f2fs: use sbi->write_mutex for write bios

This patch removes an unnecessary semaphore (i.e., sbi->bio_sem).
There is no reason to use the semaphore when f2fs submits read and write IOs.
Instead, let's use a write mutex and cover the sbi->bio[] by the lock.

Change log from v1:
 o split write_mutex suggested by Chao Yu

Chao described,
"All DATA/NODE/META bio buffers in superblock is protected by
'sbi->write_mutex', but each bio buffer area is independent, So we
should split write_mutex to three for DATA/NODE/META."

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index a022412c66ea..e194578b3594 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -820,6 +820,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
         struct buffer_head *raw_super_buf;
         struct inode *root;
         long err = -EINVAL;
+        int i;
 
         /* allocate memory for f2fs-specific super block info */
         sbi = kzalloc(sizeof(struct f2fs_sb_info), GFP_KERNEL);
@@ -876,7 +877,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
         mutex_init(&sbi->node_write);
         sbi->por_doing = false;
         spin_lock_init(&sbi->stat_lock);
-        init_rwsem(&sbi->bio_sem);
+
+        for (i = 0; i < NR_PAGE_TYPE; i++)
+                mutex_init(&sbi->write_mutex[i]);
+
         init_rwsem(&sbi->cp_rwsem);
         init_waitqueue_head(&sbi->cp_wait);
         init_sb_info(sbi);