From 971767caf632190f77a40b4011c19948232eed75 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Mon, 18 Nov 2013 17:16:17 +0900 Subject: [PATCH] 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 Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 4 ---- fs/f2fs/f2fs.h | 2 +- fs/f2fs/segment.c | 13 +++++++++---- fs/f2fs/super.c | 6 +++++- 4 files changed, 15 insertions(+), 10 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 076a60cb8dbb..5920639ca377 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -383,8 +383,6 @@ int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page, trace_f2fs_readpage(page, blk_addr, type); - down_read(&sbi->bio_sem); - /* Allocate a new bio */ bio = f2fs_bio_alloc(bdev, 1); @@ -394,13 +392,11 @@ int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page, if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) { bio_put(bio); - up_read(&sbi->bio_sem); f2fs_put_page(page, 1); return -EFAULT; } submit_bio(type, bio); - up_read(&sbi->bio_sem); return 0; } diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 38963b4b500a..c2de54919725 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -374,7 +374,7 @@ struct f2fs_sb_info { struct f2fs_sm_info *sm_info; /* segment manager */ struct bio *bio[NR_PAGE_TYPE]; /* bios to merge */ sector_t last_block_in_bio[NR_PAGE_TYPE]; /* last block number */ - struct rw_semaphore bio_sem; /* IO semaphore */ + struct mutex write_mutex[NR_PAGE_TYPE]; /* mutex for writing IOs */ /* for checkpoint */ struct f2fs_checkpoint *ckpt; /* raw checkpoint pointer */ diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index d5043bdaa1af..68b8a2bdf6d8 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -869,9 +869,14 @@ static void do_submit_bio(struct f2fs_sb_info *sbi, void f2fs_submit_bio(struct f2fs_sb_info *sbi, enum page_type type, bool sync) { - down_write(&sbi->bio_sem); + enum page_type btype = PAGE_TYPE_OF_BIO(type); + + if (!sbi->bio[btype]) + return; + + mutex_lock(&sbi->write_mutex[btype]); do_submit_bio(sbi, type, sync); - up_write(&sbi->bio_sem); + mutex_unlock(&sbi->write_mutex[btype]); } static void submit_write_page(struct f2fs_sb_info *sbi, struct page *page, @@ -882,7 +887,7 @@ static void submit_write_page(struct f2fs_sb_info *sbi, struct page *page, verify_block_addr(sbi, blk_addr); - down_write(&sbi->bio_sem); + mutex_lock(&sbi->write_mutex[type]); inc_page_count(sbi, F2FS_WRITEBACK); @@ -917,7 +922,7 @@ retry: sbi->last_block_in_bio[type] = blk_addr; - up_write(&sbi->bio_sem); + mutex_unlock(&sbi->write_mutex[type]); trace_f2fs_submit_write_page(page, blk_addr, type); } 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);