From 26dfdd8e29f28c08aa67861b3c83d0f3f7d30cee Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Sun, 18 Jul 2010 10:42:23 +0900 Subject: [PATCH] nilfs2: add read ahead mode to nilfs_btnode_submit_block This adds mode argument to nilfs_btnode_submit_block() function and allows it to issue a read-ahead request. An optional submit_ptr argument is also added to store the actual block address for which bio is sent. submit_ptr is used for a series of read-ahead requests, and helps to decide if each requested block is continous to the previous one on disk. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/btnode.c | 17 ++++++++++++++--- fs/nilfs2/btnode.h | 4 ++-- fs/nilfs2/btree.c | 3 ++- fs/nilfs2/gcinode.c | 6 ++++-- 4 files changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index 0a6834b..f78ab10 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -96,7 +96,8 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) } int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, - sector_t pblocknr, struct buffer_head **pbh) + sector_t pblocknr, int mode, + struct buffer_head **pbh, sector_t *submit_ptr) { struct buffer_head *bh; struct inode *inode = NILFS_BTNC_I(btnc); @@ -127,7 +128,16 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, } } } - lock_buffer(bh); + + if (mode == READA) { + if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) { + err = -EBUSY; /* internal code */ + brelse(bh); + goto out_locked; + } + } else { /* mode == READ */ + lock_buffer(bh); + } if (buffer_uptodate(bh)) { unlock_buffer(bh); err = -EEXIST; /* internal code */ @@ -138,8 +148,9 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, bh->b_blocknr = pblocknr; /* set block address for read */ bh->b_end_io = end_buffer_read_sync; get_bh(bh); - submit_bh(READ, bh); + submit_bh(mode, bh); bh->b_blocknr = blocknr; /* set back to the given block address */ + *submit_ptr = pblocknr; err = 0; found: *pbh = bh; diff --git a/fs/nilfs2/btnode.h b/fs/nilfs2/btnode.h index 07da83f..7903749 100644 --- a/fs/nilfs2/btnode.h +++ b/fs/nilfs2/btnode.h @@ -42,8 +42,8 @@ void nilfs_btnode_cache_init(struct address_space *, struct backing_dev_info *); void nilfs_btnode_cache_clear(struct address_space *); struct buffer_head *nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr); -int nilfs_btnode_submit_block(struct address_space *, __u64, sector_t, - struct buffer_head **); +int nilfs_btnode_submit_block(struct address_space *, __u64, sector_t, int, + struct buffer_head **, sector_t *); void nilfs_btnode_delete(struct buffer_head *); int nilfs_btnode_prepare_change_key(struct address_space *, struct nilfs_btnode_chkey_ctxt *); diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index 6462c70..4669389 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -71,9 +71,10 @@ static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr, { struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache; struct buffer_head *bh; + sector_t pbn = 0; int err; - err = nilfs_btnode_submit_block(btnc, ptr, 0, bhp); + err = nilfs_btnode_submit_block(btnc, ptr, pbn, READ, bhp, &pbn); if (err) return err == -EEXIST ? 0 : err; diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c index b634382..bed3a78 100644 --- a/fs/nilfs2/gcinode.c +++ b/fs/nilfs2/gcinode.c @@ -151,8 +151,10 @@ int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff, int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn, __u64 vbn, struct buffer_head **out_bh) { - int ret = nilfs_btnode_submit_block(&NILFS_I(inode)->i_btnode_cache, - vbn ? : pbn, pbn, out_bh); + int ret; + + ret = nilfs_btnode_submit_block(&NILFS_I(inode)->i_btnode_cache, + vbn ? : pbn, pbn, READ, out_bh, &pbn); if (ret == -EEXIST) /* internal code (cache hit) */ ret = 0; return ret; -- 2.7.4