From d98237b3ede7ab98892f7fa62201a13694c526e2 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 28 Mar 2007 13:57:48 -0400 Subject: Btrfs: use a btree inode instead of sb_getblk Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 174 +++++++++++++++++++++++++++++++++++++++++++++---- fs/btrfs/disk-io.h | 5 +- fs/btrfs/extent-tree.c | 8 +-- fs/btrfs/super.c | 8 ++- fs/btrfs/transaction.c | 2 +- 6 files changed, 174 insertions(+), 24 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1897f3a..b2ebed7 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -233,6 +233,7 @@ struct btrfs_fs_info { struct btrfs_super_block *disk_super; struct buffer_head *sb_buffer; struct super_block *sb; + struct inode *btree_inode; struct mutex trans_mutex; struct mutex fs_mutex; }; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 758a62a..970103f 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1,14 +1,17 @@ #include #include +#include #include "ctree.h" #include "disk-io.h" #include "transaction.h" + static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf) { struct btrfs_node *node = btrfs_buffer_node(buf); - if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) + if (buf->b_blocknr != btrfs_header_blocknr(&node->header)) { BUG(); + } if (root->node && btrfs_header_parentid(&node->header) != btrfs_header_parentid(btrfs_buffer_header(root->node))) { BUG(); @@ -16,25 +19,154 @@ static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf) return 0; } -struct buffer_head *alloc_tree_block(struct btrfs_root *root, u64 blocknr) +struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr) +{ + struct address_space *mapping = root->fs_info->btree_inode->i_mapping; + int blockbits = root->fs_info->sb->s_blocksize_bits; + unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits); + struct page *page; + struct buffer_head *bh; + struct buffer_head *head; + struct buffer_head *ret = NULL; + + page = find_lock_page(mapping, index); + if (!page) + return NULL; + + if (!page_has_buffers(page)) + goto out_unlock; + + head = page_buffers(page); + bh = head; + do { + if (buffer_mapped(bh) && bh->b_blocknr == blocknr) { + ret = bh; + get_bh(bh); + goto out_unlock; + } + bh = bh->b_this_page; + } while (bh != head); +out_unlock: + unlock_page(page); + page_cache_release(page); + return ret; +} + +struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root, + u64 blocknr) +{ + struct address_space *mapping = root->fs_info->btree_inode->i_mapping; + int blockbits = root->fs_info->sb->s_blocksize_bits; + unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits); + struct page *page; + struct buffer_head *bh; + struct buffer_head *head; + struct buffer_head *ret = NULL; + u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits); + page = grab_cache_page(mapping, index); + if (!page) + return NULL; + + wait_on_page_writeback(page); + if (!page_has_buffers(page)) + create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0); + head = page_buffers(page); + bh = head; + do { + if (!buffer_mapped(bh)) { + bh->b_bdev = root->fs_info->sb->s_bdev; + bh->b_blocknr = first_block; + set_buffer_mapped(bh); + } + if (bh->b_blocknr == blocknr) { + ret = bh; + get_bh(bh); + goto out_unlock; + } + bh = bh->b_this_page; + first_block++; + } while (bh != head); +out_unlock: + unlock_page(page); + page_cache_release(page); + return ret; +} + +static sector_t max_block(struct block_device *bdev) +{ + sector_t retval = ~((sector_t)0); + loff_t sz = i_size_read(bdev->bd_inode); + + if (sz) { + unsigned int size = block_size(bdev); + unsigned int sizebits = blksize_bits(size); + retval = (sz >> sizebits); + } + return retval; +} + +static int btree_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int create) +{ + if (iblock >= max_block(inode->i_sb->s_bdev)) { + if (create) + return -EIO; + + /* + * for reads, we're just trying to fill a partial page. + * return a hole, they will have to call get_block again + * before they can fill it, and they will get -EIO at that + * time + */ + return 0; + } + bh->b_bdev = inode->i_sb->s_bdev; + bh->b_blocknr = iblock; + set_buffer_mapped(bh); + return 0; +} + +static int btree_writepage(struct page *page, struct writeback_control *wbc) { - return sb_getblk(root->fs_info->sb, blocknr); + return block_write_full_page(page, btree_get_block, wbc); } -struct buffer_head *find_tree_block(struct btrfs_root *root, u64 blocknr) +static int btree_readpage(struct file * file, struct page * page) { - return sb_getblk(root->fs_info->sb, blocknr); + return block_read_full_page(page, btree_get_block); } +static struct address_space_operations btree_aops = { + .readpage = btree_readpage, + .writepage = btree_writepage, + .sync_page = block_sync_page, +}; + struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr) { - struct buffer_head *buf = sb_bread(root->fs_info->sb, blocknr); + struct buffer_head *bh = NULL; - if (!buf) - return buf; - if (check_tree_block(root, buf)) + bh = btrfs_find_create_tree_block(root, blocknr); + if (!bh) + return bh; + lock_buffer(bh); + if (!buffer_uptodate(bh)) { + get_bh(bh); + bh->b_end_io = end_buffer_read_sync; + submit_bh(READ, bh); + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) + goto fail; + } else { + unlock_buffer(bh); + } + if (check_tree_block(root, bh)) BUG(); - return buf; + return bh; +fail: + brelse(bh); + return NULL; + } int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -101,11 +233,11 @@ struct btrfs_root *open_ctree(struct super_block *sb, GFP_NOFS); int ret; - /* FIXME: don't be stupid */ if (!btrfs_super_root(disk_super)) return NULL; init_bit_radix(&fs_info->pinned_radix); init_bit_radix(&fs_info->pending_del_radix); + sb_set_blocksize(sb, sb_buffer->b_size); fs_info->running_transaction = NULL; fs_info->fs_root = root; fs_info->tree_root = tree_root; @@ -114,14 +246,30 @@ struct btrfs_root *open_ctree(struct super_block *sb, fs_info->last_inode_alloc = 0; fs_info->last_inode_alloc_dirid = 0; fs_info->disk_super = disk_super; - fs_info->sb_buffer = sb_buffer; fs_info->sb = sb; + fs_info->btree_inode = new_inode(sb); + fs_info->btree_inode->i_ino = 1; + fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size; + fs_info->btree_inode->i_mapping->a_ops = &btree_aops; + mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS); + mutex_init(&fs_info->trans_mutex); mutex_init(&fs_info->fs_mutex); memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert)); memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert)); __setup_root(disk_super, tree_root, fs_info, BTRFS_ROOT_TREE_OBJECTID); + + fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr); + + if (!fs_info->sb_buffer) + return NULL; + + brelse(sb_buffer); + sb_buffer = NULL; + disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data; + fs_info->disk_super = disk_super; + tree_root->node = read_tree_block(tree_root, btrfs_super_root(disk_super)); BUG_ON(!tree_root->node); @@ -137,7 +285,6 @@ struct btrfs_root *open_ctree(struct super_block *sb, ret = find_and_setup_root(disk_super, tree_root, fs_info, BTRFS_FS_TREE_OBJECTID, root); BUG_ON(ret); - root->commit_root = root->node; get_bh(root->node); root->ref_cows = 1; @@ -191,6 +338,7 @@ int close_ctree(struct btrfs_root *root) root->fs_info->tree_root->node); btrfs_block_release(root, root->commit_root); btrfs_block_release(root, root->fs_info->sb_buffer); + iput(root->fs_info->btree_inode); kfree(root->fs_info->extent_root); kfree(root->fs_info->inode_root); kfree(root->fs_info->tree_root); diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index 099f7ee..c2c38bd 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -21,7 +21,8 @@ static inline struct btrfs_header *btrfs_buffer_header(struct buffer_head *bh) } struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr); -struct buffer_head *find_tree_block(struct btrfs_root *root, u64 blocknr); +struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root, + u64 blocknr); int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct buffer_head *buf); int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -37,5 +38,5 @@ int close_ctree(struct btrfs_root *root); void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf); int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root *root); -int mkfs(int fd, u64 num_blocks, u32 blocksize); +struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr); #endif diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 176c6dc..b2ae8e7 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -172,8 +172,8 @@ static int pin_down_block(struct btrfs_root *root, u64 blocknr, int pending) struct buffer_head *bh; if (!pending) { - bh = sb_find_get_block(root->fs_info->sb, blocknr); - if (bh) { + bh = btrfs_find_tree_block(root, blocknr); + if (bh && buffer_uptodate(bh)) { header = btrfs_buffer_header(bh); if (btrfs_header_generation(header) == root->fs_info->running_transaction->transid) { @@ -291,12 +291,10 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 blocknr, u64 num_blocks, int pin) { struct btrfs_root *extent_root = root->fs_info->extent_root; - struct buffer_head *t; int pending_ret; int ret; if (root == extent_root) { - t = find_tree_block(root, blocknr); pin_down_block(root, blocknr, 1); return 0; } @@ -482,7 +480,7 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, BUG(); return NULL; } - buf = find_tree_block(root, ins.objectid); + buf = btrfs_find_create_tree_block(root, ins.objectid); set_buffer_uptodate(buf); return buf; } diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 67659b6..8f07f46 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -474,6 +474,8 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent) disk_super = (struct btrfs_super_block *)bh->b_data; root = open_ctree(sb, bh, disk_super); sb->s_fs_info = root; + disk_super = root->fs_info->disk_super; + if (!root) { printk("btrfs: open_ctree failed\n"); return -EIO; @@ -734,15 +736,15 @@ static int btrfs_sync_fs(struct super_block *sb, int wait) struct btrfs_trans_handle *trans; struct btrfs_root *root; int ret; + root = btrfs_sb(sb); sb->s_dirt = 0; if (!wait) { - filemap_flush(sb->s_bdev->bd_inode->i_mapping); + filemap_flush(root->fs_info->btree_inode->i_mapping); return 0; } - filemap_write_and_wait(sb->s_bdev->bd_inode->i_mapping); + filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); - root = btrfs_sb(sb); mutex_lock(&root->fs_info->fs_mutex); trans = btrfs_start_transaction(root, 1); ret = btrfs_commit_transaction(trans, root); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 46a596e..b20fb53 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -74,7 +74,7 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans, int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - filemap_write_and_wait(root->fs_info->sb->s_bdev->bd_inode->i_mapping); + filemap_write_and_wait(root->fs_info->btree_inode->i_mapping); return 0; } -- cgit v1.1