f2fs: introduce a bio array for per-page write bios

The f2fs has three bio types, NODE, DATA, and META, and manages some data
structures per each bio types.

The codes are a little bit messy, thus, this patch introduces a bio array
which groups individual data structures as follows.

struct f2fs_bio_info {
	struct bio *bio;		/* bios to merge */
	sector_t last_block_in_bio;	/* last block number */
	struct mutex io_mutex;		/* mutex for bio */
};

struct f2fs_sb_info {
	...
	struct f2fs_bio_info write_io[NR_PAGE_TYPE];	/* for write bios */
	...
};

The code changes from this new data structure are trivial.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e9038bb..05f8fe1 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -361,6 +361,12 @@ enum page_type {
        META_FLUSH,
 };
 
+struct f2fs_bio_info {
+       struct bio *bio;                /* bios to merge */
+       sector_t last_block_in_bio;     /* last block number */
+       struct mutex io_mutex;          /* mutex for bio */
+};
+
 struct f2fs_sb_info {
        struct super_block *sb;                 /* pointer to VFS super block */
        struct proc_dir_entry *s_proc;          /* proc entry */
@@ -374,9 +380,9 @@ struct f2fs_sb_info {
 
        /* for segment-related operations */
        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 mutex write_mutex[NR_PAGE_TYPE]; /* mutex for writing IOs */
+
+       /* for bio operations */
+       struct f2fs_bio_info write_io[NR_PAGE_TYPE];    /* for write bios */
 
        /* for checkpoint */
        struct f2fs_checkpoint *ckpt;           /* raw checkpoint pointer */

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 68b8a2b..38c1a89 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -836,65 +836,65 @@ static void do_submit_bio(struct f2fs_sb_info *sbi,
 {
        int rw = sync ? WRITE_SYNC : WRITE;
        enum page_type btype = PAGE_TYPE_OF_BIO(type);
-       struct bio *bio = sbi->bio[btype];
+       struct f2fs_bio_info *io = &sbi->write_io[btype];
        struct bio_private *p;
 
-       if (!bio)
+       if (!io->bio)
                return;
 
-       sbi->bio[btype] = NULL;
-
        if (type >= META_FLUSH)
                rw = WRITE_FLUSH_FUA;
        if (btype == META)
                rw |= REQ_META;
 
-       p = bio->bi_private;
+       p = io->bio->bi_private;
        p->sbi = sbi;
-       bio->bi_end_io = f2fs_end_io_write;
+       io->bio->bi_end_io = f2fs_end_io_write;
 
-       trace_f2fs_do_submit_bio(sbi->sb, btype, sync, bio);
+       trace_f2fs_do_submit_bio(sbi->sb, btype, sync, io->bio);
 
        if (type == META_FLUSH) {
                DECLARE_COMPLETION_ONSTACK(wait);
                p->is_sync = true;
                p->wait = &wait;
-               submit_bio(rw, bio);
+               submit_bio(rw, io->bio);
                wait_for_completion(&wait);
        } else {
                p->is_sync = false;
-               submit_bio(rw, bio);
+               submit_bio(rw, io->bio);
        }
+       io->bio = NULL;
 }
 
 void f2fs_submit_bio(struct f2fs_sb_info *sbi, enum page_type type, bool sync)
 {
-       enum page_type btype = PAGE_TYPE_OF_BIO(type);
+       struct f2fs_bio_info *io = &sbi->write_io[PAGE_TYPE_OF_BIO(type)];
 
-       if (!sbi->bio[btype])
+       if (!io->bio)
                return;
 
-       mutex_lock(&sbi->write_mutex[btype]);
+       mutex_lock(&io->io_mutex);
        do_submit_bio(sbi, type, sync);
-       mutex_unlock(&sbi->write_mutex[btype]);
+       mutex_unlock(&io->io_mutex);
 }
 
 static void submit_write_page(struct f2fs_sb_info *sbi, struct page *page,
                                block_t blk_addr, enum page_type type)
 {
        struct block_device *bdev = sbi->sb->s_bdev;
+       struct f2fs_bio_info *io = &sbi->write_io[type];
        int bio_blocks;
 
        verify_block_addr(sbi, blk_addr);
 
-       mutex_lock(&sbi->write_mutex[type]);
+       mutex_lock(&io->io_mutex);
 
        inc_page_count(sbi, F2FS_WRITEBACK);
 
-       if (sbi->bio[type] && sbi->last_block_in_bio[type] != blk_addr - 1)
+       if (io->bio && io->last_block_in_bio != blk_addr - 1)
                do_submit_bio(sbi, type, false);
 alloc_new:
-       if (sbi->bio[type] == NULL) {
+       if (io->bio == NULL) {
                struct bio_private *priv;
 retry:
                priv = kmalloc(sizeof(struct bio_private), GFP_NOFS);
@@ -904,9 +904,9 @@ retry:
                }
 
                bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
-               sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks);
-               sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
-               sbi->bio[type]->bi_private = priv;
+               io->bio = f2fs_bio_alloc(bdev, bio_blocks);
+               io->bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
+               io->bio->bi_private = priv;
                /*
                 * The end_io will be assigned at the sumbission phase.
                 * Until then, let bio_add_page() merge consecutive IOs as much
@@ -914,15 +914,15 @@ retry:
                 */
        }
 
-       if (bio_add_page(sbi->bio[type], page, PAGE_CACHE_SIZE, 0) <
+       if (bio_add_page(io->bio, page, PAGE_CACHE_SIZE, 0) <
                                                        PAGE_CACHE_SIZE) {
                do_submit_bio(sbi, type, false);
                goto alloc_new;
        }
 
-       sbi->last_block_in_bio[type] = blk_addr;
+       io->last_block_in_bio = blk_addr;
 
-       mutex_unlock(&sbi->write_mutex[type]);
+       mutex_unlock(&io->io_mutex);
        trace_f2fs_submit_write_page(page, blk_addr, type);
 }
 

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index e194578..8c677e9 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -879,7 +879,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
        spin_lock_init(&sbi->stat_lock);
 
        for (i = 0; i < NR_PAGE_TYPE; i++)
-               mutex_init(&sbi->write_mutex[i]);
+               mutex_init(&sbi->write_io[i].io_mutex);
 
        init_rwsem(&sbi->cp_rwsem);
        init_waitqueue_head(&sbi->cp_wait);