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authorChao Yu2017-08-07 23:12:46 +0800
committerJaegeuk Kim2017-08-15 10:40:14 -0700
commitb8c502b81e3f899c6488967dec61eed0f5907db3 (patch)
treeec5f157c9804945eb46dc13b2fc3ab58d9e03bc6 /fs
parent9a20d391cd099d547c0f17626bf6f13e06da519a (diff)
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/f2fs/gc.c2
-rw-r--r--fs/f2fs/gc.h23
2 files changed, 16 insertions, 9 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 8da7c14a9d29..e60480f71bb5 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -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;
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 57a9000ce3af..9325191fab2d 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -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)