f2fs: change to use rwsem for gc_mutex
Mutex lock won't serialize callers, in order to avoid starving of unlucky
caller, let's use rwsem lock instead.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 593dc3d..65a7a43 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1238,9 +1238,9 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
cpc.reason = __get_cp_reason(sbi);
- mutex_lock(&sbi->gc_mutex);
+ down_write(&sbi->gc_lock);
err = f2fs_write_checkpoint(sbi, &cpc);
- mutex_unlock(&sbi->gc_mutex);
+ up_write(&sbi->gc_lock);
}
f2fs_trace_ios(NULL, 1);
@@ -1621,7 +1621,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
f2fs_update_time(sbi, DISABLE_TIME);
while (!f2fs_time_over(sbi, DISABLE_TIME)) {
- mutex_lock(&sbi->gc_mutex);
+ down_write(&sbi->gc_lock);
err = f2fs_gc(sbi, true, false, NULL_SEGNO);
if (err == -ENODATA) {
err = 0;
@@ -1643,7 +1643,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
goto restore_flag;
}
- mutex_lock(&sbi->gc_mutex);
+ down_write(&sbi->gc_lock);
cpc.reason = CP_PAUSE;
set_sbi_flag(sbi, SBI_CP_DISABLED);
err = f2fs_write_checkpoint(sbi, &cpc);
@@ -1655,7 +1655,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
spin_unlock(&sbi->stat_lock);
out_unlock:
- mutex_unlock(&sbi->gc_mutex);
+ up_write(&sbi->gc_lock);
restore_flag:
sbi->sb->s_flags = s_flags; /* Restore MS_RDONLY status */
return err;
@@ -1663,12 +1663,12 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
{
- mutex_lock(&sbi->gc_mutex);
+ down_write(&sbi->gc_lock);
f2fs_dirty_to_prefree(sbi);
clear_sbi_flag(sbi, SBI_CP_DISABLED);
set_sbi_flag(sbi, SBI_IS_DIRTY);
- mutex_unlock(&sbi->gc_mutex);
+ up_write(&sbi->gc_lock);
f2fs_sync_fs(sbi->sb, 1);
}
@@ -3398,7 +3398,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
/* init f2fs-specific super block info */
sbi->valid_super_block = valid_super_block;
- mutex_init(&sbi->gc_mutex);
+ init_rwsem(&sbi->gc_lock);
mutex_init(&sbi->writepages);
mutex_init(&sbi->cp_mutex);
mutex_init(&sbi->resize_mutex);