diff options
Diffstat (limited to 'fs/btrfs/tree-log.c')
| -rw-r--r-- | fs/btrfs/tree-log.c | 2804 |
1 files changed, 2804 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c new file mode 100644 index 000000000000..d1ce8314b948 --- /dev/null +++ b/fs/btrfs/tree-log.c @@ -0,0 +1,2804 @@ +/* + * Copyright (C) 2008 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/sched.h> +#include "ctree.h" +#include "transaction.h" +#include "disk-io.h" +#include "locking.h" +#include "print-tree.h" +#include "compat.h" + +/* magic values for the inode_only field in btrfs_log_inode: + * + * LOG_INODE_ALL means to log everything + * LOG_INODE_EXISTS means to log just enough to recreate the inode + * during log replay + */ +#define LOG_INODE_ALL 0 +#define LOG_INODE_EXISTS 1 + +/* + * stages for the tree walking. The first + * stage (0) is to only pin down the blocks we find + * the second stage (1) is to make sure that all the inodes + * we find in the log are created in the subvolume. + * + * The last stage is to deal with directories and links and extents + * and all the other fun semantics + */ +#define LOG_WALK_PIN_ONLY 0 +#define LOG_WALK_REPLAY_INODES 1 +#define LOG_WALK_REPLAY_ALL 2 + +static int __btrfs_log_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + int inode_only); + +/* + * tree logging is a special write ahead log used to make sure that + * fsyncs and O_SYNCs can happen without doing full tree commits. + * + * Full tree commits are expensive because they require commonly + * modified blocks to be recowed, creating many dirty pages in the + * extent tree an 4x-6x higher write load than ext3. + * + * Instead of doing a tree commit on every fsync, we use the + * key ranges and transaction ids to find items for a given file or directory + * that have changed in this transaction. Those items are copied into + * a special tree (one per subvolume root), that tree is written to disk + * and then the fsync is considered complete. + * + * After a crash, items are copied out of the log-tree back into the + * subvolume tree. Any file data extents found are recorded in the extent + * allocation tree, and the log-tree freed. + * + * The log tree is read three times, once to pin down all the extents it is + * using in ram and once, once to create all the inodes logged in the tree + * and once to do all the other items. + */ + +/* + * btrfs_add_log_tree adds a new per-subvolume log tree into the + * tree of log tree roots. This must be called with a tree log transaction + * running (see start_log_trans). + */ +int btrfs_add_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_key key; + struct btrfs_root_item root_item; + struct btrfs_inode_item *inode_item; + struct extent_buffer *leaf; + struct btrfs_root *new_root = root; + int ret; + u64 objectid = root->root_key.objectid; + + leaf = btrfs_alloc_free_block(trans, root, root->leafsize, + BTRFS_TREE_LOG_OBJECTID, + 0, 0, 0, 0, 0); + if (IS_ERR(leaf)) { + ret = PTR_ERR(leaf); + return ret; + } + + btrfs_set_header_nritems(leaf, 0); + btrfs_set_header_level(leaf, 0); + btrfs_set_header_bytenr(leaf, leaf->start); + btrfs_set_header_generation(leaf, trans->transid); + btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID); + + write_extent_buffer(leaf, root->fs_info->fsid, + (unsigned long)btrfs_header_fsid(leaf), + BTRFS_FSID_SIZE); + btrfs_mark_buffer_dirty(leaf); + + inode_item = &root_item.inode; + memset(inode_item, 0, sizeof(*inode_item)); + inode_item->generation = cpu_to_le64(1); + inode_item->size = cpu_to_le64(3); + inode_item->nlink = cpu_to_le32(1); + inode_item->nblocks = cpu_to_le64(1); + inode_item->mode = cpu_to_le32(S_IFDIR | 0755); + + btrfs_set_root_bytenr(&root_item, leaf->start); + btrfs_set_root_level(&root_item, 0); + btrfs_set_root_refs(&root_item, 0); + btrfs_set_root_used(&root_item, 0); + + memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); + root_item.drop_level = 0; + + btrfs_tree_unlock(leaf); + free_extent_buffer(leaf); + leaf = NULL; + + btrfs_set_root_dirid(&root_item, 0); + + key.objectid = BTRFS_TREE_LOG_OBJECTID; + key.offset = objectid; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key, + &root_item); + if (ret) + goto fail; + + new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree, + &key); + BUG_ON(!new_root); + + WARN_ON(root->log_root); + root->log_root = new_root; + + /* + * log trees do not get reference counted because they go away + * before a real commit is actually done. They do store pointers + * to file data extents, and those reference counts still get + * updated (along with back refs to the log tree). + */ + new_root->ref_cows = 0; + new_root->last_trans = trans->transid; +fail: + return ret; +} + +/* + * start a sub transaction and setup the log tree + * this increments the log tree writer count to make the people + * syncing the tree wait for us to finish + */ +static int start_log_trans(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + int ret; + mutex_lock(&root->fs_info->tree_log_mutex); + if (!root->fs_info->log_root_tree) { + ret = btrfs_init_log_root_tree(trans, root->fs_info); + BUG_ON(ret); + } + if (!root->log_root) { + ret = btrfs_add_log_tree(trans, root); + BUG_ON(ret); + } + atomic_inc(&root->fs_info->tree_log_writers); + root->fs_info->tree_log_batch++; + mutex_unlock(&root->fs_info->tree_log_mutex); + return 0; +} + +/* + * returns 0 if there was a log transaction running and we were able + * to join, or returns -ENOENT if there were not transactions + * in progress + */ +static int join_running_log_trans(struct btrfs_root *root) +{ + int ret = -ENOENT; + + smp_mb(); + if (!root->log_root) + return -ENOENT; + + mutex_lock(&root->fs_info->tree_log_mutex); + if (root->log_root) { + ret = 0; + atomic_inc(&root->fs_info->tree_log_writers); + root->fs_info->tree_log_batch++; + } + mutex_unlock(&root->fs_info->tree_log_mutex); + return ret; +} + +/* + * indicate we're done making changes to the log tree + * and wake up anyone waiting to do a sync + */ +static int end_log_trans(struct btrfs_root *root) +{ + atomic_dec(&root->fs_info->tree_log_writers); + smp_mb(); + if (waitqueue_active(&root->fs_info->tree_log_wait)) + wake_up(&root->fs_info->tree_log_wait); + return 0; +} + + +/* + * the walk control struct is used to pass state down the chain when + * processing the log tree. The stage field tells us which part + * of the log tree processing we are currently doing. The others + * are state fields used for that specific part + */ +struct walk_control { + /* should we free the extent on disk when done? This is used + * at transaction commit time while freeing a log tree + */ + int free; + + /* should we write out the extent buffer? This is used + * while flushing the log tree to disk during a sync + */ + int write; + + /* should we wait for the extent buffer io to finish? Also used + * while flushing the log tree to disk for a sync + */ + int wait; + + /* pin only walk, we record which extents on disk belong to the + * log trees + */ + int pin; + + /* what stage of the replay code we're currently in */ + int stage; + + /* the root we are currently replaying */ + struct btrfs_root *replay_dest; + + /* the trans handle for the current replay */ + struct btrfs_trans_handle *trans; + + /* the function that gets used to process blocks we find in the + * tree. Note the extent_buffer might not be up to date when it is + * passed in, and it must be checked or read if you need the data + * inside it + */ + int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb, + struct walk_control *wc, u64 gen); +}; + +/* + * process_func used to pin down extents, write them or wait on them + */ +static int process_one_buffer(struct btrfs_root *log, + struct extent_buffer *eb, + struct walk_control *wc, u64 gen) +{ + if (wc->pin) { + mutex_lock(&log->fs_info->alloc_mutex); + btrfs_update_pinned_extents(log->fs_info->extent_root, + eb->start, eb->len, 1); + mutex_unlock(&log->fs_info->alloc_mutex); + } + + if (btrfs_buffer_uptodate(eb, gen)) { + if (wc->write) + btrfs_write_tree_block(eb); + if (wc->wait) + btrfs_wait_tree_block_writeback(eb); + } + return 0; +} + +/* + * Item overwrite used by replay and tree logging. eb, slot and key all refer + * to the src data we are copying out. + * + * root is the tree we are copying into, and path is a scratch + * path for use in this function (it should be released on entry and + * will be released on exit). + * + * If the key is already in the destination tree the existing item is + * overwritten. If the existing item isn't big enough, it is extended. + * If it is too large, it is truncated. + * + * If the key isn't in the destination yet, a new item is inserted. + */ +static noinline int overwrite_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *eb, int slot, + struct btrfs_key *key) +{ + int ret; + u32 item_size; + u64 saved_i_size = 0; + int save_old_i_size = 0; + unsigned long src_ptr; + unsigned long dst_ptr; + int overwrite_root = 0; + + if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) + overwrite_root = 1; + + item_size = btrfs_item_size_nr(eb, slot); + src_ptr = btrfs_item_ptr_offset(eb, slot); + + /* look for the key in the destination tree */ + ret = btrfs_search_slot(NULL, root, key, path, 0, 0); + if (ret == 0) { + char *src_copy; + char *dst_copy; + u32 dst_size = btrfs_item_size_nr(path->nodes[0], + path->slots[0]); + if (dst_size != item_size) + goto insert; + + if (item_size == 0) { + btrfs_release_path(root, path); + return 0; + } + dst_copy = kmalloc(item_size, GFP_NOFS); + src_copy = kmalloc(item_size, GFP_NOFS); + + read_extent_buffer(eb, src_copy, src_ptr, item_size); + + dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); + read_extent_buffer(path->nodes[0], dst_copy, dst_ptr, + item_size); + ret = memcmp(dst_copy, src_copy, item_size); + + kfree(dst_copy); + kfree(src_copy); + /* + * they have the same contents, just return, this saves + * us from cowing blocks in the destination tree and doing + * extra writes that may not have been done by a previous + * sync + */ + if (ret == 0) { + btrfs_release_path(root, path); + return 0; + } + + } +insert: + btrfs_release_path(root, path); + /* try to insert the key into the destination tree */ + ret = btrfs_insert_empty_item(trans, root, path, + key, item_size); + + /* make sure any existing item is the correct size */ + if (ret == -EEXIST) { + u32 found_size; + found_size = btrfs_item_size_nr(path->nodes[0], + path->slots[0]); + if (found_size > item_size) { + btrfs_truncate_item(trans, root, path, item_size, 1); + } else if (found_size < item_size) { + ret = btrfs_del_item(trans, root, + path); + BUG_ON(ret); + + btrfs_release_path(root, path); + ret = btrfs_insert_empty_item(trans, + root, path, key, item_size); + BUG_ON(ret); + } + } else if (ret) { + BUG(); + } + dst_ptr = btrfs_item_ptr_offset(path->nodes[0], + path->slots[0]); + + /* don't overwrite an existing inode if the generation number + * was logged as zero. This is done when the tree logging code + * is just logging an inode to make sure it exists after recovery. + * + * Also, don't overwrite i_size on directories during replay. + * log replay inserts and removes directory items based on the + * state of the tree found in the subvolume, and i_size is modified + * as it goes + */ + if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) { + struct btrfs_inode_item *src_item; + struct btrfs_inode_item *dst_item; + + src_item = (struct btrfs_inode_item *)src_ptr; + dst_item = (struct btrfs_inode_item *)dst_ptr; + + if (btrfs_inode_generation(eb, src_item) == 0) + goto no_copy; + + if (overwrite_root && + S_ISDIR(btrfs_inode_mode(eb, src_item)) && + S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) { + save_old_i_size = 1; + saved_i_size = btrfs_inode_size(path->nodes[0], + dst_item); + } + } + + copy_extent_buffer(path->nodes[0], eb, dst_ptr, + src_ptr, item_size); + + if (save_old_i_size) { + struct btrfs_inode_item *dst_item; + dst_item = (struct btrfs_inode_item *)dst_ptr; + btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size); + } + + /* make sure the generation is filled in */ + if (key->type == BTRFS_INODE_ITEM_KEY) { + struct btrfs_inode_item *dst_item; + dst_item = (struct btrfs_inode_item *)dst_ptr; + if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) { + btrfs_set_inode_generation(path->nodes[0], dst_item, + trans->transid); + } + } +no_copy: + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_release_path(root, path); + return 0; +} + +/* + * simple helper to read an inode off the disk from a given root + * This can only be called for subvolume roots and not for the log + */ +static noinline struct inode *read_one_inode(struct btrfs_root *root, + u64 objectid) +{ + struct inode *inode; + inode = btrfs_iget_locked(root->fs_info->sb, objectid, root); + if (inode->i_state & I_NEW) { + BTRFS_I(inode)->root = root; + BTRFS_I(inode)->location.objectid = objectid; + BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.offset = 0; + btrfs_read_locked_inode(inode); + unlock_new_inode(inode); + + } + if (is_bad_inode(inode)) { + iput(inode); + inode = NULL; + } + return inode; +} + +/* replays a single extent in 'eb' at 'slot' with 'key' into the + * subvolume 'root'. path is released on entry and should be released + * on exit. + * + * extents in the log tree have not been allocated out of the extent + * tree yet. So, this completes the allocation, taking a reference + * as required if the extent already exists or creating a new extent + * if it isn't in the extent allocation tree yet. + * + * The extent is inserted into the file, dropping any existing extents + * from the file that overlap the new one. + */ +static noinline int replay_one_extent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *eb, int slot, + struct btrfs_key *key) +{ + int found_type; + u64 mask = root->sectorsize - 1; + u64 extent_end; + u64 alloc_hint; + u64 start = key->offset; + struct btrfs_file_extent_item *item; + struct inode *inode = NULL; + unsigned long size; + int ret = 0; + + item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); + found_type = btrfs_file_extent_type(eb, item); + + if (found_type == BTRFS_FILE_EXTENT_REG) + extent_end = start + btrfs_file_extent_num_bytes(eb, item); + else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + size = btrfs_file_extent_inline_len(eb, + btrfs_item_nr(eb, slot)); + extent_end = (start + size + mask) & ~mask; + } else { + ret = 0; + goto out; + } + + inode = read_one_inode(root, key->objectid); + if (!inode) { + ret = -EIO; + goto out; + } + + /* + * first check to see if we already have this extent in the + * file. This must be done before the btrfs_drop_extents run + * so we don't try to drop this extent. + */ + ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, + start, 0); + + if (ret == 0 && found_type == BTRFS_FILE_EXTENT_REG) { + struct btrfs_file_extent_item cmp1; + struct btrfs_file_extent_item cmp2; + struct btrfs_file_extent_item *existing; + struct extent_buffer *leaf; + + leaf = path->nodes[0]; + existing = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + + read_extent_buffer(eb, &cmp1, (unsigned long)item, + sizeof(cmp1)); + read_extent_buffer(leaf, &cmp2, (unsigned long)existing, + sizeof(cmp2)); + + /* + * we already have a pointer to this exact extent, + * we don't have to do anything + */ + if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) { + btrfs_release_path(root, path); + goto out; + } + } + btrfs_release_path(root, path); + + /* drop any overlapping extents */ + ret = btrfs_drop_extents(trans, root, inode, + start, extent_end, start, &alloc_hint); + BUG_ON(ret); + + BUG_ON(ret); + if (found_type == BTRFS_FILE_EXTENT_REG) { + struct btrfs_key ins; + + ins.objectid = btrfs_file_extent_disk_bytenr(eb, item); + ins.offset = btrfs_file_extent_disk_num_bytes(eb, item); + ins.type = BTRFS_EXTENT_ITEM_KEY; + + /* insert the extent pointer in the file */ + ret = overwrite_item(trans, root, path, eb, slot, key); + BUG_ON(ret); + + /* + * is this extent already allocated in the extent + * allocation tree? If so, just add a reference + */ + ret = btrfs_lookup_extent(root, path, ins.objectid, ins.offset); + btrfs_release_path(root, path); + if (ret == 0) { + ret = btrfs_inc_extent_ref(trans, root, + ins.objectid, ins.offset, + root->root_key.objectid, + trans->transid, key->objectid, start); + } else { + /* + * insert the extent pointer in the extent + * allocation tree + */ + ret = btrfs_alloc_logged_extent(trans, root, + root->root_key.objectid, + trans->transid, key->objectid, + start, &ins); + BUG_ON(ret); + } + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + /* inline extents are easy, we just overwrite them */ + ret = overwrite_item(trans, root, path, eb, slot, key); + BUG_ON(ret); + } + /* btrfs_drop_extents changes i_blocks, update it here */ + inode->i_blocks += (extent_end - start) >> 9; + btrfs_update_inode(trans, root, inode); +out: + if (inode) + iput(inode); + return ret; +} + +/* + * when cleaning up conflicts between the directory names in the + * subvolume, directory names in the log and directory names in the + * inode back references, we may have to unlink inodes from directories. + * + * This is a helper function to do the unlink of a specific directory + * item + */ +static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct inode *dir, + struct btrfs_dir_item *di) +{ + struct inode *inode; + char *name; + int name_len; + struct extent_buffer *leaf; + struct btrfs_key location; + int ret; + + leaf = path->nodes[0]; + + btrfs_dir_item_key_to_cpu(leaf, di, &location); + name_len = btrfs_dir_name_len(leaf, di); + name = kmalloc(name_len, GFP_NOFS); + read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len); + btrfs_release_path(root, path); + + inode = read_one_inode(root, location.objectid); + BUG_ON(!inode); + + btrfs_inc_nlink(inode); + ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len); + kfree(name); + + iput(inode); + return ret; +} + +/* + * helper function to see if a given name and sequence number found + * in an inode back reference are already in a directory and correctly + * point to this inode + */ +static noinline int inode_in_dir(struct btrfs_root *root, + struct btrfs_path *path, + u64 dirid, u64 objectid, u64 index, + const char *name, int name_len) +{ + struct btrfs_dir_item *di; + struct btrfs_key location; + int match = 0; + + di = btrfs_lookup_dir_index_item(NULL, root, path, dirid, + index, name, name_len, 0); + if (di && !IS_ERR(di)) { + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); + if (location.objectid != objectid) + goto out; + } else + goto out; + btrfs_release_path(root, path); + + di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0); + if (di && !IS_ERR(di)) { + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); + if (location.objectid != objectid) + goto out; + } else + goto out; + match = 1; +out: + btrfs_release_path(root, path); + return match; +} + +/* + * helper function to check a log tree for a named back reference in + * an inode. This is used to decide if a back reference that is + * found in the subvolume conflicts with what we find in the log. + * + * inode backreferences may have multiple refs in a single item, + * during replay we process one reference at a time, and we don't + * want to delete valid links to a file from the subvolume if that + * link is also in the log. + */ +static noinline int backref_in_log(struct btrfs_root *log, + struct btrfs_key *key, + char *name, int namelen) +{ + struct btrfs_path *path; + struct btrfs_inode_ref *ref; + unsigned long ptr; + unsigned long ptr_end; + unsigned long name_ptr; + int found_name_len; + int item_size; + int ret; + int match = 0; + + path = btrfs_alloc_path(); + ret = btrfs_search_slot(NULL, log, key, path, 0, 0); + if (ret != 0) + goto out; + + item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); + ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); + ptr_end = ptr + item_size; + while (ptr < ptr_end) { + ref = (struct btrfs_inode_ref *)ptr; + found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref); + if (found_name_len == namelen) { + name_ptr = (unsigned long)(ref + 1); + ret = memcmp_extent_buffer(path->nodes[0], name, + name_ptr, namelen); + if (ret == 0) { + match = 1; + goto out; + } + } + ptr = (unsigned long)(ref + 1) + found_name_len; + } +out: + btrfs_free_path(path); + return match; +} + + +/* + * replay one inode back reference item found in the log tree. + * eb, slot and key refer to the buffer and key found in the log tree. + * root is the destination we are replaying into, and path is for temp + * use by this function. (it should be released on return). + */ +static noinline int add_inode_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_root *log, + struct btrfs_path *path, + struct extent_buffer *eb, int slot, + struct btrfs_key *key) +{ + struct inode *dir; + int ret; + struct btrfs_key location; + struct btrfs_inode_ref *ref; + struct btrfs_dir_item *di; + struct inode *inode; + char *name; + int namelen; + unsigned long ref_ptr; + unsigned long ref_end; + + location.objectid = key->objectid; + location.type = BTRFS_INODE_ITEM_KEY; + location.offset = 0; + + /* + * it is possible that we didn't log all the parent directories + * for a given inode. If we don't find the dir, just don't + * copy the back ref in. The link count fixup code will take + * care of the rest + */ + dir = read_one_inode(root, key->offset); + if (!dir) + return -ENOENT; + + inode = read_one_inode(root, key->objectid); + BUG_ON(!dir); + + ref_ptr = btrfs_item_ptr_offset(eb, slot); + ref_end = ref_ptr + btrfs_item_size_nr(eb, slot); + +again: + ref = (struct btrfs_inode_ref *)ref_ptr; + + namelen = btrfs_inode_ref_name_len(eb, ref); + name = kmalloc(namelen, GFP_NOFS); + BUG_ON(!name); + + read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen); + + /* if we already have a perfect match, we're done */ + if (inode_in_dir(root, path, dir->i_ino, inode->i_ino, + btrfs_inode_ref_index(eb, ref), + name, namelen)) { + goto out; + } + + /* + * look for a conflicting back reference in the metadata. + * if we find one we have to unlink that name of the file + * before we add our new link. Later on, we overwrite any + * existing back reference, and we don't want to create + * dangling pointers in the directory. + */ +conflict_again: + ret = btrfs_search_slot(NULL, root, key, path, 0, 0); + if (ret == 0) { + char *victim_name; + int victim_name_len; + struct btrfs_inode_ref *victim_ref; + unsigned long ptr; + unsigned long ptr_end; + struct extent_buffer *leaf = path->nodes[0]; + + /* are we trying to overwrite a back ref for the root directory + * if so, just jump out, we're done + */ + if (key->objectid == key->offset) + goto out_nowrite; + + /* check all the names in this back reference to see + * if they are in the log. if so, we allow them to stay + * otherwise they must be unlinked as a conflict + */ + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]); + while(ptr < ptr_end) { + victim_ref = (struct btrfs_inode_ref *)ptr; + victim_name_len = btrfs_inode_ref_name_len(leaf, + victim_ref); + victim_name = kmalloc(victim_name_len, GFP_NOFS); + BUG_ON(!victim_name); + + read_extent_buffer(leaf, victim_name, + (unsigned long)(victim_ref + 1), + victim_name_len); + + if (!backref_in_log(log, key, victim_name, + victim_name_len)) { + btrfs_inc_nlink(inode); + btrfs_release_path(root, path); + ret = btrfs_unlink_inode(trans, root, dir, + inode, victim_name, + victim_name_len); + kfree(victim_name); + btrfs_release_path(root, path); + goto conflict_again; + } + kfree(victim_name); + ptr = (unsigned long)(victim_ref + 1) + victim_name_len; + } + BUG_ON(ret); + } + btrfs_release_path(root, path); + + /* look for a conflicting sequence number */ + di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, + btrfs_inode_ref_index(eb, ref), + name, namelen, 0); + if (di && !IS_ERR(di)) { + ret = drop_one_dir_item(trans, root, path, dir, di); + BUG_ON(ret); + } + btrfs_release_path(root, path); + + + /* look for a conflicting name */ + di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino, + name, namelen, 0); + if (di && !IS_ERR(di)) { + ret = drop_one_dir_item(trans, root, path, dir, di); + BUG_ON(ret); + } + btrfs_release_path(root, path); + + /* insert our name */ + ret = btrfs_add_link(trans, dir, inode, name, namelen, 0, + btrfs_inode_ref_index(eb, ref)); + BUG_ON(ret); + + btrfs_update_inode(trans, root, inode); + +out: + ref_ptr = (unsigned long)(ref + 1) + namelen; + kfree(name); + if (ref_ptr < ref_end) + goto again; + + /* finally write the back reference in the inode */ + ret = overwrite_item(trans, root, path, eb, slot, key); + BUG_ON(ret); + +out_nowrite: + btrfs_release_path(root, path); + iput(dir); + iput(inode); + return 0; +} + +/* + * replay one csum item from the log tree into the subvolume 'root' + * eb, slot and key all refer to the log tree + * path is for temp use by this function and should be released on return + * + * This copies the checksums out of the log tree and inserts them into + * the subvolume. Any existing checksums for this range in the file + * are overwritten, and new items are added where required. + * + * We keep this simple by reusing the btrfs_ordered_sum code from + * the data=ordered mode. This basically means making a copy + * of all the checksums in ram, which we have to do anyway for kmap + * rules. + * + * The copy is then sent down to btrfs_csum_file_blocks, which + * does all the hard work of finding existing items in the file + * or adding new ones. + */ +static noinline int replay_one_csum(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *eb, int slot, + struct btrfs_key *key) +{ + int ret; + u32 item_size = btrfs_item_size_nr(eb, slot); + u64 cur_offset; + unsigned long file_bytes; + struct btrfs_ordered_sum *sums; + struct btrfs_sector_sum *sector_sum; + struct inode *inode; + unsigned long ptr; + + file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize; + inode = read_one_inode(root, key->objectid); + if (!inode) { + return -EIO; + } + + sums = kzalloc(btrfs_ordered_sum_size(root, file_bytes), GFP_NOFS); + if (!sums) { + iput(inode); + return -ENOMEM; + } + + INIT_LIST_HEAD(&sums->list); + sums->len = file_bytes; + sums->file_offset = key->offset; + + /* + * copy all the sums into the ordered sum struct + */ + sector_sum = sums->sums; + cur_offset = key->offset; + ptr = btrfs_item_ptr_offset(eb, slot); + while(item_size > 0) { + sector_sum->offset = cur_offset; + read_extent_buffer(eb, §or_sum->sum, ptr, BTRFS_CRC32_SIZE); + sector_sum++; + item_size -= BTRFS_CRC32_SIZE; + ptr += BTRFS_CRC32_SIZE; + cur_offset += root->sectorsize; + } + + /* let btrfs_csum_file_blocks add them into the file */ + ret = btrfs_csum_file_blocks(trans, root, inode, sums); + BUG_ON(ret); + kfree(sums); + iput(inode); + + return 0; +} +/* + * There are a few corners where the link count of the file can't + * be properly maintained during replay. So, instead of adding + * lots of complexity to the log code, we just scan the backrefs + * for any file that has been through replay. + * + * The scan will update the link count on the inode to reflect the + * number of back refs found. If it goes down to zero, the iput + * will free the inode. + */ +static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode) +{ + struct btrfs_path *path; + int ret; + struct btrfs_key key; + u64 nlink = 0; + unsigned long ptr; + unsigned long ptr_end; + int name_len; + + key.objectid = inode->i_ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = (u64)-1; + + path = btrfs_alloc_path(); + + while(1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + break; + if (ret > 0) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid != inode->i_ino || + key.type != BTRFS_INODE_REF_KEY) + break; + ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); + ptr_end = ptr + btrfs_item_size_nr(path->nodes[0], + path->slots[0]); + while(ptr < ptr_end) { + struct btrfs_inode_ref *ref; + + ref = (struct btrfs_inode_ref *)ptr; + name_len = btrfs_inode_ref_name_len(path->nodes[0], + ref); + ptr = (unsigned long)(ref + 1) + name_len; + nlink++; + } + + if (key.offset == 0) + break; + key.offset--; + btrfs_release_path(root, path); + } + btrfs_free_path(path); + if (nlink != inode->i_nlink) { + inode->i_nlink = nlink; + btrfs_update_inode(trans, root, inode); + } + + return 0; +} + +static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path) +{ + int ret; + struct btrfs_key key; + struct inode *inode; + + key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = (u64)-1; + while(1) { + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + break; + + if (ret == 1) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID || + key.type != BTRFS_ORPHAN_ITEM_KEY) + break; + + ret = btrfs_del_item(trans, root, path); + BUG_ON(ret); + + btrfs_release_path(root, path); + inode = read_one_inode(root, key.offset); + BUG_ON(!inode); + + ret = fixup_inode_link_count(trans, root, inode); + BUG_ON(ret); + + iput(inode); + + if (key.offset == 0) + break; + key.offset--; + } + btrfs_release_path(root, path); + return 0; +} + + +/* + * record a given inode in the fixup dir so we can check its link + * count when replay is done. The link count is incremented here + * so the inode won't go away until we check it + */ +static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + u64 objectid) +{ + struct btrfs_key key; + int ret = 0; + struct inode *inode; + + inode = read_one_inode(root, objectid); + BUG_ON(!inode); + + key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; + btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); + key.offset = objectid; + + ret = btrfs_insert_empty_item(trans, root, path, &key, 0); + + btrfs_release_path(root, path); + if (ret == 0) { + btrfs_inc_nlink(inode); + btrfs_update_inode(trans, root, inode); + } else if (ret == -EEXIST) { + ret = 0; + } else { + BUG(); + } + iput(inode); + + return ret; +} + +/* + * when replaying the log for a directory, we only insert names + * for inodes that actually exist. This means an fsync on a directory + * does not implicitly fsync all the new files in it + */ +static noinline int insert_one_name(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + u64 dirid, u64 index, + char *name, int name_len, u8 type, + struct btrfs_key *location) +{ + struct inode *inode; + struct inode *dir; + int ret; + + inode = read_one_inode(root, location->objectid); + if (!inode) + return -ENOENT; + + dir = read_one_inode(root, dirid); + if (!dir) { + iput(inode); + return -EIO; + } + ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index); + + /* FIXME, put inode into FIXUP list */ + + iput(inode); + iput(dir); + return ret; +} + +/* + * take a single entry in a log directory item and replay it into + * the subvolume. + * + * if a conflicting item exists in the subdirectory already, + * the inode it points to is unlinked and put into the link count + * fix up tree. + * + * If a name from the log points to a file or directory that does + * not exist in the FS, it is skipped. fsyncs on directories + * do not force down inodes inside that directory, just changes to the + * names or unlinks in a directory. + */ +static noinline int replay_one_name(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *eb, + struct btrfs_dir_item *di, + struct btrfs_key *key) +{ + char *name; + int name_len; + struct btrfs_dir_item *dst_di; + struct btrfs_key found_key; + struct btrfs_key log_key; + struct inode *dir; + struct inode *inode; + u8 log_type; + int ret; + + dir = read_one_inode(root, key->objectid); + BUG_ON(!dir); + + name_len = btrfs_dir_name_len(eb, di); + name = kmalloc(name_len, GFP_NOFS); + log_type = btrfs_dir_type(eb, di); + read_extent_buffer(eb, name, (unsigned long)(di + 1), + name_len); + + btrfs_dir_item_key_to_cpu(eb, di, &log_key); + if (key->type == BTRFS_DIR_ITEM_KEY) { + dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid, + name, name_len, 1); + } + else if (key->type == BTRFS_DIR_INDEX_KEY) { + dst_di = btrfs_lookup_dir_index_item(trans, root, path, + key->objectid, + key->offset, name, + name_len, 1); + } else { + BUG(); + } + if (!dst_di || IS_ERR(dst_di)) { + /* we need a sequence number to insert, so we only + * do inserts for the BTRFS_DIR_INDEX_KEY types + */ + if (key->type != BTRFS_DIR_INDEX_KEY) + goto out; + goto insert; + } + + btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key); + /* the existing item matches the logged item */ + if (found_key.objectid == log_key.objectid && + found_key.type == log_key.type && + found_key.offset == log_key.offset && + btrfs_dir_type(path->nodes[0], dst_di) == log_type) { + goto out; + } + + /* + * don't drop the conflicting directory entry if the inode + * for the new entry doesn't exist + */ + inode = read_one_inode(root, log_key.objectid); + if (!inode) + goto out; + + iput(inode); + ret = drop_one_dir_item(trans, root, path, dir, dst_di); + BUG_ON(ret); + + if (key->type == BTRFS_DIR_INDEX_KEY) + goto insert; +out: + btrfs_release_path(root, path); + kfree(name); + iput(dir); + return 0; + +insert: + btrfs_release_path(root, path); + ret = insert_one_name(trans, root, path, key->objectid, key->offset, + name, name_len, log_type, &log_key); + + if (ret && ret != -ENOENT) + BUG(); + goto out; +} + +/* + * find all the names in a directory item and reconcile them into + * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than + * one name in a directory item, but the same code gets used for + * both directory index types + */ +static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *eb, int slot, + struct btrfs_key *key) +{ + int ret; + u32 item_size = btrfs_item_size_nr(eb, slot); + struct btrfs_dir_item *di; + int name_len; + unsigned long ptr; + unsigned long ptr_end; + + ptr = btrfs_item_ptr_offset(eb, slot); + ptr_end = ptr + item_size; + while(ptr < ptr_end) { + di = (struct btrfs_dir_item *)ptr; + name_len = btrfs_dir_name_len(eb, di); + ret = replay_one_name(trans, root, path, eb, di, key); + BUG_ON(ret); + ptr = (unsigned long)(di + 1); + ptr += name_len; + } + return 0; +} + +/* + * directory replay has two parts. There are the standard directory + * items in the log copied from the subvolume, and range items + * created in the log while the subvolume was logged. + * + * The range items tell us which parts of the key space the log + * is authoritative for. During replay, if a key in the subvolume + * directory is in a logged range item, but not actually in the log + * that means it was deleted from the directory before the fsync + * and should be removed. + */ +static noinline int find_dir_range(struct btrfs_root *root, + struct btrfs_path *path, + u64 dirid, int key_type, + u64 *start_ret, u64 *end_ret) +{ + struct btrfs_key key; + u64 found_end; + struct btrfs_dir_log_item *item; + int ret; + int nritems; + + if (*start_ret == (u64)-1) + return 1; + + key.objectid = dirid; + key.type = key_type; + key.offset = *start_ret; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { + if (path->slots[0] == 0) + goto out; + path->slots[0]--; + } + if (ret != 0) + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type != key_type || key.objectid != dirid) { + ret = 1; + goto next; + } + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_log_item); + found_end = btrfs_dir_log_end(path->nodes[0], item); + + if (*start_ret >= key.offset && *start_ret <= found_end) { + ret = 0; + *start_ret = key.offset; + *end_ret = found_end; + goto out; + } + ret = 1; +next: + /* check the next slot in the tree to see if it is a valid item */ + nritems = btrfs_header_nritems(path->nodes[0]); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) + goto out; + } else { + path->slots[0]++; + } + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type != key_type || key.objectid != dirid) { + ret = 1; + goto out; + } + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_log_item); + found_end = btrfs_dir_log_end(path->nodes[0], item); + *start_ret = key.offset; + *end_ret = found_end; + ret = 0; +out: + btrfs_release_path(root, path); + return ret; +} + +/* + * this looks for a given directory item in the log. If the directory + * item is not in the log, the item is removed and the inode it points + * to is unlinked + */ +static noinline int check_item_in_log(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_root *log, + struct btrfs_path *path, + struct btrfs_path *log_path, + struct inode *dir, + struct btrfs_key *dir_key) +{ + int ret; + struct extent_buffer *eb; + int slot; + u32 item_size; + struct btrfs_dir_item *di; + struct btrfs_dir_item *log_di; + int name_len; + unsigned long ptr; + unsigned long ptr_end; + char *name; + struct inode *inode; + struct btrfs_key location; + +again: + eb = path->nodes[0]; + slot = path->slots[0]; + item_size = btrfs_item_size_nr(eb, slot); + ptr = btrfs_item_ptr_offset(eb, slot); + ptr_end = ptr + item_size; + while(ptr < ptr_end) { + di = (struct btrfs_dir_item *)ptr; + name_len = btrfs_dir_name_len(eb, di); + name = kmalloc(name_len, GFP_NOFS); + if (!name) { + ret = -ENOMEM; + goto out; + } + read_extent_buffer(eb, name, (unsigned long)(di + 1), + name_len); + log_di = NULL; + if (dir_key->type == BTRFS_DIR_ITEM_KEY) { + log_di = btrfs_lookup_dir_item(trans, log, log_path, + dir_key->objectid, + name, name_len, 0); + } else if (dir_key->type == BTRFS_DIR_INDEX_KEY) { + log_di = btrfs_lookup_dir_index_item(trans, log, + log_path, + dir_key->objectid, + dir_key->offset, + name, name_len, 0); + } + if (!log_di || IS_ERR(log_di)) { + btrfs_dir_item_key_to_cpu(eb, di, &location); + btrfs_release_path(root, path); + btrfs_release_path(log, log_path); + inode = read_one_inode(root, location.objectid); + BUG_ON(!inode); + + ret = link_to_fixup_dir(trans, root, + path, location.objectid); + BUG_ON(ret); + btrfs_inc_nlink(inode); + ret = btrfs_unlink_inode(trans, root, dir, inode, + name, name_len); + BUG_ON(ret); + kfree(name); + iput(inode); + + /* there might still be more names under this key + * check and repeat if required + */ + ret = btrfs_search_slot(NULL, root, dir_key, path, + 0, 0); + if (ret == 0) + goto again; + ret = 0; + goto out; + } + btrfs_release_path(log, log_path); + kfree(name); + + ptr = (unsigned long)(di + 1); + ptr += name_len; + } + ret = 0; +out: + btrfs_release_path(root, path); + btrfs_release_path(log, log_path); + return ret; +} + +/* + * deletion replay happens before we copy any new directory items + * out of the log or out of backreferences from inodes. It + * scans the log to find ranges of keys that log is authoritative for, + * and then scans the directory to find items in those ranges that are + * not present in the log. + * + * Anything we don't find in the log is unlinked and removed from the + * directory. + */ +static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_root *log, + struct btrfs_path *path, + u64 dirid) +{ + u64 range_start; + u64 range_end; + int key_type = BTRFS_DIR_LOG_ITEM_KEY; + int ret = 0; + struct btrfs_key dir_key; + struct btrfs_key found_key; + struct btrfs_path *log_path; + struct inode *dir; + + dir_key.objectid = dirid; + dir_key.type = BTRFS_DIR_ITEM_KEY; + log_path = btrfs_alloc_path(); + if (!log_path) + return -ENOMEM; + + dir = read_one_inode(root, dirid); + /* it isn't an error if the inode isn't there, that can happen + * because we replay the deletes before we copy in the inode item + * from the log + */ + if (!dir) { + btrfs_free_path(log_path); + return 0; + } +again: + range_start = 0; + range_end = 0; + while(1) { + ret = find_dir_range(log, path, dirid, key_type, + &range_start, &range_end); + if (ret != 0) + break; + + dir_key.offset = range_start; + while(1) { + int nritems; + ret = btrfs_search_slot(NULL, root, &dir_key, path, + 0, 0); + if (ret < 0) + goto out; + + nritems = btrfs_header_nritems(path->nodes[0]); + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) + break; + } + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + if (found_key.objectid != dirid || + found_key.type != dir_key.type) + goto next_type; + + if (found_key.offset > range_end) + break; + + ret = check_item_in_log(trans, root, log, path, + log_path, dir, &found_key); + BUG_ON(ret); + if (found_key.offset == (u64)-1) + break; + dir_key.offset = found_key.offset + 1; + } + btrfs_release_path(root, path); + if (range_end == (u64)-1) + break; + range_start = range_end + 1; + } + +next_type: + ret = 0; + if (key_type == BTRFS_DIR_LOG_ITEM_KEY) { + key_type = BTRFS_DIR_LOG_INDEX_KEY; + dir_key.type = BTRFS_DIR_INDEX_KEY; + btrfs_release_path(root, path); + goto again; + } +out: + btrfs_release_path(root, path); + btrfs_free_path(log_path); + iput(dir); + return ret; +} + +/* + * the process_func used to replay items from the log tree. This + * gets called in two different stages. The first stage just looks + * for inodes and makes sure they are all copied into the subvolume. + * + * The second stage copies all the other item types from the log into + * the subvolume. The two stage approach is slower, but gets rid of + * lots of complexity around inodes referencing other inodes that exist + * only in the log (references come from either directory items or inode + * back refs). + */ +static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb, + struct walk_control *wc, u64 gen) +{ + int nritems; + struct btrfs_path *path; + struct btrfs_root *root = wc->replay_dest; + struct btrfs_key key; + u32 item_size; + int level; + int i; + int ret; + + btrfs_read_buffer(eb, gen); + + level = btrfs_header_level(eb); + + if (level != 0) + return 0; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + nritems = btrfs_header_nritems(eb); + for (i = 0; i < nritems; i++) { + btrfs_item_key_to_cpu(eb, &key, i); + item_size = btrfs_item_size_nr(eb, i); + + /* inode keys are done during the first stage */ + if (key.type == BTRFS_INODE_ITEM_KEY && + wc->stage == LOG_WALK_REPLAY_INODES) { + struct inode *inode; + struct btrfs_inode_item *inode_item; + u32 mode; + + inode_item = btrfs_item_ptr(eb, i, + struct btrfs_inode_item); + mode = btrfs_inode_mode(eb, inode_item); + if (S_ISDIR(mode)) { + ret = replay_dir_deletes(wc->trans, + root, log, path, key.objectid); + BUG_ON(ret); + } + ret = overwrite_item(wc->trans, root, path, + eb, i, &key); + BUG_ON(ret); + + /* for regular files, truncate away + * extents past the new EOF + */ + if (S_ISREG(mode)) { + inode = read_one_inode(root, + key.objectid); + BUG_ON(!inode); + + ret = btrfs_truncate_inode_items(wc->trans, + root, inode, inode->i_size, + BTRFS_EXTENT_DATA_KEY); + BUG_ON(ret); + iput(inode); + } + ret = link_to_fixup_dir(wc->trans, root, + path, key.objectid); + BUG_ON(ret); + } + if (wc->stage < LOG_WALK_REPLAY_ALL) + continue; + + /* these keys are simply copied */ + if (key.type == BTRFS_XATTR_ITEM_KEY) { + ret = overwrite_item(wc->trans, root, path, + eb, i, &key); + BUG_ON(ret); + } else if (key.type == BTRFS_INODE_REF_KEY) { + ret = add_inode_ref(wc->trans, root, log, path, + eb, i, &key); + BUG_ON(ret && ret != -ENOENT); + } else if (key.type == BTRFS_EXTENT_DATA_KEY) { + ret = replay_one_extent(wc->trans, root, path, + eb, i, &key); + BUG_ON(ret); + } else if (key.type == BTRFS_CSUM_ITEM_KEY) { + ret = replay_one_csum(wc->trans, root, path, + eb, i, &key); + BUG_ON(ret); + } else if (key.type == BTRFS_DIR_ITEM_KEY || + key.type == BTRFS_DIR_INDEX_KEY) { + ret = replay_one_dir_item(wc->trans, root, path, + eb, i, &key); + BUG_ON(ret); + } + } + btrfs_free_path(path); + return 0; +} + +static int noinline walk_down_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int *level, + struct walk_control *wc) +{ + u64 root_owner; + u64 root_gen; + u64 bytenr; + u64 ptr_gen; + struct extent_buffer *next; + struct extent_buffer *cur; + struct extent_buffer *parent; + u32 blocksize; + int ret = 0; + + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + + while(*level > 0) { + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + cur = path->nodes[*level]; + + if (btrfs_header_level(cur) != *level) + WARN_ON(1); + + if (path->slots[*level] >= + btrfs_header_nritems(cur)) + break; + + bytenr = btrfs_node_blockptr(cur, path->slots[*level]); + ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); + blocksize = btrfs_level_size(root, *level - 1); + + parent = path->nodes[*level]; + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + + next = btrfs_find_create_tree_block(root, bytenr, blocksize); + + wc->process_func(root, next, wc, ptr_gen); + + if (*level == 1) { + path->slots[*level]++; + if (wc->free) { + btrfs_read_buffer(next, ptr_gen); + + btrfs_tree_lock(next); + clean_tree_block(trans, root, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + + ret = btrfs_drop_leaf_ref(trans, root, next); + BUG_ON(ret); + + WARN_ON(root_owner != + BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_extent(trans, root, bytenr, + blocksize, root_owner, + root_gen, 0, 0, 1); + BUG_ON(ret); + } + free_extent_buffer(next); + continue; + } + btrfs_read_buffer(next, ptr_gen); + + WARN_ON(*level <= 0); + if (path->nodes[*level-1]) + free_extent_buffer(path->nodes[*level-1]); + path->nodes[*level-1] = next; + *level = btrfs_header_level(next); + path->slots[*level] = 0; + cond_resched(); + } + WARN_ON(*level < 0); + WARN_ON(*level >= BTRFS_MAX_LEVEL); + + if (path->nodes[*level] == root->node) { + parent = path->nodes[*level]; + } else { + parent = path->nodes[*level + 1]; + } + bytenr = path->nodes[*level]->start; + + blocksize = btrfs_level_size(root, *level); + root_owner = btrfs_header_owner(parent); + root_gen = btrfs_header_generation(parent); + + wc->process_func(root, path->nodes[*level], wc, + btrfs_header_generation(path->nodes[*level])); + + if (wc->free) { + next = path->nodes[*level]; + btrfs_tree_lock(next); + clean_tree_block(trans, root, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + + if (*level == 0) { + ret = btrfs_drop_leaf_ref(trans, root, next); + BUG_ON(ret); + } + WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_extent(trans, root, bytenr, blocksize, + root_owner, root_gen, 0, 0, 1); + BUG_ON(ret); + } + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level += 1; + + cond_resched(); + return 0; +} + +static int noinline walk_up_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, int *level, + struct walk_control *wc) +{ + u64 root_owner; + u64 root_gen; + int i; + int slot; + int ret; + + for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { + slot = path->slots[i]; + if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { + struct extent_buffer *node; + node = path->nodes[i]; + path->slots[i]++; + *level = i; + WARN_ON(*level == 0); + return 0; + } else { + if (path->nodes[*level] == root->node) { + root_owner = root->root_key.objectid; + root_gen = + btrfs_header_generation(path->nodes[*level]); + } else { + struct extent_buffer *node; + node = path->nodes[*level + 1]; + root_owner = btrfs_header_owner(node); + root_gen = btrfs_header_generation(node); + } + wc->process_func(root, path->nodes[*level], wc, + btrfs_header_generation(path->nodes[*level])); + if (wc->free) { + struct extent_buffer *next; + + next = path->nodes[*level]; + + btrfs_tree_lock(next); + clean_tree_block(trans, root, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + + if (*level == 0) { + ret = btrfs_drop_leaf_ref(trans, root, + next); + BUG_ON(ret); + } + + WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_extent(trans, root, + path->nodes[*level]->start, + path->nodes[*level]->len, + root_owner, root_gen, 0, 0, 1); + BUG_ON(ret); + } + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level = i + 1; + } + } + return 1; +} + +/* + * drop the reference count on the tree rooted at 'snap'. This traverses + * the tree freeing any blocks that have a ref count of zero after being + * decremented. + */ +static int walk_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *log, struct walk_control *wc) +{ + int ret = 0; + int wret; + int level; + struct btrfs_path *path; + int i; + int orig_level; + + path = btrfs_alloc_path(); + BUG_ON(!path); + + level = btrfs_header_level(log->node); + orig_level = level; + path->nodes[level] = log->node; + extent_buffer_get(log->node); + path->slots[level] = 0; + + while(1) { + wret = walk_down_log_tree(trans, log, path, &level, wc); + if (wret > 0) + break; + if (wret < 0) + ret = wret; + + wret = walk_up_log_tree(trans, log, path, &level, wc); + if (wret > 0) + break; + if (wret < 0) + ret = wret; + } + + /* was the root node processed? if not, catch it here */ + if (path->nodes[orig_level]) { + wc->process_func(log, path->nodes[orig_level], wc, + btrfs_header_generation(path->nodes[orig_level])); + if (wc->free) { + struct extent_buffer *next; + + next = path->nodes[orig_level]; + + btrfs_tree_lock(next); + clean_tree_block(trans, log, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + + if (orig_level == 0) { + ret = btrfs_drop_leaf_ref(trans, log, + next); + BUG_ON(ret); + } + WARN_ON(log->root_key.objectid != + BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_extent(trans, log, + next->start, next->len, + log->root_key.objectid, + btrfs_header_generation(next), + 0, 0, 1); + BUG_ON(ret); + } + } + + for (i = 0; i <= orig_level; i++) { + if (path->nodes[i]) { + free_extent_buffer(path->nodes[i]); + path->nodes[i] = NULL; + } + } + btrfs_free_path(path); + if (wc->free) + free_extent_buffer(log->node); + return ret; +} + +int wait_log_commit(struct btrfs_root *log) +{ + DEFINE_WAIT(wait); + u64 transid = log->fs_info->tree_log_transid; + + do { + prepare_to_wait(&log->fs_info->tree_log_wait, &wait, + TASK_UNINTERRUPTIBLE); + mutex_unlock(&log->fs_info->tree_log_mutex); + if (atomic_read(&log->fs_info->tree_log_commit)) + schedule(); + finish_wait(&log->fs_info->tree_log_wait, &wait); + mutex_lock(&log->fs_info->tree_log_mutex); + } while(transid == log->fs_info->tree_log_transid && + atomic_read(&log->fs_info->tree_log_commit)); + return 0; +} + +/* + * btrfs_sync_log does sends a given tree log down to the disk and + * updates the super blocks to record it. When this call is done, + * you know that any inodes previously logged are safely on disk + */ +int btrfs_sync_log(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + int ret; + unsigned long batch; + struct btrfs_root *log = root->log_root; + struct walk_control wc = { + .write = 1, + .process_func = process_one_buffer + }; + + mutex_lock(&log->fs_info->tree_log_mutex); + if (atomic_read(&log->fs_info->tree_log_commit)) { + wait_log_commit(log); + goto out; + } + atomic_set(&log->fs_info->tree_log_commit, 1); + + while(1) { + mutex_unlock(&log->fs_info->tree_log_mutex); + schedule_timeout_uninterruptible(1); + mutex_lock(&log->fs_info->tree_log_mutex); + batch = log->fs_info->tree_log_batch; + + while(atomic_read(&log->fs_info->tree_log_writers)) { + DEFINE_WAIT(wait); + prepare_to_wait(&log->fs_info->tree_log_wait, &wait, + TASK_UNINTERRUPTIBLE); + batch = log->fs_info->tree_log_batch; + mutex_unlock(&log->fs_info->tree_log_mutex); + if (atomic_read(&log->fs_info->tree_log_writers)) + schedule(); + mutex_lock(&log->fs_info->tree_log_mutex); + finish_wait(&log->fs_info->tree_log_wait, &wait); + } + if (batch == log->fs_info->tree_log_batch) + break; + } + ret = walk_log_tree(trans, log, &wc); + BUG_ON(ret); + + ret = walk_log_tree(trans, log->fs_info->log_root_tree, &wc); + BUG_ON(ret); + + wc.wait = 1; + + ret = walk_log_tree(trans, log, &wc); + BUG_ON(ret); + + ret = walk_log_tree(trans, log->fs_info->log_root_tree, &wc); + BUG_ON(ret); + + btrfs_set_super_log_root(&root->fs_info->super_for_commit, + log->fs_info->log_root_tree->node->start); + btrfs_set_super_log_root_level(&root->fs_info->super_for_commit, + btrfs_header_level(log->fs_info->log_root_tree->node)); + + write_ctree_super(trans, log->fs_info->tree_root); + log->fs_info->tree_log_transid++; + log->fs_info->tree_log_batch = 0; + atomic_set(&log->fs_info->tree_log_commit, 0); + smp_mb(); + if (waitqueue_active(&log->fs_info->tree_log_wait)) + wake_up(&log->fs_info->tree_log_wait); +out: + mutex_unlock(&log->fs_info->tree_log_mutex); + return 0; + +} + +/* + * free all the extents used by the tree log. This should be called + * at commit time of the full transaction + */ +int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) +{ + int ret; + struct btrfs_root *log; + struct key; + struct walk_control wc = { + .free = 1, + .process_func = process_one_buffer + }; + + if (!root->log_root) + return 0; + + log = root->log_root; + ret = walk_log_tree(trans, log, &wc); + BUG_ON(ret); + + log = root->log_root; + ret = btrfs_del_root(trans, root->fs_info->log_root_tree, + &log->root_key); + BUG_ON(ret); + root->log_root = NULL; + kfree(root->log_root); + return 0; +} + +/* + * helper function to update the item for a given subvolumes log root + * in the tree of log roots + */ +static int update_log_root(struct btrfs_trans_handle *trans, + struct btrfs_root *log) +{ + u64 bytenr = btrfs_root_bytenr(&log->root_item); + int ret; + + if (log->node->start == bytenr) + return 0; + + btrfs_set_root_bytenr(&log->root_item, log->node->start); + btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node)); + ret = btrfs_update_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + BUG_ON(ret); + return ret; +} + +/* + * If both a file and directory are logged, and unlinks or renames are + * mixed in, we have a few interesting corners: + * + * create file X in dir Y + * link file X to X.link in dir Y + * fsync file X + * unlink file X but leave X.link + * fsync dir Y + * + * After a crash we would expect only X.link to exist. But file X + * didn't get fsync'd again so the log has back refs for X and X.link. + * + * We solve this by removing directory entries and inode backrefs from the + * log when a file that was logged in the current transaction is + * unlinked. Any later fsync will include the updated log entries, and + * we'll be able to reconstruct the proper directory items from backrefs. + * + * This optimizations allows us to avoid relogging the entire inode + * or the entire directory. + */ +int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const char *name, int name_len, + struct inode *dir, u64 index) +{ + struct btrfs_root *log; + struct btrfs_dir_item *di; + struct btrfs_path *path; + int ret; + int bytes_del = 0; + + ret = join_running_log_trans(root); + if (ret) + return 0; + + mutex_lock(&BTRFS_I(dir)->log_mutex); + + log = root->log_root; + path = btrfs_alloc_path(); + di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino, + name, name_len, -1); + if (di && !IS_ERR(di)) { + ret = btrfs_delete_one_dir_name(trans, log, path, di); + bytes_del += name_len; + BUG_ON(ret); + } + btrfs_release_path(log, path); + di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino, + index, name, name_len, -1); + if (di && !IS_ERR(di)) { + ret = btrfs_delete_one_dir_name(trans, log, path, di); + bytes_del += name_len; + BUG_ON(ret); + } + + /* update the directory size in the log to reflect the names + * we have removed + */ + if (bytes_del) { + struct btrfs_key key; + + key.objectid = dir->i_ino; + key.offset = 0; + key.type = BTRFS_INODE_ITEM_KEY; + btrfs_release_path(log, path); + + ret = btrfs_search_slot(trans, log, &key, path, 0, 1); + if (ret == 0) { + struct btrfs_inode_item *item; + u64 i_size; + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + i_size = btrfs_inode_size(path->nodes[0], item); + if (i_size > bytes_del) + i_size -= bytes_del; + else + i_size = 0; + btrfs_set_inode_size(path->nodes[0], item, i_size); + btrfs_mark_buffer_dirty(path->nodes[0]); + } else + ret = 0; + btrfs_release_path(log, path); + } + + btrfs_free_path(path); + mutex_unlock(&BTRFS_I(dir)->log_mutex); + end_log_trans(root); + + return 0; +} + +/* see comments for btrfs_del_dir_entries_in_log */ +int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const char *name, int name_len, + struct inode *inode, u64 dirid) +{ + struct btrfs_root *log; + u64 index; + int ret; + + ret = join_running_log_trans(root); + if (ret) + return 0; + log = root->log_root; + mutex_lock(&BTRFS_I(inode)->log_mutex); + + ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino, + dirid, &index); + mutex_unlock(&BTRFS_I(inode)->log_mutex); + end_log_trans(root); + + if (ret == 0 || ret == -ENOENT) + return 0; + return ret; +} + +/* + * creates a range item in the log for 'dirid'. first_offset and + * last_offset tell us which parts of the key space the log should + * be considered authoritative for. + */ +static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + int key_type, u64 dirid, + u64 first_offset, u64 last_offset) +{ + int ret; + struct btrfs_key key; + struct btrfs_dir_log_item *item; + + key.objectid = dirid; + key.offset = first_offset; + if (key_type == BTRFS_DIR_ITEM_KEY) + key.type = BTRFS_DIR_LOG_ITEM_KEY; + else + key.type = BTRFS_DIR_LOG_INDEX_KEY; + ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item)); + BUG_ON(ret); + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_log_item); + btrfs_set_dir_log_end(path->nodes[0], item, last_offset); + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_release_path(log, path); + return 0; +} + +/* + * log all the items included in the current transaction for a given + * directory. This also creates the range items in the log tree required + * to replay anything deleted before the fsync + */ +static noinline int log_dir_items(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path, int key_type, + u64 min_offset, u64 *last_offset_ret) +{ + struct btrfs_key min_key; + struct btrfs_key max_key; + struct btrfs_root *log = root->log_root; + struct extent_buffer *src; + int ret; + int i; + int nritems; + u64 first_offset = min_offset; + u64 last_offset = (u64)-1; + + log = root->log_root; + max_key.objectid = inode->i_ino; + max_key.offset = (u64)-1; + max_key.type = key_type; + + min_key.objectid = inode->i_ino; + min_key.type = key_type; + min_key.offset = min_offset; + + path->keep_locks = 1; + + ret = btrfs_search_forward(root, &min_key, &max_key, + path, 0, trans->transid); + + /* + * we didn't find anything from this transaction, see if there + * is anything at all + */ + if (ret != 0 || min_key.objectid != inode->i_ino || + min_key.type != key_type) { + min_key.objectid = inode->i_ino; + min_key.type = key_type; + min_key.offset = (u64)-1; + btrfs_release_path(root, path); + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (ret < 0) { + btrfs_release_path(root, path); + return ret; + } + ret = btrfs_previous_item(root, path, inode->i_ino, key_type); + + /* if ret == 0 there are items for this type, + * create a range to tell us the last key of this type. + * otherwise, there are no items in this directory after + * *min_offset, and we create a range to indicate that. + */ + if (ret == 0) { + struct btrfs_key tmp; + btrfs_item_key_to_cpu(path->nodes[0], &tmp, + path->slots[0]); + if (key_type == tmp.type) { + first_offset = max(min_offset, tmp.offset) + 1; + } + } + goto done; + } + + /* go backward to find any previous key */ + ret = btrfs_previous_item(root, path, inode->i_ino, key_type); + if (ret == 0) { + struct btrfs_key tmp; + btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); + if (key_type == tmp.type) { + first_offset = tmp.offset; + ret = overwrite_item(trans, log, dst_path, + path->nodes[0], path->slots[0], + &tmp); + } + } + btrfs_release_path(root, path); + + /* find the first key from this transaction again */ + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (ret != 0) { + WARN_ON(1); + goto done; + } + + /* + * we have a block from this transaction, log every item in it + * from our directory + */ + while(1) { + struct btrfs_key tmp; + src = path->nodes[0]; + nritems = btrfs_header_nritems(src); + for (i = path->slots[0]; i < nritems; i++) { + btrfs_item_key_to_cpu(src, &min_key, i); + + if (min_key.objectid != inode->i_ino || + min_key.type != key_type) + goto done; + ret = overwrite_item(trans, log, dst_path, src, i, + &min_key); + BUG_ON(ret); + } + path->slots[0] = nritems; + + /* + * look ahead to the next item and see if it is also + * from this directory and from this transaction + */ + ret = btrfs_next_leaf(root, path); + if (ret == 1) { + last_offset = (u64)-1; + goto done; + } + btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); + if (tmp.objectid != inode->i_ino || tmp.type != key_type) { + last_offset = (u64)-1; + goto done; + } + if (btrfs_header_generation(path->nodes[0]) != trans->transid) { + ret = overwrite_item(trans, log, dst_path, + path->nodes[0], path->slots[0], + &tmp); + + BUG_ON(ret); + last_offset = tmp.offset; + goto done; + } + } +done: + *last_offset_ret = last_offset; + btrfs_release_path(root, path); + btrfs_release_path(log, dst_path); + + /* insert the log range keys to indicate where the log is valid */ + ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino, + first_offset, last_offset); + BUG_ON(ret); + return 0; +} + +/* + * logging directories is very similar to logging inodes, We find all the items + * from the current transaction and write them to the log. + * + * The recovery code scans the directory in the subvolume, and if it finds a + * key in the range logged that is not present in the log tree, then it means + * that dir entry was unlinked during the transaction. + * + * In order for that scan to work, we must include one key smaller than + * the smallest logged by this transaction and one key larger than the largest + * key logged by this transaction. + */ +static noinline int log_directory_changes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path) +{ + u64 min_key; + u64 max_key; + int ret; + int key_type = BTRFS_DIR_ITEM_KEY; + +again: + min_key = 0; + max_key = 0; + while(1) { + ret = log_dir_items(trans, root, inode, path, + dst_path, key_type, min_key, + &max_key); + BUG_ON(ret); + if (max_key == (u64)-1) + break; + min_key = max_key + 1; + } + + if (key_type == BTRFS_DIR_ITEM_KEY) { + key_type = BTRFS_DIR_INDEX_KEY; + goto again; + } + return 0; +} + +/* + * a helper function to drop items from the log before we relog an + * inode. max_key_type indicates the highest item type to remove. + * This cannot be run for file data extents because it does not + * free the extents they point to. + */ +static int drop_objectid_items(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + u64 objectid, int max_key_type) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + + key.objectid = objectid; + key.type = max_key_type; + key.offset = (u64)-1; + + while(1) { + ret = btrfs_search_slot(trans, log, &key, path, -1, 1); + + if (ret != 1) + break; + + if (path->slots[0] == 0) + break; + + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + + if (found_key.objectid != objectid) + break; + + ret = btrfs_del_item(trans, log, path); + BUG_ON(ret); + btrfs_release_path(log, path); + } + btrfs_release_path(log, path); + return 0; +} + +/* log a single inode in the tree log. + * At least one parent directory for this inode must exist in the tree + * or be logged already. + * + * Any items from this inode changed by the current transaction are copied + * to the log tree. An extra reference is taken on any extents in this + * file, allowing us to avoid a whole pile of corner cases around logging + * blocks that have been removed from the tree. + * + * See LOG_INODE_ALL and related defines for a description of what inode_only + * does. + * + * This handles both files and directories. + */ +static int __btrfs_log_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + int inode_only) +{ + struct btrfs_path *path; + struct btrfs_path *dst_path; + struct btrfs_key min_key; + struct btrfs_key max_key; + struct btrfs_root *log = root->log_root; + unsigned long src_offset; + unsigned long dst_offset; + struct extent_buffer *src; + struct btrfs_file_extent_item *extent; + struct btrfs_inode_item *inode_item; + u32 size; + int ret; + + log = root->log_root; + + path = btrfs_alloc_path(); + dst_path = btrfs_alloc_path(); + + min_key.objectid = inode->i_ino; + min_key.type = BTRFS_INODE_ITEM_KEY; + min_key.offset = 0; + + max_key.objectid = inode->i_ino; + if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode)) + max_key.type = BTRFS_XATTR_ITEM_KEY; + else + max_key.type = (u8)-1; + max_key.offset = (u64)-1; + + /* + * if this inode has already been logged and we're in inode_only + * mode, we don't want to delete the things that have already + * been written to the log. + * + * But, if the inode has been through an inode_only log, + * the logged_trans field is not set. This allows us to catch + * any new names for this inode in the backrefs by logging it + * again + */ + if (inode_only == LOG_INODE_EXISTS && + BTRFS_I(inode)->logged_trans == trans->transid) { + btrfs_free_path(path); + btrfs_free_path(dst_path); + goto out; + } + mutex_lock(&BTRFS_I(inode)->log_mutex); + + /* + * a brute force approach to making sure we get the most uptodate + * copies of everything. + */ + if (S_ISDIR(inode->i_mode)) { + int max_key_type = BTRFS_DIR_LOG_INDEX_KEY; + + if (inode_only == LOG_INODE_EXISTS) + max_key_type = BTRFS_XATTR_ITEM_KEY; + ret = drop_objectid_items(trans, log, path, + inode->i_ino, max_key_type); + } else { + ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0); + } + BUG_ON(ret); + path->keep_locks = 1; + + while(1) { + ret = btrfs_search_forward(root, &min_key, &max_key, + path, 0, trans->transid); + if (ret != 0) + break; + + if (min_key.objectid != inode->i_ino) + break; + if (min_key.type > max_key.type) + break; + + src = path->nodes[0]; + size = btrfs_item_size_nr(src, path->slots[0]); + ret = btrfs_insert_empty_item(trans, log, dst_path, &min_key, + size); + if (ret) + BUG(); + + dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], + dst_path->slots[0]); + + src_offset = btrfs_item_ptr_offset(src, path->slots[0]); + + copy_extent_buffer(dst_path->nodes[0], src, dst_offset, + src_offset, size); + + if (inode_only == LOG_INODE_EXISTS && + min_key.type == BTRFS_INODE_ITEM_KEY) { + inode_item = btrfs_item_ptr(dst_path->nodes[0], + dst_path->slots[0], + struct btrfs_inode_item); + btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0); + + /* set the generation to zero so the recover code + * can tell the difference between an logging + * just to say 'this inode exists' and a logging + * to say 'update this inode with these values' + */ + btrfs_set_inode_generation(dst_path->nodes[0], + inode_item, 0); + } + /* take a reference on file data extents so that truncates + * or deletes of this inode don't have to relog the inode + * again + */ + if (btrfs_key_type(&min_key) == BTRFS_EXTENT_DATA_KEY) { + int found_type; + extent = btrfs_item_ptr(src, path->slots[0], + struct btrfs_file_extent_item); + + found_type = btrfs_file_extent_type(src, extent); + if (found_type == BTRFS_FILE_EXTENT_REG) { + u64 ds = btrfs_file_extent_disk_bytenr(src, + extent); + u64 dl = btrfs_file_extent_disk_num_bytes(src, + extent); + /* ds == 0 is a hole */ + if (ds != 0) { + ret = btrfs_inc_extent_ref(trans, log, + ds, dl, + log->root_key.objectid, + 0, + inode->i_ino, + min_key.offset); + BUG_ON(ret); + } + } + } + + btrfs_mark_buffer_dirty(dst_path->nodes[0]); + btrfs_release_path(root, path); + btrfs_release_path(log, dst_path); + + if (min_key.offset < (u64)-1) + min_key.offset++; + else if (min_key.type < (u8)-1) + min_key.type++; + else if (min_key.objectid < (u64)-1) + min_key.objectid++; + else + break; + } + if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) { + btrfs_release_path(root, path); + btrfs_release_path(log, dst_path); + ret = log_directory_changes(trans, root, inode, path, dst_path); + BUG_ON(ret); + } + mutex_unlock(&BTRFS_I(inode)->log_mutex); + + btrfs_free_path(path); + btrfs_free_path(dst_path); + + mutex_lock(&root->fs_info->tree_log_mutex); + ret = update_log_root(trans, log); + BUG_ON(ret); + mutex_unlock(&root->fs_info->tree_log_mutex); +out: + return 0; +} + +int btrfs_log_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + int inode_only) +{ + int ret; + + start_log_trans(trans, root); + ret = __btrfs_log_inode(trans, root, inode, inode_only); + end_log_trans(root); + return ret; +} + +/* + * helper function around btrfs_log_inode to make sure newly created + * parent directories also end up in the log. A minimal inode and backref + * only logging is done of any parent directories that are older than + * the last committed transaction + */ +int btrfs_log_dentry(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct dentry *dentry) +{ + int inode_only = LOG_INODE_ALL; + struct super_block *sb; + int ret; + + start_log_trans(trans, root); + sb = dentry->d_inode->i_sb; + while(1) { + ret = __btrfs_log_inode(trans, root, dentry->d_inode, + inode_only); + BUG_ON(ret); + inode_only = LOG_INODE_EXISTS; + + dentry = dentry->d_parent; + if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb) + break; + + if (BTRFS_I(dentry->d_inode)->generation <= + root->fs_info->last_trans_committed) + break; + } + end_log_trans(root); + return 0; +} + +/* + * it is not safe to log dentry if the chunk root has added new + * chunks. This returns 0 if the dentry was logged, and 1 otherwise. + * If this returns 1, you must commit the transaction to safely get your + * data on disk. + */ +int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct dentry *dentry) +{ + u64 gen; + gen = root->fs_info->last_trans_new_blockgroup; + if (gen > root->fs_info->last_trans_committed) + return 1; + else + return btrfs_log_dentry(trans, root, dentry); +} + +/* + * should be called during mount to recover any replay any log trees + * from the FS + */ +int btrfs_recover_log_trees(struct btrfs_root *log_root_tree) +{ + int ret; + struct btrfs_path *path; + struct btrfs_trans_handle *trans; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_key tmp_key; + struct btrfs_root *log; + struct btrfs_fs_info *fs_info = log_root_tree->fs_info; + struct walk_control wc = { + .process_func = process_one_buffer, + .stage = 0, + }; + + fs_info->log_root_recovering = 1; + path = btrfs_alloc_path(); + BUG_ON(!path); + + trans = btrfs_start_transaction(fs_info->tree_root, 1); + + wc.trans = trans; + wc.pin = 1; + + walk_log_tree(trans, log_root_tree, &wc); + +again: + key.objectid = BTRFS_TREE_LOG_OBJECTID; + key.offset = (u64)-1; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + + while(1) { + ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0); + if (ret < 0) + break; + if (ret > 0) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + btrfs_release_path(log_root_tree, path); + if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID) + break; + + log = btrfs_read_fs_root_no_radix(log_root_tree, + &found_key); + BUG_ON(!log); + + + tmp_key.objectid = found_key.offset; + tmp_key.type = BTRFS_ROOT_ITEM_KEY; + tmp_key.offset = (u64)-1; + + wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key); + + BUG_ON(!wc.replay_dest); + + btrfs_record_root_in_trans(wc.replay_dest); + ret = walk_log_tree(trans, log, &wc); + BUG_ON(ret); + + if (wc.stage == LOG_WALK_REPLAY_ALL) { + ret = fixup_inode_link_counts(trans, wc.replay_dest, + path); + BUG_ON(ret); + } + + key.offset = found_key.offset - 1; + free_extent_buffer(log->node); + kfree(log); + + if (found_key.offset == 0) + break; + } + btrfs_release_path(log_root_tree, path); + + /* step one is to pin it all, step two is to replay just inodes */ + if (wc.pin) { + wc.pin = 0; + wc.process_func = replay_one_buffer; + wc.stage = LOG_WALK_REPLAY_INODES; + goto again; + } + /* step three is to replay everything */ + if (wc.stage < LOG_WALK_REPLAY_ALL) { + wc.stage++; + goto again; + } + + btrfs_free_path(path); + + free_extent_buffer(log_root_tree->node); + log_root_tree->log_root = NULL; + fs_info->log_root_recovering = 0; + + /* step 4: commit the transaction, which also unpins the blocks */ + btrfs_commit_transaction(trans, fs_info->tree_root); + + kfree(log_root_tree); + return 0; +} |