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f2fs: fix potential overflow when adjusting GC cycle 

While comparing signed and unsigned variables, compiler will converts the
signed value to unsigned one, due to this reason, {in,de}crease_sleep_time
may return overflowed result.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2017-08-07 23:12:46 +08:00 committed by Jaegeuk Kim
parent 9a20d391cd
commit b8c502b81e
3 changed files with 19 additions and 12 deletions
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2
fs/f2fs/gc.c
View File

@ -28,7 +28,7 @@ static int gc_thread_func(void *data)
struct f2fs_sb_info *sbi = data;
struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
long wait_ms;
unsigned int wait_ms;
wait_ms = gc_th->min_sleep_time;

23
fs/f2fs/gc.h
View File

@ -69,25 +69,32 @@ static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
}
static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
long *wait)
unsigned int *wait)
{
unsigned int min_time = gc_th->min_sleep_time;
unsigned int max_time = gc_th->max_sleep_time;
if (*wait == gc_th->no_gc_sleep_time)
return;
*wait += gc_th->min_sleep_time;
if (*wait > gc_th->max_sleep_time)
*wait = gc_th->max_sleep_time;
if ((long long)*wait + (long long)min_time > (long long)max_time)
*wait = max_time;
else
*wait += min_time;
}
static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
long *wait)
unsigned int *wait)
{
unsigned int min_time = gc_th->min_sleep_time;
if (*wait == gc_th->no_gc_sleep_time)
*wait = gc_th->max_sleep_time;
*wait -= gc_th->min_sleep_time;
if (*wait <= gc_th->min_sleep_time)
*wait = gc_th->min_sleep_time;
if ((long long)*wait - (long long)min_time < (long long)min_time)
*wait = min_time;
else
*wait -= min_time;
}
static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)

6
include/trace/events/f2fs.h
View File

@ -543,14 +543,14 @@ TRACE_EVENT(f2fs_map_blocks,
TRACE_EVENT(f2fs_background_gc,
TP_PROTO(struct super_block *sb, long wait_ms,
TP_PROTO(struct super_block *sb, unsigned int wait_ms,
unsigned int prefree, unsigned int free),
TP_ARGS(sb, wait_ms, prefree, free),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(long, wait_ms)
__field(unsigned int, wait_ms)
__field(unsigned int, prefree)
__field(unsigned int, free)
),
@ -562,7 +562,7 @@ TRACE_EVENT(f2fs_background_gc,
__entry->free = free;
),
TP_printk("dev = (%d,%d), wait_ms = %ld, prefree = %u, free = %u",
TP_printk("dev = (%d,%d), wait_ms = %u, prefree = %u, free = %u",
show_dev(__entry->dev),
__entry->wait_ms,
__entry->prefree,