Implementation btrfs .metadata_readahead. In btrfs, all metadata pages are in a special btree_inode. We do readahead in it.
Signed-off-by: Shaohua Li <[email protected]> --- fs/btrfs/disk-io.c | 10 ++++++++++ fs/btrfs/super.c | 13 +++++++++++++ mm/readahead.c | 1 + 3 files changed, 24 insertions(+) Index: linux/fs/btrfs/disk-io.c =================================================================== --- linux.orig/fs/btrfs/disk-io.c 2010-12-07 13:32:24.000000000 +0800 +++ linux/fs/btrfs/disk-io.c 2010-12-07 13:33:08.000000000 +0800 @@ -776,6 +776,15 @@ static int btree_readpage(struct file *f return extent_read_full_page(tree, page, btree_get_extent); } +static int btree_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + struct extent_io_tree *tree; + tree = &BTRFS_I(mapping->host)->io_tree; + return extent_readpages(tree, mapping, pages, nr_pages, + btree_get_extent); +} + static int btree_releasepage(struct page *page, gfp_t gfp_flags) { struct extent_io_tree *tree; @@ -819,6 +828,7 @@ static void btree_invalidatepage(struct static const struct address_space_operations btree_aops = { .readpage = btree_readpage, + .readpages = btree_readpages, .writepage = btree_writepage, .writepages = btree_writepages, .releasepage = btree_releasepage, Index: linux/fs/btrfs/super.c =================================================================== --- linux.orig/fs/btrfs/super.c 2010-12-07 13:32:24.000000000 +0800 +++ linux/fs/btrfs/super.c 2010-12-07 13:33:08.000000000 +0800 @@ -892,6 +892,18 @@ out: return -ENOENT; } +static int btrfs_metadata_readahead(struct super_block *sb, loff_t offset, + ssize_t size) +{ + struct btrfs_root *tree_root = btrfs_sb(sb); + struct inode *btree_inode = tree_root->fs_info->btree_inode; + struct address_space *mapping = btree_inode->i_mapping; + + force_page_cache_readahead(mapping, NULL, offset >> PAGE_CACHE_SHIFT, + size >> PAGE_CACHE_SHIFT); + return 0; +} + static const struct super_operations btrfs_super_ops = { .drop_inode = btrfs_drop_inode, .evict_inode = btrfs_evict_inode, @@ -907,6 +919,7 @@ static const struct super_operations btr .freeze_fs = btrfs_freeze, .unfreeze_fs = btrfs_unfreeze, .metadata_incore = btrfs_metadata_incore, + .metadata_readahead = btrfs_metadata_readahead, }; static const struct file_operations btrfs_ctl_fops = { Index: linux/mm/readahead.c =================================================================== --- linux.orig/mm/readahead.c 2010-12-07 13:32:24.000000000 +0800 +++ linux/mm/readahead.c 2010-12-07 13:33:08.000000000 +0800 @@ -228,6 +228,7 @@ int force_page_cache_readahead(struct ad } return ret; } +EXPORT_SYMBOL_GPL(force_page_cache_readahead); /* * Given a desired number of PAGE_CACHE_SIZE readahead pages, return a -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
