diff options
Diffstat (limited to 'fs/btrfs/ordered-data.c')
| -rw-r--r-- | fs/btrfs/ordered-data.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c new file mode 100644 index 00000000000..411aba84d30 --- /dev/null +++ b/fs/btrfs/ordered-data.c @@ -0,0 +1,221 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <linux/gfp.h> +#include <linux/slab.h> +#include "ctree.h" +#include "transaction.h" +#include "btrfs_inode.h" + +struct tree_entry { + u64 root_objectid; + u64 objectid; + struct rb_node rb_node; +}; + +/* + * returns > 0 if entry passed (root, objectid) is > entry, + * < 0 if (root, objectid) < entry and zero if they are equal + */ +static int comp_entry(struct tree_entry *entry, u64 root_objectid, + u64 objectid) +{ + if (root_objectid < entry->root_objectid) + return -1; + if (root_objectid > entry->root_objectid) + return 1; + if (objectid < entry->objectid) + return -1; + if (objectid > entry->objectid) + return 1; + return 0; +} + +static struct rb_node *tree_insert(struct rb_root *root, u64 root_objectid, + u64 objectid, struct rb_node *node) +{ + struct rb_node ** p = &root->rb_node; + struct rb_node * parent = NULL; + struct tree_entry *entry; + int comp; + + while(*p) { + parent = *p; + entry = rb_entry(parent, struct tree_entry, rb_node); + + comp = comp_entry(entry, root_objectid, objectid); + if (comp < 0) + p = &(*p)->rb_left; + else if (comp > 0) + p = &(*p)->rb_right; + else + return parent; + } + + rb_link_node(node, parent, p); + rb_insert_color(node, root); + return NULL; +} + +static struct rb_node *__tree_search(struct rb_root *root, u64 root_objectid, + u64 objectid, struct rb_node **prev_ret) +{ + struct rb_node * n = root->rb_node; + struct rb_node *prev = NULL; + struct tree_entry *entry; + struct tree_entry *prev_entry = NULL; + int comp; + + while(n) { + entry = rb_entry(n, struct tree_entry, rb_node); + prev = n; + prev_entry = entry; + comp = comp_entry(entry, root_objectid, objectid); + + if (comp < 0) + n = n->rb_left; + else if (comp > 0) + n = n->rb_right; + else + return n; + } + if (!prev_ret) + return NULL; + + while(prev && comp_entry(prev_entry, root_objectid, objectid) >= 0) { + prev = rb_next(prev); + prev_entry = rb_entry(prev, struct tree_entry, rb_node); + } + *prev_ret = prev; + return NULL; +} + +static inline struct rb_node *tree_search(struct rb_root *root, + u64 root_objectid, u64 objectid) +{ + struct rb_node *prev; + struct rb_node *ret; + ret = __tree_search(root, root_objectid, objectid, &prev); + if (!ret) + return prev; + return ret; +} + +int btrfs_add_ordered_inode(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 root_objectid = root->root_key.objectid; + u64 transid = root->fs_info->running_transaction->transid; + struct tree_entry *entry; + struct rb_node *node; + struct btrfs_ordered_inode_tree *tree; + + if (transid <= BTRFS_I(inode)->ordered_trans) + return 0; + + tree = &root->fs_info->running_transaction->ordered_inode_tree; + + read_lock(&tree->lock); + node = __tree_search(&tree->tree, root_objectid, inode->i_ino, NULL); + read_unlock(&tree->lock); + if (node) { + return 0; + } + + entry = kmalloc(sizeof(*entry), GFP_NOFS); + if (!entry) + return -ENOMEM; + + write_lock(&tree->lock); + entry->objectid = inode->i_ino; + entry->root_objectid = root_objectid; + + node = tree_insert(&tree->tree, root_objectid, + inode->i_ino, &entry->rb_node); + + BTRFS_I(inode)->ordered_trans = transid; + + write_unlock(&tree->lock); + if (node) + kfree(entry); + return 0; +} + +int btrfs_find_first_ordered_inode(struct btrfs_ordered_inode_tree *tree, + u64 *root_objectid, u64 *objectid) +{ + struct tree_entry *entry; + struct rb_node *node; + + write_lock(&tree->lock); + node = tree_search(&tree->tree, *root_objectid, *objectid); + if (!node) { + write_unlock(&tree->lock); + return 0; + } + entry = rb_entry(node, struct tree_entry, rb_node); + + while(comp_entry(entry, *root_objectid, *objectid) >= 0) { + node = rb_next(node); + if (!node) + break; + entry = rb_entry(node, struct tree_entry, rb_node); + } + if (!node) { + write_unlock(&tree->lock); + return 0; + } + + *root_objectid = entry->root_objectid; + *objectid = entry->objectid; + write_unlock(&tree->lock); + return 1; +} + +int btrfs_find_del_first_ordered_inode(struct btrfs_ordered_inode_tree *tree, + u64 *root_objectid, u64 *objectid) +{ + struct tree_entry *entry; + struct rb_node *node; + + write_lock(&tree->lock); + node = tree_search(&tree->tree, *root_objectid, *objectid); + if (!node) { + write_unlock(&tree->lock); + return 0; + } + + entry = rb_entry(node, struct tree_entry, rb_node); + while(comp_entry(entry, *root_objectid, *objectid) >= 0) { + node = rb_next(node); + if (!node) + break; + entry = rb_entry(node, struct tree_entry, rb_node); + } + if (!node) { + write_unlock(&tree->lock); + return 0; + } + + *root_objectid = entry->root_objectid; + *objectid = entry->objectid; + rb_erase(node, &tree->tree); + write_unlock(&tree->lock); + kfree(entry); + return 1; +} |