From c635757365c39411bfcc7b1fc624c43848ef1c1d Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Fri, 6 Aug 2021 16:12:41 +0800 Subject: [PATCH] btrfs: defrag: remove the old infrastructure Now the old infrastructure can all be removed, defrag Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 313 ----------------------------------------------- 1 file changed, 313 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index d66fc025b884..502eba108118 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -986,107 +986,6 @@ out: return ret; } -/* - * When we're defragging a range, we don't want to kick it off again - * if it is really just waiting for delalloc to send it down. - * If we find a nice big extent or delalloc range for the bytes in the - * file you want to defrag, we return 0 to let you know to skip this - * part of the file - */ -static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh) -{ - struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; - struct extent_map *em = NULL; - struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; - const u32 sectorsize = btrfs_sb(inode->i_sb)->sectorsize; - u64 end; - - read_lock(&em_tree->lock); - em = lookup_extent_mapping(em_tree, offset, sectorsize); - read_unlock(&em_tree->lock); - - if (em) { - end = extent_map_end(em); - free_extent_map(em); - if (end - offset > thresh) - return 0; - } - /* if we already have a nice delalloc here, just stop */ - thresh /= 2; - end = count_range_bits(io_tree, &offset, offset + thresh, - thresh, EXTENT_DELALLOC, 1); - if (end >= thresh) - return 0; - return 1; -} - -/* - * helper function to walk through a file and find extents - * newer than a specific transid, and smaller than thresh. - * - * This is used by the defragging code to find new and small - * extents - */ -static int find_new_extents(struct btrfs_root *root, - struct inode *inode, u64 newer_than, - u64 *off, u32 thresh) -{ - struct btrfs_path *path; - struct btrfs_key min_key; - struct extent_buffer *leaf; - struct btrfs_file_extent_item *extent; - int type; - int ret; - u64 ino = btrfs_ino(BTRFS_I(inode)); - - path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - - min_key.objectid = ino; - min_key.type = BTRFS_EXTENT_DATA_KEY; - min_key.offset = *off; - - while (1) { - ret = btrfs_search_forward(root, &min_key, path, newer_than); - if (ret != 0) - goto none; -process_slot: - if (min_key.objectid != ino) - goto none; - if (min_key.type != BTRFS_EXTENT_DATA_KEY) - goto none; - - leaf = path->nodes[0]; - extent = btrfs_item_ptr(leaf, path->slots[0], - struct btrfs_file_extent_item); - - type = btrfs_file_extent_type(leaf, extent); - if (type == BTRFS_FILE_EXTENT_REG && - btrfs_file_extent_num_bytes(leaf, extent) < thresh && - check_defrag_in_cache(inode, min_key.offset, thresh)) { - *off = min_key.offset; - btrfs_free_path(path); - return 0; - } - - path->slots[0]++; - if (path->slots[0] < btrfs_header_nritems(leaf)) { - btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]); - goto process_slot; - } - - if (min_key.offset == (u64)-1) - goto none; - - min_key.offset++; - btrfs_release_path(path); - } -none: - btrfs_free_path(path); - return -ENOENT; -} - static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start, bool locked) { @@ -1142,66 +1041,6 @@ static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em, return ret; } -static int should_defrag_range(struct inode *inode, u64 start, u32 thresh, - u64 *last_len, u64 *skip, u64 *defrag_end, - int compress) -{ - struct extent_map *em; - int ret = 1; - bool next_mergeable = true; - bool prev_mergeable = true; - - /* - * make sure that once we start defragging an extent, we keep on - * defragging it - */ - if (start < *defrag_end) - return 1; - - *skip = 0; - - em = defrag_lookup_extent(inode, start, false); - if (!em) - return 0; - - /* this will cover holes, and inline extents */ - if (em->block_start >= EXTENT_MAP_LAST_BYTE) { - ret = 0; - goto out; - } - - if (!*defrag_end) - prev_mergeable = false; - - next_mergeable = defrag_check_next_extent(inode, em, false); - /* - * we hit a real extent, if it is big or the next extent is not a - * real extent, don't bother defragging it - */ - if (!compress && (*last_len == 0 || *last_len >= thresh) && - (em->len >= thresh || (!next_mergeable && !prev_mergeable))) - ret = 0; -out: - /* - * last_len ends up being a counter of how many bytes we've defragged. - * every time we choose not to defrag an extent, we reset *last_len - * so that the next tiny extent will force a defrag. - * - * The end result of this is that tiny extents before a single big - * extent will force at least part of that big extent to be defragged. - */ - if (ret) { - *defrag_end = extent_map_end(em); - } else { - *last_len = 0; - *skip = extent_map_end(em); - *defrag_end = 0; - } - - free_extent_map(em); - return ret; -} - /* * Prepare one page to be defragged. * @@ -1284,158 +1123,6 @@ again: return page; } -/* - * it doesn't do much good to defrag one or two pages - * at a time. This pulls in a nice chunk of pages - * to COW and defrag. - * - * It also makes sure the delalloc code has enough - * dirty data to avoid making new small extents as part - * of the defrag - * - * It's a good idea to start RA on this range - * before calling this. - */ -static int cluster_pages_for_defrag(struct inode *inode, - struct page **pages, - unsigned long start_index, - unsigned long num_pages) -{ - unsigned long file_end; - u64 isize = i_size_read(inode); - u64 page_start; - u64 page_end; - u64 page_cnt; - u64 start = (u64)start_index << PAGE_SHIFT; - u64 search_start; - int ret; - int i; - int i_done; - struct extent_state *cached_state = NULL; - struct extent_changeset *data_reserved = NULL; - - file_end = (isize - 1) >> PAGE_SHIFT; - if (!isize || start_index > file_end) - return 0; - - page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1); - - ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved, - start, page_cnt << PAGE_SHIFT); - if (ret) - return ret; - i_done = 0; - - /* step one, lock all the pages */ - for (i = 0; i < page_cnt; i++) { - struct page *page; - - page = defrag_prepare_one_page(BTRFS_I(inode), start_index + i); - if (IS_ERR(page)) { - ret = PTR_ERR(page); - break; - } - pages[i] = page; - i_done++; - } - if (!i_done || ret) - goto out; - - if (!(inode->i_sb->s_flags & SB_ACTIVE)) - goto out; - - /* - * Now we have a nice long stream of locked and up to date pages, let's - * wait on them. - */ - for (i = 0; i < i_done; i++) - wait_on_page_writeback(pages[i]); - - page_start = page_offset(pages[0]); - page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE; - - lock_extent_bits(&BTRFS_I(inode)->io_tree, - page_start, page_end - 1, &cached_state); - - /* - * When defragmenting we skip ranges that have holes or inline extents, - * (check should_defrag_range()), to avoid unnecessary IO and wasting - * space. At btrfs_defrag_file(), we check if a range should be defragged - * before locking the inode and then, if it should, we trigger a sync - * page cache readahead - we lock the inode only after that to avoid - * blocking for too long other tasks that possibly want to operate on - * other file ranges. But before we were able to get the inode lock, - * some other task may have punched a hole in the range, or we may have - * now an inline extent, in which case we should not defrag. So check - * for that here, where we have the inode and the range locked, and bail - * out if that happened. - */ - search_start = page_start; - while (search_start < page_end) { - struct extent_map *em; - - em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, search_start, - page_end - search_start); - if (IS_ERR(em)) { - ret = PTR_ERR(em); - goto out_unlock_range; - } - if (em->block_start >= EXTENT_MAP_LAST_BYTE) { - free_extent_map(em); - /* Ok, 0 means we did not defrag anything */ - ret = 0; - goto out_unlock_range; - } - search_start = extent_map_end(em); - free_extent_map(em); - } - - clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, - page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | - EXTENT_DEFRAG, 0, 0, &cached_state); - - if (i_done != page_cnt) { - spin_lock(&BTRFS_I(inode)->lock); - btrfs_mod_outstanding_extents(BTRFS_I(inode), 1); - spin_unlock(&BTRFS_I(inode)->lock); - btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, - start, (page_cnt - i_done) << PAGE_SHIFT, true); - } - - - set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1, - &cached_state); - - unlock_extent_cached(&BTRFS_I(inode)->io_tree, - page_start, page_end - 1, &cached_state); - - for (i = 0; i < i_done; i++) { - clear_page_dirty_for_io(pages[i]); - ClearPageChecked(pages[i]); - set_page_dirty(pages[i]); - unlock_page(pages[i]); - put_page(pages[i]); - } - btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT); - extent_changeset_free(data_reserved); - return i_done; - -out_unlock_range: - unlock_extent_cached(&BTRFS_I(inode)->io_tree, - page_start, page_end - 1, &cached_state); -out: - for (i = 0; i < i_done; i++) { - unlock_page(pages[i]); - put_page(pages[i]); - } - btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, - start, page_cnt << PAGE_SHIFT, true); - btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT); - extent_changeset_free(data_reserved); - return ret; - -} - struct defrag_target_range { struct list_head list; u64 start;