diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/tree-log.c | 6182 |
1 files changed, 6182 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c new file mode 100644 index 000000000..e00c50ea2 --- /dev/null +++ b/fs/btrfs/tree-log.c @@ -0,0 +1,6182 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2008 Oracle. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/blkdev.h> +#include <linux/list_sort.h> +#include <linux/iversion.h> +#include "ctree.h" +#include "tree-log.h" +#include "disk-io.h" +#include "locking.h" +#include "print-tree.h" +#include "backref.h" +#include "compression.h" +#include "qgroup.h" +#include "inode-map.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 +#define LOG_OTHER_INODE 2 + +/* + * 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 btrfs_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) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + int ret = 0; + + mutex_lock(&root->log_mutex); + + if (root->log_root) { + if (btrfs_need_log_full_commit(fs_info, trans)) { + ret = -EAGAIN; + goto out; + } + + if (!root->log_start_pid) { + clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + root->log_start_pid = current->pid; + } else if (root->log_start_pid != current->pid) { + set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); + } + } else { + mutex_lock(&fs_info->tree_log_mutex); + if (!fs_info->log_root_tree) + ret = btrfs_init_log_root_tree(trans, fs_info); + mutex_unlock(&fs_info->tree_log_mutex); + if (ret) + goto out; + + 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) { + int 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)) { + /* atomic_dec_and_test implies a barrier */ + cond_wake_up_nomb(&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; + + /* + * Ignore any items from the inode currently being processed. Needs + * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in + * the LOG_WALK_REPLAY_INODES stage. + */ + bool ignore_cur_inode; + + /* 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, int level); +}; + +/* + * 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 level) +{ + struct btrfs_fs_info *fs_info = log->fs_info; + 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(fs_info, MIXED_GROUPS)) { + ret = btrfs_read_buffer(eb, gen, level, NULL); + if (ret) + return ret; + } + + if (wc->pin) + ret = btrfs_pin_extent_for_log_replay(fs_info, 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(fs_info, 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) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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(fs_info, path, item_size, 1); + else if (found_size < item_size) + btrfs_extend_item(fs_info, 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; + 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) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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_ram_bytes(eb, item); + nbytes = btrfs_file_extent_ram_bytes(eb, item); + extent_end = ALIGN(start + size, + fs_info->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(BTRFS_I(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; + + if (btrfs_file_extent_disk_bytenr(eb, item) == 0 && + btrfs_fs_incompat(fs_info, NO_HOLES)) + goto update_inode; + + 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); + + /* + * Manually record dirty extent, as here we did a shallow + * file extent item copy and skip normal backref update, + * but modifying extent tree all by ourselves. + * So need to manually record dirty extent for qgroup, + * as the owner of the file extent changed from log tree + * (doesn't affect qgroup) to fs/file tree(affects qgroup) + */ + ret = btrfs_qgroup_trace_extent(trans, + btrfs_file_extent_disk_bytenr(eb, item), + btrfs_file_extent_disk_num_bytes(eb, item), + GFP_NOFS); + if (ret < 0) + goto out; + + 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(fs_info, 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); + if (ret) + goto out; + } else { + /* + * insert the extent pointer in the extent + * allocation tree + */ + ret = btrfs_alloc_logged_file_extent(trans, + 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; + /* + * Now delete all existing cums in the csum root that + * cover our range. We do this because we can have an + * extent that is completely referenced by one file + * extent item and partially referenced by another + * file extent item (like after using the clone or + * extent_same ioctls). In this case if we end up doing + * the replay of the one that partially references the + * extent first, and we do not do the csum deletion + * below, we can get 2 csum items in the csum tree that + * overlap each other. For example, imagine our log has + * the two following file extent items: + * + * key (257 EXTENT_DATA 409600) + * extent data disk byte 12845056 nr 102400 + * extent data offset 20480 nr 20480 ram 102400 + * + * key (257 EXTENT_DATA 819200) + * extent data disk byte 12845056 nr 102400 + * extent data offset 0 nr 102400 ram 102400 + * + * Where the second one fully references the 100K extent + * that starts at disk byte 12845056, and the log tree + * has a single csum item that covers the entire range + * of the extent: + * + * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 + * + * After the first file extent item is replayed, the + * csum tree gets the following csum item: + * + * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 + * + * Which covers the 20K sub-range starting at offset 20K + * of our extent. Now when we replay the second file + * extent item, if we do not delete existing csum items + * that cover any of its blocks, we end up getting two + * csum items in our csum tree that overlap each other: + * + * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 + * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 + * + * Which is a problem, because after this anyone trying + * to lookup up for the checksum of any block of our + * extent starting at an offset of 40K or higher, will + * end up looking at the second csum item only, which + * does not contain the checksum for any block starting + * at offset 40K or higher of our extent. + */ + 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_del_csums(trans, + fs_info->csum_root, + sums->bytenr, + sums->len); + if (!ret) + ret = btrfs_csum_file_blocks(trans, + 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); +update_inode: + 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 btrfs_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, BTRFS_I(inode), name, + name_len); + if (ret) + goto out; + else + ret = btrfs_run_delayed_items(trans); +out: + kfree(name); + iput(inode); + return ret; +} + +/* + * 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. + * + * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it + * exists. + */ +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 ret = 0; + + di = btrfs_lookup_dir_index_item(NULL, root, path, dirid, + index, name, name_len, 0); + if (IS_ERR(di)) { + if (PTR_ERR(di) != -ENOENT) + ret = PTR_ERR(di); + goto out; + } else if (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 (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } else if (di) { + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); + if (location.objectid == objectid) + ret = 1; + } +out: + btrfs_release_path(path); + return ret; +} + +/* + * 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->nodes[0], + path->slots[0], + 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 btrfs_inode *dir, + struct btrfs_inode *inode, + 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->vfs_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); + 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 + * corresponding 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->vfs_inode); + btrfs_release_path(path); + + ret = btrfs_unlink_inode(trans, root, + BTRFS_I(victim_parent), + inode, + victim_name, + victim_name_len); + if (!ret) + ret = btrfs_run_delayed_items( + trans); + } + iput(victim_parent); + kfree(victim_name); + if (ret) + return ret; + *search_done = 1; + goto again; + } + kfree(victim_name); +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 (IS_ERR(di)) { + if (PTR_ERR(di) != -ENOENT) + return PTR_ERR(di); + } else if (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 (IS_ERR(di)) { + return PTR_ERR(di); + } else if (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); + + if (index) + *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); + + if (index) + *index = btrfs_inode_ref_index(eb, ref); + + return 0; +} + +/* + * Take an inode reference item from the log tree and iterate all names from the + * inode reference item in the subvolume tree with the same key (if it exists). + * For any name that is not in the inode reference item from the log tree, do a + * proper unlink of that name (that is, remove its entry from the inode + * reference item and both dir index keys). + */ +static int unlink_old_inode_refs(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_inode *inode, + struct extent_buffer *log_eb, + int log_slot, + struct btrfs_key *key) +{ + int ret; + unsigned long ref_ptr; + unsigned long ref_end; + struct extent_buffer *eb; + +again: + btrfs_release_path(path); + ret = btrfs_search_slot(NULL, root, key, path, 0, 0); + if (ret > 0) { + ret = 0; + goto out; + } + if (ret < 0) + goto out; + + eb = path->nodes[0]; + ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]); + ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]); + while (ref_ptr < ref_end) { + char *name = NULL; + int namelen; + u64 parent_id; + + if (key->type == BTRFS_INODE_EXTREF_KEY) { + ret = extref_get_fields(eb, ref_ptr, &namelen, &name, + NULL, &parent_id); + } else { + parent_id = key->offset; + ret = ref_get_fields(eb, ref_ptr, &namelen, &name, + NULL); + } + if (ret) + goto out; + + if (key->type == BTRFS_INODE_EXTREF_KEY) + ret = btrfs_find_name_in_ext_backref(log_eb, log_slot, + parent_id, name, + namelen, NULL); + else + ret = btrfs_find_name_in_backref(log_eb, log_slot, name, + namelen, NULL); + + if (!ret) { + struct inode *dir; + + btrfs_release_path(path); + dir = read_one_inode(root, parent_id); + if (!dir) { + ret = -ENOENT; + kfree(name); + goto out; + } + ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), + inode, name, namelen); + kfree(name); + iput(dir); + /* + * Whenever we need to check if a name exists or not, we + * check the subvolume tree. So after an unlink we must + * run delayed items, so that future checks for a name + * during log replay see that the name does not exists + * anymore. + */ + if (!ret) + ret = btrfs_run_delayed_items(trans); + if (ret) + goto out; + goto again; + } + + kfree(name); + ref_ptr += namelen; + if (key->type == BTRFS_INODE_EXTREF_KEY) + ref_ptr += sizeof(struct btrfs_inode_extref); + else + ref_ptr += sizeof(struct btrfs_inode_ref); + } + ret = 0; + out: + btrfs_release_path(path); + return ret; +} + +static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir, + const u8 ref_type, const char *name, + const int namelen) +{ + struct btrfs_key key; + struct btrfs_path *path; + const u64 parent_id = btrfs_ino(BTRFS_I(dir)); + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = btrfs_ino(BTRFS_I(inode)); + key.type = ref_type; + if (key.type == BTRFS_INODE_REF_KEY) + key.offset = parent_id; + else + key.offset = btrfs_extref_hash(parent_id, name, namelen); + + ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + goto out; + } + if (key.type == BTRFS_INODE_EXTREF_KEY) + ret = btrfs_find_name_in_ext_backref(path->nodes[0], + path->slots[0], parent_id, + name, namelen, NULL); + else + ret = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], + name, namelen, NULL); + +out: + btrfs_free_path(path); + return ret; +} + +/* + * 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; + + ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)), + btrfs_ino(BTRFS_I(inode)), ref_index, + name, namelen); + if (ret < 0) { + goto out; + } else if (ret == 0) { + /* + * 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, + BTRFS_I(dir), + BTRFS_I(inode), + inode_objectid, + parent_objectid, + ref_index, name, namelen, + &search_done); + if (ret) { + if (ret == 1) + ret = 0; + goto out; + } + } + + /* + * If a reference item already exists for this inode + * with the same parent and name, but different index, + * drop it and the corresponding directory index entries + * from the parent before adding the new reference item + * and dir index entries, otherwise we would fail with + * -EEXIST returned from btrfs_add_link() below. + */ + ret = btrfs_inode_ref_exists(inode, dir, key->type, + name, namelen); + if (ret > 0) { + ret = btrfs_unlink_inode(trans, root, + BTRFS_I(dir), + BTRFS_I(inode), + name, namelen); + /* + * If we dropped the link count to 0, bump it so + * that later the iput() on the inode will not + * free it. We will fixup the link count later. + */ + if (!ret && inode->i_nlink == 0) + inc_nlink(inode); + /* + * Whenever we need to check if a name exists or + * not, we check the subvolume tree. So after an + * unlink we must run delayed items, so that future + * checks for a name during log replay see that the + * name does not exists anymore. + */ + if (!ret) + ret = btrfs_run_delayed_items(trans); + } + if (ret < 0) + goto out; + + /* insert our name */ + ret = btrfs_add_link(trans, BTRFS_I(dir), + BTRFS_I(inode), + name, namelen, 0, ref_index); + if (ret) + goto out; + + btrfs_update_inode(trans, root, inode); + } + /* Else, ret == 1, we already have a perfect match, we're done. */ + + ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen; + kfree(name); + name = NULL; + if (log_ref_ver) { + iput(dir); + dir = NULL; + } + } + + /* + * Before we overwrite the inode reference item in the subvolume tree + * with the item from the log tree, we must unlink all names from the + * parent directory that are in the subvolume's tree inode reference + * item, otherwise we end up with an inconsistent subvolume tree where + * dir index entries exist for a name but there is no inode reference + * item with the same name. + */ + ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot, + key); + if (ret) + goto out; + + /* 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 btrfs_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 btrfs_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(BTRFS_I(inode)); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = count_inode_refs(root, BTRFS_I(inode), path); + if (ret < 0) + goto out; + + nlink = ret; + + ret = count_inode_extrefs(root, BTRFS_I(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) { + ret = 0; + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID || + key.type != BTRFS_ORPHAN_ITEM_KEY) + break; + + ret = btrfs_del_item(trans, root, path); + if (ret) + break; + + btrfs_release_path(path); + inode = read_one_inode(root, key.offset); + if (!inode) { + ret = -EIO; + break; + } + + ret = fixup_inode_link_count(trans, root, inode); + iput(inode); + if (ret) + break; + + /* + * fixup on a directory may create new entries, + * make sure we always look for the highset possible + * offset + */ + key.offset = (u64)-1; + } + 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; + } + 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, + u64 dirid, u64 index, + char *name, int name_len, + 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, BTRFS_I(dir), BTRFS_I(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. + * + * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a + * non-existing inode) and 1 if the name was replayed. + */ +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; + bool exists; + int ret; + bool update_size = (key->type == BTRFS_DIR_INDEX_KEY); + bool name_added = false; + + 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); + ret = btrfs_lookup_inode(trans, root, path, &log_key, 0); + btrfs_release_path(path); + if (ret < 0) + goto out; + exists = (ret == 0); + ret = 0; + + 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 (dst_di == ERR_PTR(-ENOENT)) + dst_di = NULL; + + if (IS_ERR(dst_di)) { + ret = PTR_ERR(dst_di); + goto out; + } else if (!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, BTRFS_I(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(BTRFS_I(dir), dir->i_size + name_len * 2); + ret = btrfs_update_inode(trans, root, dir); + } + kfree(name); + iput(dir); + if (!ret && name_added) + ret = 1; + 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, key->objectid, key->offset, + name, name_len, &log_key); + if (ret && ret != -ENOENT && ret != -EEXIST) + goto out; + if (!ret) + name_added = true; + 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 = 0; + u32 item_size = btrfs_item_size_nr(eb, slot); + struct btrfs_dir_item *di; + int name_len; + unsigned long ptr; + unsigned long ptr_end; + struct btrfs_path *fixup_path = NULL; + + ptr = btrfs_item_ptr_offset(eb, slot); + ptr_end = ptr + item_size; + while (ptr < ptr_end) { + di = (struct btrfs_dir_item *)ptr; + name_len = btrfs_dir_name_len(eb, di); + ret = replay_one_name(trans, root, path, eb, di, key); + if (ret < 0) + break; + ptr = (unsigned long)(di + 1); + ptr += name_len; + + /* + * If this entry refers to a non-directory (directories can not + * have a link count > 1) and it was added in the transaction + * that was not committed, make sure we fixup the link count of + * the inode it the entry points to. Otherwise something like + * the following would result in a directory pointing to an + * inode with a wrong link that does not account for this dir + * entry: + * + * mkdir testdir + * touch testdir/foo + * touch testdir/bar + * sync + * + * ln testdir/bar testdir/bar_link + * ln testdir/foo testdir/foo_link + * xfs_io -c "fsync" testdir/bar + * + * <power failure> + * + * mount fs, log replay happens + * + * File foo would remain with a link count of 1 when it has two + * entries pointing to it in the directory testdir. This would + * make it impossible to ever delete the parent directory has + * it would result in stale dentries that can never be deleted. + */ + if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) { + struct btrfs_key di_key; + + if (!fixup_path) { + fixup_path = btrfs_alloc_path(); + if (!fixup_path) { + ret = -ENOMEM; + break; + } + } + + btrfs_dir_item_key_to_cpu(eb, di, &di_key); + ret = link_to_fixup_dir(trans, root, fixup_path, + di_key.objectid); + if (ret) + break; + } + ret = 0; + } + btrfs_free_path(fixup_path); + return ret; +} + +/* + * 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]); + path->slots[0]++; + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) + goto out; + } + + 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; + 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 || log_di == ERR_PTR(-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, BTRFS_I(dir), + BTRFS_I(inode), name, name_len); + if (!ret) + ret = btrfs_run_delayed_items(trans); + 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) + goto out; + else 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 == 1) + break; + else if (ret < 0) + goto out; + } + 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 level) +{ + int nritems; + struct btrfs_path *path; + struct btrfs_root *root = wc->replay_dest; + struct btrfs_key key; + int i; + int ret; + + ret = btrfs_read_buffer(eb, gen, level, NULL); + 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); + /* + * If we have a tmpfile (O_TMPFILE) that got fsync'ed + * and never got linked before the fsync, skip it, as + * replaying it is pointless since it would be deleted + * later. We skip logging tmpfiles, but it's always + * possible we are replaying a log created with a kernel + * that used to log tmpfiles. + */ + if (btrfs_inode_nlink(eb, inode_item) == 0) { + wc->ignore_cur_inode = true; + continue; + } else { + wc->ignore_cur_inode = false; + } + 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; + + /* + * Before replaying extents, truncate the inode to its + * size. We need to do it now and not after log replay + * because before an fsync we can have prealloc extents + * added beyond the inode's i_size. If we did it after, + * through orphan cleanup for example, we would drop + * those prealloc extents just after replaying them. + */ + if (S_ISREG(mode)) { + struct inode *inode; + u64 from; + + inode = read_one_inode(root, key.objectid); + if (!inode) { + ret = -EIO; + break; + } + from = ALIGN(i_size_read(inode), + root->fs_info->sectorsize); + ret = btrfs_drop_extents(wc->trans, root, inode, + from, (u64)-1, 1); + if (!ret) { + /* Update the inode's nbytes. */ + ret = btrfs_update_inode(wc->trans, + root, inode); + } + iput(inode); + if (ret) + break; + } + + ret = link_to_fixup_dir(wc->trans, root, + path, key.objectid); + if (ret) + break; + } + + if (wc->ignore_cur_inode) + continue; + + 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) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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) { + struct btrfs_key first_key; + + 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]); + btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]); + blocksize = fs_info->nodesize; + + parent = path->nodes[*level]; + root_owner = btrfs_header_owner(parent); + + next = btrfs_find_create_tree_block(fs_info, bytenr); + if (IS_ERR(next)) + return PTR_ERR(next); + + if (*level == 1) { + ret = wc->process_func(root, next, wc, ptr_gen, + *level - 1); + if (ret) { + free_extent_buffer(next); + return ret; + } + + path->slots[*level]++; + if (wc->free) { + ret = btrfs_read_buffer(next, ptr_gen, + *level - 1, &first_key); + if (ret) { + free_extent_buffer(next); + return ret; + } + + if (trans) { + btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); + clean_tree_block(fs_info, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + } else { + if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) + clear_extent_buffer_dirty(next); + } + + WARN_ON(root_owner != + BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_and_pin_reserved_extent( + fs_info, bytenr, + blocksize); + if (ret) { + free_extent_buffer(next); + return ret; + } + } + free_extent_buffer(next); + continue; + } + ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key); + 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) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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]), + *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(fs_info, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + } else { + if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) + clear_extent_buffer_dirty(next); + } + + WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_and_pin_reserved_extent( + fs_info, + 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) +{ + struct btrfs_fs_info *fs_info = log->fs_info; + 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]), + 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(fs_info, next); + btrfs_wait_tree_block_writeback(next); + btrfs_tree_unlock(next); + } else { + if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) + clear_extent_buffer_dirty(next); + } + + WARN_ON(log->root_key.objectid != + BTRFS_TREE_LOG_OBJECTID); + ret = btrfs_free_and_pin_reserved_extent(fs_info, + 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, + struct btrfs_root_item *root_item) +{ + struct btrfs_fs_info *fs_info = log->fs_info; + int ret; + + if (log->log_transid == 1) { + /* insert root item on the first sync */ + ret = btrfs_insert_root(trans, fs_info->log_root_tree, + &log->root_key, root_item); + } else { + ret = btrfs_update_root(trans, fs_info->log_root_tree, + &log->root_key, root_item); + } + return ret; +} + +static void wait_log_commit(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 + */ + for (;;) { + prepare_to_wait(&root->log_commit_wait[index], + &wait, TASK_UNINTERRUPTIBLE); + + if (!(root->log_transid_committed < transid && + atomic_read(&root->log_commit[index]))) + break; + + mutex_unlock(&root->log_mutex); + schedule(); + mutex_lock(&root->log_mutex); + } + finish_wait(&root->log_commit_wait[index], &wait); +} + +static void wait_for_writer(struct btrfs_root *root) +{ + DEFINE_WAIT(wait); + + for (;;) { + prepare_to_wait(&root->log_writer_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (!atomic_read(&root->log_writers)) + break; + + mutex_unlock(&root->log_mutex); + schedule(); + mutex_lock(&root->log_mutex); + } + finish_wait(&root->log_writer_wait, &wait); +} + +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; + struct btrfs_log_ctx *safe; + + list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) { + list_del_init(&ctx->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_fs_info *fs_info = root->fs_info; + struct btrfs_root *log = root->log_root; + struct btrfs_root *log_root_tree = fs_info->log_root_tree; + struct btrfs_root_item new_root_item; + 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(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(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(fs_info, 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(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(fs_info, trans)) { + ret = -EAGAIN; + 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(fs_info, &log->dirty_log_pages, mark); + if (ret) { + blk_finish_plug(&plug); + btrfs_abort_transaction(trans, ret); + btrfs_set_log_full_commit(fs_info, trans); + mutex_unlock(&root->log_mutex); + goto out; + } + + /* + * We _must_ update under the root->log_mutex in order to make sure we + * have a consistent view of the log root we are trying to commit at + * this moment. + * + * We _must_ copy this into a local copy, because we are not holding the + * log_root_tree->log_mutex yet. This is important because when we + * commit the log_root_tree we must have a consistent view of the + * log_root_tree when we update the super block to point at the + * log_root_tree bytenr. If we update the log_root_tree here we'll race + * with the commit and possibly point at the new block which we may not + * have written out. + */ + btrfs_set_root_node(&log->root_item, log->node); + memcpy(&new_root_item, &log->root_item, sizeof(new_root_item)); + + 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, NULL); + + 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); + + mutex_lock(&log_root_tree->log_mutex); + + /* + * Now we are safe to update the log_root_tree because we're under the + * log_mutex, and we're a current writer so we're holding the commit + * open until we drop the log_mutex. + */ + ret = update_log_root(trans, log, &new_root_item); + + if (atomic_dec_and_test(&log_root_tree->log_writers)) { + /* atomic_dec_and_test implies a barrier */ + cond_wake_up_nomb(&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(fs_info, trans); + + if (ret != -ENOSPC) { + btrfs_abort_transaction(trans, ret); + mutex_unlock(&log_root_tree->log_mutex); + goto out; + } + btrfs_wait_tree_log_extents(log, mark); + 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); + list_del_init(&root_log_ctx.list); + 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_tree_log_extents(log, mark); + wait_log_commit(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(log_root_tree, + root_log_ctx.log_transid - 1); + } + + wait_for_writer(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(fs_info, trans)) { + blk_finish_plug(&plug); + btrfs_wait_tree_log_extents(log, mark); + mutex_unlock(&log_root_tree->log_mutex); + ret = -EAGAIN; + goto out_wake_log_root; + } + + ret = btrfs_write_marked_extents(fs_info, + &log_root_tree->dirty_log_pages, + EXTENT_DIRTY | EXTENT_NEW); + blk_finish_plug(&plug); + if (ret) { + btrfs_set_log_full_commit(fs_info, trans); + btrfs_abort_transaction(trans, ret); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } + ret = btrfs_wait_tree_log_extents(log, mark); + if (!ret) + ret = btrfs_wait_tree_log_extents(log_root_tree, + EXTENT_NEW | EXTENT_DIRTY); + if (ret) { + btrfs_set_log_full_commit(fs_info, trans); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } + + btrfs_set_super_log_root(fs_info->super_for_commit, + log_root_tree->node->start); + btrfs_set_super_log_root_level(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_all_supers(fs_info, 1); + if (ret) { + btrfs_set_log_full_commit(fs_info, trans); + btrfs_abort_transaction(trans, 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: + mutex_lock(&log_root_tree->log_mutex); + btrfs_remove_all_log_ctxs(log_root_tree, index2, ret); + + log_root_tree->log_transid_committed++; + atomic_set(&log_root_tree->log_commit[index2], 0); + mutex_unlock(&log_root_tree->log_mutex); + + /* + * The barrier before waitqueue_active (in cond_wake_up) is needed so + * all the updates above are seen by the woken threads. It might not be + * necessary, but proving that seems to be hard. + */ + cond_wake_up(&log_root_tree->log_commit_wait[index2]); +out: + mutex_lock(&root->log_mutex); + btrfs_remove_all_log_ctxs(root, index1, ret); + root->log_transid_committed++; + atomic_set(&root->log_commit[index1], 0); + mutex_unlock(&root->log_mutex); + + /* + * The barrier before waitqueue_active (in cond_wake_up) is needed so + * all the updates above are seen by the woken threads. It might not be + * necessary, but proving that seems to be hard. + */ + cond_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); + if (ret) { + if (trans) + btrfs_abort_transaction(trans, ret); + else + btrfs_handle_fs_error(log->fs_info, ret, NULL); + } + + while (1) { + ret = find_first_extent_bit(&log->dirty_log_pages, + 0, &start, &end, + EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT, + NULL); + if (ret) + break; + + clear_extent_bits(&log->dirty_log_pages, start, end, + EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT); + } + + 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; +} + +/* + * Check if an inode was logged in the current transaction. We can't always rely + * on an inode's logged_trans value, because it's an in-memory only field and + * therefore not persisted. This means that its value is lost if the inode gets + * evicted and loaded again from disk (in which case it has a value of 0, and + * certainly it is smaller then any possible transaction ID), when that happens + * the full_sync flag is set in the inode's runtime flags, so on that case we + * assume eviction happened and ignore the logged_trans value, assuming the + * worst case, that the inode was logged before in the current transaction. + */ +static bool inode_logged(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + if (inode->logged_trans == trans->transid) + return true; + + if (inode->last_trans == trans->transid && + test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) && + !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags)) + return true; + + return false; +} + +/* + * 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 btrfs_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 (!inode_logged(trans, dir)) + return 0; + + ret = join_running_log_trans(root); + if (ret) + return 0; + + mutex_lock(&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(&dir->log_mutex); + if (err == -ENOSPC) { + btrfs_set_log_full_commit(root->fs_info, trans); + err = 0; + } else if (err < 0 && err != -ENOENT) { + /* ENOENT can be returned if the entry hasn't been fsynced yet */ + btrfs_abort_transaction(trans, err); + } + + 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 btrfs_inode *inode, u64 dirid) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_root *log; + u64 index; + int ret; + + if (!inode_logged(trans, inode)) + return 0; + + ret = join_running_log_trans(root); + if (ret) + return 0; + log = root->log_root; + mutex_lock(&inode->log_mutex); + + ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode), + dirid, &index); + mutex_unlock(&inode->log_mutex); + if (ret == -ENOSPC) { + btrfs_set_log_full_commit(fs_info, trans); + ret = 0; + } else if (ret < 0 && ret != -ENOENT) + btrfs_abort_transaction(trans, 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 btrfs_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. See the note for + * log_new_dir_dentries, if we're logging a directory recursively we + * won't be holding its i_mutex, which means we can modify the directory + * while we're logging it. If we remove an entry between our first + * search and this search we'll not find the key again and can just + * bail. + */ +search: + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (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; + + if (need_resched()) { + btrfs_release_path(path); + cond_resched(); + goto search; + } + + 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) { + if (ret == 1) + last_offset = (u64)-1; + else + err = ret; + 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 btrfs_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_peek_iversion(inode), &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 btrfs_inode *inode) +{ + struct btrfs_inode_item *inode_item; + int ret; + + ret = btrfs_insert_empty_item(trans, log, path, + &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->vfs_inode, + 0, 0); + btrfs_release_path(path); + return 0; +} + +static int log_csums(struct btrfs_trans_handle *trans, + struct btrfs_root *log_root, + struct btrfs_ordered_sum *sums) +{ + int ret; + + /* + * Due to extent cloning, we might have logged a csum item that covers a + * subrange of a cloned extent, and later we can end up logging a csum + * item for a larger subrange of the same extent or the entire range. + * This would leave csum items in the log tree that cover the same range + * and break the searches for checksums in the log tree, resulting in + * some checksums missing in the fs/subvolume tree. So just delete (or + * trim and adjust) any existing csum items in the log for this range. + */ + ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len); + if (ret) + return ret; + + return btrfs_csum_file_blocks(trans, log_root, sums); +} + +static noinline int copy_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *dst_path, + struct btrfs_path *src_path, + int start_slot, int nr, int inode_only, + u64 logged_isize) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + unsigned long src_offset; + unsigned long dst_offset; + struct btrfs_root *log = inode->root->log_root; + struct btrfs_file_extent_item *extent; + struct btrfs_inode_item *inode_item; + struct extent_buffer *src = src_path->nodes[0]; + int ret; + struct btrfs_key *ins_keys; + u32 *ins_sizes; + char *ins_data; + int i; + struct list_head ordered_sums; + int skip_csum = inode->flags & BTRFS_INODE_NODATASUM; + + INIT_LIST_HEAD(&ordered_sums); + + ins_data = kmalloc(nr * sizeof(struct btrfs_key) + + nr * sizeof(u32), GFP_NOFS); + if (!ins_data) + return -ENOMEM; + + 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 (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->vfs_inode, + inode_only == LOG_INODE_EXISTS, + logged_isize); + } else { + copy_extent_buffer(dst_path->nodes[0], src, dst_offset, + src_offset, ins_sizes[i]); + } + + /* 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( + fs_info->csum_root, + ds + cs, ds + cs + cl - 1, + &ordered_sums, 0); + if (ret) + break; + } + } + } + + 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. + */ + while (!list_empty(&ordered_sums)) { + struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, + struct btrfs_ordered_sum, + list); + if (!ret) + ret = log_csums(trans, log, sums); + list_del(&sums->list); + kfree(sums); + } + + 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 log_extent_csums(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_root *log_root, + const struct extent_map *em) +{ + u64 csum_offset; + u64 csum_len; + LIST_HEAD(ordered_sums); + int ret = 0; + + if (inode->flags & BTRFS_INODE_NODATASUM || + test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || + em->block_start == EXTENT_MAP_HOLE) + return 0; + + /* If we're compressed we have to save the entire range of csums. */ + if (em->compress_type) { + csum_offset = 0; + csum_len = max(em->block_len, em->orig_block_len); + } else { + csum_offset = em->mod_start - em->start; + csum_len = em->mod_len; + } + + /* block start is already adjusted for the file extent offset. */ + ret = btrfs_lookup_csums_range(trans->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 = log_csums(trans, log_root, sums); + list_del(&sums->list); + kfree(sums); + } + + return ret; +} + +static int log_one_extent(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, struct btrfs_root *root, + const struct extent_map *em, + struct btrfs_path *path, + 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; + + ret = log_extent_csums(trans, inode, log, em); + if (ret) + return ret; + + btrfs_init_map_token(&token); + + ret = __btrfs_drop_extents(trans, log, &inode->vfs_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; +} + +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + struct btrfs_path *dst_path = NULL; + bool dropped_extents = false; + u64 truncate_offset = i_size; + struct extent_buffer *leaf; + int slot; + int ins_nr = 0; + int start_slot; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + /* + * We must check if there is a prealloc extent that starts before the + * i_size and crosses the i_size boundary. This is to ensure later we + * truncate down to the end of that extent and not to the i_size, as + * otherwise we end up losing part of the prealloc extent after a log + * replay and with an implicit hole if there is another prealloc extent + * that starts at an offset beyond i_size. + */ + ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY); + if (ret < 0) + goto out; + + if (ret == 0) { + struct btrfs_file_extent_item *ei; + + leaf = path->nodes[0]; + slot = path->slots[0]; + ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + + if (btrfs_file_extent_type(leaf, ei) == + BTRFS_FILE_EXTENT_PREALLOC) { + u64 extent_end; + + btrfs_item_key_to_cpu(leaf, &key, slot); + extent_end = key.offset + + btrfs_file_extent_num_bytes(leaf, ei); + + if (extent_end > i_size) + truncate_offset = extent_end; + } + } else { + ret = 0; + } + + while (true) { + leaf = path->nodes[0]; + slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + if (!dropped_extents) { + /* + * Avoid logging extent items logged in past fsync calls + * and leading to duplicate keys in the log tree. + */ + do { + ret = btrfs_truncate_inode_items(trans, + root->log_root, + &inode->vfs_inode, + truncate_offset, + BTRFS_EXTENT_DATA_KEY); + } while (ret == -EAGAIN); + if (ret) + goto out; + dropped_extents = true; + } + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0); + if (ret > 0) + ret = 0; + } +out: + btrfs_release_path(path); + btrfs_free_path(dst_path); + return ret; +} + +static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_log_ctx *ctx, + const u64 start, + const u64 end) +{ + struct extent_map *em, *n; + struct list_head extents; + struct extent_map_tree *tree = &inode->extent_tree; + u64 logged_start, logged_end; + 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; + logged_start = start; + logged_end = end; + + list_for_each_entry_safe(em, n, &tree->modified_extents, list) { + /* + * Skip extents outside our logging range. It's important to do + * it for correctness because if we don't ignore them, we may + * log them before their ordered extent completes, and therefore + * we could log them without logging their respective checksums + * (the checksum items are added to the csum tree at the very + * end of btrfs_finish_ordered_io()). Also leave such extents + * outside of our range in the list, since we may have another + * ranged fsync in the near future that needs them. If an extent + * outside our range corresponds to a hole, log it to avoid + * leaving gaps between extents (fsck will complain when we are + * not using the NO_HOLES feature). + */ + if ((em->start > end || em->start + em->len <= start) && + em->block_start != EXTENT_MAP_HOLE) + continue; + + 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; + + /* We log prealloc extents beyond eof later. */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + + if (em->start < logged_start) + logged_start = em->start; + if ((em->start + em->len - 1) > logged_end) + logged_end = em->start + em->len - 1; + + /* Need a ref to keep it from getting evicted from cache */ + refcount_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, 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); + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path); + + return ret; +} + +static int logged_inode_size(struct btrfs_root *log, struct btrfs_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); + /* + * If the in-memory inode's i_size is smaller then the inode + * size stored in the btree, return the inode's i_size, so + * that we get a correct inode size after replaying the log + * when before a power failure we had a shrinking truncate + * followed by addition of a new name (rename / new hard link). + * Otherwise return the inode size from the btree, to avoid + * data loss when replaying a log due to previously doing a + * write that expands the inode's size and logging a new name + * immediately after. + */ + if (*size_ret > inode->vfs_inode.i_size) + *size_ret = inode->vfs_inode.i_size; + } + + btrfs_release_path(path); + return 0; +} + +/* + * At the moment we always log all xattrs. This is to figure out at log replay + * time which xattrs must have their deletion replayed. If a xattr is missing + * in the log tree and exists in the fs/subvol tree, we delete it. This is + * because if a xattr is deleted, the inode is fsynced and a power failure + * happens, causing the log to be replayed the next time the fs is mounted, + * we want the xattr to not exist anymore (same behaviour as other filesystems + * with a journal, ext3/4, xfs, f2fs, etc). + */ +static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path) +{ + int ret; + struct btrfs_key key; + const u64 ino = btrfs_ino(inode); + int ins_nr = 0; + int start_slot = 0; + + key.objectid = ino; + key.type = BTRFS_XATTR_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + + while (true) { + int slot = path->slots[0]; + struct extent_buffer *leaf = path->nodes[0]; + int nritems = btrfs_header_nritems(leaf); + + if (slot >= nritems) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0); + if (ret < 0) + return ret; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) + break; + + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + cond_resched(); + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0); + if (ret < 0) + return ret; + } + + return 0; +} + +/* + * When using the NO_HOLES feature if we punched a hole that causes the + * deletion of entire leafs or all the extent items of the first leaf (the one + * that contains the inode item and references) we may end up not processing + * any extents, because there are no leafs with a generation matching the + * current transaction that have extent items for our inode. So we need to find + * if any holes exist and then log them. We also need to log holes after any + * truncate operation that changes the inode's size. + */ +static int btrfs_log_holes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_key key; + const u64 ino = btrfs_ino(inode); + const u64 i_size = i_size_read(&inode->vfs_inode); + u64 prev_extent_end = 0; + int ret; + + if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + + while (true) { + struct btrfs_file_extent_item *extent; + struct extent_buffer *leaf = path->nodes[0]; + u64 len; + + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + if (ret > 0) { + ret = 0; + break; + } + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) + break; + + /* We have a hole, log it. */ + if (prev_extent_end < key.offset) { + const u64 hole_len = key.offset - prev_extent_end; + + /* + * Release the path to avoid deadlocks with other code + * paths that search the root while holding locks on + * leafs from the log root. + */ + btrfs_release_path(path); + ret = btrfs_insert_file_extent(trans, root->log_root, + ino, prev_extent_end, 0, + 0, hole_len, 0, hole_len, + 0, 0, 0); + if (ret < 0) + return ret; + + /* + * Search for the same key again in the root. Since it's + * an extent item and we are holding the inode lock, the + * key must still exist. If it doesn't just emit warning + * and return an error to fall back to a transaction + * commit. + */ + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + if (WARN_ON(ret > 0)) + return -ENOENT; + leaf = path->nodes[0]; + } + + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(leaf, extent) == + BTRFS_FILE_EXTENT_INLINE) { + len = btrfs_file_extent_ram_bytes(leaf, extent); + prev_extent_end = ALIGN(key.offset + len, + fs_info->sectorsize); + } else { + len = btrfs_file_extent_num_bytes(leaf, extent); + prev_extent_end = key.offset + len; + } + + path->slots[0]++; + cond_resched(); + } + + if (prev_extent_end < i_size) { + u64 hole_len; + + btrfs_release_path(path); + hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize); + ret = btrfs_insert_file_extent(trans, root->log_root, + ino, prev_extent_end, 0, 0, + hole_len, 0, hole_len, + 0, 0, 0); + if (ret < 0) + return ret; + } + + return 0; +} + +/* + * When we are logging a new inode X, check if it doesn't have a reference that + * matches the reference from some other inode Y created in a past transaction + * and that was renamed in the current transaction. If we don't do this, then at + * log replay time we can lose inode Y (and all its files if it's a directory): + * + * mkdir /mnt/x + * echo "hello world" > /mnt/x/foobar + * sync + * mv /mnt/x /mnt/y + * mkdir /mnt/x # or touch /mnt/x + * xfs_io -c fsync /mnt/x + * <power fail> + * mount fs, trigger log replay + * + * After the log replay procedure, we would lose the first directory and all its + * files (file foobar). + * For the case where inode Y is not a directory we simply end up losing it: + * + * echo "123" > /mnt/foo + * sync + * mv /mnt/foo /mnt/bar + * echo "abc" > /mnt/foo + * xfs_io -c fsync /mnt/foo + * <power fail> + * + * We also need this for cases where a snapshot entry is replaced by some other + * entry (file or directory) otherwise we end up with an unreplayable log due to + * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as + * if it were a regular entry: + * + * mkdir /mnt/x + * btrfs subvolume snapshot /mnt /mnt/x/snap + * btrfs subvolume delete /mnt/x/snap + * rmdir /mnt/x + * mkdir /mnt/x + * fsync /mnt/x or fsync some new file inside it + * <power fail> + * + * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in + * the same transaction. + */ +static int btrfs_check_ref_name_override(struct extent_buffer *eb, + const int slot, + const struct btrfs_key *key, + struct btrfs_inode *inode, + u64 *other_ino) +{ + int ret; + struct btrfs_path *search_path; + char *name = NULL; + u32 name_len = 0; + u32 item_size = btrfs_item_size_nr(eb, slot); + u32 cur_offset = 0; + unsigned long ptr = btrfs_item_ptr_offset(eb, slot); + + search_path = btrfs_alloc_path(); + if (!search_path) + return -ENOMEM; + search_path->search_commit_root = 1; + search_path->skip_locking = 1; + + while (cur_offset < item_size) { + u64 parent; + u32 this_name_len; + u32 this_len; + unsigned long name_ptr; + struct btrfs_dir_item *di; + + if (key->type == BTRFS_INODE_REF_KEY) { + struct btrfs_inode_ref *iref; + + iref = (struct btrfs_inode_ref *)(ptr + cur_offset); + parent = key->offset; + this_name_len = btrfs_inode_ref_name_len(eb, iref); + name_ptr = (unsigned long)(iref + 1); + this_len = sizeof(*iref) + this_name_len; + } else { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *)(ptr + + cur_offset); + parent = btrfs_inode_extref_parent(eb, extref); + this_name_len = btrfs_inode_extref_name_len(eb, extref); + name_ptr = (unsigned long)&extref->name; + this_len = sizeof(*extref) + this_name_len; + } + + if (this_name_len > name_len) { + char *new_name; + + new_name = krealloc(name, this_name_len, GFP_NOFS); + if (!new_name) { + ret = -ENOMEM; + goto out; + } + name_len = this_name_len; + name = new_name; + } + + read_extent_buffer(eb, name, name_ptr, this_name_len); + di = btrfs_lookup_dir_item(NULL, inode->root, search_path, + parent, name, this_name_len, 0); + if (di && !IS_ERR(di)) { + struct btrfs_key di_key; + + btrfs_dir_item_key_to_cpu(search_path->nodes[0], + di, &di_key); + if (di_key.type == BTRFS_INODE_ITEM_KEY) { + ret = 1; + *other_ino = di_key.objectid; + } else { + ret = -EAGAIN; + } + goto out; + } else if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } + btrfs_release_path(search_path); + + cur_offset += this_len; + } + ret = 0; +out: + btrfs_free_path(search_path); + kfree(name); + return ret; +} + +/* 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 btrfs_inode *inode, + int inode_only, + const loff_t start, + const loff_t end, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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; + 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 = &inode->extent_tree; + u64 logged_isize = 0; + bool need_log_inode_item = true; + bool xattrs_logged = false; + + 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->vfs_inode.i_mode) || + (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &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->vfs_inode.i_mode) || + inode->generation > 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; + } + + if (inode_only == LOG_OTHER_INODE) { + inode_only = LOG_INODE_EXISTS; + mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING); + } else { + mutex_lock(&inode->log_mutex); + } + + /* + * For symlinks, we must always log their content, which is stored in an + * inline extent, otherwise we could end up with an empty symlink after + * log replay, which is invalid on linux (symlink(2) returns -ENOENT if + * one attempts to create an empty symlink). + * We don't need to worry about flushing delalloc, because when we create + * the inline extent when the symlink is created (we never have delalloc + * for symlinks). + */ + if (S_ISLNK(inode->vfs_inode.i_mode)) + inode_only = LOG_INODE_ALL; + + /* + * a brute force approach to making sure we get the most uptodate + * copies of everything. + */ + if (S_ISDIR(inode->vfs_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, + &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, + &inode->runtime_flags); + clear_bit(BTRFS_INODE_COPY_EVERYTHING, + &inode->runtime_flags); + while(1) { + ret = btrfs_truncate_inode_items(trans, + log, &inode->vfs_inode, 0, 0); + if (ret != -EAGAIN) + break; + } + } + } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING, + &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; + 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) { + err = ret; + goto out_unlock; + } + 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; + + if (min_key.type == BTRFS_INODE_ITEM_KEY) + need_log_inode_item = false; + + if ((min_key.type == BTRFS_INODE_REF_KEY || + min_key.type == BTRFS_INODE_EXTREF_KEY) && + inode->generation == trans->transid) { + u64 other_ino = 0; + + ret = btrfs_check_ref_name_override(path->nodes[0], + path->slots[0], &min_key, inode, + &other_ino); + if (ret < 0) { + err = ret; + goto out_unlock; + } else if (ret > 0 && ctx && + other_ino != btrfs_ino(BTRFS_I(ctx->inode))) { + struct btrfs_key inode_key; + struct inode *other_inode; + + if (ins_nr > 0) { + ins_nr++; + } else { + ins_nr = 1; + ins_start_slot = path->slots[0]; + } + ret = copy_items(trans, inode, dst_path, path, + ins_start_slot, + ins_nr, inode_only, + logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ins_nr = 0; + btrfs_release_path(path); + inode_key.objectid = other_ino; + inode_key.type = BTRFS_INODE_ITEM_KEY; + inode_key.offset = 0; + other_inode = btrfs_iget(fs_info->sb, + &inode_key, root, + NULL); + /* + * If the other inode that had a conflicting dir + * entry was deleted in the current transaction, + * we don't need to do more work nor fallback to + * a transaction commit. + */ + if (other_inode == ERR_PTR(-ENOENT)) { + goto next_key; + } else if (IS_ERR(other_inode)) { + err = PTR_ERR(other_inode); + goto out_unlock; + } + /* + * We are safe logging the other inode without + * acquiring its i_mutex as long as we log with + * the LOG_INODE_EXISTS mode. We're safe against + * concurrent renames of the other inode as well + * because during a rename we pin the log and + * update the log with the new name before we + * unpin it. + */ + err = btrfs_log_inode(trans, root, + BTRFS_I(other_inode), + LOG_OTHER_INODE, 0, LLONG_MAX, + ctx); + btrfs_add_delayed_iput(other_inode); + if (err) + goto out_unlock; + else + goto next_key; + } + } + + /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */ + if (min_key.type == BTRFS_XATTR_ITEM_KEY) { + if (ins_nr == 0) + goto next_slot; + ret = copy_items(trans, inode, dst_path, path, + ins_start_slot, + ins_nr, inode_only, logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ins_nr = 0; + goto next_slot; + } + + 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, + ins_start_slot, ins_nr, inode_only, + logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + 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, + ins_start_slot, + ins_nr, inode_only, logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ins_nr = 0; + } + btrfs_release_path(path); +next_key: + 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, + ins_start_slot, ins_nr, inode_only, + logged_isize); + if (ret < 0) { + err = ret; + goto out_unlock; + } + ins_nr = 0; + } + + btrfs_release_path(path); + btrfs_release_path(dst_path); + err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path); + if (err) + goto out_unlock; + xattrs_logged = true; + if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) { + btrfs_release_path(path); + btrfs_release_path(dst_path); + err = btrfs_log_holes(trans, root, inode, path); + if (err) + goto out_unlock; + } +log_extents: + btrfs_release_path(path); + btrfs_release_path(dst_path); + if (need_log_inode_item) { + err = log_inode_item(trans, log, dst_path, inode); + if (!err && !xattrs_logged) { + err = btrfs_log_all_xattrs(trans, root, inode, path, + dst_path); + btrfs_release_path(path); + } + if (err) + goto out_unlock; + } + if (fast_search) { + ret = btrfs_log_changed_extents(trans, root, inode, dst_path, + ctx, start, end); + 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->vfs_inode.i_mode)) { + ret = log_directory_changes(trans, root, inode, path, dst_path, + ctx); + if (ret) { + err = ret; + goto out_unlock; + } + } + + /* + * Don't update last_log_commit if we logged that an inode exists after + * it was loaded to memory (full_sync bit set). + * This is to prevent data loss when we do a write to the inode, then + * the inode gets evicted after all delalloc was flushed, then we log + * it exists (due to a rename for example) and then fsync it. This last + * fsync would do nothing (not logging the extents previously written). + */ + spin_lock(&inode->lock); + inode->logged_trans = trans->transid; + if (inode_only != LOG_INODE_EXISTS || + !test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags)) + inode->last_log_commit = inode->last_sub_trans; + spin_unlock(&inode->lock); +out_unlock: + mutex_unlock(&inode->log_mutex); + + btrfs_free_path(path); + btrfs_free_path(dst_path); + return err; +} + +/* + * Check if we must fallback to a transaction commit when logging an inode. + * This must be called after logging the inode and is used only in the context + * when fsyncing an inode requires the need to log some other inode - in which + * case we can't lock the i_mutex of each other inode we need to log as that + * can lead to deadlocks with concurrent fsync against other inodes (as we can + * log inodes up or down in the hierarchy) or rename operations for example. So + * we take the log_mutex of the inode after we have logged it and then check for + * its last_unlink_trans value - this is safe because any task setting + * last_unlink_trans must take the log_mutex and it must do this before it does + * the actual unlink operation, so if we do this check before a concurrent task + * sets last_unlink_trans it means we've logged a consistent version/state of + * all the inode items, otherwise we are not sure and must do a transaction + * commit (the concurrent task might have only updated last_unlink_trans before + * we logged the inode or it might have also done the unlink). + */ +static bool btrfs_must_commit_transaction(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + bool ret = false; + + mutex_lock(&inode->log_mutex); + if (inode->last_unlink_trans > fs_info->last_trans_committed) { + /* + * Make sure any commits to the log are forced to be full + * commits. + */ + btrfs_set_log_full_commit(fs_info, trans); + ret = true; + } + mutex_unlock(&inode->log_mutex); + + return ret; +} + +/* + * 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 btrfs_inode *inode, + struct dentry *parent, + struct super_block *sb, + u64 last_committed) +{ + int ret = 0; + struct dentry *old_parent = NULL; + + /* + * 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->vfs_inode.i_mode) && + inode->generation <= last_committed && + inode->last_unlink_trans <= last_committed) + goto out; + + if (!S_ISDIR(inode->vfs_inode.i_mode)) { + if (!parent || d_really_is_negative(parent) || sb != parent->d_sb) + goto out; + inode = BTRFS_I(d_inode(parent)); + } + + while (1) { + if (btrfs_must_commit_transaction(trans, inode)) { + ret = 1; + break; + } + + if (!parent || d_really_is_negative(parent) || sb != parent->d_sb) + break; + + if (IS_ROOT(parent)) { + inode = BTRFS_I(d_inode(parent)); + if (btrfs_must_commit_transaction(trans, inode)) + ret = 1; + break; + } + + parent = dget_parent(parent); + dput(old_parent); + old_parent = parent; + inode = BTRFS_I(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 btrfs_inode *start_inode, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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; + + btrfs_release_path(path); + di_inode = btrfs_iget(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(BTRFS_I(di_inode), trans->transid)) { + btrfs_add_delayed_iput(di_inode); + break; + } + + ctx->log_new_dentries = false; + if (type == BTRFS_FT_DIR) + log_mode = LOG_INODE_ALL; + ret = btrfs_log_inode(trans, root, BTRFS_I(di_inode), + log_mode, 0, LLONG_MAX, ctx); + if (!ret && + btrfs_must_commit_transaction(trans, BTRFS_I(di_inode))) + ret = 1; + btrfs_add_delayed_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; +} + +static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + int ret; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_root *root = inode->root; + const u64 ino = btrfs_ino(inode); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->skip_locking = 1; + path->search_commit_root = 1; + + key.objectid = ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + u32 cur_offset = 0; + u32 item_size; + unsigned long ptr; + + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */ + if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY) + break; + + item_size = btrfs_item_size_nr(leaf, slot); + ptr = btrfs_item_ptr_offset(leaf, slot); + while (cur_offset < item_size) { + struct btrfs_key inode_key; + struct inode *dir_inode; + + inode_key.type = BTRFS_INODE_ITEM_KEY; + inode_key.offset = 0; + + if (key.type == BTRFS_INODE_EXTREF_KEY) { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *) + (ptr + cur_offset); + inode_key.objectid = btrfs_inode_extref_parent( + leaf, extref); + cur_offset += sizeof(*extref); + cur_offset += btrfs_inode_extref_name_len(leaf, + extref); + } else { + inode_key.objectid = key.offset; + cur_offset = item_size; + } + + dir_inode = btrfs_iget(fs_info->sb, &inode_key, + root, NULL); + /* + * If the parent inode was deleted, return an error to + * fallback to a transaction commit. This is to prevent + * getting an inode that was moved from one parent A to + * a parent B, got its former parent A deleted and then + * it got fsync'ed, from existing at both parents after + * a log replay (and the old parent still existing). + * Example: + * + * mkdir /mnt/A + * mkdir /mnt/B + * touch /mnt/B/bar + * sync + * mv /mnt/B/bar /mnt/A/bar + * mv -T /mnt/A /mnt/B + * fsync /mnt/B/bar + * <power fail> + * + * If we ignore the old parent B which got deleted, + * after a log replay we would have file bar linked + * at both parents and the old parent B would still + * exist. + */ + if (IS_ERR(dir_inode)) { + ret = PTR_ERR(dir_inode); + goto out; + } + + if (ctx) + ctx->log_new_dentries = false; + ret = btrfs_log_inode(trans, root, BTRFS_I(dir_inode), + LOG_INODE_ALL, 0, LLONG_MAX, ctx); + if (!ret && + btrfs_must_commit_transaction(trans, BTRFS_I(dir_inode))) + ret = 1; + if (!ret && ctx && ctx->log_new_dentries) + ret = log_new_dir_dentries(trans, root, + BTRFS_I(dir_inode), ctx); + btrfs_add_delayed_iput(dir_inode); + if (ret) + goto out; + } + path->slots[0]++; + } + ret = 0; +out: + 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_inode *inode, + struct dentry *parent, + const loff_t start, + const loff_t end, + int inode_only, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct super_block *sb; + struct dentry *old_parent = NULL; + int ret = 0; + u64 last_committed = fs_info->last_trans_committed; + bool log_dentries = false; + struct btrfs_inode *orig_inode = inode; + + sb = inode->vfs_inode.i_sb; + + if (btrfs_test_opt(fs_info, NOTREELOG)) { + ret = 1; + goto end_no_trans; + } + + /* + * The prev transaction commit doesn't complete, we need do + * full commit by ourselves. + */ + if (fs_info->last_trans_log_full_commit > + fs_info->last_trans_committed) { + ret = 1; + goto end_no_trans; + } + + if (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; + + /* + * Skip already logged inodes or inodes corresponding to tmpfiles + * (since logging them is pointless, a link count of 0 means they + * will never be accessible). + */ + if (btrfs_inode_in_log(inode, trans->transid) || + inode->vfs_inode.i_nlink == 0) { + 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->vfs_inode.i_mode) && + inode->generation <= last_committed && + inode->last_unlink_trans <= last_committed) { + ret = 0; + goto end_trans; + } + + if (S_ISDIR(inode->vfs_inode.i_mode) && ctx && ctx->log_new_dentries) + log_dentries = true; + + /* + * On unlink we must make sure all our current and old parent directory + * inodes are fully logged. This is to prevent leaving dangling + * directory index entries in directories that were our parents but are + * not anymore. Not doing this results in old parent directory being + * impossible to delete after log replay (rmdir will always fail with + * error -ENOTEMPTY). + * + * Example 1: + * + * mkdir testdir + * touch testdir/foo + * ln testdir/foo testdir/bar + * sync + * unlink testdir/bar + * xfs_io -c fsync testdir/foo + * <power failure> + * mount fs, triggers log replay + * + * If we don't log the parent directory (testdir), after log replay the + * directory still has an entry pointing to the file inode using the bar + * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and + * the file inode has a link count of 1. + * + * Example 2: + * + * mkdir testdir + * touch foo + * ln foo testdir/foo2 + * ln foo testdir/foo3 + * sync + * unlink testdir/foo3 + * xfs_io -c fsync foo + * <power failure> + * mount fs, triggers log replay + * + * Similar as the first example, after log replay the parent directory + * testdir still has an entry pointing to the inode file with name foo3 + * but the file inode does not have a matching BTRFS_INODE_REF_KEY item + * and has a link count of 2. + */ + if (inode->last_unlink_trans > last_committed) { + ret = btrfs_log_all_parents(trans, orig_inode, ctx); + if (ret) + goto end_trans; + } + + /* + * If a new hard link was added to the inode in the current transaction + * and its link count is now greater than 1, we need to fallback to a + * transaction commit, otherwise we can end up not logging all its new + * parents for all the hard links. Here just from the dentry used to + * fsync, we can not visit the ancestor inodes for all the other hard + * links to figure out if any is new, so we fallback to a transaction + * commit (instead of adding a lot of complexity of scanning a btree, + * since this scenario is not a common use case). + */ + if (inode->vfs_inode.i_nlink > 1 && + inode->last_link_trans > last_committed) { + ret = -EMLINK; + goto end_trans; + } + + while (1) { + if (!parent || d_really_is_negative(parent) || sb != parent->d_sb) + break; + + inode = BTRFS_I(d_inode(parent)); + if (root != inode->root) + break; + + if (inode->generation > last_committed) { + ret = btrfs_log_inode(trans, root, inode, + LOG_INODE_EXISTS, 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(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 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, BTRFS_I(d_inode(dentry)), parent, + start, end, LOG_INODE_ALL, 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; + + set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); + + 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_handle_fs_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_handle_fs_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_handle_fs_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); + + /* + * We didn't find the subvol, likely because it was + * deleted. This is ok, simply skip this log and go to + * the next one. + * + * We need to exclude the root because we can't have + * other log replays overwriting this log as we'll read + * it back in a few more times. This will keep our + * block from being modified, and we'll just bail for + * each subsequent pass. + */ + if (ret == -ENOENT) + ret = btrfs_pin_extent_for_log_replay(fs_info, + log->node->start, + log->node->len); + free_extent_buffer(log->node); + free_extent_buffer(log->commit_root); + kfree(log); + + if (!ret) + goto next; + btrfs_handle_fs_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); + } + + if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) { + struct btrfs_root *root = wc.replay_dest; + + btrfs_release_path(path); + + /* + * We have just replayed everything, and the highest + * objectid of fs roots probably has changed in case + * some inode_item's got replayed. + * + * root->objectid_mutex is not acquired as log replay + * could only happen during mount. + */ + ret = btrfs_find_highest_objectid(root, + &root->highest_objectid); + } + + wc.replay_dest->log_root = NULL; + free_extent_buffer(log->node); + free_extent_buffer(log->commit_root); + kfree(log); + + if (ret) + goto error; +next: + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + 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); + if (ret) + return ret; + + free_extent_buffer(log_root_tree->node); + log_root_tree->log_root = NULL; + clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); + kfree(log_root_tree); + + return 0; +error: + if (wc.trans) + btrfs_end_transaction(wc.trans); + clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); + 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. + * + * Must be called before the unlink operations (updates to the subvolume tree, + * inodes, etc) are done. + */ +void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir, struct btrfs_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. + */ + mutex_lock(&inode->log_mutex); + inode->last_unlink_trans = trans->transid; + mutex_unlock(&inode->log_mutex); + + /* + * if this directory was already logged any new + * names for this file/dir will get recorded + */ + if (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 (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: + mutex_lock(&dir->log_mutex); + dir->last_unlink_trans = trans->transid; + mutex_unlock(&dir->log_mutex); +} + +/* + * Make sure that if someone attempts to fsync the parent directory of a deleted + * snapshot, it ends up triggering a transaction commit. This is to guarantee + * that after replaying the log tree of the parent directory's root we will not + * see the snapshot anymore and at log replay time we will not see any log tree + * corresponding to the deleted snapshot's root, which could lead to replaying + * it after replaying the log tree of the parent directory (which would replay + * the snapshot delete operation). + * + * Must be called before the actual snapshot destroy operation (updates to the + * parent root and tree of tree roots trees, etc) are done. + */ +void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir) +{ + mutex_lock(&dir->log_mutex); + dir->last_unlink_trans = trans->transid; + mutex_unlock(&dir->log_mutex); +} + +/* + * Call this after adding a new name for a file and it will properly + * update the log to reflect the new name. + * + * @ctx can not be NULL when @sync_log is false, and should be NULL when it's + * true (because it's not used). + * + * Return value depends on whether @sync_log is true or false. + * When true: returns BTRFS_NEED_TRANS_COMMIT if the transaction needs to be + * committed by the caller, and BTRFS_DONT_NEED_TRANS_COMMIT + * otherwise. + * When false: returns BTRFS_DONT_NEED_LOG_SYNC if the caller does not need to + * to sync the log, BTRFS_NEED_LOG_SYNC if it needs to sync the log, + * or BTRFS_NEED_TRANS_COMMIT if the transaction needs to be + * committed (without attempting to sync the log). + */ +int btrfs_log_new_name(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, struct btrfs_inode *old_dir, + struct dentry *parent, + bool sync_log, struct btrfs_log_ctx *ctx) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + int ret; + + /* + * this will force the logging code to walk the dentry chain + * up for the file + */ + if (!S_ISDIR(inode->vfs_inode.i_mode)) + 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 (inode->logged_trans <= fs_info->last_trans_committed && + (!old_dir || old_dir->logged_trans <= fs_info->last_trans_committed)) + return sync_log ? BTRFS_DONT_NEED_TRANS_COMMIT : + BTRFS_DONT_NEED_LOG_SYNC; + + if (sync_log) { + struct btrfs_log_ctx ctx2; + + btrfs_init_log_ctx(&ctx2, &inode->vfs_inode); + ret = btrfs_log_inode_parent(trans, inode, parent, 0, LLONG_MAX, + LOG_INODE_EXISTS, &ctx2); + if (ret == BTRFS_NO_LOG_SYNC) + return BTRFS_DONT_NEED_TRANS_COMMIT; + else if (ret) + return BTRFS_NEED_TRANS_COMMIT; + + ret = btrfs_sync_log(trans, inode->root, &ctx2); + if (ret) + return BTRFS_NEED_TRANS_COMMIT; + return BTRFS_DONT_NEED_TRANS_COMMIT; + } + + ASSERT(ctx); + ret = btrfs_log_inode_parent(trans, inode, parent, 0, LLONG_MAX, + LOG_INODE_EXISTS, ctx); + if (ret == BTRFS_NO_LOG_SYNC) + return BTRFS_DONT_NEED_LOG_SYNC; + else if (ret) + return BTRFS_NEED_TRANS_COMMIT; + + return BTRFS_NEED_LOG_SYNC; +} + |