From 7b508037d4cac3bcde7187b70170caf81cae3aad Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Thu, 27 May 2021 20:33:22 +0800 Subject: [PATCH] btrfs: defrag: use defrag_one_cluster() to implement btrfs_defrag_file() The function defrag_one_cluster() is able to defrag one range well enough, we only need to do preparation for it, including: - Clamp and align the defrag range - Exclude invalid cases - Proper inode locking The old infrastructures will not be removed in this patch, as it would be too noisy to review. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 206 +++++++++++++---------------------------------- 1 file changed, 56 insertions(+), 150 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 777cb3a3413c..d66fc025b884 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1760,25 +1760,15 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra, u64 newer_than, unsigned long max_to_defrag) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); - struct btrfs_root *root = BTRFS_I(inode)->root; - unsigned long last_index; + unsigned long sectors_defragged = 0; u64 isize = i_size_read(inode); - u64 last_len = 0; - u64 skip = 0; - u64 defrag_end = 0; - u64 newer_off = range->start; - unsigned long i; - unsigned long ra_index = 0; - int ret; - int defrag_count = 0; - int compress_type = BTRFS_COMPRESS_ZLIB; - u32 extent_thresh = range->extent_thresh; - unsigned long max_cluster = SZ_256K >> PAGE_SHIFT; - unsigned long cluster = max_cluster; - u64 new_align = ~((u64)SZ_128K - 1); - struct page **pages = NULL; + u64 cur; + u64 last_byte; bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS; bool ra_allocated = false; + int compress_type = BTRFS_COMPRESS_ZLIB; + int ret = 0; + u32 extent_thresh = range->extent_thresh; if (isize == 0) return 0; @@ -1796,6 +1786,14 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra, if (extent_thresh == 0) extent_thresh = SZ_256K; + if (range->start + range->len > range->start) { + /* Got a specific range */ + last_byte = min(isize, range->start + range->len) - 1; + } else { + /* Defrag until file end */ + last_byte = isize - 1; + } + /* * If we were not given a ra, allocate a readahead context. As * readahead is just an optimization, defrag will work without it so @@ -1808,159 +1806,67 @@ int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra, file_ra_state_init(ra, inode->i_mapping); } - pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL); - if (!pages) { - ret = -ENOMEM; - goto out_ra; - } + /* Align the range */ + cur = round_down(range->start, fs_info->sectorsize); + last_byte = round_up(last_byte, fs_info->sectorsize) - 1; - /* find the last page to defrag */ - if (range->start + range->len > range->start) { - last_index = min_t(u64, isize - 1, - range->start + range->len - 1) >> PAGE_SHIFT; - } else { - last_index = (isize - 1) >> PAGE_SHIFT; - } + while (cur < last_byte) { + u64 cluster_end; - if (newer_than) { - ret = find_new_extents(root, inode, newer_than, - &newer_off, SZ_64K); - if (!ret) { - range->start = newer_off; - /* - * we always align our defrag to help keep - * the extents in the file evenly spaced - */ - i = (newer_off & new_align) >> PAGE_SHIFT; - } else - goto out_ra; - } else { - i = range->start >> PAGE_SHIFT; - } - if (!max_to_defrag) - max_to_defrag = last_index - i + 1; + /* The cluster size 256K should always be page aligned */ + BUILD_BUG_ON(!IS_ALIGNED(CLUSTER_SIZE, PAGE_SIZE)); - /* - * make writeback starts from i, so the defrag range can be - * written sequentially. - */ - if (i < inode->i_mapping->writeback_index) - inode->i_mapping->writeback_index = i; - - while (i <= last_index && defrag_count < max_to_defrag && - (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) { - /* - * make sure we stop running if someone unmounts - * the FS - */ - if (!(inode->i_sb->s_flags & SB_ACTIVE)) - break; - - if (btrfs_defrag_cancelled(fs_info)) { - btrfs_debug(fs_info, "defrag_file cancelled"); - ret = -EAGAIN; - goto error; - } - - if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT, - extent_thresh, &last_len, &skip, - &defrag_end, do_compress)){ - unsigned long next; - /* - * the should_defrag function tells us how much to skip - * bump our counter by the suggested amount - */ - next = DIV_ROUND_UP(skip, PAGE_SIZE); - i = max(i + 1, next); - continue; - } - - if (!newer_than) { - cluster = (PAGE_ALIGN(defrag_end) >> - PAGE_SHIFT) - i; - cluster = min(cluster, max_cluster); - } else { - cluster = max_cluster; - } - - if (i + cluster > ra_index) { - ra_index = max(i, ra_index); - if (ra) - page_cache_sync_readahead(inode->i_mapping, ra, - NULL, ra_index, cluster); - ra_index += cluster; - } + /* We want the cluster end at page boundary when possible */ + cluster_end = (((cur >> PAGE_SHIFT) + + (SZ_256K >> PAGE_SHIFT)) << PAGE_SHIFT) - 1; + cluster_end = min(cluster_end, last_byte); btrfs_inode_lock(inode, 0); if (IS_SWAPFILE(inode)) { ret = -ETXTBSY; - } else { - if (do_compress) - BTRFS_I(inode)->defrag_compress = compress_type; - ret = cluster_pages_for_defrag(inode, pages, i, cluster); - } - if (ret < 0) { btrfs_inode_unlock(inode, 0); - goto out_ra; + break; } - - defrag_count += ret; - balance_dirty_pages_ratelimited(inode->i_mapping); + if (!(inode->i_sb->s_flags & SB_ACTIVE)) { + btrfs_inode_unlock(inode, 0); + break; + } + if (do_compress) + BTRFS_I(inode)->defrag_compress = compress_type; + ret = defrag_one_cluster(BTRFS_I(inode), ra, cur, + cluster_end + 1 - cur, extent_thresh, + newer_than, do_compress, + §ors_defragged, max_to_defrag); btrfs_inode_unlock(inode, 0); - - if (newer_than) { - if (newer_off == (u64)-1) - break; - - if (ret > 0) - i += ret; - - newer_off = max(newer_off + 1, - (u64)i << PAGE_SHIFT); - - ret = find_new_extents(root, inode, newer_than, - &newer_off, SZ_64K); - if (!ret) { - range->start = newer_off; - i = (newer_off & new_align) >> PAGE_SHIFT; - } else { - break; - } - } else { - if (ret > 0) { - i += ret; - last_len += ret << PAGE_SHIFT; - } else { - i++; - last_len = 0; - } - } + if (ret < 0) + break; + cur = cluster_end + 1; } - ret = defrag_count; -error: - if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) { - filemap_flush(inode->i_mapping); - if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, - &BTRFS_I(inode)->runtime_flags)) + if (ra_allocated) + kfree(ra); + if (sectors_defragged) { + /* + * We have defragged some sectors, for compression case they + * need to be written back immediately. + */ + if (range->flags & BTRFS_DEFRAG_RANGE_START_IO) { filemap_flush(inode->i_mapping); + if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) + filemap_flush(inode->i_mapping); + } + if (range->compress_type == BTRFS_COMPRESS_LZO) + btrfs_set_fs_incompat(fs_info, COMPRESS_LZO); + else if (range->compress_type == BTRFS_COMPRESS_ZSTD) + btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD); + ret = sectors_defragged; } - - if (range->compress_type == BTRFS_COMPRESS_LZO) { - btrfs_set_fs_incompat(fs_info, COMPRESS_LZO); - } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) { - btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD); - } - -out_ra: if (do_compress) { btrfs_inode_lock(inode, 0); BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE; btrfs_inode_unlock(inode, 0); } - if (ra_allocated) - kfree(ra); - kfree(pages); return ret; }