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.
Signed-off-by: Jaegeuk Kim <[email protected]> --- fs/f2fs/data.c | 4 ---- fs/f2fs/f2fs.h | 2 +- fs/f2fs/segment.c | 13 +++++++++---- fs/f2fs/super.c | 2 +- 4 files changed, 11 insertions(+), 10 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 84867dc..7550026 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -390,8 +390,6 @@ 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); @@ -401,13 +399,11 @@ 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 1c783fd..76f5586 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -375,7 +375,7 @@ 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; /* 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 dad5f1a..893d489 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -871,9 +871,14 @@ 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); do_submit_bio(sbi, type, sync); - up_write(&sbi->bio_sem); + mutex_unlock(&sbi->write_mutex); } static void submit_write_page(struct f2fs_sb_info *sbi, struct page *page, @@ -884,7 +889,7 @@ 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); inc_page_count(sbi, F2FS_WRITEBACK); @@ -919,7 +924,7 @@ retry: sbi->last_block_in_bio[type] = blk_addr; - up_write(&sbi->bio_sem); + mutex_unlock(&sbi->write_mutex); trace_f2fs_submit_write_page(page, blk_addr, type); } diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 2c52527..c7b6300 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -882,7 +882,7 @@ 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); + mutex_init(&sbi->write_mutex); init_rwsem(&sbi->cp_rwsem); init_waitqueue_head(&sbi->cp_wait); init_sb_info(sbi); -- 1.8.4.474.g128a96c -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
