From dee26a9f7aab7ffe1193cd1415b23a69426acc9f Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 26 Mar 2007 16:00:06 -0400 Subject: [PATCH] btrfs_get_block, file read/write Signed-off-by: Chris Mason --- fs/btrfs/TODO | 1 + fs/btrfs/ctree.h | 26 +++++- fs/btrfs/extent-tree.c | 4 +- fs/btrfs/file-item.c | 52 +++++++++++- fs/btrfs/super.c | 188 +++++++++++++++++++++++++++++++++-------- 5 files changed, 230 insertions(+), 41 deletions(-) diff --git a/fs/btrfs/TODO b/fs/btrfs/TODO index 454028b6bd46..2ca301b289a6 100644 --- a/fs/btrfs/TODO +++ b/fs/btrfs/TODO @@ -8,6 +8,7 @@ * Add block mapping tree (simple dm layer) * Add simple tree locking (semaphore per tree) * Make allocator smarter +* Make directory hashing work on 32 bit * Do actual block accounting * Check compat and incompat flags on the inode * Add virtual filesystems, mountable snapshots diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 0aa1052d9f67..7b7120d3ab42 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -198,7 +198,7 @@ struct btrfs_file_extent_item { __le64 disk_blocknr; __le64 disk_num_blocks; /* - * the logical offset in file bytes (no csums) + * the logical offset in file blocks (no csums) * this extent record is for. This allows a file extent to point * into the middle of an existing extent on disk, sharing it * between two snapshots (useful if some bytes in the middle of the @@ -812,12 +812,19 @@ static inline struct btrfs_root *btrfs_sb(struct super_block *sb) ((type *)(btrfs_leaf_data(leaf) + \ btrfs_item_offset((leaf)->items + (slot)))) +/* extent-item.c */ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, struct btrfs_root *root); +int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root + *root, u64 num_blocks, u64 search_start, u64 + search_end, u64 owner, struct btrfs_key *ins); int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct buffer_head *buf); int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 blocknr, u64 num_blocks, int pin); +int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct + btrfs_root *root); +/* ctree.c */ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *p, int ins_len, int cow); @@ -834,8 +841,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path); int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf); int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct buffer_head *snap); -int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct - btrfs_root *root); +/* root-item.c */ int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key); int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root @@ -846,6 +852,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root *item); int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct btrfs_root_item *item, struct btrfs_key *key); +/* dir-item.c */ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, u64 dir, u64 objectid, u8 type); @@ -854,6 +861,7 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root const char *name, int name_len, int mod); int btrfs_match_dir_item_name(struct btrfs_root *root, struct btrfs_path *path, const char *name, int name_len); +/* inode-map.c */ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans, struct btrfs_root *fs_root, u64 dirid, u64 *objectid); @@ -863,9 +871,21 @@ int btrfs_insert_inode_map(struct btrfs_trans_handle *trans, int btrfs_lookup_inode_map(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, int mod); +/* inode-item.c */ int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, struct btrfs_inode_item *inode_item); int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, int mod); + +/* file-item.c */ +int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 objectid, u64 offset, + u64 num_blocks, u64 hint_block, + u64 *result); +int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, u64 objectid, + u64 blocknr, u64 num_blocks, int mod); #endif diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index b14104276eea..82f6e9eed1d0 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -403,7 +403,7 @@ error: * * returns 0 if everything worked, non-zero otherwise. */ -static int alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root +int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_blocks, u64 search_start, u64 search_end, u64 owner, struct btrfs_key *ins) { @@ -458,7 +458,7 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, int ret; struct buffer_head *buf; - ret = alloc_extent(trans, root, 1, 0, (unsigned long)-1, + ret = btrfs_alloc_extent(trans, root, 1, 0, (unsigned long)-1, btrfs_header_parentid(btrfs_buffer_header(root->node)), &ins); if (ret) { BUG(); diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 8e1e5b4ccfaf..4a0367d702b7 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -1,9 +1,57 @@ #include #include "ctree.h" +#include "disk-io.h" #include "transaction.h" -int btrfs_create_file(struct btrfs_trans_handle *trans, - struct btrfs_root *root, u64 dirid, u64 *objectid) +int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 objectid, u64 offset, + u64 num_blocks, u64 hint_block, + u64 *result) { + struct btrfs_key ins; + int ret = 0; + struct btrfs_file_extent_item *item; + struct btrfs_key file_key; + struct btrfs_path path; + + btrfs_init_path(&path); + ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block, + (u64)-1, objectid, &ins); + BUG_ON(ret); + file_key.objectid = objectid; + file_key.offset = offset; + file_key.flags = 0; + btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); + + ret = btrfs_insert_empty_item(trans, root, &path, &file_key, + sizeof(*item)); + item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_disk_blocknr(item, ins.objectid); + btrfs_set_file_extent_disk_num_blocks(item, ins.offset); + btrfs_set_file_extent_offset(item, 0); + btrfs_set_file_extent_num_blocks(item, ins.offset); + mark_buffer_dirty(path.nodes[0]); + *result = ins.objectid; + btrfs_release_path(root, &path); return 0; } + +int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, u64 objectid, + u64 blocknr, u64 num_blocks, int mod) +{ + int ret; + struct btrfs_key file_key; + int ins_len = mod < 0 ? -1 : 0; + int cow = mod != 0; + + file_key.objectid = objectid; + file_key.offset = blocknr; + file_key.flags = 0; + btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY); + ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); + return ret; +} diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 905b093a85fe..2c2883f2856d 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "ctree.h" #include "disk-io.h" #include "transaction.h" @@ -17,6 +18,9 @@ static struct inode_operations btrfs_dir_inode_operations; static struct super_operations btrfs_super_ops; static struct file_operations btrfs_dir_file_operations; +static struct inode_operations btrfs_file_inode_operations; +static struct address_space_operations btrfs_aops; +static struct file_operations btrfs_file_operations; static void btrfs_read_locked_inode(struct inode *inode) { @@ -57,6 +61,9 @@ static void btrfs_read_locked_inode(struct inode *inode) break; #endif case S_IFREG: + inode->i_mapping->a_ops = &btrfs_aops; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; break; case S_IFDIR: inode->i_op = &btrfs_dir_inode_operations; @@ -214,35 +221,6 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, return d_splice_alias(inode, dentry); } -static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path) -{ - struct buffer_head *bh; - struct btrfs_node *node; - int i; - int nritems; - u64 objectid; - u64 item_objectid; - u64 blocknr; - int slot; - - if (!path->nodes[1]) - return; - node = btrfs_buffer_node(path->nodes[1]); - slot = path->slots[1]; - objectid = btrfs_disk_key_objectid(&node->ptrs[slot].key); - nritems = btrfs_header_nritems(&node->header); - for (i = slot; i < nritems; i++) { - item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key); - if (item_objectid != objectid) - break; - blocknr = btrfs_node_blockptr(node, i); - bh = sb_getblk(root->fs_info->sb, blocknr); - ll_rw_block(READ, 1, &bh); - brelse(bh); - } - -} - static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) { struct inode *inode = filp->f_path.dentry->d_inode; @@ -269,21 +247,18 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) goto err; } advance = 0; - reada_leaves(root, &path); while(1) { leaf = btrfs_buffer_leaf(path.nodes[0]); nritems = btrfs_header_nritems(&leaf->header); slot = path.slots[0]; - if (advance) { - if (slot == nritems -1) { + if (advance || slot >= nritems) { + if (slot >= nritems -1) { ret = btrfs_next_leaf(root, &path); if (ret) break; leaf = btrfs_buffer_leaf(path.nodes[0]); nritems = btrfs_header_nritems(&leaf->header); slot = path.slots[0]; - if (path.nodes[1] && path.slots[1] == 0) - reada_leaves(root, &path); } else { slot++; path.slots[0]++; @@ -297,6 +272,8 @@ static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir) continue; if (btrfs_disk_key_offset(&item->key) < filp->f_pos) continue; + + advance = 1; di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); over = filldir(dirent, (const char *)(di + 1), btrfs_dir_name_len(di), @@ -524,6 +501,11 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry, err = btrfs_add_nondir(trans, dentry, inode); if (err) drop_inode = 1; + else { + inode->i_mapping->a_ops = &btrfs_aops; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + } dir->i_sb->s_dirt = 1; btrfs_end_transaction(trans, root); out_unlock: @@ -623,11 +605,124 @@ printk("btrfs sync_fs\n"); return 0; } +static int btrfs_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *result, int create) +{ + int ret; + int err = 0; + u64 blocknr; + u64 extent_start = 0; + u64 extent_end = 0; + u64 objectid = inode->i_ino; + struct btrfs_path path; + struct btrfs_root *root = btrfs_sb(inode->i_sb); + struct btrfs_trans_handle *trans = NULL; + struct btrfs_file_extent_item *item; + struct btrfs_leaf *leaf; + struct btrfs_disk_key *found_key; + + btrfs_init_path(&path); + mutex_lock(&root->fs_info->fs_mutex); + if (create) + trans = btrfs_start_transaction(root, 1); + + + ret = btrfs_lookup_file_extent(trans, root, &path, + inode->i_ino, iblock, 1, 0); + if (ret < 0) { + btrfs_release_path(root, &path); + err = ret; + goto out; + } + + if (ret != 0) { + if (path.slots[0] == 0) { + btrfs_release_path(root, &path); + goto allocate; + } + path.slots[0]--; + } + + item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0], + struct btrfs_file_extent_item); + leaf = btrfs_buffer_leaf(path.nodes[0]); + blocknr = btrfs_file_extent_disk_blocknr(item); + blocknr += btrfs_file_extent_offset(item); + + /* exact match found, use it */ + if (ret == 0) { + err = 0; + map_bh(result, inode->i_sb, blocknr); + btrfs_release_path(root, &path); + goto out; + } + + /* are we inside the extent that was found? */ + found_key = &leaf->items[path.slots[0]].key; + if (btrfs_disk_key_objectid(found_key) != objectid || + btrfs_disk_key_type(found_key) != BTRFS_EXTENT_DATA_KEY) { + extent_end = 0; + extent_start = 0; + btrfs_release_path(root, &path); + goto allocate; + } + + extent_start = btrfs_disk_key_offset(&leaf->items[path.slots[0]].key); + extent_start += btrfs_file_extent_offset(item); + extent_end = extent_start + btrfs_file_extent_num_blocks(item); + btrfs_release_path(root, &path); + if (iblock >= extent_start && iblock < extent_end) { + err = 0; + map_bh(result, inode->i_sb, blocknr + iblock - extent_start); + goto out; + } +allocate: + /* ok, create a new extent */ + if (!create) { + err = 0; + goto out; + } + ret = btrfs_alloc_file_extent(trans, root, objectid, iblock, + 1, extent_end, &blocknr); + if (ret) { + err = ret; + goto out; + } + map_bh(result, inode->i_sb, blocknr); + +out: + if (trans) + btrfs_end_transaction(trans, root); + mutex_unlock(&root->fs_info->fs_mutex); + return err; +} + +static int btrfs_prepare_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + return block_prepare_write(page, from, to, btrfs_get_block); +} + static void btrfs_write_super(struct super_block *sb) { btrfs_sync_fs(sb, 1); } +static int btrfs_readpage(struct file *file, struct page *page) +{ + return mpage_readpage(page, btrfs_get_block); +} + +static int btrfs_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + return mpage_readpages(mapping, pages, nr_pages, btrfs_get_block); +} + +static int btrfs_writepage(struct page *page, struct writeback_control *wbc) +{ + return block_write_full_page(page, btrfs_get_block, wbc); +} static int btrfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) @@ -667,6 +762,31 @@ static struct file_operations btrfs_dir_file_operations = { .readdir = btrfs_readdir, }; +static struct address_space_operations btrfs_aops = { + .readpage = btrfs_readpage, + .readpages = btrfs_readpages, + .writepage = btrfs_writepage, + .sync_page = block_sync_page, + .prepare_write = btrfs_prepare_write, + .commit_write = generic_commit_write, +}; + +static struct inode_operations btrfs_file_inode_operations = { + .truncate = NULL, +}; + +static struct file_operations btrfs_file_operations = { + .llseek = generic_file_llseek, + .read = do_sync_read, + .write = do_sync_write, + .aio_read = generic_file_aio_read, + .aio_write = generic_file_aio_write, + .mmap = generic_file_mmap, + .open = generic_file_open, + .sendfile = generic_file_sendfile, + .splice_read = generic_file_splice_read, + .splice_write = generic_file_splice_write, +}; static int __init init_btrfs_fs(void) {