diff options
| -rw-r--r-- | fs/btrfs/extent-tree.c | 50 | ||||
| -rw-r--r-- | fs/btrfs/free-space-cache.c | 296 | ||||
| -rw-r--r-- | fs/btrfs/free-space-cache.h | 2 |
3 files changed, 345 insertions, 3 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index d5455a2bf60b..9a325e465ad9 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -421,7 +421,9 @@ err: return 0; } -static int cache_block_group(struct btrfs_block_group_cache *cache) +static int cache_block_group(struct btrfs_block_group_cache *cache, + struct btrfs_trans_handle *trans, + int load_cache_only) { struct btrfs_fs_info *fs_info = cache->fs_info; struct btrfs_caching_control *caching_ctl; @@ -432,6 +434,36 @@ static int cache_block_group(struct btrfs_block_group_cache *cache) if (cache->cached != BTRFS_CACHE_NO) return 0; + /* + * We can't do the read from on-disk cache during a commit since we need + * to have the normal tree locking. + */ + if (!trans->transaction->in_commit) { + spin_lock(&cache->lock); + if (cache->cached != BTRFS_CACHE_NO) { + spin_unlock(&cache->lock); + return 0; + } + cache->cached = BTRFS_CACHE_STARTED; + spin_unlock(&cache->lock); + + ret = load_free_space_cache(fs_info, cache); + + spin_lock(&cache->lock); + if (ret == 1) { + cache->cached = BTRFS_CACHE_FINISHED; + cache->last_byte_to_unpin = (u64)-1; + } else { + cache->cached = BTRFS_CACHE_NO; + } + spin_unlock(&cache->lock); + if (ret == 1) + return 0; + } + + if (load_cache_only) + return 0; + caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL); BUG_ON(!caching_ctl); @@ -3984,6 +4016,14 @@ static int update_block_group(struct btrfs_trans_handle *trans, factor = 2; else factor = 1; + /* + * If this block group has free space cache written out, we + * need to make sure to load it if we are removing space. This + * is because we need the unpinning stage to actually add the + * space back to the block group, otherwise we will leak space. + */ + if (!alloc && cache->cached == BTRFS_CACHE_NO) + cache_block_group(cache, trans, 1); byte_in_group = bytenr - cache->key.objectid; WARN_ON(byte_in_group > cache->key.offset); @@ -4828,6 +4868,10 @@ have_block_group: if (unlikely(block_group->cached == BTRFS_CACHE_NO)) { u64 free_percent; + ret = cache_block_group(block_group, trans, 1); + if (block_group->cached == BTRFS_CACHE_FINISHED) + goto have_block_group; + free_percent = btrfs_block_group_used(&block_group->item); free_percent *= 100; free_percent = div64_u64(free_percent, @@ -4848,7 +4892,7 @@ have_block_group: if (loop > LOOP_CACHING_NOWAIT || (loop > LOOP_FIND_IDEAL && atomic_read(&space_info->caching_threads) < 2)) { - ret = cache_block_group(block_group); + ret = cache_block_group(block_group, trans, 0); BUG_ON(ret); } found_uncached_bg = true; @@ -5405,7 +5449,7 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, u64 num_bytes = ins->offset; block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); - cache_block_group(block_group); + cache_block_group(block_group, trans, 0); caching_ctl = get_caching_control(block_group); if (!caching_ctl) { diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 7f972e59cc04..baa193423fb8 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -187,6 +187,302 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root, return btrfs_update_inode(trans, root, inode); } +static int readahead_cache(struct inode *inode) +{ + struct file_ra_state *ra; + unsigned long last_index; + + ra = kzalloc(sizeof(*ra), GFP_NOFS); + if (!ra) + return -ENOMEM; + + file_ra_state_init(ra, inode->i_mapping); + last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT; + + page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index); + + kfree(ra); + + return 0; +} + +int load_free_space_cache(struct btrfs_fs_info *fs_info, + struct btrfs_block_group_cache *block_group) +{ + struct btrfs_root *root = fs_info->tree_root; + struct inode *inode; + struct btrfs_free_space_header *header; + struct extent_buffer *leaf; + struct page *page; + struct btrfs_path *path; + u32 *checksums = NULL, *crc; + char *disk_crcs = NULL; + struct btrfs_key key; + struct list_head bitmaps; + u64 num_entries; + u64 num_bitmaps; + u64 generation; + u32 cur_crc = ~(u32)0; + pgoff_t index = 0; + unsigned long first_page_offset; + int num_checksums; + int ret = 0; + + /* + * If we're unmounting then just return, since this does a search on the + * normal root and not the commit root and we could deadlock. + */ + smp_mb(); + if (fs_info->closing) + return 0; + + /* + * If this block group has been marked to be cleared for one reason or + * another then we can't trust the on disk cache, so just return. + */ + spin_lock(&block_group->lock); + if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) { + printk(KERN_ERR "not reading block group %llu, dcs is %d\n", block_group->key.objectid, + block_group->disk_cache_state); + spin_unlock(&block_group->lock); + return 0; + } + spin_unlock(&block_group->lock); + + INIT_LIST_HEAD(&bitmaps); + + path = btrfs_alloc_path(); + if (!path) + return 0; + + inode = lookup_free_space_inode(root, block_group, path); + if (IS_ERR(inode)) { + btrfs_free_path(path); + return 0; + } + + /* Nothing in the space cache, goodbye */ + if (!i_size_read(inode)) { + btrfs_free_path(path); + goto out; + } + + key.objectid = BTRFS_FREE_SPACE_OBJECTID; + key.offset = block_group->key.objectid; + key.type = 0; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret) { + btrfs_free_path(path); + goto out; + } + + leaf = path->nodes[0]; + header = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_free_space_header); + num_entries = btrfs_free_space_entries(leaf, header); + num_bitmaps = btrfs_free_space_bitmaps(leaf, header); + generation = btrfs_free_space_generation(leaf, header); + btrfs_free_path(path); + + if (BTRFS_I(inode)->generation != generation) { + printk(KERN_ERR "btrfs: free space inode generation (%llu) did" + " not match free space cache generation (%llu) for " + "block group %llu\n", + (unsigned long long)BTRFS_I(inode)->generation, + (unsigned long long)generation, + (unsigned long long)block_group->key.objectid); + goto out; + } + + if (!num_entries) + goto out; + + /* Setup everything for doing checksumming */ + num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE; + checksums = crc = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS); + if (!checksums) + goto out; + first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64); + disk_crcs = kzalloc(first_page_offset, GFP_NOFS); + if (!disk_crcs) + goto out; + + ret = readahead_cache(inode); + if (ret) { + ret = 0; + goto out; + } + + while (1) { + struct btrfs_free_space_entry *entry; + struct btrfs_free_space *e; + void *addr; + unsigned long offset = 0; + unsigned long start_offset = 0; + int need_loop = 0; + + if (!num_entries && !num_bitmaps) + break; + + if (index == 0) { + start_offset = first_page_offset; + offset = start_offset; + } + + page = grab_cache_page(inode->i_mapping, index); + if (!page) { + ret = 0; + goto free_cache; + } + + if (!PageUptodate(page)) { + btrfs_readpage(NULL, page); + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + page_cache_release(page); + printk(KERN_ERR "btrfs: error reading free " + "space cache: %llu\n", + (unsigned long long) + block_group->key.objectid); + goto free_cache; + } + } + addr = kmap(page); + + if (index == 0) { + u64 *gen; + + memcpy(disk_crcs, addr, first_page_offset); + gen = addr + (sizeof(u32) * num_checksums); + if (*gen != BTRFS_I(inode)->generation) { + printk(KERN_ERR "btrfs: space cache generation" + " (%llu) does not match inode (%llu) " + "for block group %llu\n", + (unsigned long long)*gen, + (unsigned long long) + BTRFS_I(inode)->generation, + (unsigned long long) + block_group->key.objectid); + kunmap(page); + unlock_page(page); + page_cache_release(page); + goto free_cache; + } + crc = (u32 *)disk_crcs; + } + entry = addr + start_offset; + + /* First lets check our crc before we do anything fun */ + cur_crc = ~(u32)0; + cur_crc = btrfs_csum_data(root, addr + start_offset, cur_crc, + PAGE_CACHE_SIZE - start_offset); + btrfs_csum_final(cur_crc, (char *)&cur_crc); + if (cur_crc != *crc) { + printk(KERN_ERR "btrfs: crc mismatch for page %lu in " + "block group %llu\n", index, + (unsigned long long)block_group->key.objectid); + kunmap(page); + unlock_page(page); + page_cache_release(page); + goto free_cache; + } + crc++; + + while (1) { + if (!num_entries) + break; + + need_loop = 1; + e = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS); + if (!e) { + kunmap(page); + unlock_page(page); + page_cache_release(page); + goto free_cache; + } + + e->offset = le64_to_cpu(entry->offset); + e->bytes = le64_to_cpu(entry->bytes); + if (!e->bytes) { + kunmap(page); + kfree(e); + unlock_page(page); + page_cache_release(page); + goto free_cache; + } + + if (entry->type == BTRFS_FREE_SPACE_EXTENT) { + spin_lock(&block_group->tree_lock); + ret = link_free_space(block_group, e); + spin_unlock(&block_group->tree_lock); + BUG_ON(ret); + } else { + e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); + if (!e->bitmap) { + kunmap(page); + kfree(e); + unlock_page(page); + page_cache_release(page); + goto free_cache; + } + spin_lock(&block_group->tree_lock); + ret = link_free_space(block_group, e); + block_group->total_bitmaps++; + recalculate_thresholds(block_group); + spin_unlock(&block_group->tree_lock); + list_add_tail(&e->list, &bitmaps); + } + + num_entries--; + offset += sizeof(struct btrfs_free_space_entry); + if (offset + sizeof(struct btrfs_free_space_entry) >= + PAGE_CACHE_SIZE) + break; + entry++; + } + + /* + * We read an entry out of this page, we need to move on to the + * next page. + */ + if (need_loop) { + kunmap(page); + goto next; + } + + /* + * We add the bitmaps at the end of the entries in order that + * the bitmap entries are added to the cache. + */ + e = list_entry(bitmaps.next, struct btrfs_free_space, list); + list_del_init(&e->list); + memcpy(e->bitmap, addr, PAGE_CACHE_SIZE); + kunmap(page); + num_bitmaps--; +next: + unlock_page(page); + page_cache_release(page); + index++; + } + + ret = 1; +out: + kfree(checksums); + kfree(disk_crcs); + iput(inode); + return ret; + +free_cache: + /* This cache is bogus, make sure it gets cleared */ + spin_lock(&block_group->lock); + block_group->disk_cache_state = BTRFS_DC_CLEAR; + spin_unlock(&block_group->lock); + btrfs_remove_free_space_cache(block_group); + goto out; +} + int btrfs_write_out_cache(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_block_group_cache *block_group, diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h index 189f740bd3c0..e49ca5c321b5 100644 --- a/fs/btrfs/free-space-cache.h +++ b/fs/btrfs/free-space-cache.h @@ -39,6 +39,8 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_path *path, struct inode *inode); +int load_free_space_cache(struct btrfs_fs_info *fs_info, + struct btrfs_block_group_cache *block_group); int btrfs_write_out_cache(struct btrfs_root *root, struct btrfs_trans_handle *trans, struct btrfs_block_group_cache *block_group, |