diff options
author | Dimitri John Ledkov <xnox@ubuntu.com> | 2017-10-18 13:15:59 +0100 |
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committer | Dimitri John Ledkov <xnox@ubuntu.com> | 2017-10-18 13:15:59 +0100 |
commit | 74d288e05c2d0cb97186f51049813b3e5b5bb0cd (patch) | |
tree | 4fc213398dc89e053d53ff7d42102942470e9cb5 /transaction.c | |
parent | 569a646293cd782de7665b6158514f3b48d229d3 (diff) |
New upstream release.
Diffstat (limited to 'transaction.c')
-rw-r--r-- | transaction.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/transaction.c b/transaction.c new file mode 100644 index 00000000..ad705728 --- /dev/null +++ b/transaction.c @@ -0,0 +1,185 @@ +/* + * 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 "kerncompat.h" +#include "disk-io.h" +#include "transaction.h" + +#include "messages.h" + +struct btrfs_trans_handle* btrfs_start_transaction(struct btrfs_root *root, + int num_blocks) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_trans_handle *h = kzalloc(sizeof(*h), GFP_NOFS); + + if (fs_info->transaction_aborted) + return ERR_PTR(-EROFS); + + if (!h) + return ERR_PTR(-ENOMEM); + if (root->commit_root) { + error("commit_root aleady set when starting transaction"); + kfree(h); + return ERR_PTR(-EINVAL); + } + if (fs_info->running_transaction) { + error("attempt to start transaction over already running one"); + kfree(h); + return ERR_PTR(-EINVAL); + } + h->fs_info = fs_info; + fs_info->running_transaction = h; + fs_info->generation++; + h->transid = fs_info->generation; + h->blocks_reserved = num_blocks; + root->last_trans = h->transid; + root->commit_root = root->node; + extent_buffer_get(root->node); + + return h; +} + +static int update_cowonly_root(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + int ret; + u64 old_root_bytenr; + struct btrfs_root *tree_root = root->fs_info->tree_root; + + btrfs_write_dirty_block_groups(trans, root); + while(1) { + old_root_bytenr = btrfs_root_bytenr(&root->root_item); + if (old_root_bytenr == root->node->start) + break; + btrfs_set_root_bytenr(&root->root_item, + root->node->start); + btrfs_set_root_generation(&root->root_item, + trans->transid); + root->root_item.level = btrfs_header_level(root->node); + ret = btrfs_update_root(trans, tree_root, + &root->root_key, + &root->root_item); + BUG_ON(ret); + btrfs_write_dirty_block_groups(trans, root); + } + return 0; +} + +int commit_tree_roots(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root; + struct list_head *next; + struct extent_buffer *eb; + int ret; + + if (fs_info->readonly) + return 0; + + eb = fs_info->tree_root->node; + extent_buffer_get(eb); + ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb); + free_extent_buffer(eb); + if (ret) + return ret; + + while(!list_empty(&fs_info->dirty_cowonly_roots)) { + next = fs_info->dirty_cowonly_roots.next; + list_del_init(next); + root = list_entry(next, struct btrfs_root, dirty_list); + update_cowonly_root(trans, root); + free_extent_buffer(root->commit_root); + root->commit_root = NULL; + } + + return 0; +} + +int __commit_transaction(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + u64 start; + u64 end; + struct btrfs_fs_info *fs_info = root->fs_info; + struct extent_buffer *eb; + struct extent_io_tree *tree = &fs_info->extent_cache; + int ret; + + while(1) { + ret = find_first_extent_bit(tree, 0, &start, &end, + EXTENT_DIRTY); + if (ret) + break; + while(start <= end) { + eb = find_first_extent_buffer(tree, start); + BUG_ON(!eb || eb->start != start); + ret = write_tree_block(trans, fs_info, eb); + BUG_ON(ret); + start += eb->len; + clear_extent_buffer_dirty(eb); + free_extent_buffer(eb); + } + } + return 0; +} + +int btrfs_commit_transaction(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + u64 transid = trans->transid; + int ret = 0; + struct btrfs_fs_info *fs_info = root->fs_info; + + if (trans->fs_info->transaction_aborted) + return -EROFS; + + if (root->commit_root == root->node) + goto commit_tree; + if (root == root->fs_info->tree_root) + goto commit_tree; + if (root == root->fs_info->chunk_root) + goto commit_tree; + + free_extent_buffer(root->commit_root); + root->commit_root = NULL; + + btrfs_set_root_bytenr(&root->root_item, root->node->start); + btrfs_set_root_generation(&root->root_item, trans->transid); + root->root_item.level = btrfs_header_level(root->node); + ret = btrfs_update_root(trans, root->fs_info->tree_root, + &root->root_key, &root->root_item); + BUG_ON(ret); +commit_tree: + ret = commit_tree_roots(trans, fs_info); + BUG_ON(ret); + ret = __commit_transaction(trans, root); + BUG_ON(ret); + write_ctree_super(trans, fs_info); + btrfs_finish_extent_commit(trans, fs_info->extent_root, + &fs_info->pinned_extents); + kfree(trans); + free_extent_buffer(root->commit_root); + root->commit_root = NULL; + fs_info->running_transaction = NULL; + fs_info->last_trans_committed = transid; + return 0; +} + +void btrfs_abort_transaction(struct btrfs_trans_handle *trans, int error) +{ + trans->fs_info->transaction_aborted = error; +} |