From b4d07a3e1a6e783132be7506aeb171dc5728f077 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 23 Dec 2015 13:48:58 -0800 Subject: [PATCH] f2fs: avoid f2fs_lock_op in f2fs_write_begin If f2fs_write_begin is to update data, we can bypass calling f2fs_lock_op() in order to avoid the checkpoint latency in the write syscall. Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 42 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index d4839fc2b4ca..f2a023edfc1d 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1418,10 +1418,16 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, pgoff_t index = page->index; struct dnode_of_data dn; struct page *ipage; + bool locked = false; + struct extent_info ei; int err = 0; - f2fs_lock_op(sbi); - + if (f2fs_has_inline_data(inode) || + (pos & PAGE_CACHE_MASK) >= i_size_read(inode)) { + f2fs_lock_op(sbi); + locked = true; + } +restart: /* check inline_data */ ipage = get_node_page(sbi, inode->i_ino); if (IS_ERR(ipage)) { @@ -1436,22 +1442,42 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, read_inline_data(page, ipage); set_inode_flag(F2FS_I(inode), FI_DATA_EXIST); sync_inode_page(&dn); - goto done; } else { err = f2fs_convert_inline_page(&dn, page); if (err) - goto err_out; + goto out; + if (dn.data_blkaddr == NULL_ADDR) + err = f2fs_get_block(&dn, index); + } + } else if (locked) { + err = f2fs_get_block(&dn, index); + } else { + if (f2fs_lookup_extent_cache(inode, index, &ei)) { + dn.data_blkaddr = ei.blk + index - ei.fofs; + } else { + bool restart = false; + + /* hole case */ + err = get_dnode_of_data(&dn, index, LOOKUP_NODE); + if (err || (!err && dn.data_blkaddr == NULL_ADDR)) + restart = true; + if (restart) { + f2fs_put_dnode(&dn); + f2fs_lock_op(sbi); + locked = true; + goto restart; + } } } - err = f2fs_get_block(&dn, index); -done: + /* convert_inline_page can make node_changed */ *blk_addr = dn.data_blkaddr; *node_changed = dn.node_changed; -err_out: +out: f2fs_put_dnode(&dn); unlock_out: - f2fs_unlock_op(sbi); + if (locked) + f2fs_unlock_op(sbi); return err; } -- 2.34.1