @@ static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
node_page = get_node_page(sbi, nid);
if (IS_ERR(node_page))
- return GC_NEXT;
+ return 0;
get_node_info(sbi, nid, dni);
if (sum->version != dni->version) {
f2fs_put_page(node_page, 1);
- return GC_NEXT;
+ return 0;
}
*nofs = ofs_of_node(node_page);
@@ -480,8 +471,8 @@ static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
f2fs_put_page(node_page, 1);
if (source_blkaddr != blkaddr)
- return GC_NEXT;
- return GC_OK;
+ return 0;
+ return 1;
}
static void move_data_page(struct inode *inode, struct page *page, int gc_type)
@@ -522,13 +513,13 @@ out:
* If the parent node is not valid or the data block address is different,
* the victim data block is ignored.
*/
-static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
+static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
struct list_head *ilist, unsigned int segno, int gc_type)
{
struct super_block *sb = sbi->sb;
struct f2fs_summary *entry;
block_t start_addr;
- int err, off;
+ int off;
int phase = 0;
start_addr = START_BLOCK(sbi, segno);
@@ -542,20 +533,11 @@ next_step:
unsigned int ofs_in_node, nofs;
block_t start_bidx;
- /*
- * It makes sure that free segments are able to write
- * all the dirty node pages before CP after this CP.
- * So let's check the space of dirty node pages.
- */
- if (should_do_checkpoint(sbi)) {
- mutex_lock(&sbi->cp_mutex);
- block_operations(sbi);
- err = GC_BLOCKED;
- goto stop;
- }
+ /* stop BG_GC if there is not enough free sections. */
+ if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
+ return;
- err = check_valid_map(sbi, segno, off);
- if (err == GC_NEXT)
+ if (check_valid_map(sbi, segno, off) == 0)
continue;
if (phase == 0) {
@@ -564,8 +546,7 @@ next_step:
}
/* Get an inode by ino with checking validity */
- err = check_dnode(sbi, entry, &dni, start_addr + off, &nofs);
- if (err == GC_NEXT)
+ if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0)
continue;
if (phase == 1) {
@@ -605,11 +586,9 @@ next_iput:
}
if (++phase < 4)
goto next_step;
- err = GC_DONE;
-stop:
+
if (gc_type == FG_GC)
f2fs_submit_bio(sbi, DATA, true);
- return err;
}
static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
@@ -623,17 +602,16 @@ static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
return ret;
}
-static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
+static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
struct list_head *ilist, int gc_type)
{
struct page *sum_page;
struct f2fs_summary_block *sum;
- int ret = GC_DONE;
/* read segment summary of victim */
sum_page = get_sum_page(sbi, segno);
if (IS_ERR(sum_page))
- return GC_ERROR;
+ return;
/*
* CP needs to lock sum_page. In this time, we don't need
@@ -645,17 +623,16 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
switch (GET_SUM_TYPE((&sum->footer))) {
case SUM_TYPE_NODE:
- ret = gc_node_segment(sbi, sum->entries, segno, gc_type);
+ gc_node_segment(sbi, sum->entries, segno, gc_type);
break;
case SUM_TYPE_DATA:
- ret = gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
+ gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
break;
}
stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
stat_inc_call_count(sbi->stat_info);
f2fs_put_page(sum_page, 0);
- return ret;
}
int f2fs_gc(struct f2fs_sb_info *sbi)
@@ -663,40 +640,38 @@ int f2fs_gc(struct f2fs_sb_info *sbi)
struct list_head ilist;
unsigned int segno, i;
int gc_type = BG_GC;
- int gc_status = GC_NONE;
+ int nfree = 0;
+ int ret = -1;
INIT_LIST_HEAD(&ilist);
gc_more:
if (!(sbi->sb->s_flags & MS_ACTIVE))
goto stop;
- if (gc_type == BG_GC && has_not_enough_free_secs(sbi))
+ if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree))
gc_type = FG_GC;
if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
goto stop;
+ ret = 0;
- for (i = 0; i < sbi->segs_per_sec; i++) {
- /*
- * do_garbage_collect will give us three gc_status:
- * GC_ERROR, GC_DONE, and GC_BLOCKED.
- * If GC is finished uncleanly, we have to return
- * the victim to dirty segment list.
- */
- gc_status = do_garbage_collect(sbi, segno + i, &ilist, gc_type);
- if (gc_status != GC_DONE)
- break;
- }
- if (has_not_enough_free_secs(sbi)) {
- write_checkpoint(sbi, (gc_status == GC_BLOCKED), false);
- if (has_not_enough_free_secs(sbi))
- goto gc_more;
- }
+ for (i = 0; i < sbi->segs_per_sec; i++)
+ do_garbage_collect(sbi, segno + i, &ilist, gc_type);
+
+ if (gc_type == FG_GC &&
+ get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
+ nfree++;
+
+ if (has_not_enough_free_secs(sbi, nfree))
+ goto gc_more;
+
+ if (gc_type == FG_GC)
+ write_checkpoint(sbi, false);
stop:
mutex_unlock(&sbi->gc_mutex);
put_gc_inode(&ilist);
- return gc_status;
+ return ret;
}
void build_gc_manager(struct f2fs_sb_info *sbi)
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index c407a75..30b2db0 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -22,15 +22,6 @@
/* Search max. number of dirty segments to select a victim segment */
#define MAX_VICTIM_SEARCH 20
-enum {
- GC_NONE = 0,
- GC_ERROR,
- GC_OK,
- GC_NEXT,
- GC_BLOCKED,
- GC_DONE,
-};
-
struct f2fs_gc_kthread {
struct task_struct *f2fs_gc_task;
wait_queue_head_t gc_wait_queue_head;
@@ -103,10 +94,3 @@ static inline int is_idle(struct f2fs_sb_info *sbi)
struct request_list *rl = &q->root_rl;
return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
}
-
-static inline bool should_do_checkpoint(struct f2fs_sb_info *sbi)
-{
- int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
- int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
- return free_sections(sbi) <= (node_secs + 2 * dent_secs + 2);
-}
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 33fa6d5..43ce164 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1135,7 +1135,7 @@ static int f2fs_write_node_pages(struct address_space *mapping,
/* First check balancing cached NAT entries */
if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK)) {
- write_checkpoint(sbi, false, false);
+ write_checkpoint(sbi, false);
return 0;
}
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index e2a3e1a..01e1a03 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -373,5 +373,5 @@ void recover_fsync_data(struct f2fs_sb_info *sbi)
out:
destroy_fsync_dnodes(sbi, &inode_list);
kmem_cache_destroy(fsync_entry_slab);
- write_checkpoint(sbi, false, false);
+ write_checkpoint(sbi, false);
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 7aa270f..777f17e 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -29,7 +29,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi)
* We should do GC or end up with checkpoint, if there are so many dirty
* dir/node pages without enough free segments.
*/
- if (has_not_enough_free_secs(sbi)) {
+ if (has_not_enough_free_secs(sbi, 0)) {
mutex_lock(&sbi->gc_mutex);
f2fs_gc(sbi);
}
@@ -308,7 +308,7 @@ static unsigned int check_prefree_segments(struct f2fs_sb_info *sbi,
* If there is not enough reserved sections,
* we should not reuse prefree segments.
*/
- if (has_not_enough_free_secs(sbi))
+ if (has_not_enough_free_secs(sbi, 0))
return NULL_SEGNO;
/*
@@ -536,6 +536,23 @@ static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
}
}
+static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
+{
+ struct curseg_info *curseg = CURSEG_I(sbi, type);
+ const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
+
+ if (IS_NODESEG(type) || !has_not_enough_free_secs(sbi, 0))
+ return v_ops->get_victim(sbi,
+ &(curseg)->next_segno, BG_GC, type, SSR);
+
+ /* For data segments, let's do SSR more intensively */
+ for (; type >= CURSEG_HOT_DATA; type--)
+ if (v_ops->get_victim(sbi, &(curseg)->next_segno,
+ BG_GC, type, SSR))
+ return 1;
+ return 0;
+}
+
/*
* flush out current segment and replace it with new segment
* This function should be returned with success, otherwise BUG
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 458bf5c..552dadb 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -450,21 +450,15 @@ static inline bool need_SSR(struct f2fs_sb_info *sbi)
return (free_sections(sbi) < overprovision_sections(sbi));
}
-static inline int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
-{
- struct curseg_info *curseg = CURSEG_I(sbi, type);
- return DIRTY_I(sbi)->v_ops->get_victim(sbi,
- &(curseg)->next_segno, BG_GC, type, SSR);
-}
-
-static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi)
+static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed)
{
int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
+
if (sbi->por_doing)
return false;
- return (free_sections(sbi) <= (node_secs + 2 * dent_secs +
+ return ((free_sections(sbi) + freed) <= (node_secs + 2 * dent_secs +
reserved_sections(sbi)));
}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index ddb665f..8c11764 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -112,7 +112,7 @@ static void f2fs_put_super(struct super_block *sb)
f2fs_destroy_stats(sbi);
stop_gc_thread(sbi);
- write_checkpoint(sbi, false, true);
+ write_checkpoint(sbi, true);
iput(sbi->node_inode);
iput(sbi->meta_inode);
@@ -136,7 +136,7 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
return 0;
if (sync)
- write_checkpoint(sbi, false, false);
+ write_checkpoint(sbi, false);
else
f2fs_balance_fs(sbi);
--
1.8.0.1.250.gb7973fb
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