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f2fs: introduce sbi->gc_mode to determine the policy
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This is to avoid sbi->gc_thread pointer access.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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Jaegeuk Kim committed May 31, 2018
1 parent 107a805 commit 5b0e953
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Showing 5 changed files with 47 additions and 28 deletions.
8 changes: 8 additions & 0 deletions fs/f2fs/f2fs.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1066,6 +1066,13 @@ enum {
MAX_TIME,
};

enum {
GC_NORMAL,
GC_IDLE_CB,
GC_IDLE_GREEDY,
GC_URGENT,
};

enum {
WHINT_MODE_OFF, /* not pass down write hints */
WHINT_MODE_USER, /* try to pass down hints given by users */
Expand Down Expand Up @@ -1197,6 +1204,7 @@ struct f2fs_sb_info {
struct mutex gc_mutex; /* mutex for GC */
struct f2fs_gc_kthread *gc_thread; /* GC thread */
unsigned int cur_victim_sec; /* current victim section num */
unsigned int gc_mode; /* current GC state */

/* threshold for gc trials on pinned files */
u64 gc_pin_file_threshold;
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28 changes: 12 additions & 16 deletions fs/f2fs/gc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -76,7 +76,7 @@ static int gc_thread_func(void *data)
* invalidated soon after by user update or deletion.
* So, I'd like to wait some time to collect dirty segments.
*/
if (gc_th->gc_urgent) {
if (sbi->gc_mode == GC_URGENT) {
wait_ms = gc_th->urgent_sleep_time;
mutex_lock(&sbi->gc_mutex);
goto do_gc;
Expand Down Expand Up @@ -131,8 +131,6 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;

gc_th->gc_idle = 0;
gc_th->gc_urgent = 0;
gc_th->gc_wake= 0;

sbi->gc_thread = gc_th;
Expand All @@ -158,21 +156,19 @@ void stop_gc_thread(struct f2fs_sb_info *sbi)
sbi->gc_thread = NULL;
}

static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
{
int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;

if (!gc_th)
return gc_mode;

if (gc_th->gc_idle) {
if (gc_th->gc_idle == 1)
gc_mode = GC_CB;
else if (gc_th->gc_idle == 2)
gc_mode = GC_GREEDY;
}
if (gc_th->gc_urgent)
switch (sbi->gc_mode) {
case GC_IDLE_CB:
gc_mode = GC_CB;
break;
case GC_IDLE_GREEDY:
case GC_URGENT:
gc_mode = GC_GREEDY;
break;
}
return gc_mode;
}

Expand All @@ -187,15 +183,15 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
p->max_search = dirty_i->nr_dirty[type];
p->ofs_unit = 1;
} else {
p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
p->gc_mode = select_gc_type(sbi, gc_type);
p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
p->max_search = dirty_i->nr_dirty[DIRTY];
p->ofs_unit = sbi->segs_per_sec;
}

/* we need to check every dirty segments in the FG_GC case */
if (gc_type != FG_GC &&
(sbi->gc_thread && !sbi->gc_thread->gc_urgent) &&
(sbi->gc_mode != GC_URGENT) &&
p->max_search > sbi->max_victim_search)
p->max_search = sbi->max_victim_search;

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2 changes: 0 additions & 2 deletions fs/f2fs/gc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -36,8 +36,6 @@ struct f2fs_gc_kthread {
unsigned int no_gc_sleep_time;

/* for changing gc mode */
unsigned int gc_idle;
unsigned int gc_urgent;
unsigned int gc_wake;
};

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4 changes: 2 additions & 2 deletions fs/f2fs/segment.c
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Original file line number Diff line number Diff line change
Expand Up @@ -177,7 +177,7 @@ bool need_SSR(struct f2fs_sb_info *sbi)

if (test_opt(sbi, LFS))
return false;
if (sbi->gc_thread && sbi->gc_thread->gc_urgent)
if (sbi->gc_mode == GC_URGENT)
return true;

return free_sections(sbi) <= (node_secs + 2 * dent_secs + imeta_secs +
Expand Down Expand Up @@ -1405,7 +1405,7 @@ static int issue_discard_thread(void *data)
if (dcc->discard_wake)
dcc->discard_wake = 0;

if (sbi->gc_thread && sbi->gc_thread->gc_urgent)
if (sbi->gc_mode == GC_URGENT)
__init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1);

sb_start_intwrite(sbi->sb);
Expand Down
33 changes: 25 additions & 8 deletions fs/f2fs/sysfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -248,16 +248,33 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
if (!strcmp(a->attr.name, "trim_sections"))
return -EINVAL;

if (!strcmp(a->attr.name, "gc_urgent")) {
if (t >= 1) {
sbi->gc_mode = GC_URGENT;
if (sbi->gc_thread) {
wake_up_interruptible_all(
&sbi->gc_thread->gc_wait_queue_head);
wake_up_discard_thread(sbi, true);
}
} else {
sbi->gc_mode = GC_NORMAL;
}
return count;
}
if (!strcmp(a->attr.name, "gc_idle")) {
if (t == GC_IDLE_CB)
sbi->gc_mode = GC_IDLE_CB;
else if (t == GC_IDLE_GREEDY)
sbi->gc_mode = GC_IDLE_GREEDY;
else
sbi->gc_mode = GC_NORMAL;
return count;
}

*ui = t;

if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0)
f2fs_reset_iostat(sbi);
if (!strcmp(a->attr.name, "gc_urgent") && t == 1 && sbi->gc_thread) {
sbi->gc_thread->gc_wake = 1;
wake_up_interruptible_all(&sbi->gc_thread->gc_wait_queue_head);
wake_up_discard_thread(sbi, true);
}

return count;
}

Expand Down Expand Up @@ -349,8 +366,8 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_urgent_sleep_time,
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_urgent, gc_urgent);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_idle, gc_mode);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_urgent, gc_mode);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);
F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);
Expand Down

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