diff options
Diffstat (limited to 'kernel/fs/btrfs/tree-log.c')
| -rw-r--r-- | kernel/fs/btrfs/tree-log.c | 5089 |
1 files changed, 5089 insertions, 0 deletions
diff --git a/kernel/fs/btrfs/tree-log.c b/kernel/fs/btrfs/tree-log.c new file mode 100644 index 000000000..d04968374 --- /dev/null +++ b/kernel/fs/btrfs/tree-log.c @@ -0,0 +1,5089 @@ +/* + * 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 <linux/slab.h> +#include <linux/blkdev.h> +#include <linux/list_sort.h> +#include "tree-log.h" +#include "disk-io.h" +#include "locking.h" +#include "print-tree.h" +#include "backref.h" +#include "hash.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 + +/* + * directory trouble cases + * + * 1) on rename or unlink, if the inode being unlinked isn't in the fsync + * log, we must force a full commit before doing an fsync of the directory + * where the unlink was done. + * ---> record transid of last unlink/rename per directory + * + * mkdir foo/some_dir + * normal commit + * rename foo/some_dir foo2/some_dir + * mkdir foo/some_dir + * fsync foo/some_dir/some_file + * + * The fsync above will unlink the original some_dir without recording + * it in its new location (foo2). After a crash, some_dir will be gone + * unless the fsync of some_file forces a full commit + * + * 2) we must log any new names for any file or dir that is in the fsync + * log. ---> check inode while renaming/linking. + * + * 2a) we must log any new names for any file or dir during rename + * when the directory they are being removed from was logged. + * ---> check inode and old parent dir during rename + * + * 2a is actually the more important variant. With the extra logging + * a crash might unlink the old name without recreating the new one + * + * 3) after a crash, we must go through any directories with a link count + * of zero and redo the rm -rf + * + * mkdir f1/foo + * normal commit + * rm -rf f1/foo + * fsync(f1) + * + * The directory f1 was fully removed from the FS, but fsync was never + * called on f1, only its parent dir. After a crash the rm -rf must + * be replayed. This must be able to recurse down the entire + * directory tree. The inode link count fixup code takes care of the + * ugly details. + */ + +/* + * 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_DIR_INDEX 2 +#define LOG_WALK_REPLAY_ALL 3 + +static int btrfs_log_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + int inode_only, + const loff_t start, + const loff_t end, + struct btrfs_log_ctx *ctx); +static int link_to_fixup_dir(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, u64 objectid); +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, int del_all); + +/* + * 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. + */ + +/* + * 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, + struct btrfs_log_ctx *ctx) +{ + int index; + int ret; + + mutex_lock(&root->log_mutex); + if (root->log_root) { + if (btrfs_need_log_full_commit(root->fs_info, trans)) { + ret = -EAGAIN; + goto out; + } + if (!root->log_start_pid) { + root->log_start_pid = current->pid; + clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + } else if (root->log_start_pid != current->pid) { + set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + } + + atomic_inc(&root->log_batch); + atomic_inc(&root->log_writers); + if (ctx) { + index = root->log_transid % 2; + list_add_tail(&ctx->list, &root->log_ctxs[index]); + ctx->log_transid = root->log_transid; + } + mutex_unlock(&root->log_mutex); + return 0; + } + + ret = 0; + 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); + mutex_unlock(&root->fs_info->tree_log_mutex); + if (ret) + goto out; + + if (!root->log_root) { + ret = btrfs_add_log_tree(trans, root); + if (ret) + goto out; + } + clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + root->log_start_pid = current->pid; + atomic_inc(&root->log_batch); + atomic_inc(&root->log_writers); + if (ctx) { + index = root->log_transid % 2; + list_add_tail(&ctx->list, &root->log_ctxs[index]); + ctx->log_transid = root->log_transid; + } +out: + mutex_unlock(&root->log_mutex); + return ret; +} + +/* + * 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->log_mutex); + if (root->log_root) { + ret = 0; + atomic_inc(&root->log_writers); + } + mutex_unlock(&root->log_mutex); + return ret; +} + +/* + * This either makes the current running log transaction wait + * until you call btrfs_end_log_trans() or it makes any future + * log transactions wait until you call btrfs_end_log_trans() + */ +int btrfs_pin_log_trans(struct btrfs_root *root) +{ + int ret = -ENOENT; + + mutex_lock(&root->log_mutex); + atomic_inc(&root->log_writers); + mutex_unlock(&root->log_mutex); + return ret; +} + +/* + * indicate we're done making changes to the log tree + * and wake up anyone waiting to do a sync + */ +void btrfs_end_log_trans(struct btrfs_root *root) +{ + if (atomic_dec_and_test(&root->log_writers)) { + smp_mb(); + if (waitqueue_active(&root->log_writer_wait)) + wake_up(&root->log_writer_wait); + } +} + + +/* + * 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) +{ + int ret = 0; + + /* + * If this fs is mixed then we need to be able to process the leaves to + * pin down any logged extents, so we have to read the block. + */ + if (btrfs_fs_incompat(log->fs_info, MIXED_GROUPS)) { + ret = btrfs_read_buffer(eb, gen); + if (ret) + return ret; + } + + if (wc->pin) + ret = btrfs_pin_extent_for_log_replay(log->fs_info->extent_root, + eb->start, eb->len); + + if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) { + if (wc->pin && btrfs_header_level(eb) == 0) + ret = btrfs_exclude_logged_extents(log, eb); + if (wc->write) + btrfs_write_tree_block(eb); + if (wc->wait) + btrfs_wait_tree_block_writeback(eb); + } + return ret; +} + +/* + * 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; + bool inode_item = key->type == BTRFS_INODE_ITEM_KEY; + + 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) + return ret; + + 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(path); + return 0; + } + dst_copy = kmalloc(item_size, GFP_NOFS); + src_copy = kmalloc(item_size, GFP_NOFS); + if (!dst_copy || !src_copy) { + btrfs_release_path(path); + kfree(dst_copy); + kfree(src_copy); + return -ENOMEM; + } + + 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(path); + return 0; + } + + /* + * We need to load the old nbytes into the inode so when we + * replay the extents we've logged we get the right nbytes. + */ + if (inode_item) { + struct btrfs_inode_item *item; + u64 nbytes; + u32 mode; + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + nbytes = btrfs_inode_nbytes(path->nodes[0], item); + item = btrfs_item_ptr(eb, slot, + struct btrfs_inode_item); + btrfs_set_inode_nbytes(eb, item, nbytes); + + /* + * If this is a directory we need to reset the i_size to + * 0 so that we can set it up properly when replaying + * the rest of the items in this log. + */ + mode = btrfs_inode_mode(eb, item); + if (S_ISDIR(mode)) + btrfs_set_inode_size(eb, item, 0); + } + } else if (inode_item) { + struct btrfs_inode_item *item; + u32 mode; + + /* + * New inode, set nbytes to 0 so that the nbytes comes out + * properly when we replay the extents. + */ + item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); + btrfs_set_inode_nbytes(eb, item, 0); + + /* + * If this is a directory we need to reset the i_size to 0 so + * that we can set it up properly when replaying the rest of + * the items in this log. + */ + mode = btrfs_inode_mode(eb, item); + if (S_ISDIR(mode)) + btrfs_set_inode_size(eb, item, 0); + } +insert: + btrfs_release_path(path); + /* try to insert the key into the destination tree */ + path->skip_release_on_error = 1; + ret = btrfs_insert_empty_item(trans, root, path, + key, item_size); + path->skip_release_on_error = 0; + + /* make sure any existing item is the correct size */ + if (ret == -EEXIST || ret == -EOVERFLOW) { + u32 found_size; + found_size = btrfs_item_size_nr(path->nodes[0], + path->slots[0]); + if (found_size > item_size) + btrfs_truncate_item(root, path, item_size, 1); + else if (found_size < item_size) + btrfs_extend_item(root, path, + item_size - found_size); + } else if (ret) { + return ret; + } + 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) { + struct extent_buffer *dst_eb = path->nodes[0]; + const u64 ino_size = btrfs_inode_size(eb, src_item); + + /* + * For regular files an ino_size == 0 is used only when + * logging that an inode exists, as part of a directory + * fsync, and the inode wasn't fsynced before. In this + * case don't set the size of the inode in the fs/subvol + * tree, otherwise we would be throwing valid data away. + */ + if (S_ISREG(btrfs_inode_mode(eb, src_item)) && + S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) && + ino_size != 0) { + struct btrfs_map_token token; + + btrfs_init_map_token(&token); + btrfs_set_token_inode_size(dst_eb, dst_item, + ino_size, &token); + } + 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(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 btrfs_key key; + struct inode *inode; + + key.objectid = objectid; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); + if (IS_ERR(inode)) { + inode = NULL; + } else 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 extent_end; + u64 start = key->offset; + u64 nbytes = 0; + 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 || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + nbytes = btrfs_file_extent_num_bytes(eb, item); + extent_end = start + nbytes; + + /* + * We don't add to the inodes nbytes if we are prealloc or a + * hole. + */ + if (btrfs_file_extent_disk_bytenr(eb, item) == 0) + nbytes = 0; + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + size = btrfs_file_extent_inline_len(eb, slot, item); + nbytes = btrfs_file_extent_ram_bytes(eb, item); + extent_end = ALIGN(start + size, root->sectorsize); + } 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, btrfs_ino(inode), + start, 0); + + if (ret == 0 && + (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC)) { + 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(path); + goto out; + } + } + btrfs_release_path(path); + + /* drop any overlapping extents */ + ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1); + if (ret) + goto out; + + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + u64 offset; + unsigned long dest_offset; + struct btrfs_key ins; + + ret = btrfs_insert_empty_item(trans, root, path, key, + sizeof(*item)); + if (ret) + goto out; + dest_offset = btrfs_item_ptr_offset(path->nodes[0], + path->slots[0]); + copy_extent_buffer(path->nodes[0], eb, dest_offset, + (unsigned long)item, sizeof(*item)); + + 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; + offset = key->offset - btrfs_file_extent_offset(eb, item); + + if (ins.objectid > 0) { + u64 csum_start; + u64 csum_end; + LIST_HEAD(ordered_sums); + /* + * is this extent already allocated in the extent + * allocation tree? If so, just add a reference + */ + ret = btrfs_lookup_data_extent(root, ins.objectid, + ins.offset); + if (ret == 0) { + ret = btrfs_inc_extent_ref(trans, root, + ins.objectid, ins.offset, + 0, root->root_key.objectid, + key->objectid, offset, 0); + if (ret) + goto out; + } else { + /* + * insert the extent pointer in the extent + * allocation tree + */ + ret = btrfs_alloc_logged_file_extent(trans, + root, root->root_key.objectid, + key->objectid, offset, &ins); + if (ret) + goto out; + } + btrfs_release_path(path); + + if (btrfs_file_extent_compression(eb, item)) { + csum_start = ins.objectid; + csum_end = csum_start + ins.offset; + } else { + csum_start = ins.objectid + + btrfs_file_extent_offset(eb, item); + csum_end = csum_start + + btrfs_file_extent_num_bytes(eb, item); + } + + ret = btrfs_lookup_csums_range(root->log_root, + csum_start, csum_end - 1, + &ordered_sums, 0); + if (ret) + goto out; + while (!list_empty(&ordered_sums)) { + struct btrfs_ordered_sum *sums; + sums = list_entry(ordered_sums.next, + struct btrfs_ordered_sum, + list); + if (!ret) + ret = btrfs_csum_file_blocks(trans, + root->fs_info->csum_root, + sums); + list_del(&sums->list); + kfree(sums); + } + if (ret) + goto out; + } else { + btrfs_release_path(path); + } + } 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); + if (ret) + goto out; + } + + inode_add_bytes(inode, nbytes); + ret = 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); + if (!name) + return -ENOMEM; + + read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len); + btrfs_release_path(path); + + inode = read_one_inode(root, location.objectid); + if (!inode) { + ret = -EIO; + goto out; + } + + ret = link_to_fixup_dir(trans, root, path, location.objectid); + if (ret) + goto out; + + ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len); + if (ret) + goto out; + else + ret = btrfs_run_delayed_items(trans, root); +out: + 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(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(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, + u64 ref_objectid, + const 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(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(NULL, log, key, path, 0, 0); + if (ret != 0) + goto out; + + ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); + + if (key->type == BTRFS_INODE_EXTREF_KEY) { + if (btrfs_find_name_in_ext_backref(path, ref_objectid, + name, namelen, NULL)) + match = 1; + + goto out; + } + + item_size = btrfs_item_size_nr(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; +} + +static inline int __add_inode_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_root *log_root, + struct inode *dir, struct inode *inode, + struct extent_buffer *eb, + u64 inode_objectid, u64 parent_objectid, + u64 ref_index, char *name, int namelen, + int *search_done) +{ + int ret; + char *victim_name; + int victim_name_len; + struct extent_buffer *leaf; + struct btrfs_dir_item *di; + struct btrfs_key search_key; + struct btrfs_inode_extref *extref; + +again: + /* Search old style refs */ + search_key.objectid = inode_objectid; + search_key.type = BTRFS_INODE_REF_KEY; + search_key.offset = parent_objectid; + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret == 0) { + struct btrfs_inode_ref *victim_ref; + unsigned long ptr; + unsigned long ptr_end; + + 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 (search_key.objectid == search_key.offset) + return 1; + + /* 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); + if (!victim_name) + return -ENOMEM; + + read_extent_buffer(leaf, victim_name, + (unsigned long)(victim_ref + 1), + victim_name_len); + + if (!backref_in_log(log_root, &search_key, + parent_objectid, + victim_name, + victim_name_len)) { + inc_nlink(inode); + btrfs_release_path(path); + + ret = btrfs_unlink_inode(trans, root, dir, + inode, victim_name, + victim_name_len); + kfree(victim_name); + if (ret) + return ret; + ret = btrfs_run_delayed_items(trans, root); + if (ret) + return ret; + *search_done = 1; + goto again; + } + kfree(victim_name); + + ptr = (unsigned long)(victim_ref + 1) + victim_name_len; + } + + /* + * NOTE: we have searched root tree and checked the + * coresponding ref, it does not need to check again. + */ + *search_done = 1; + } + btrfs_release_path(path); + + /* Same search but for extended refs */ + extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen, + inode_objectid, parent_objectid, 0, + 0); + if (!IS_ERR_OR_NULL(extref)) { + u32 item_size; + u32 cur_offset = 0; + unsigned long base; + struct inode *victim_parent; + + leaf = path->nodes[0]; + + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + base = btrfs_item_ptr_offset(leaf, path->slots[0]); + + while (cur_offset < item_size) { + extref = (struct btrfs_inode_extref *)(base + cur_offset); + + victim_name_len = btrfs_inode_extref_name_len(leaf, extref); + + if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid) + goto next; + + victim_name = kmalloc(victim_name_len, GFP_NOFS); + if (!victim_name) + return -ENOMEM; + read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name, + victim_name_len); + + search_key.objectid = inode_objectid; + search_key.type = BTRFS_INODE_EXTREF_KEY; + search_key.offset = btrfs_extref_hash(parent_objectid, + victim_name, + victim_name_len); + ret = 0; + if (!backref_in_log(log_root, &search_key, + parent_objectid, victim_name, + victim_name_len)) { + ret = -ENOENT; + victim_parent = read_one_inode(root, + parent_objectid); + if (victim_parent) { + inc_nlink(inode); + btrfs_release_path(path); + + ret = btrfs_unlink_inode(trans, root, + victim_parent, + inode, + victim_name, + victim_name_len); + if (!ret) + ret = btrfs_run_delayed_items( + trans, root); + } + iput(victim_parent); + kfree(victim_name); + if (ret) + return ret; + *search_done = 1; + goto again; + } + kfree(victim_name); + if (ret) + return ret; +next: + cur_offset += victim_name_len + sizeof(*extref); + } + *search_done = 1; + } + btrfs_release_path(path); + + /* look for a conflicting sequence number */ + di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir), + ref_index, name, namelen, 0); + if (di && !IS_ERR(di)) { + ret = drop_one_dir_item(trans, root, path, dir, di); + if (ret) + return ret; + } + btrfs_release_path(path); + + /* look for a conflicing name */ + di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir), + name, namelen, 0); + if (di && !IS_ERR(di)) { + ret = drop_one_dir_item(trans, root, path, dir, di); + if (ret) + return ret; + } + btrfs_release_path(path); + + return 0; +} + +static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, + u32 *namelen, char **name, u64 *index, + u64 *parent_objectid) +{ + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *)ref_ptr; + + *namelen = btrfs_inode_extref_name_len(eb, extref); + *name = kmalloc(*namelen, GFP_NOFS); + if (*name == NULL) + return -ENOMEM; + + read_extent_buffer(eb, *name, (unsigned long)&extref->name, + *namelen); + + *index = btrfs_inode_extref_index(eb, extref); + if (parent_objectid) + *parent_objectid = btrfs_inode_extref_parent(eb, extref); + + return 0; +} + +static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, + u32 *namelen, char **name, u64 *index) +{ + struct btrfs_inode_ref *ref; + + ref = (struct btrfs_inode_ref *)ref_ptr; + + *namelen = btrfs_inode_ref_name_len(eb, ref); + *name = kmalloc(*namelen, GFP_NOFS); + if (*name == NULL) + return -ENOMEM; + + read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen); + + *index = btrfs_inode_ref_index(eb, ref); + + return 0; +} + +/* + * 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 = NULL; + struct inode *inode = NULL; + unsigned long ref_ptr; + unsigned long ref_end; + char *name = NULL; + int namelen; + int ret; + int search_done = 0; + int log_ref_ver = 0; + u64 parent_objectid; + u64 inode_objectid; + u64 ref_index = 0; + int ref_struct_size; + + ref_ptr = btrfs_item_ptr_offset(eb, slot); + ref_end = ref_ptr + btrfs_item_size_nr(eb, slot); + + if (key->type == BTRFS_INODE_EXTREF_KEY) { + struct btrfs_inode_extref *r; + + ref_struct_size = sizeof(struct btrfs_inode_extref); + log_ref_ver = 1; + r = (struct btrfs_inode_extref *)ref_ptr; + parent_objectid = btrfs_inode_extref_parent(eb, r); + } else { + ref_struct_size = sizeof(struct btrfs_inode_ref); + parent_objectid = key->offset; + } + inode_objectid = key->objectid; + + /* + * 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, parent_objectid); + if (!dir) { + ret = -ENOENT; + goto out; + } + + inode = read_one_inode(root, inode_objectid); + if (!inode) { + ret = -EIO; + goto out; + } + + while (ref_ptr < ref_end) { + if (log_ref_ver) { + ret = extref_get_fields(eb, ref_ptr, &namelen, &name, + &ref_index, &parent_objectid); + /* + * parent object can change from one array + * item to another. + */ + if (!dir) + dir = read_one_inode(root, parent_objectid); + if (!dir) { + ret = -ENOENT; + goto out; + } + } else { + ret = ref_get_fields(eb, ref_ptr, &namelen, &name, + &ref_index); + } + if (ret) + goto out; + + /* if we already have a perfect match, we're done */ + if (!inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode), + ref_index, name, namelen)) { + /* + * 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. + */ + + if (!search_done) { + ret = __add_inode_ref(trans, root, path, log, + dir, inode, eb, + inode_objectid, + parent_objectid, + ref_index, name, namelen, + &search_done); + if (ret) { + if (ret == 1) + ret = 0; + goto out; + } + } + + /* insert our name */ + ret = btrfs_add_link(trans, dir, inode, name, namelen, + 0, ref_index); + if (ret) + goto out; + + btrfs_update_inode(trans, root, inode); + } + + ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen; + kfree(name); + name = NULL; + if (log_ref_ver) { + iput(dir); + dir = NULL; + } + } + + /* finally write the back reference in the inode */ + ret = overwrite_item(trans, root, path, eb, slot, key); +out: + btrfs_release_path(path); + kfree(name); + iput(dir); + iput(inode); + return ret; +} + +static int insert_orphan_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 ino) +{ + int ret; + + ret = btrfs_insert_orphan_item(trans, root, ino); + if (ret == -EEXIST) + ret = 0; + + return ret; +} + +static int count_inode_extrefs(struct btrfs_root *root, + struct inode *inode, struct btrfs_path *path) +{ + int ret = 0; + int name_len; + unsigned int nlink = 0; + u32 item_size; + u32 cur_offset = 0; + u64 inode_objectid = btrfs_ino(inode); + u64 offset = 0; + unsigned long ptr; + struct btrfs_inode_extref *extref; + struct extent_buffer *leaf; + + while (1) { + ret = btrfs_find_one_extref(root, inode_objectid, offset, path, + &extref, &offset); + if (ret) + break; + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + cur_offset = 0; + + while (cur_offset < item_size) { + extref = (struct btrfs_inode_extref *) (ptr + cur_offset); + name_len = btrfs_inode_extref_name_len(leaf, extref); + + nlink++; + + cur_offset += name_len + sizeof(*extref); + } + + offset++; + btrfs_release_path(path); + } + btrfs_release_path(path); + + if (ret < 0 && ret != -ENOENT) + return ret; + return nlink; +} + +static int count_inode_refs(struct btrfs_root *root, + struct inode *inode, struct btrfs_path *path) +{ + int ret; + struct btrfs_key key; + unsigned int nlink = 0; + unsigned long ptr; + unsigned long ptr_end; + int name_len; + u64 ino = btrfs_ino(inode); + + key.objectid = ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = (u64)-1; + + 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]--; + } +process_slot: + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid != 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; + if (path->slots[0] > 0) { + path->slots[0]--; + goto process_slot; + } + key.offset--; + btrfs_release_path(path); + } + btrfs_release_path(path); + + return nlink; +} + +/* + * 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; + u64 nlink = 0; + u64 ino = btrfs_ino(inode); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = count_inode_refs(root, inode, path); + if (ret < 0) + goto out; + + nlink = ret; + + ret = count_inode_extrefs(root, inode, path); + if (ret < 0) + goto out; + + nlink += ret; + + ret = 0; + + if (nlink != inode->i_nlink) { + set_nlink(inode, nlink); + btrfs_update_inode(trans, root, inode); + } + BTRFS_I(inode)->index_cnt = (u64)-1; + + if (inode->i_nlink == 0) { + if (S_ISDIR(inode->i_mode)) { + ret = replay_dir_deletes(trans, root, NULL, path, + ino, 1); + if (ret) + goto out; + } + ret = insert_orphan_item(trans, root, ino); + } + +out: + btrfs_free_path(path); + return ret; +} + +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); + if (ret) + goto out; + + btrfs_release_path(path); + inode = read_one_inode(root, key.offset); + if (!inode) + return -EIO; + + ret = fixup_inode_link_count(trans, root, inode); + iput(inode); + if (ret) + goto out; + + /* + * fixup on a directory may create new entries, + * make sure we always look for the highset possible + * offset + */ + key.offset = (u64)-1; + } + ret = 0; +out: + btrfs_release_path(path); + return ret; +} + + +/* + * 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); + if (!inode) + return -EIO; + + key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = objectid; + + ret = btrfs_insert_empty_item(trans, root, path, &key, 0); + + btrfs_release_path(path); + if (ret == 0) { + if (!inode->i_nlink) + set_nlink(inode, 1); + else + inc_nlink(inode); + ret = btrfs_update_inode(trans, root, inode); + } else if (ret == -EEXIST) { + ret = 0; + } else { + BUG(); /* Logic Error */ + } + 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; +} + +/* + * Return true if an inode reference exists in the log for the given name, + * inode and parent inode. + */ +static bool name_in_log_ref(struct btrfs_root *log_root, + const char *name, const int name_len, + const u64 dirid, const u64 ino) +{ + struct btrfs_key search_key; + + search_key.objectid = ino; + search_key.type = BTRFS_INODE_REF_KEY; + search_key.offset = dirid; + if (backref_in_log(log_root, &search_key, dirid, name, name_len)) + return true; + + search_key.type = BTRFS_INODE_EXTREF_KEY; + search_key.offset = btrfs_extref_hash(dirid, name, name_len); + if (backref_in_log(log_root, &search_key, dirid, name, name_len)) + return true; + + return false; +} + +/* + * 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; + u8 log_type; + int exists; + int ret = 0; + bool update_size = (key->type == BTRFS_DIR_INDEX_KEY); + + dir = read_one_inode(root, key->objectid); + if (!dir) + return -EIO; + + name_len = btrfs_dir_name_len(eb, di); + name = kmalloc(name_len, GFP_NOFS); + if (!name) { + ret = -ENOMEM; + goto out; + } + + 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); + exists = btrfs_lookup_inode(trans, root, path, &log_key, 0); + if (exists == 0) + exists = 1; + else + exists = 0; + btrfs_release_path(path); + + 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 { + /* Corruption */ + ret = -EINVAL; + goto out; + } + if (IS_ERR_OR_NULL(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) { + update_size = false; + goto out; + } + + /* + * don't drop the conflicting directory entry if the inode + * for the new entry doesn't exist + */ + if (!exists) + goto out; + + ret = drop_one_dir_item(trans, root, path, dir, dst_di); + if (ret) + goto out; + + if (key->type == BTRFS_DIR_INDEX_KEY) + goto insert; +out: + btrfs_release_path(path); + if (!ret && update_size) { + btrfs_i_size_write(dir, dir->i_size + name_len * 2); + ret = btrfs_update_inode(trans, root, dir); + } + kfree(name); + iput(dir); + return ret; + +insert: + if (name_in_log_ref(root->log_root, name, name_len, + key->objectid, log_key.objectid)) { + /* The dentry will be added later. */ + ret = 0; + update_size = false; + goto out; + } + btrfs_release_path(path); + ret = insert_one_name(trans, root, path, key->objectid, key->offset, + name, name_len, log_type, &log_key); + if (ret && ret != -ENOENT && ret != -EEXIST) + goto out; + update_size = false; + ret = 0; + 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; + if (verify_dir_item(root, eb, di)) + return -EIO; + name_len = btrfs_dir_name_len(eb, di); + ret = replay_one_name(trans, root, path, eb, di, key); + if (ret) + return 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(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; + if (verify_dir_item(root, eb, di)) { + ret = -EIO; + goto out; + } + + 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 (log && 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 (log && 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) && PTR_ERR(log_di) == -ENOENT)) { + btrfs_dir_item_key_to_cpu(eb, di, &location); + btrfs_release_path(path); + btrfs_release_path(log_path); + inode = read_one_inode(root, location.objectid); + if (!inode) { + kfree(name); + return -EIO; + } + + ret = link_to_fixup_dir(trans, root, + path, location.objectid); + if (ret) { + kfree(name); + iput(inode); + goto out; + } + + inc_nlink(inode); + ret = btrfs_unlink_inode(trans, root, dir, inode, + name, name_len); + if (!ret) + ret = btrfs_run_delayed_items(trans, root); + kfree(name); + iput(inode); + if (ret) + goto out; + + /* 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; + } else if (IS_ERR(log_di)) { + kfree(name); + return PTR_ERR(log_di); + } + btrfs_release_path(log_path); + kfree(name); + + ptr = (unsigned long)(di + 1); + ptr += name_len; + } + ret = 0; +out: + btrfs_release_path(path); + btrfs_release_path(log_path); + return ret; +} + +static int replay_xattr_deletes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_root *log, + struct btrfs_path *path, + const u64 ino) +{ + struct btrfs_key search_key; + struct btrfs_path *log_path; + int i; + int nritems; + int ret; + + log_path = btrfs_alloc_path(); + if (!log_path) + return -ENOMEM; + + search_key.objectid = ino; + search_key.type = BTRFS_XATTR_ITEM_KEY; + search_key.offset = 0; +again: + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + goto out; +process_leaf: + nritems = btrfs_header_nritems(path->nodes[0]); + for (i = path->slots[0]; i < nritems; i++) { + struct btrfs_key key; + struct btrfs_dir_item *di; + struct btrfs_dir_item *log_di; + u32 total_size; + u32 cur; + + btrfs_item_key_to_cpu(path->nodes[0], &key, i); + if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) { + ret = 0; + goto out; + } + + di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item); + total_size = btrfs_item_size_nr(path->nodes[0], i); + cur = 0; + while (cur < total_size) { + u16 name_len = btrfs_dir_name_len(path->nodes[0], di); + u16 data_len = btrfs_dir_data_len(path->nodes[0], di); + u32 this_len = sizeof(*di) + name_len + data_len; + char *name; + + name = kmalloc(name_len, GFP_NOFS); + if (!name) { + ret = -ENOMEM; + goto out; + } + read_extent_buffer(path->nodes[0], name, + (unsigned long)(di + 1), name_len); + + log_di = btrfs_lookup_xattr(NULL, log, log_path, ino, + name, name_len, 0); + btrfs_release_path(log_path); + if (!log_di) { + /* Doesn't exist in log tree, so delete it. */ + btrfs_release_path(path); + di = btrfs_lookup_xattr(trans, root, path, ino, + name, name_len, -1); + kfree(name); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + ASSERT(di); + ret = btrfs_delete_one_dir_name(trans, root, + path, di); + if (ret) + goto out; + btrfs_release_path(path); + search_key = key; + goto again; + } + kfree(name); + if (IS_ERR(log_di)) { + ret = PTR_ERR(log_di); + goto out; + } + cur += this_len; + di = (struct btrfs_dir_item *)((char *)di + this_len); + } + } + ret = btrfs_next_leaf(root, path); + if (ret > 0) + ret = 0; + else if (ret == 0) + goto process_leaf; +out: + btrfs_free_path(log_path); + btrfs_release_path(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, int del_all) +{ + 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) { + if (del_all) + range_end = (u64)-1; + else { + 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); + if (ret) + goto out; + if (found_key.offset == (u64)-1) + break; + dir_key.offset = found_key.offset + 1; + } + btrfs_release_path(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(path); + goto again; + } +out: + btrfs_release_path(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; + int level; + int i; + int ret; + + ret = btrfs_read_buffer(eb, gen); + if (ret) + return ret; + + level = btrfs_header_level(eb); + + if (level != 0) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + nritems = btrfs_header_nritems(eb); + for (i = 0; i < nritems; i++) { + btrfs_item_key_to_cpu(eb, &key, i); + + /* inode keys are done during the first stage */ + if (key.type == BTRFS_INODE_ITEM_KEY && + wc->stage == LOG_WALK_REPLAY_INODES) { + struct btrfs_inode_item *inode_item; + u32 mode; + + inode_item = btrfs_item_ptr(eb, i, + struct btrfs_inode_item); + ret = replay_xattr_deletes(wc->trans, root, log, + path, key.objectid); + if (ret) + break; + mode = btrfs_inode_mode(eb, inode_item); + if (S_ISDIR(mode)) { + ret = replay_dir_deletes(wc->trans, + root, log, path, key.objectid, 0); + if (ret) + break; + } + ret = overwrite_item(wc->trans, root, path, + eb, i, &key); + if (ret) + break; + + /* for regular files, make sure corresponding + * orhpan item exist. extents past the new EOF + * will be truncated later by orphan cleanup. + */ + if (S_ISREG(mode)) { + ret = insert_orphan_item(wc->trans, root, + key.objectid); + if (ret) + break; + } + + ret = link_to_fixup_dir(wc->trans, root, + path, key.objectid); + if (ret) + break; + } + + if (key.type == BTRFS_DIR_INDEX_KEY && + wc->stage == LOG_WALK_REPLAY_DIR_INDEX) { + ret = replay_one_dir_item(wc->trans, root, path, + eb, i, &key); + if (ret) + break; + } + + 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); + if (ret) + break; + } else if (key.type == BTRFS_INODE_REF_KEY || + key.type == BTRFS_INODE_EXTREF_KEY) { + ret = add_inode_ref(wc->trans, root, log, path, + eb, i, &key); + if (ret && ret != -ENOENT) + break; + ret = 0; + } else if (key.type == BTRFS_EXTENT_DATA_KEY) { + ret = replay_one_extent(wc->trans, root, path, + eb, i, &key); + if (ret) + break; + } else if (key.type == BTRFS_DIR_ITEM_KEY) { + ret = replay_one_dir_item(wc->trans, root, path, + eb, i, &key); + if (ret) + break; + } + } + btrfs_free_path(path); + return ret; +} + +static noinline int 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 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]; + + WARN_ON(btrfs_header_level(cur) != *level); + + 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 = root->nodesize; + + parent = path->nodes[*level]; + root_owner = btrfs_header_owner(parent); + + next = btrfs_find_create_tree_block(root, bytenr); + if (!next) + return -ENOMEM; + + if (*level == 1) { + ret = wc->process_func(root, next, wc, ptr_gen); + if (ret) { + free_extent_buffer(next); + return ret; + } + + path->slots[*level]++; + if (wc->free) { + ret = btrfs_read_buffer(next, ptr_gen); + if (ret) { + free_extent_buffer(next); + return ret; + } + + if (trans) { + btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); + clean_tree_block(trans, root->fs_info, + next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + } + + WARN_ON(root_owner != + BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_and_pin_reserved_extent(root, + bytenr, blocksize); + if (ret) { + free_extent_buffer(next); + return ret; + } + } + free_extent_buffer(next); + continue; + } + ret = btrfs_read_buffer(next, ptr_gen); + if (ret) { + free_extent_buffer(next); + return ret; + } + + 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); + + path->slots[*level] = btrfs_header_nritems(path->nodes[*level]); + + cond_resched(); + return 0; +} + +static noinline int 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; + int i; + int slot; + int ret; + + for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { + slot = path->slots[i]; + if (slot + 1 < btrfs_header_nritems(path->nodes[i])) { + path->slots[i]++; + *level = i; + WARN_ON(*level == 0); + return 0; + } else { + struct extent_buffer *parent; + if (path->nodes[*level] == root->node) + parent = path->nodes[*level]; + else + parent = path->nodes[*level + 1]; + + root_owner = btrfs_header_owner(parent); + ret = wc->process_func(root, path->nodes[*level], wc, + btrfs_header_generation(path->nodes[*level])); + if (ret) + return ret; + + if (wc->free) { + struct extent_buffer *next; + + next = path->nodes[*level]; + + if (trans) { + btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); + clean_tree_block(trans, root->fs_info, + next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + } + + WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_and_pin_reserved_extent(root, + path->nodes[*level]->start, + path->nodes[*level]->len); + if (ret) + return 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 orig_level; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + 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; + goto out; + } + + wret = walk_up_log_tree(trans, log, path, &level, wc); + if (wret > 0) + break; + if (wret < 0) { + ret = wret; + goto out; + } + } + + /* was the root node processed? if not, catch it here */ + if (path->nodes[orig_level]) { + ret = wc->process_func(log, path->nodes[orig_level], wc, + btrfs_header_generation(path->nodes[orig_level])); + if (ret) + goto out; + if (wc->free) { + struct extent_buffer *next; + + next = path->nodes[orig_level]; + + if (trans) { + btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); + clean_tree_block(trans, log->fs_info, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + } + + WARN_ON(log->root_key.objectid != + BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_and_pin_reserved_extent(log, next->start, + next->len); + if (ret) + goto out; + } + } + +out: + btrfs_free_path(path); + return ret; +} + +/* + * 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) +{ + int ret; + + if (log->log_transid == 1) { + /* insert root item on the first sync */ + ret = btrfs_insert_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + } else { + ret = btrfs_update_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + } + return ret; +} + +static void wait_log_commit(struct btrfs_trans_handle *trans, + struct btrfs_root *root, int transid) +{ + DEFINE_WAIT(wait); + int index = transid % 2; + + /* + * we only allow two pending log transactions at a time, + * so we know that if ours is more than 2 older than the + * current transaction, we're done + */ + do { + prepare_to_wait(&root->log_commit_wait[index], + &wait, TASK_UNINTERRUPTIBLE); + mutex_unlock(&root->log_mutex); + + if (root->log_transid_committed < transid && + atomic_read(&root->log_commit[index])) + schedule(); + + finish_wait(&root->log_commit_wait[index], &wait); + mutex_lock(&root->log_mutex); + } while (root->log_transid_committed < transid && + atomic_read(&root->log_commit[index])); +} + +static void wait_for_writer(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + DEFINE_WAIT(wait); + + while (atomic_read(&root->log_writers)) { + prepare_to_wait(&root->log_writer_wait, + &wait, TASK_UNINTERRUPTIBLE); + mutex_unlock(&root->log_mutex); + if (atomic_read(&root->log_writers)) + schedule(); + finish_wait(&root->log_writer_wait, &wait); + mutex_lock(&root->log_mutex); + } +} + +static inline void btrfs_remove_log_ctx(struct btrfs_root *root, + struct btrfs_log_ctx *ctx) +{ + if (!ctx) + return; + + mutex_lock(&root->log_mutex); + list_del_init(&ctx->list); + mutex_unlock(&root->log_mutex); +} + +/* + * Invoked in log mutex context, or be sure there is no other task which + * can access the list. + */ +static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root, + int index, int error) +{ + struct btrfs_log_ctx *ctx; + + if (!error) { + INIT_LIST_HEAD(&root->log_ctxs[index]); + return; + } + + list_for_each_entry(ctx, &root->log_ctxs[index], list) + ctx->log_ret = error; + + INIT_LIST_HEAD(&root->log_ctxs[index]); +} + +/* + * 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 only + * if it returns 0. + * + * Any other return value means you need to call btrfs_commit_transaction. + * Some of the edge cases for fsyncing directories that have had unlinks + * or renames done in the past mean that sometimes the only safe + * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN, + * that has happened. + */ +int btrfs_sync_log(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_log_ctx *ctx) +{ + int index1; + int index2; + int mark; + int ret; + struct btrfs_root *log = root->log_root; + struct btrfs_root *log_root_tree = root->fs_info->log_root_tree; + int log_transid = 0; + struct btrfs_log_ctx root_log_ctx; + struct blk_plug plug; + + mutex_lock(&root->log_mutex); + log_transid = ctx->log_transid; + if (root->log_transid_committed >= log_transid) { + mutex_unlock(&root->log_mutex); + return ctx->log_ret; + } + + index1 = log_transid % 2; + if (atomic_read(&root->log_commit[index1])) { + wait_log_commit(trans, root, log_transid); + mutex_unlock(&root->log_mutex); + return ctx->log_ret; + } + ASSERT(log_transid == root->log_transid); + atomic_set(&root->log_commit[index1], 1); + + /* wait for previous tree log sync to complete */ + if (atomic_read(&root->log_commit[(index1 + 1) % 2])) + wait_log_commit(trans, root, log_transid - 1); + + while (1) { + int batch = atomic_read(&root->log_batch); + /* when we're on an ssd, just kick the log commit out */ + if (!btrfs_test_opt(root, SSD) && + test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) { + mutex_unlock(&root->log_mutex); + schedule_timeout_uninterruptible(1); + mutex_lock(&root->log_mutex); + } + wait_for_writer(trans, root); + if (batch == atomic_read(&root->log_batch)) + break; + } + + /* bail out if we need to do a full commit */ + if (btrfs_need_log_full_commit(root->fs_info, trans)) { + ret = -EAGAIN; + btrfs_free_logged_extents(log, log_transid); + mutex_unlock(&root->log_mutex); + goto out; + } + + if (log_transid % 2 == 0) + mark = EXTENT_DIRTY; + else + mark = EXTENT_NEW; + + /* we start IO on all the marked extents here, but we don't actually + * wait for them until later. + */ + blk_start_plug(&plug); + ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark); + if (ret) { + blk_finish_plug(&plug); + btrfs_abort_transaction(trans, root, ret); + btrfs_free_logged_extents(log, log_transid); + btrfs_set_log_full_commit(root->fs_info, trans); + mutex_unlock(&root->log_mutex); + goto out; + } + + btrfs_set_root_node(&log->root_item, log->node); + + root->log_transid++; + log->log_transid = root->log_transid; + root->log_start_pid = 0; + /* + * IO has been started, blocks of the log tree have WRITTEN flag set + * in their headers. new modifications of the log will be written to + * new positions. so it's safe to allow log writers to go in. + */ + mutex_unlock(&root->log_mutex); + + btrfs_init_log_ctx(&root_log_ctx); + + mutex_lock(&log_root_tree->log_mutex); + atomic_inc(&log_root_tree->log_batch); + atomic_inc(&log_root_tree->log_writers); + + index2 = log_root_tree->log_transid % 2; + list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]); + root_log_ctx.log_transid = log_root_tree->log_transid; + + mutex_unlock(&log_root_tree->log_mutex); + + ret = update_log_root(trans, log); + + mutex_lock(&log_root_tree->log_mutex); + if (atomic_dec_and_test(&log_root_tree->log_writers)) { + smp_mb(); + if (waitqueue_active(&log_root_tree->log_writer_wait)) + wake_up(&log_root_tree->log_writer_wait); + } + + if (ret) { + if (!list_empty(&root_log_ctx.list)) + list_del_init(&root_log_ctx.list); + + blk_finish_plug(&plug); + btrfs_set_log_full_commit(root->fs_info, trans); + + if (ret != -ENOSPC) { + btrfs_abort_transaction(trans, root, ret); + mutex_unlock(&log_root_tree->log_mutex); + goto out; + } + btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); + btrfs_free_logged_extents(log, log_transid); + mutex_unlock(&log_root_tree->log_mutex); + ret = -EAGAIN; + goto out; + } + + if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) { + blk_finish_plug(&plug); + mutex_unlock(&log_root_tree->log_mutex); + ret = root_log_ctx.log_ret; + goto out; + } + + index2 = root_log_ctx.log_transid % 2; + if (atomic_read(&log_root_tree->log_commit[index2])) { + blk_finish_plug(&plug); + ret = btrfs_wait_marked_extents(log, &log->dirty_log_pages, + mark); + btrfs_wait_logged_extents(trans, log, log_transid); + wait_log_commit(trans, log_root_tree, + root_log_ctx.log_transid); + mutex_unlock(&log_root_tree->log_mutex); + if (!ret) + ret = root_log_ctx.log_ret; + goto out; + } + ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid); + atomic_set(&log_root_tree->log_commit[index2], 1); + + if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) { + wait_log_commit(trans, log_root_tree, + root_log_ctx.log_transid - 1); + } + + wait_for_writer(trans, log_root_tree); + + /* + * now that we've moved on to the tree of log tree roots, + * check the full commit flag again + */ + if (btrfs_need_log_full_commit(root->fs_info, trans)) { + blk_finish_plug(&plug); + btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); + btrfs_free_logged_extents(log, log_transid); + mutex_unlock(&log_root_tree->log_mutex); + ret = -EAGAIN; + goto out_wake_log_root; + } + + ret = btrfs_write_marked_extents(log_root_tree, + &log_root_tree->dirty_log_pages, + EXTENT_DIRTY | EXTENT_NEW); + blk_finish_plug(&plug); + if (ret) { + btrfs_set_log_full_commit(root->fs_info, trans); + btrfs_abort_transaction(trans, root, ret); + btrfs_free_logged_extents(log, log_transid); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } + ret = btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); + if (!ret) + ret = btrfs_wait_marked_extents(log_root_tree, + &log_root_tree->dirty_log_pages, + EXTENT_NEW | EXTENT_DIRTY); + if (ret) { + btrfs_set_log_full_commit(root->fs_info, trans); + btrfs_free_logged_extents(log, log_transid); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } + btrfs_wait_logged_extents(trans, log, log_transid); + + btrfs_set_super_log_root(root->fs_info->super_for_commit, + log_root_tree->node->start); + btrfs_set_super_log_root_level(root->fs_info->super_for_commit, + btrfs_header_level(log_root_tree->node)); + + log_root_tree->log_transid++; + mutex_unlock(&log_root_tree->log_mutex); + + /* + * nobody else is going to jump in and write the the ctree + * super here because the log_commit atomic below is protecting + * us. We must be called with a transaction handle pinning + * the running transaction open, so a full commit can't hop + * in and cause problems either. + */ + ret = write_ctree_super(trans, root->fs_info->tree_root, 1); + if (ret) { + btrfs_set_log_full_commit(root->fs_info, trans); + btrfs_abort_transaction(trans, root, ret); + goto out_wake_log_root; + } + + mutex_lock(&root->log_mutex); + if (root->last_log_commit < log_transid) + root->last_log_commit = log_transid; + mutex_unlock(&root->log_mutex); + +out_wake_log_root: + /* + * We needn't get log_mutex here because we are sure all + * the other tasks are blocked. + */ + btrfs_remove_all_log_ctxs(log_root_tree, index2, ret); + + mutex_lock(&log_root_tree->log_mutex); + log_root_tree->log_transid_committed++; + atomic_set(&log_root_tree->log_commit[index2], 0); + mutex_unlock(&log_root_tree->log_mutex); + + if (waitqueue_active(&log_root_tree->log_commit_wait[index2])) + wake_up(&log_root_tree->log_commit_wait[index2]); +out: + /* See above. */ + btrfs_remove_all_log_ctxs(root, index1, ret); + + mutex_lock(&root->log_mutex); + root->log_transid_committed++; + atomic_set(&root->log_commit[index1], 0); + mutex_unlock(&root->log_mutex); + + if (waitqueue_active(&root->log_commit_wait[index1])) + wake_up(&root->log_commit_wait[index1]); + return ret; +} + +static void free_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *log) +{ + int ret; + u64 start; + u64 end; + struct walk_control wc = { + .free = 1, + .process_func = process_one_buffer + }; + + ret = walk_log_tree(trans, log, &wc); + /* I don't think this can happen but just in case */ + if (ret) + btrfs_abort_transaction(trans, log, ret); + + while (1) { + ret = find_first_extent_bit(&log->dirty_log_pages, + 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW, + NULL); + if (ret) + break; + + clear_extent_bits(&log->dirty_log_pages, start, end, + EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS); + } + + /* + * We may have short-circuited the log tree with the full commit logic + * and left ordered extents on our list, so clear these out to keep us + * from leaking inodes and memory. + */ + btrfs_free_logged_extents(log, 0); + btrfs_free_logged_extents(log, 1); + + free_extent_buffer(log->node); + kfree(log); +} + +/* + * 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) +{ + if (root->log_root) { + free_log_tree(trans, root->log_root); + root->log_root = NULL; + } + return 0; +} + +int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info) +{ + if (fs_info->log_root_tree) { + free_log_tree(trans, fs_info->log_root_tree); + fs_info->log_root_tree = NULL; + } + return 0; +} + +/* + * 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 err = 0; + int bytes_del = 0; + u64 dir_ino = btrfs_ino(dir); + + if (BTRFS_I(dir)->logged_trans < trans->transid) + return 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(); + if (!path) { + err = -ENOMEM; + goto out_unlock; + } + + di = btrfs_lookup_dir_item(trans, log, path, dir_ino, + name, name_len, -1); + if (IS_ERR(di)) { + err = PTR_ERR(di); + goto fail; + } + if (di) { + ret = btrfs_delete_one_dir_name(trans, log, path, di); + bytes_del += name_len; + if (ret) { + err = ret; + goto fail; + } + } + btrfs_release_path(path); + di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino, + index, name, name_len, -1); + if (IS_ERR(di)) { + err = PTR_ERR(di); + goto fail; + } + if (di) { + ret = btrfs_delete_one_dir_name(trans, log, path, di); + bytes_del += name_len; + if (ret) { + err = ret; + goto fail; + } + } + + /* update the directory size in the log to reflect the names + * we have removed + */ + if (bytes_del) { + struct btrfs_key key; + + key.objectid = dir_ino; + key.offset = 0; + key.type = BTRFS_INODE_ITEM_KEY; + btrfs_release_path(path); + + ret = btrfs_search_slot(trans, log, &key, path, 0, 1); + if (ret < 0) { + err = ret; + goto fail; + } + 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(path); + } +fail: + btrfs_free_path(path); +out_unlock: + mutex_unlock(&BTRFS_I(dir)->log_mutex); + if (ret == -ENOSPC) { + btrfs_set_log_full_commit(root->fs_info, trans); + ret = 0; + } else if (ret < 0) + btrfs_abort_transaction(trans, root, ret); + + btrfs_end_log_trans(root); + + return err; +} + +/* 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; + + if (BTRFS_I(inode)->logged_trans < trans->transid) + return 0; + + 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, btrfs_ino(inode), + dirid, &index); + mutex_unlock(&BTRFS_I(inode)->log_mutex); + if (ret == -ENOSPC) { + btrfs_set_log_full_commit(root->fs_info, trans); + ret = 0; + } else if (ret < 0 && ret != -ENOENT) + btrfs_abort_transaction(trans, root, ret); + btrfs_end_log_trans(root); + + 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)); + if (ret) + return 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(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, + struct btrfs_log_ctx *ctx, + u64 min_offset, u64 *last_offset_ret) +{ + struct btrfs_key min_key; + struct btrfs_root *log = root->log_root; + struct extent_buffer *src; + int err = 0; + int ret; + int i; + int nritems; + u64 first_offset = min_offset; + u64 last_offset = (u64)-1; + u64 ino = btrfs_ino(inode); + + log = root->log_root; + + min_key.objectid = ino; + min_key.type = key_type; + min_key.offset = min_offset; + + ret = btrfs_search_forward(root, &min_key, path, trans->transid); + + /* + * we didn't find anything from this transaction, see if there + * is anything at all + */ + if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) { + min_key.objectid = ino; + min_key.type = key_type; + min_key.offset = (u64)-1; + btrfs_release_path(path); + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (ret < 0) { + btrfs_release_path(path); + return ret; + } + ret = btrfs_previous_item(root, path, 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, 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); + if (ret) { + err = ret; + goto done; + } + } + } + btrfs_release_path(path); + + /* find the first key from this transaction again */ + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (WARN_ON(ret != 0)) + 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++) { + struct btrfs_dir_item *di; + + btrfs_item_key_to_cpu(src, &min_key, i); + + if (min_key.objectid != ino || min_key.type != key_type) + goto done; + ret = overwrite_item(trans, log, dst_path, src, i, + &min_key); + if (ret) { + err = ret; + goto done; + } + + /* + * We must make sure that when we log a directory entry, + * the corresponding inode, after log replay, has a + * matching link count. For example: + * + * touch foo + * mkdir mydir + * sync + * ln foo mydir/bar + * xfs_io -c "fsync" mydir + * <crash> + * <mount fs and log replay> + * + * Would result in a fsync log that when replayed, our + * file inode would have a link count of 1, but we get + * two directory entries pointing to the same inode. + * After removing one of the names, it would not be + * possible to remove the other name, which resulted + * always in stale file handle errors, and would not + * be possible to rmdir the parent directory, since + * its i_size could never decrement to the value + * BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors. + */ + di = btrfs_item_ptr(src, i, struct btrfs_dir_item); + btrfs_dir_item_key_to_cpu(src, di, &tmp); + if (ctx && + (btrfs_dir_transid(src, di) == trans->transid || + btrfs_dir_type(src, di) == BTRFS_FT_DIR) && + tmp.type != BTRFS_ROOT_ITEM_KEY) + ctx->log_new_dentries = true; + } + 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 != 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); + if (ret) + err = ret; + else + last_offset = tmp.offset; + goto done; + } + } +done: + btrfs_release_path(path); + btrfs_release_path(dst_path); + + if (err == 0) { + *last_offset_ret = last_offset; + /* + * insert the log range keys to indicate where the log + * is valid + */ + ret = insert_dir_log_key(trans, log, path, key_type, + ino, first_offset, last_offset); + if (ret) + err = ret; + } + return err; +} + +/* + * 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, + struct btrfs_log_ctx *ctx) +{ + 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, ctx, min_key, + &max_key); + if (ret) + return 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; + int start_slot; + + key.objectid = objectid; + key.type = max_key_type; + key.offset = (u64)-1; + + while (1) { + ret = btrfs_search_slot(trans, log, &key, path, -1, 1); + BUG_ON(ret == 0); /* Logic error */ + if (ret < 0) + 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; + + found_key.offset = 0; + found_key.type = 0; + ret = btrfs_bin_search(path->nodes[0], &found_key, 0, + &start_slot); + + ret = btrfs_del_items(trans, log, path, start_slot, + path->slots[0] - start_slot + 1); + /* + * If start slot isn't 0 then we don't need to re-search, we've + * found the last guy with the objectid in this tree. + */ + if (ret || start_slot != 0) + break; + btrfs_release_path(path); + } + btrfs_release_path(path); + if (ret > 0) + ret = 0; + return ret; +} + +static void fill_inode_item(struct btrfs_trans_handle *trans, + struct extent_buffer *leaf, + struct btrfs_inode_item *item, + struct inode *inode, int log_inode_only, + u64 logged_isize) +{ + struct btrfs_map_token token; + + btrfs_init_map_token(&token); + + if (log_inode_only) { + /* 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_token_inode_generation(leaf, item, 0, &token); + btrfs_set_token_inode_size(leaf, item, logged_isize, &token); + } else { + btrfs_set_token_inode_generation(leaf, item, + BTRFS_I(inode)->generation, + &token); + btrfs_set_token_inode_size(leaf, item, inode->i_size, &token); + } + + btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); + btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); + btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); + btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); + + btrfs_set_token_timespec_sec(leaf, &item->atime, + inode->i_atime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->atime, + inode->i_atime.tv_nsec, &token); + + btrfs_set_token_timespec_sec(leaf, &item->mtime, + inode->i_mtime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->mtime, + inode->i_mtime.tv_nsec, &token); + + btrfs_set_token_timespec_sec(leaf, &item->ctime, + inode->i_ctime.tv_sec, &token); + btrfs_set_token_timespec_nsec(leaf, &item->ctime, + inode->i_ctime.tv_nsec, &token); + + btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), + &token); + + btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); + btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); + btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); + btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); + btrfs_set_token_inode_block_group(leaf, item, 0, &token); +} + +static int log_inode_item(struct btrfs_trans_handle *trans, + struct btrfs_root *log, struct btrfs_path *path, + struct inode *inode) +{ + struct btrfs_inode_item *inode_item; + int ret; + + ret = btrfs_insert_empty_item(trans, log, path, + &BTRFS_I(inode)->location, + sizeof(*inode_item)); + if (ret && ret != -EEXIST) + return ret; + inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + fill_inode_item(trans, path->nodes[0], inode_item, inode, 0, 0); + btrfs_release_path(path); + return 0; +} + +static noinline int copy_items(struct btrfs_trans_handle *trans, + struct inode *inode, + struct btrfs_path *dst_path, + struct btrfs_path *src_path, u64 *last_extent, + int start_slot, int nr, int inode_only, + u64 logged_isize) +{ + unsigned long src_offset; + unsigned long dst_offset; + struct btrfs_root *log = BTRFS_I(inode)->root->log_root; + struct btrfs_file_extent_item *extent; + struct btrfs_inode_item *inode_item; + struct extent_buffer *src = src_path->nodes[0]; + struct btrfs_key first_key, last_key, key; + int ret; + struct btrfs_key *ins_keys; + u32 *ins_sizes; + char *ins_data; + int i; + struct list_head ordered_sums; + int skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; + bool has_extents = false; + bool need_find_last_extent = true; + bool done = false; + + INIT_LIST_HEAD(&ordered_sums); + + ins_data = kmalloc(nr * sizeof(struct btrfs_key) + + nr * sizeof(u32), GFP_NOFS); + if (!ins_data) + return -ENOMEM; + + first_key.objectid = (u64)-1; + + ins_sizes = (u32 *)ins_data; + ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32)); + + for (i = 0; i < nr; i++) { + ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot); + btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot); + } + ret = btrfs_insert_empty_items(trans, log, dst_path, + ins_keys, ins_sizes, nr); + if (ret) { + kfree(ins_data); + return ret; + } + + for (i = 0; i < nr; i++, dst_path->slots[0]++) { + dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], + dst_path->slots[0]); + + src_offset = btrfs_item_ptr_offset(src, start_slot + i); + + if ((i == (nr - 1))) + last_key = ins_keys[i]; + + if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) { + inode_item = btrfs_item_ptr(dst_path->nodes[0], + dst_path->slots[0], + struct btrfs_inode_item); + fill_inode_item(trans, dst_path->nodes[0], inode_item, + inode, inode_only == LOG_INODE_EXISTS, + logged_isize); + } else { + copy_extent_buffer(dst_path->nodes[0], src, dst_offset, + src_offset, ins_sizes[i]); + } + + /* + * We set need_find_last_extent here in case we know we were + * processing other items and then walk into the first extent in + * the inode. If we don't hit an extent then nothing changes, + * we'll do the last search the next time around. + */ + if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY) { + has_extents = true; + if (first_key.objectid == (u64)-1) + first_key = ins_keys[i]; + } else { + need_find_last_extent = false; + } + + /* take a reference on file data extents so that truncates + * or deletes of this inode don't have to relog the inode + * again + */ + if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY && + !skip_csum) { + int found_type; + extent = btrfs_item_ptr(src, start_slot + i, + struct btrfs_file_extent_item); + + if (btrfs_file_extent_generation(src, extent) < trans->transid) + continue; + + found_type = btrfs_file_extent_type(src, extent); + if (found_type == BTRFS_FILE_EXTENT_REG) { + u64 ds, dl, cs, cl; + ds = btrfs_file_extent_disk_bytenr(src, + extent); + /* ds == 0 is a hole */ + if (ds == 0) + continue; + + dl = btrfs_file_extent_disk_num_bytes(src, + extent); + cs = btrfs_file_extent_offset(src, extent); + cl = btrfs_file_extent_num_bytes(src, + extent); + if (btrfs_file_extent_compression(src, + extent)) { + cs = 0; + cl = dl; + } + + ret = btrfs_lookup_csums_range( + log->fs_info->csum_root, + ds + cs, ds + cs + cl - 1, + &ordered_sums, 0); + if (ret) { + btrfs_release_path(dst_path); + kfree(ins_data); + return ret; + } + } + } + } + + btrfs_mark_buffer_dirty(dst_path->nodes[0]); + btrfs_release_path(dst_path); + kfree(ins_data); + + /* + * we have to do this after the loop above to avoid changing the + * log tree while trying to change the log tree. + */ + ret = 0; + while (!list_empty(&ordered_sums)) { + struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, + struct btrfs_ordered_sum, + list); + if (!ret) + ret = btrfs_csum_file_blocks(trans, log, sums); + list_del(&sums->list); + kfree(sums); + } + + if (!has_extents) + return ret; + + if (need_find_last_extent && *last_extent == first_key.offset) { + /* + * We don't have any leafs between our current one and the one + * we processed before that can have file extent items for our + * inode (and have a generation number smaller than our current + * transaction id). + */ + need_find_last_extent = false; + } + + /* + * Because we use btrfs_search_forward we could skip leaves that were + * not modified and then assume *last_extent is valid when it really + * isn't. So back up to the previous leaf and read the end of the last + * extent before we go and fill in holes. + */ + if (need_find_last_extent) { + u64 len; + + ret = btrfs_prev_leaf(BTRFS_I(inode)->root, src_path); + if (ret < 0) + return ret; + if (ret) + goto fill_holes; + if (src_path->slots[0]) + src_path->slots[0]--; + src = src_path->nodes[0]; + btrfs_item_key_to_cpu(src, &key, src_path->slots[0]); + if (key.objectid != btrfs_ino(inode) || + key.type != BTRFS_EXTENT_DATA_KEY) + goto fill_holes; + extent = btrfs_item_ptr(src, src_path->slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(src, extent) == + BTRFS_FILE_EXTENT_INLINE) { + len = btrfs_file_extent_inline_len(src, + src_path->slots[0], + extent); + *last_extent = ALIGN(key.offset + len, + log->sectorsize); + } else { + len = btrfs_file_extent_num_bytes(src, extent); + *last_extent = key.offset + len; + } + } +fill_holes: + /* So we did prev_leaf, now we need to move to the next leaf, but a few + * things could have happened + * + * 1) A merge could have happened, so we could currently be on a leaf + * that holds what we were copying in the first place. + * 2) A split could have happened, and now not all of the items we want + * are on the same leaf. + * + * So we need to adjust how we search for holes, we need to drop the + * path and re-search for the first extent key we found, and then walk + * forward until we hit the last one we copied. + */ + if (need_find_last_extent) { + /* btrfs_prev_leaf could return 1 without releasing the path */ + btrfs_release_path(src_path); + ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &first_key, + src_path, 0, 0); + if (ret < 0) + return ret; + ASSERT(ret == 0); + src = src_path->nodes[0]; + i = src_path->slots[0]; + } else { + i = start_slot; + } + + /* + * Ok so here we need to go through and fill in any holes we may have + * to make sure that holes are punched for those areas in case they had + * extents previously. + */ + while (!done) { + u64 offset, len; + u64 extent_end; + + if (i >= btrfs_header_nritems(src_path->nodes[0])) { + ret = btrfs_next_leaf(BTRFS_I(inode)->root, src_path); + if (ret < 0) + return ret; + ASSERT(ret == 0); + src = src_path->nodes[0]; + i = 0; + } + + btrfs_item_key_to_cpu(src, &key, i); + if (!btrfs_comp_cpu_keys(&key, &last_key)) + done = true; + if (key.objectid != btrfs_ino(inode) || + key.type != BTRFS_EXTENT_DATA_KEY) { + i++; + continue; + } + extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item); + if (btrfs_file_extent_type(src, extent) == + BTRFS_FILE_EXTENT_INLINE) { + len = btrfs_file_extent_inline_len(src, i, extent); + extent_end = ALIGN(key.offset + len, log->sectorsize); + } else { + len = btrfs_file_extent_num_bytes(src, extent); + extent_end = key.offset + len; + } + i++; + + if (*last_extent == key.offset) { + *last_extent = extent_end; + continue; + } + offset = *last_extent; + len = key.offset - *last_extent; + ret = btrfs_insert_file_extent(trans, log, btrfs_ino(inode), + offset, 0, 0, len, 0, len, 0, + 0, 0); + if (ret) + break; + *last_extent = extent_end; + } + /* + * Need to let the callers know we dropped the path so they should + * re-search. + */ + if (!ret && need_find_last_extent) + ret = 1; + return ret; +} + +static int extent_cmp(void *priv, struct list_head *a, struct list_head *b) +{ + struct extent_map *em1, *em2; + + em1 = list_entry(a, struct extent_map, list); + em2 = list_entry(b, struct extent_map, list); + + if (em1->start < em2->start) + return -1; + else if (em1->start > em2->start) + return 1; + return 0; +} + +static int wait_ordered_extents(struct btrfs_trans_handle *trans, + struct inode *inode, + struct btrfs_root *root, + const struct extent_map *em, + const struct list_head *logged_list, + bool *ordered_io_error) +{ + struct btrfs_ordered_extent *ordered; + struct btrfs_root *log = root->log_root; + u64 mod_start = em->mod_start; + u64 mod_len = em->mod_len; + const bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; + u64 csum_offset; + u64 csum_len; + LIST_HEAD(ordered_sums); + int ret = 0; + + *ordered_io_error = false; + + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || + em->block_start == EXTENT_MAP_HOLE) + return 0; + + /* + * Wait far any ordered extent that covers our extent map. If it + * finishes without an error, first check and see if our csums are on + * our outstanding ordered extents. + */ + list_for_each_entry(ordered, logged_list, log_list) { + struct btrfs_ordered_sum *sum; + + if (!mod_len) + break; + + if (ordered->file_offset + ordered->len <= mod_start || + mod_start + mod_len <= ordered->file_offset) + continue; + + if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) && + !test_bit(BTRFS_ORDERED_IOERR, &ordered->flags) && + !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) { + const u64 start = ordered->file_offset; + const u64 end = ordered->file_offset + ordered->len - 1; + + WARN_ON(ordered->inode != inode); + filemap_fdatawrite_range(inode->i_mapping, start, end); + } + + wait_event(ordered->wait, + (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) || + test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))); + + if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) { + /* + * Clear the AS_EIO/AS_ENOSPC flags from the inode's + * i_mapping flags, so that the next fsync won't get + * an outdated io error too. + */ + btrfs_inode_check_errors(inode); + *ordered_io_error = true; + break; + } + /* + * We are going to copy all the csums on this ordered extent, so + * go ahead and adjust mod_start and mod_len in case this + * ordered extent has already been logged. + */ + if (ordered->file_offset > mod_start) { + if (ordered->file_offset + ordered->len >= + mod_start + mod_len) + mod_len = ordered->file_offset - mod_start; + /* + * If we have this case + * + * |--------- logged extent ---------| + * |----- ordered extent ----| + * + * Just don't mess with mod_start and mod_len, we'll + * just end up logging more csums than we need and it + * will be ok. + */ + } else { + if (ordered->file_offset + ordered->len < + mod_start + mod_len) { + mod_len = (mod_start + mod_len) - + (ordered->file_offset + ordered->len); + mod_start = ordered->file_offset + + ordered->len; + } else { + mod_len = 0; + } + } + + if (skip_csum) + continue; + + /* + * To keep us from looping for the above case of an ordered + * extent that falls inside of the logged extent. + */ + if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, + &ordered->flags)) + continue; + + if (ordered->csum_bytes_left) { + btrfs_start_ordered_extent(inode, ordered, 0); + wait_event(ordered->wait, + ordered->csum_bytes_left == 0); + } + + list_for_each_entry(sum, &ordered->list, list) { + ret = btrfs_csum_file_blocks(trans, log, sum); + if (ret) + break; + } + } + + if (*ordered_io_error || !mod_len || ret || skip_csum) + return ret; + + if (em->compress_type) { + csum_offset = 0; + csum_len = max(em->block_len, em->orig_block_len); + } else { + csum_offset = mod_start - em->start; + csum_len = mod_len; + } + + /* block start is already adjusted for the file extent offset. */ + ret = btrfs_lookup_csums_range(log->fs_info->csum_root, + em->block_start + csum_offset, + em->block_start + csum_offset + + csum_len - 1, &ordered_sums, 0); + if (ret) + return ret; + + while (!list_empty(&ordered_sums)) { + struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, + struct btrfs_ordered_sum, + list); + if (!ret) + ret = btrfs_csum_file_blocks(trans, log, sums); + list_del(&sums->list); + kfree(sums); + } + + return ret; +} + +static int log_one_extent(struct btrfs_trans_handle *trans, + struct inode *inode, struct btrfs_root *root, + const struct extent_map *em, + struct btrfs_path *path, + const struct list_head *logged_list, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *log = root->log_root; + struct btrfs_file_extent_item *fi; + struct extent_buffer *leaf; + struct btrfs_map_token token; + struct btrfs_key key; + u64 extent_offset = em->start - em->orig_start; + u64 block_len; + int ret; + int extent_inserted = 0; + bool ordered_io_err = false; + + ret = wait_ordered_extents(trans, inode, root, em, logged_list, + &ordered_io_err); + if (ret) + return ret; + + if (ordered_io_err) { + ctx->io_err = -EIO; + return 0; + } + + btrfs_init_map_token(&token); + + ret = __btrfs_drop_extents(trans, log, inode, path, em->start, + em->start + em->len, NULL, 0, 1, + sizeof(*fi), &extent_inserted); + if (ret) + return ret; + + if (!extent_inserted) { + key.objectid = btrfs_ino(inode); + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = em->start; + + ret = btrfs_insert_empty_item(trans, log, path, &key, + sizeof(*fi)); + if (ret) + return ret; + } + leaf = path->nodes[0]; + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + + btrfs_set_token_file_extent_generation(leaf, fi, trans->transid, + &token); + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + btrfs_set_token_file_extent_type(leaf, fi, + BTRFS_FILE_EXTENT_PREALLOC, + &token); + else + btrfs_set_token_file_extent_type(leaf, fi, + BTRFS_FILE_EXTENT_REG, + &token); + + block_len = max(em->block_len, em->orig_block_len); + if (em->compress_type != BTRFS_COMPRESS_NONE) { + btrfs_set_token_file_extent_disk_bytenr(leaf, fi, + em->block_start, + &token); + btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len, + &token); + } else if (em->block_start < EXTENT_MAP_LAST_BYTE) { + btrfs_set_token_file_extent_disk_bytenr(leaf, fi, + em->block_start - + extent_offset, &token); + btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len, + &token); + } else { + btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token); + btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0, + &token); + } + + btrfs_set_token_file_extent_offset(leaf, fi, extent_offset, &token); + btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token); + btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token); + btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type, + &token); + btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token); + btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token); + btrfs_mark_buffer_dirty(leaf); + + btrfs_release_path(path); + + return ret; +} + +static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, + struct btrfs_path *path, + struct list_head *logged_list, + struct btrfs_log_ctx *ctx) +{ + struct extent_map *em, *n; + struct list_head extents; + struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree; + u64 test_gen; + int ret = 0; + int num = 0; + + INIT_LIST_HEAD(&extents); + + write_lock(&tree->lock); + test_gen = root->fs_info->last_trans_committed; + + list_for_each_entry_safe(em, n, &tree->modified_extents, list) { + list_del_init(&em->list); + + /* + * Just an arbitrary number, this can be really CPU intensive + * once we start getting a lot of extents, and really once we + * have a bunch of extents we just want to commit since it will + * be faster. + */ + if (++num > 32768) { + list_del_init(&tree->modified_extents); + ret = -EFBIG; + goto process; + } + + if (em->generation <= test_gen) + continue; + /* Need a ref to keep it from getting evicted from cache */ + atomic_inc(&em->refs); + set_bit(EXTENT_FLAG_LOGGING, &em->flags); + list_add_tail(&em->list, &extents); + num++; + } + + list_sort(NULL, &extents, extent_cmp); + +process: + while (!list_empty(&extents)) { + em = list_entry(extents.next, struct extent_map, list); + + list_del_init(&em->list); + + /* + * If we had an error we just need to delete everybody from our + * private list. + */ + if (ret) { + clear_em_logging(tree, em); + free_extent_map(em); + continue; + } + + write_unlock(&tree->lock); + + ret = log_one_extent(trans, inode, root, em, path, logged_list, + ctx); + write_lock(&tree->lock); + clear_em_logging(tree, em); + free_extent_map(em); + } + WARN_ON(!list_empty(&extents)); + write_unlock(&tree->lock); + + btrfs_release_path(path); + return ret; +} + +static int logged_inode_size(struct btrfs_root *log, struct inode *inode, + struct btrfs_path *path, u64 *size_ret) +{ + struct btrfs_key key; + int ret; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, log, &key, path, 0, 0); + if (ret < 0) { + return ret; + } else if (ret > 0) { + *size_ret = 0; + } else { + struct btrfs_inode_item *item; + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + *size_ret = btrfs_inode_size(path->nodes[0], item); + } + + btrfs_release_path(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, + const loff_t start, + const loff_t end, + struct btrfs_log_ctx *ctx) +{ + 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; + struct extent_buffer *src = NULL; + LIST_HEAD(logged_list); + u64 last_extent = 0; + int err = 0; + int ret; + int nritems; + int ins_start_slot = 0; + int ins_nr; + bool fast_search = false; + u64 ino = btrfs_ino(inode); + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + u64 logged_isize = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + dst_path = btrfs_alloc_path(); + if (!dst_path) { + btrfs_free_path(path); + return -ENOMEM; + } + + min_key.objectid = ino; + min_key.type = BTRFS_INODE_ITEM_KEY; + min_key.offset = 0; + + max_key.objectid = ino; + + + /* today the code can only do partial logging of directories */ + if (S_ISDIR(inode->i_mode) || + (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags) && + inode_only == LOG_INODE_EXISTS)) + max_key.type = BTRFS_XATTR_ITEM_KEY; + else + max_key.type = (u8)-1; + max_key.offset = (u64)-1; + + /* + * Only run delayed items if we are a dir or a new file. + * Otherwise commit the delayed inode only, which is needed in + * order for the log replay code to mark inodes for link count + * fixup (create temporary BTRFS_TREE_LOG_FIXUP_OBJECTID items). + */ + if (S_ISDIR(inode->i_mode) || + BTRFS_I(inode)->generation > root->fs_info->last_trans_committed) + ret = btrfs_commit_inode_delayed_items(trans, inode); + else + ret = btrfs_commit_inode_delayed_inode(inode); + + if (ret) { + btrfs_free_path(path); + btrfs_free_path(dst_path); + return ret; + } + + mutex_lock(&BTRFS_I(inode)->log_mutex); + + btrfs_get_logged_extents(inode, &logged_list, start, end); + + /* + * 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, ino, max_key_type); + } else { + if (inode_only == LOG_INODE_EXISTS) { + /* + * Make sure the new inode item we write to the log has + * the same isize as the current one (if it exists). + * This is necessary to prevent data loss after log + * replay, and also to prevent doing a wrong expanding + * truncate - for e.g. create file, write 4K into offset + * 0, fsync, write 4K into offset 4096, add hard link, + * fsync some other file (to sync log), power fail - if + * we use the inode's current i_size, after log replay + * we get a 8Kb file, with the last 4Kb extent as a hole + * (zeroes), as if an expanding truncate happened, + * instead of getting a file of 4Kb only. + */ + err = logged_inode_size(log, inode, path, + &logged_isize); + if (err) + goto out_unlock; + } + if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags)) { + if (inode_only == LOG_INODE_EXISTS) { + max_key.type = BTRFS_XATTR_ITEM_KEY; + ret = drop_objectid_items(trans, log, path, ino, + max_key.type); + } else { + clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + clear_bit(BTRFS_INODE_COPY_EVERYTHING, + &BTRFS_I(inode)->runtime_flags); + while(1) { + ret = btrfs_truncate_inode_items(trans, + log, inode, 0, 0); + if (ret != -EAGAIN) + break; + } + } + } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING, + &BTRFS_I(inode)->runtime_flags) || + inode_only == LOG_INODE_EXISTS) { + if (inode_only == LOG_INODE_ALL) + fast_search = true; + max_key.type = BTRFS_XATTR_ITEM_KEY; + ret = drop_objectid_items(trans, log, path, ino, + max_key.type); + } else { + if (inode_only == LOG_INODE_ALL) + fast_search = true; + ret = log_inode_item(trans, log, dst_path, inode); + if (ret) { + err = ret; + goto out_unlock; + } + goto log_extents; + } + + } + if (ret) { + err = ret; + goto out_unlock; + } + + while (1) { + ins_nr = 0; + ret = btrfs_search_forward(root, &min_key, + path, trans->transid); + if (ret != 0) + break; +again: + /* note, ins_nr might be > 0 here, cleanup outside the loop */ + if (min_key.objectid != ino) + break; + if (min_key.type > max_key.type) + break; + + src = path->nodes[0]; + if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) { + ins_nr++; + goto next_slot; + } else if (!ins_nr) { + ins_start_slot = path->slots[0]; + ins_nr = 1; + goto next_slot; + } + + ret = copy_items(trans, inode, dst_path, path, &last_extent, + ins_start_slot, ins_nr, inode_only, + logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + if (ret) { + ins_nr = 0; + btrfs_release_path(path); + continue; + } + ins_nr = 1; + ins_start_slot = path->slots[0]; +next_slot: + + nritems = btrfs_header_nritems(path->nodes[0]); + path->slots[0]++; + if (path->slots[0] < nritems) { + btrfs_item_key_to_cpu(path->nodes[0], &min_key, + path->slots[0]); + goto again; + } + if (ins_nr) { + ret = copy_items(trans, inode, dst_path, path, + &last_extent, ins_start_slot, + ins_nr, inode_only, logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ret = 0; + ins_nr = 0; + } + btrfs_release_path(path); + + if (min_key.offset < (u64)-1) { + min_key.offset++; + } else if (min_key.type < max_key.type) { + min_key.type++; + min_key.offset = 0; + } else { + break; + } + } + if (ins_nr) { + ret = copy_items(trans, inode, dst_path, path, &last_extent, + ins_start_slot, ins_nr, inode_only, + logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ret = 0; + ins_nr = 0; + } + +log_extents: + btrfs_release_path(path); + btrfs_release_path(dst_path); + if (fast_search) { + /* + * Some ordered extents started by fsync might have completed + * before we collected the ordered extents in logged_list, which + * means they're gone, not in our logged_list nor in the inode's + * ordered tree. We want the application/user space to know an + * error happened while attempting to persist file data so that + * it can take proper action. If such error happened, we leave + * without writing to the log tree and the fsync must report the + * file data write error and not commit the current transaction. + */ + err = btrfs_inode_check_errors(inode); + if (err) { + ctx->io_err = err; + goto out_unlock; + } + ret = btrfs_log_changed_extents(trans, root, inode, dst_path, + &logged_list, ctx); + if (ret) { + err = ret; + goto out_unlock; + } + } else if (inode_only == LOG_INODE_ALL) { + struct extent_map *em, *n; + + write_lock(&em_tree->lock); + /* + * We can't just remove every em if we're called for a ranged + * fsync - that is, one that doesn't cover the whole possible + * file range (0 to LLONG_MAX). This is because we can have + * em's that fall outside the range we're logging and therefore + * their ordered operations haven't completed yet + * (btrfs_finish_ordered_io() not invoked yet). This means we + * didn't get their respective file extent item in the fs/subvol + * tree yet, and need to let the next fast fsync (one which + * consults the list of modified extent maps) find the em so + * that it logs a matching file extent item and waits for the + * respective ordered operation to complete (if it's still + * running). + * + * Removing every em outside the range we're logging would make + * the next fast fsync not log their matching file extent items, + * therefore making us lose data after a log replay. + */ + list_for_each_entry_safe(em, n, &em_tree->modified_extents, + list) { + const u64 mod_end = em->mod_start + em->mod_len - 1; + + if (em->mod_start >= start && mod_end <= end) + list_del_init(&em->list); + } + write_unlock(&em_tree->lock); + } + + if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) { + ret = log_directory_changes(trans, root, inode, path, dst_path, + ctx); + if (ret) { + err = ret; + goto out_unlock; + } + } + + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->logged_trans = trans->transid; + BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->last_sub_trans; + spin_unlock(&BTRFS_I(inode)->lock); +out_unlock: + if (unlikely(err)) + btrfs_put_logged_extents(&logged_list); + else + btrfs_submit_logged_extents(&logged_list, log); + mutex_unlock(&BTRFS_I(inode)->log_mutex); + + btrfs_free_path(path); + btrfs_free_path(dst_path); + return err; +} + +/* + * follow the dentry parent pointers up the chain and see if any + * of the directories in it require a full commit before they can + * be logged. Returns zero if nothing special needs to be done or 1 if + * a full commit is required. + */ +static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans, + struct inode *inode, + struct dentry *parent, + struct super_block *sb, + u64 last_committed) +{ + int ret = 0; + struct btrfs_root *root; + struct dentry *old_parent = NULL; + struct inode *orig_inode = inode; + + /* + * for regular files, if its inode is already on disk, we don't + * have to worry about the parents at all. This is because + * we can use the last_unlink_trans field to record renames + * and other fun in this file. + */ + if (S_ISREG(inode->i_mode) && + BTRFS_I(inode)->generation <= last_committed && + BTRFS_I(inode)->last_unlink_trans <= last_committed) + goto out; + + if (!S_ISDIR(inode->i_mode)) { + if (!parent || d_really_is_negative(parent) || sb != d_inode(parent)->i_sb) + goto out; + inode = d_inode(parent); + } + + while (1) { + /* + * If we are logging a directory then we start with our inode, + * not our parents inode, so we need to skipp setting the + * logged_trans so that further down in the log code we don't + * think this inode has already been logged. + */ + if (inode != orig_inode) + BTRFS_I(inode)->logged_trans = trans->transid; + smp_mb(); + + if (BTRFS_I(inode)->last_unlink_trans > last_committed) { + root = BTRFS_I(inode)->root; + + /* + * make sure any commits to the log are forced + * to be full commits + */ + btrfs_set_log_full_commit(root->fs_info, trans); + ret = 1; + break; + } + + if (!parent || d_really_is_negative(parent) || sb != d_inode(parent)->i_sb) + break; + + if (IS_ROOT(parent)) + break; + + parent = dget_parent(parent); + dput(old_parent); + old_parent = parent; + inode = d_inode(parent); + + } + dput(old_parent); +out: + return ret; +} + +struct btrfs_dir_list { + u64 ino; + struct list_head list; +}; + +/* + * Log the inodes of the new dentries of a directory. See log_dir_items() for + * details about the why it is needed. + * This is a recursive operation - if an existing dentry corresponds to a + * directory, that directory's new entries are logged too (same behaviour as + * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes + * the dentries point to we do not lock their i_mutex, otherwise lockdep + * complains about the following circular lock dependency / possible deadlock: + * + * CPU0 CPU1 + * ---- ---- + * lock(&type->i_mutex_dir_key#3/2); + * lock(sb_internal#2); + * lock(&type->i_mutex_dir_key#3/2); + * lock(&sb->s_type->i_mutex_key#14); + * + * Where sb_internal is the lock (a counter that works as a lock) acquired by + * sb_start_intwrite() in btrfs_start_transaction(). + * Not locking i_mutex of the inodes is still safe because: + * + * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible + * that while logging the inode new references (names) are added or removed + * from the inode, leaving the logged inode item with a link count that does + * not match the number of logged inode reference items. This is fine because + * at log replay time we compute the real number of links and correct the + * link count in the inode item (see replay_one_buffer() and + * link_to_fixup_dir()); + * + * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that + * while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and + * BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item + * has a size that doesn't match the sum of the lengths of all the logged + * names. This does not result in a problem because if a dir_item key is + * logged but its matching dir_index key is not logged, at log replay time we + * don't use it to replay the respective name (see replay_one_name()). On the + * other hand if only the dir_index key ends up being logged, the respective + * name is added to the fs/subvol tree with both the dir_item and dir_index + * keys created (see replay_one_name()). + * The directory's inode item with a wrong i_size is not a problem as well, + * since we don't use it at log replay time to set the i_size in the inode + * item of the fs/subvol tree (see overwrite_item()). + */ +static int log_new_dir_dentries(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *start_inode, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *log = root->log_root; + struct btrfs_path *path; + LIST_HEAD(dir_list); + struct btrfs_dir_list *dir_elem; + int ret = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS); + if (!dir_elem) { + btrfs_free_path(path); + return -ENOMEM; + } + dir_elem->ino = btrfs_ino(start_inode); + list_add_tail(&dir_elem->list, &dir_list); + + while (!list_empty(&dir_list)) { + struct extent_buffer *leaf; + struct btrfs_key min_key; + int nritems; + int i; + + dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, + list); + if (ret) + goto next_dir_inode; + + min_key.objectid = dir_elem->ino; + min_key.type = BTRFS_DIR_ITEM_KEY; + min_key.offset = 0; +again: + btrfs_release_path(path); + ret = btrfs_search_forward(log, &min_key, path, trans->transid); + if (ret < 0) { + goto next_dir_inode; + } else if (ret > 0) { + ret = 0; + goto next_dir_inode; + } + +process_leaf: + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + for (i = path->slots[0]; i < nritems; i++) { + struct btrfs_dir_item *di; + struct btrfs_key di_key; + struct inode *di_inode; + struct btrfs_dir_list *new_dir_elem; + int log_mode = LOG_INODE_EXISTS; + int type; + + btrfs_item_key_to_cpu(leaf, &min_key, i); + if (min_key.objectid != dir_elem->ino || + min_key.type != BTRFS_DIR_ITEM_KEY) + goto next_dir_inode; + + di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item); + type = btrfs_dir_type(leaf, di); + if (btrfs_dir_transid(leaf, di) < trans->transid && + type != BTRFS_FT_DIR) + continue; + btrfs_dir_item_key_to_cpu(leaf, di, &di_key); + if (di_key.type == BTRFS_ROOT_ITEM_KEY) + continue; + + di_inode = btrfs_iget(root->fs_info->sb, &di_key, + root, NULL); + if (IS_ERR(di_inode)) { + ret = PTR_ERR(di_inode); + goto next_dir_inode; + } + + if (btrfs_inode_in_log(di_inode, trans->transid)) { + iput(di_inode); + continue; + } + + ctx->log_new_dentries = false; + if (type == BTRFS_FT_DIR) + log_mode = LOG_INODE_ALL; + btrfs_release_path(path); + ret = btrfs_log_inode(trans, root, di_inode, + log_mode, 0, LLONG_MAX, ctx); + iput(di_inode); + if (ret) + goto next_dir_inode; + if (ctx->log_new_dentries) { + new_dir_elem = kmalloc(sizeof(*new_dir_elem), + GFP_NOFS); + if (!new_dir_elem) { + ret = -ENOMEM; + goto next_dir_inode; + } + new_dir_elem->ino = di_key.objectid; + list_add_tail(&new_dir_elem->list, &dir_list); + } + break; + } + if (i == nritems) { + ret = btrfs_next_leaf(log, path); + if (ret < 0) { + goto next_dir_inode; + } else if (ret > 0) { + ret = 0; + goto next_dir_inode; + } + goto process_leaf; + } + if (min_key.offset < (u64)-1) { + min_key.offset++; + goto again; + } +next_dir_inode: + list_del(&dir_elem->list); + kfree(dir_elem); + } + + btrfs_free_path(path); + 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 + */ +static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode, + struct dentry *parent, + const loff_t start, + const loff_t end, + int exists_only, + struct btrfs_log_ctx *ctx) +{ + int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL; + struct super_block *sb; + struct dentry *old_parent = NULL; + int ret = 0; + u64 last_committed = root->fs_info->last_trans_committed; + const struct dentry * const first_parent = parent; + const bool did_unlink = (BTRFS_I(inode)->last_unlink_trans > + last_committed); + bool log_dentries = false; + struct inode *orig_inode = inode; + + sb = inode->i_sb; + + if (btrfs_test_opt(root, NOTREELOG)) { + ret = 1; + goto end_no_trans; + } + + /* + * The prev transaction commit doesn't complete, we need do + * full commit by ourselves. + */ + if (root->fs_info->last_trans_log_full_commit > + root->fs_info->last_trans_committed) { + ret = 1; + goto end_no_trans; + } + + if (root != BTRFS_I(inode)->root || + btrfs_root_refs(&root->root_item) == 0) { + ret = 1; + goto end_no_trans; + } + + ret = check_parent_dirs_for_sync(trans, inode, parent, + sb, last_committed); + if (ret) + goto end_no_trans; + + if (btrfs_inode_in_log(inode, trans->transid)) { + ret = BTRFS_NO_LOG_SYNC; + goto end_no_trans; + } + + ret = start_log_trans(trans, root, ctx); + if (ret) + goto end_no_trans; + + ret = btrfs_log_inode(trans, root, inode, inode_only, start, end, ctx); + if (ret) + goto end_trans; + + /* + * for regular files, if its inode is already on disk, we don't + * have to worry about the parents at all. This is because + * we can use the last_unlink_trans field to record renames + * and other fun in this file. + */ + if (S_ISREG(inode->i_mode) && + BTRFS_I(inode)->generation <= last_committed && + BTRFS_I(inode)->last_unlink_trans <= last_committed) { + ret = 0; + goto end_trans; + } + + if (S_ISDIR(inode->i_mode) && ctx && ctx->log_new_dentries) + log_dentries = true; + + while (1) { + if (!parent || d_really_is_negative(parent) || sb != d_inode(parent)->i_sb) + break; + + inode = d_inode(parent); + if (root != BTRFS_I(inode)->root) + break; + + /* + * On unlink we must make sure our immediate parent directory + * inode is fully logged. This is to prevent leaving dangling + * directory index entries and a wrong directory inode's i_size. + * Not doing so can result in a directory being impossible to + * delete after log replay (rmdir will always fail with error + * -ENOTEMPTY). + */ + if (did_unlink && parent == first_parent) + inode_only = LOG_INODE_ALL; + else + inode_only = LOG_INODE_EXISTS; + + if (BTRFS_I(inode)->generation > + root->fs_info->last_trans_committed || + inode_only == LOG_INODE_ALL) { + ret = btrfs_log_inode(trans, root, inode, inode_only, + 0, LLONG_MAX, ctx); + if (ret) + goto end_trans; + } + if (IS_ROOT(parent)) + break; + + parent = dget_parent(parent); + dput(old_parent); + old_parent = parent; + } + if (log_dentries) + ret = log_new_dir_dentries(trans, root, orig_inode, ctx); + else + ret = 0; +end_trans: + dput(old_parent); + if (ret < 0) { + btrfs_set_log_full_commit(root->fs_info, trans); + ret = 1; + } + + if (ret) + btrfs_remove_log_ctx(root, ctx); + btrfs_end_log_trans(root); +end_no_trans: + return ret; +} + +/* + * 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, + const loff_t start, + const loff_t end, + struct btrfs_log_ctx *ctx) +{ + struct dentry *parent = dget_parent(dentry); + int ret; + + ret = btrfs_log_inode_parent(trans, root, d_inode(dentry), parent, + start, end, 0, ctx); + dput(parent); + + return ret; +} + +/* + * 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, + }; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + fs_info->log_root_recovering = 1; + + trans = btrfs_start_transaction(fs_info->tree_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto error; + } + + wc.trans = trans; + wc.pin = 1; + + ret = walk_log_tree(trans, log_root_tree, &wc); + if (ret) { + btrfs_error(fs_info, ret, "Failed to pin buffers while " + "recovering log root tree."); + goto error; + } + +again: + key.objectid = BTRFS_TREE_LOG_OBJECTID; + key.offset = (u64)-1; + key.type = BTRFS_ROOT_ITEM_KEY; + + while (1) { + ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0); + + if (ret < 0) { + btrfs_error(fs_info, ret, + "Couldn't find tree log root."); + goto error; + } + 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(path); + if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID) + break; + + log = btrfs_read_fs_root(log_root_tree, &found_key); + if (IS_ERR(log)) { + ret = PTR_ERR(log); + btrfs_error(fs_info, ret, + "Couldn't read tree log root."); + goto error; + } + + 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); + if (IS_ERR(wc.replay_dest)) { + ret = PTR_ERR(wc.replay_dest); + free_extent_buffer(log->node); + free_extent_buffer(log->commit_root); + kfree(log); + btrfs_error(fs_info, ret, "Couldn't read target root " + "for tree log recovery."); + goto error; + } + + wc.replay_dest->log_root = log; + btrfs_record_root_in_trans(trans, wc.replay_dest); + ret = walk_log_tree(trans, log, &wc); + + if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) { + ret = fixup_inode_link_counts(trans, wc.replay_dest, + path); + } + + key.offset = found_key.offset - 1; + wc.replay_dest->log_root = NULL; + free_extent_buffer(log->node); + free_extent_buffer(log->commit_root); + kfree(log); + + if (ret) + goto error; + + if (found_key.offset == 0) + break; + } + btrfs_release_path(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); + + /* step 4: commit the transaction, which also unpins the blocks */ + ret = btrfs_commit_transaction(trans, fs_info->tree_root); + if (ret) + return ret; + + free_extent_buffer(log_root_tree->node); + log_root_tree->log_root = NULL; + fs_info->log_root_recovering = 0; + kfree(log_root_tree); + + return 0; +error: + if (wc.trans) + btrfs_end_transaction(wc.trans, fs_info->tree_root); + btrfs_free_path(path); + return ret; +} + +/* + * there are some corner cases where we want to force a full + * commit instead of allowing a directory to be logged. + * + * They revolve around files there were unlinked from the directory, and + * this function updates the parent directory so that a full commit is + * properly done if it is fsync'd later after the unlinks are done. + */ +void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans, + struct inode *dir, struct inode *inode, + int for_rename) +{ + /* + * when we're logging a file, if it hasn't been renamed + * or unlinked, and its inode is fully committed on disk, + * we don't have to worry about walking up the directory chain + * to log its parents. + * + * So, we use the last_unlink_trans field to put this transid + * into the file. When the file is logged we check it and + * don't log the parents if the file is fully on disk. + */ + if (S_ISREG(inode->i_mode)) + BTRFS_I(inode)->last_unlink_trans = trans->transid; + + /* + * if this directory was already logged any new + * names for this file/dir will get recorded + */ + smp_mb(); + if (BTRFS_I(dir)->logged_trans == trans->transid) + return; + + /* + * if the inode we're about to unlink was logged, + * the log will be properly updated for any new names + */ + if (BTRFS_I(inode)->logged_trans == trans->transid) + return; + + /* + * when renaming files across directories, if the directory + * there we're unlinking from gets fsync'd later on, there's + * no way to find the destination directory later and fsync it + * properly. So, we have to be conservative and force commits + * so the new name gets discovered. + */ + if (for_rename) + goto record; + + /* we can safely do the unlink without any special recording */ + return; + +record: + BTRFS_I(dir)->last_unlink_trans = trans->transid; +} + +/* + * Call this after adding a new name for a file and it will properly + * update the log to reflect the new name. + * + * It will return zero if all goes well, and it will return 1 if a + * full transaction commit is required. + */ +int btrfs_log_new_name(struct btrfs_trans_handle *trans, + struct inode *inode, struct inode *old_dir, + struct dentry *parent) +{ + struct btrfs_root * root = BTRFS_I(inode)->root; + + /* + * this will force the logging code to walk the dentry chain + * up for the file + */ + if (S_ISREG(inode->i_mode)) + BTRFS_I(inode)->last_unlink_trans = trans->transid; + + /* + * if this inode hasn't been logged and directory we're renaming it + * from hasn't been logged, we don't need to log it + */ + if (BTRFS_I(inode)->logged_trans <= + root->fs_info->last_trans_committed && + (!old_dir || BTRFS_I(old_dir)->logged_trans <= + root->fs_info->last_trans_committed)) + return 0; + + return btrfs_log_inode_parent(trans, root, inode, parent, 0, + LLONG_MAX, 1, NULL); +} + |