Btrfs: snapshot progress
[linux-2.6-block.git] / fs / btrfs / disk-io.c
index bb133104e2e91213cafddb63263db15b923f18b2..6b097ede80b1329a5f9987620f3ecc8f771e8fef 100644 (file)
@@ -4,21 +4,11 @@
 #include <linux/crypto.h>
 #include <linux/scatterlist.h>
 #include <linux/swap.h>
+#include <linux/radix-tree.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
-
-#define PATTERN 0xDEADBEEFUL
-static inline void check_pattern(struct buffer_head *buf)
-{
-       if (buf->b_private != (void *)PATTERN)
-               WARN_ON(1);
-}
-
-static inline void set_pattern(struct buffer_head *buf)
-{
-       buf->b_private = (void *)PATTERN;
-}
+#include "btrfs_inode.h"
 
 static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
 {
@@ -26,10 +16,6 @@ static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
        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();
-       }
        return 0;
 }
 
@@ -43,6 +29,7 @@ struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
        struct buffer_head *head;
        struct buffer_head *ret = NULL;
 
+
        page = find_lock_page(mapping, index);
        if (!page)
                return NULL;
@@ -64,7 +51,6 @@ out_unlock:
        unlock_page(page);
        if (ret) {
                touch_buffer(ret);
-               check_pattern(ret);
        }
        page_cache_release(page);
        return ret;
@@ -95,7 +81,6 @@ struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
                        bh->b_bdev = root->fs_info->sb->s_bdev;
                        bh->b_blocknr = first_block;
                        set_buffer_mapped(bh);
-                       set_pattern(bh);
                }
                if (bh->b_blocknr == blocknr) {
                        ret = bh;
@@ -173,7 +158,6 @@ static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
        int ret;
        struct btrfs_node *node;
 
-       return 0;
        ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
                              bh->b_size - BTRFS_CSUM_SIZE, result);
        if (ret)
@@ -193,9 +177,8 @@ static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
 
 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 {
-#if 0
        struct buffer_head *bh;
-       struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
+       struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
        struct buffer_head *head;
        if (!page_has_buffers(page)) {
                create_empty_buffers(page, root->fs_info->sb->s_blocksize,
@@ -208,7 +191,6 @@ static int btree_writepage(struct page *page, struct writeback_control *wbc)
                        csum_tree_block(root, bh, 0);
                bh = bh->b_this_page;
        } while (bh != head);
-#endif
        return block_write_full_page(page, btree_get_block, wbc);
 }
 
@@ -230,6 +212,8 @@ struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
        bh = btrfs_find_create_tree_block(root, blocknr);
        if (!bh)
                return bh;
+       if (buffer_uptodate(bh))
+               goto uptodate;
        lock_buffer(bh);
        if (!buffer_uptodate(bh)) {
                get_bh(bh);
@@ -239,17 +223,16 @@ struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
                if (!buffer_uptodate(bh))
                        goto fail;
                csum_tree_block(root, bh, 1);
-               set_pattern(bh);
        } else {
                unlock_buffer(bh);
        }
+uptodate:
        if (check_tree_block(root, bh))
                BUG();
        return bh;
 fail:
        brelse(bh);
        return NULL;
-
 }
 
 int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -268,22 +251,25 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
        return 0;
 }
 
-static int __setup_root(struct btrfs_super_block *super,
+static int __setup_root(int blocksize,
                        struct btrfs_root *root,
                        struct btrfs_fs_info *fs_info,
                        u64 objectid)
 {
        root->node = NULL;
+       root->inode = NULL;
        root->commit_root = NULL;
-       root->blocksize = btrfs_super_blocksize(super);
+       root->blocksize = blocksize;
        root->ref_cows = 0;
        root->fs_info = fs_info;
+       root->objectid = objectid;
+       root->last_trans = 0;
        memset(&root->root_key, 0, sizeof(root->root_key));
        memset(&root->root_item, 0, sizeof(root->root_item));
        return 0;
 }
 
-static int find_and_setup_root(struct btrfs_super_block *super,
+static int find_and_setup_root(int blocksize,
                               struct btrfs_root *tree_root,
                               struct btrfs_fs_info *fs_info,
                               u64 objectid,
@@ -291,7 +277,7 @@ static int find_and_setup_root(struct btrfs_super_block *super,
 {
        int ret;
 
-       __setup_root(super, root, fs_info, objectid);
+       __setup_root(blocksize, root, fs_info, objectid);
        ret = btrfs_find_last_root(tree_root, objectid,
                                   &root->root_item, &root->root_key);
        BUG_ON(ret);
@@ -302,12 +288,78 @@ static int find_and_setup_root(struct btrfs_super_block *super,
        return 0;
 }
 
-struct btrfs_root *open_ctree(struct super_block *sb,
-                             struct buffer_head *sb_buffer,
-                             struct btrfs_super_block *disk_super)
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+                                     struct btrfs_key *location)
+{
+       struct btrfs_root *root;
+       struct btrfs_root *tree_root = fs_info->tree_root;
+       struct btrfs_path *path;
+       struct btrfs_leaf *l;
+       int ret = 0;
+
+printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
+       root = kmalloc(sizeof(*root), GFP_NOFS);
+       if (!root) {
+printk("failed1\n");
+               return ERR_PTR(-ENOMEM);
+       }
+       if (location->offset == (u64)-1) {
+               ret = find_and_setup_root(fs_info->sb->s_blocksize,
+                                         fs_info->tree_root, fs_info,
+                                         location->objectid, root);
+               if (ret) {
+printk("failed2\n");
+                       kfree(root);
+                       return ERR_PTR(ret);
+               }
+               goto insert;
+       }
+
+       __setup_root(fs_info->sb->s_blocksize, root, fs_info,
+                    location->objectid);
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
+       if (ret != 0) {
+printk("internal search_slot gives us %d\n", ret);
+               if (ret > 0)
+                       ret = -ENOENT;
+               goto out;
+       }
+       l = btrfs_buffer_leaf(path->nodes[0]);
+       memcpy(&root->root_item,
+              btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
+              sizeof(root->root_item));
+       memcpy(&root->root_key, location, sizeof(*location));
+       ret = 0;
+out:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       if (ret) {
+               kfree(root);
+               return ERR_PTR(ret);
+       }
+       root->node = read_tree_block(root,
+                                    btrfs_root_blocknr(&root->root_item));
+       BUG_ON(!root->node);
+insert:
+printk("inserting %p\n", root);
+       root->ref_cows = 1;
+       ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root,
+                               root);
+       if (ret) {
+printk("radix_tree_insert gives us %d\n", ret);
+               brelse(root->node);
+               kfree(root);
+               return ERR_PTR(ret);
+       }
+printk("all worked\n");
+       return root;
+}
+
+struct btrfs_root *open_ctree(struct super_block *sb)
 {
-       struct btrfs_root *root = kmalloc(sizeof(struct btrfs_root),
-                                         GFP_NOFS);
        struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
                                                 GFP_NOFS);
        struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
@@ -317,84 +369,87 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
                                                GFP_NOFS);
        int ret;
+       struct btrfs_super_block *disk_super;
 
-       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);
+       INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
+       sb_set_blocksize(sb, 4096);
        fs_info->running_transaction = NULL;
-       fs_info->fs_root = root;
        fs_info->tree_root = tree_root;
        fs_info->extent_root = extent_root;
        fs_info->inode_root = inode_root;
        fs_info->last_inode_alloc = 0;
-       fs_info->last_inode_alloc_dirid = 0;
-       fs_info->disk_super = disk_super;
+       fs_info->highest_inode = 0;
        fs_info->sb = sb;
        fs_info->btree_inode = new_inode(sb);
        fs_info->btree_inode->i_ino = 1;
+       fs_info->btree_inode->i_nlink = 1;
        fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
        fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
+       BTRFS_I(fs_info->btree_inode)->root = tree_root;
+       memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
+              sizeof(struct btrfs_key));
        insert_inode_hash(fs_info->btree_inode);
-
        mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
        fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
        spin_lock_init(&fs_info->hash_lock);
-
        if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
                printk("failed to allocate sha256 hash\n");
                return NULL;
        }
-
        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);
+       __setup_root(sb->s_blocksize, tree_root,
+                    fs_info, BTRFS_ROOT_TREE_OBJECTID);
+       fs_info->sb_buffer = read_tree_block(tree_root,
+                                            BTRFS_SUPER_INFO_OFFSET /
+                                            sb->s_blocksize);
 
-       fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr);
-
-       if (!fs_info->sb_buffer) {
-printk("failed2\n");
+       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;
+       if (!btrfs_super_root(disk_super))
+               return NULL;
 
+       fs_info->disk_super = disk_super;
        tree_root->node = read_tree_block(tree_root,
                                          btrfs_super_root(disk_super));
        BUG_ON(!tree_root->node);
 
-       ret = find_and_setup_root(disk_super, tree_root, fs_info,
+       mutex_lock(&fs_info->fs_mutex);
+       ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
                                  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
        BUG_ON(ret);
 
-       ret = find_and_setup_root(disk_super, tree_root, fs_info,
+       ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
                                  BTRFS_INODE_MAP_OBJECTID, inode_root);
        BUG_ON(ret);
 
-       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;
-       root->fs_info->generation = root->root_key.offset + 1;
-       return root;
+       fs_info->generation = btrfs_super_generation(disk_super) + 1;
+       ret = btrfs_find_highest_inode(tree_root, &fs_info->last_inode_alloc);
+       if (ret == 0)
+               fs_info->highest_inode = fs_info->last_inode_alloc;
+       memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
+       kobj_set_kset_s(fs_info, btrfs_subsys);
+       kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
+       kobject_register(&fs_info->kobj);
+       mutex_unlock(&fs_info->fs_mutex);
+       return tree_root;
 }
 
 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
                      *root)
 {
        struct buffer_head *bh = root->fs_info->sb_buffer;
+
        btrfs_set_super_root(root->fs_info->disk_super,
                             root->fs_info->tree_root->node->b_blocknr);
        lock_buffer(bh);
+       WARN_ON(atomic_read(&bh->b_count) < 1);
        clear_buffer_dirty(bh);
        csum_tree_block(root, bh, 0);
        bh->b_end_io = end_buffer_write_sync;
@@ -408,11 +463,42 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
        return 0;
 }
 
+int del_fs_roots(struct btrfs_fs_info *fs_info)
+{
+       int ret;
+       struct btrfs_root *gang[8];
+       int i;
+
+       while(1) {
+               ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+                                            (void **)gang, 0,
+                                            ARRAY_SIZE(gang));
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       radix_tree_delete(&fs_info->fs_roots_radix,
+                                         (unsigned long)gang[i]);
+                       if (gang[i]->inode)
+                               iput(gang[i]->inode);
+                       else
+                               printk("no inode for root %p\n", gang[i]);
+                       if (gang[i]->node)
+                               brelse(gang[i]->node);
+                       if (gang[i]->commit_root)
+                               brelse(gang[i]->commit_root);
+                       kfree(gang[i]);
+               }
+       }
+       return 0;
+}
+
 int close_ctree(struct btrfs_root *root)
 {
        int ret;
        struct btrfs_trans_handle *trans;
+       struct btrfs_fs_info *fs_info = root->fs_info;
 
+       mutex_lock(&fs_info->fs_mutex);
        trans = btrfs_start_transaction(root, 1);
        btrfs_commit_transaction(trans, root);
        /* run commit again to  drop the original snapshot */
@@ -421,34 +507,31 @@ int close_ctree(struct btrfs_root *root)
        ret = btrfs_write_and_wait_transaction(NULL, root);
        BUG_ON(ret);
        write_ctree_super(NULL, root);
-
-       if (root->node)
-               btrfs_block_release(root, root->node);
-       if (root->fs_info->extent_root->node)
-               btrfs_block_release(root->fs_info->extent_root,
-                                   root->fs_info->extent_root->node);
-       if (root->fs_info->inode_root->node)
-               btrfs_block_release(root->fs_info->inode_root,
-                                   root->fs_info->inode_root->node);
-       if (root->fs_info->tree_root->node)
-               btrfs_block_release(root->fs_info->tree_root,
-                                   root->fs_info->tree_root->node);
-       btrfs_block_release(root, root->commit_root);
-       btrfs_block_release(root, root->fs_info->sb_buffer);
-       crypto_free_hash(root->fs_info->hash_tfm);
-       truncate_inode_pages(root->fs_info->btree_inode->i_mapping, 0);
-       iput(root->fs_info->btree_inode);
-       kfree(root->fs_info->extent_root);
-       kfree(root->fs_info->inode_root);
-       kfree(root->fs_info->tree_root);
-       kfree(root->fs_info);
-       kfree(root);
+       mutex_unlock(&fs_info->fs_mutex);
+
+       if (fs_info->extent_root->node)
+               btrfs_block_release(fs_info->extent_root,
+                                   fs_info->extent_root->node);
+       if (fs_info->inode_root->node)
+               btrfs_block_release(fs_info->inode_root,
+                                   fs_info->inode_root->node);
+       if (fs_info->tree_root->node)
+               btrfs_block_release(fs_info->tree_root,
+                                   fs_info->tree_root->node);
+       btrfs_block_release(root, fs_info->sb_buffer);
+       crypto_free_hash(fs_info->hash_tfm);
+       truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
+       iput(fs_info->btree_inode);
+       del_fs_roots(fs_info);
+       kfree(fs_info->extent_root);
+       kfree(fs_info->inode_root);
+       kfree(fs_info->tree_root);
+       kobject_unregister(&fs_info->kobj);
        return 0;
 }
 
 void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
 {
-       check_pattern(buf);
        brelse(buf);
 }