On Sat, Mar 20, 2010 at 12:24 PM, Sean Bartell <wingedtachik...@gmail.com> wrote: > An extent_io_tree is used for all free space information. This allows > removal of ext2_alloc_block and ext2_free_block, and makes > create_ext2_image less ext2-specific. > --- > convert.c | 154 > +++++++++++++++++++++++++++++++++++++++---------------------- > 1 files changed, 99 insertions(+), 55 deletions(-) > > diff --git a/convert.c b/convert.c > index d037c98..c48f8ba 100644 > --- a/convert.c > +++ b/convert.c > @@ -95,29 +95,10 @@ static int close_ext2fs(ext2_filsys fs) > return 0; > } > > -static int ext2_alloc_block(ext2_filsys fs, u64 goal, u64 *block_ret) > +static int ext2_cache_free_extents(ext2_filsys ext2_fs, > + struct extent_io_tree *free_tree) > { > - blk_t block; > - > - if (!ext2fs_new_block(fs, goal, NULL, &block)) { > - ext2fs_fast_mark_block_bitmap(fs->block_map, block); > - *block_ret = block; > - return 0; > - } > - return -ENOSPC; > -} > - > -static int ext2_free_block(ext2_filsys fs, u64 block) > -{ > - BUG_ON(block != (blk_t)block); > - ext2fs_fast_unmark_block_bitmap(fs->block_map, block); > - return 0; > -} > - > -static int cache_free_extents(struct btrfs_root *root, ext2_filsys ext2_fs) > - > -{ > - int i, ret = 0; > + int ret = 0; > blk_t block; > u64 bytenr; > u64 blocksize = ext2_fs->blocksize; > @@ -127,29 +108,68 @@ static int cache_free_extents(struct btrfs_root *root, > ext2_filsys ext2_fs) > if (ext2fs_fast_test_block_bitmap(ext2_fs->block_map, block)) > continue; > bytenr = block * blocksize; > - ret = set_extent_dirty(&root->fs_info->free_space_cache, > - bytenr, bytenr + blocksize - 1, 0); > + ret = set_extent_dirty(free_tree, bytenr, > + bytenr + blocksize - 1, 0); > BUG_ON(ret); > } > > + return 0; > +} > + > +/* mark btrfs-reserved blocks as used */ > +static void adjust_free_extents(ext2_filsys ext2_fs, > + struct extent_io_tree *free_tree) > +{ > + int i; > + u64 bytenr; > + u64 blocksize = ext2_fs->blocksize; > + > + clear_extent_dirty(free_tree, 0, BTRFS_SUPER_INFO_OFFSET - 1, 0); > + > for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { > bytenr = btrfs_sb_offset(i); > bytenr &= ~((u64)STRIPE_LEN - 1); > if (bytenr >= blocksize * ext2_fs->super->s_blocks_count) > break; > - clear_extent_dirty(&root->fs_info->free_space_cache, bytenr, > - bytenr + STRIPE_LEN - 1, 0); > + clear_extent_dirty(free_tree, bytenr, bytenr + STRIPE_LEN - 1, > + 0); > } > +} > > - clear_extent_dirty(&root->fs_info->free_space_cache, > - 0, BTRFS_SUPER_INFO_OFFSET - 1, 0); > - > +static int alloc_blocks(struct extent_io_tree *free_tree, > + u64 *blocks, int num, u64 blocksize) > +{ > + u64 start; > + u64 end; > + u64 last = 0; > + u64 mask = blocksize - 1; > + int ret; > + while(num) { > + ret = find_first_extent_bit(free_tree, last, &start, &end, > + EXTENT_DIRTY); > + if (ret) > + goto fail; > + last = end + 1; > + if (start & mask) > + start = (start & mask) + blocksize; > + if (last - start < blocksize) > + continue; > + *blocks++ = start; > + num--; > + last = start + blocksize; > + clear_extent_dirty(free_tree, start, last - 1, 0); > + } > return 0; > +fail: > + fprintf(stderr, "not enough free space\n"); > + return -ENOSPC; > } > > static int custom_alloc_extent(struct btrfs_root *root, u64 num_bytes, > u64 hint_byte, struct btrfs_key *ins) > { > + u64 blocksize = root->sectorsize; > + u64 mask = blocksize - 1; > u64 start; > u64 end; > u64 last = hint_byte; > @@ -171,6 +191,8 @@ static int custom_alloc_extent(struct btrfs_root *root, > u64 num_bytes, > > start = max(last, start); > last = end + 1; > + if (start & mask) > + start = (start & mask) + blocksize; > if (last - start < num_bytes) > continue; > > @@ -1186,9 +1208,9 @@ static int create_image_file_range(struct > btrfs_trans_handle *trans, > struct btrfs_root *root, u64 objectid, > struct btrfs_inode_item *inode, > u64 start_byte, u64 end_byte, > - ext2_filsys ext2_fs) > + struct extent_io_tree *orig_free_tree) > { > - u32 blocksize = ext2_fs->blocksize; > + u32 blocksize = root->sectorsize; > u32 block = start_byte / blocksize; > u32 last_block = (end_byte + blocksize - 1) / blocksize; > int ret = 0; > @@ -1205,7 +1227,8 @@ static int create_image_file_range(struct > btrfs_trans_handle *trans, > .errcode = 0, > }; > for (; start_byte < end_byte; block++, start_byte += blocksize) { > - if (!ext2fs_fast_test_block_bitmap(ext2_fs->block_map, block)) > + if (test_range_bit(orig_free_tree, start_byte, > + start_byte + blocksize, EXTENT_DIRTY, 1)) > continue; > ret = block_iterate_proc(NULL, block, block, &data); > if (ret & BLOCK_ABORT) { > @@ -1234,8 +1257,8 @@ fail: > /* > * Create the ext2fs image file. > */ > -static int create_ext2_image(struct btrfs_root *root, ext2_filsys ext2_fs, > - const char *name) > +static int create_ext2_image(struct btrfs_root *root, const char *name, > + struct extent_io_tree *orig_free_tree) > { > int ret; > struct btrfs_key key; > @@ -1348,7 +1371,7 @@ next: > if (bytenr > last_byte) { > ret = create_image_file_range(trans, root, objectid, > &btrfs_inode, last_byte, > - bytenr, ext2_fs); > + bytenr, orig_free_tree); > if (ret) > goto fail; > } > @@ -1370,7 +1393,7 @@ next: > if (total_bytes > last_byte) { > ret = create_image_file_range(trans, root, objectid, > &btrfs_inode, last_byte, > - total_bytes, ext2_fs); > + total_bytes, orig_free_tree); > if (ret) > goto fail; > } > @@ -2332,9 +2355,23 @@ err: > return ret; > } > > +static int copy_dirtiness(struct extent_io_tree *out, > + struct extent_io_tree *in) > +{ > + int ret; > + u64 start, end, last = 0; > + while (!find_first_extent_bit(in, last, &start, &end, EXTENT_DIRTY)) { > + ret = set_extent_dirty(out, start, end, 0); > + if (ret) > + return ret; > + last = end + 1; > + } > + return 0; > +} > + > int do_convert(const char *devname, int datacsum, int packing, int noxattr) > { > - int i, fd, ret; > + int fd, ret; > u32 blocksize; > u64 blocks[7]; > u64 total_bytes; > @@ -2342,7 +2379,11 @@ int do_convert(const char *devname, int datacsum, int > packing, int noxattr) > ext2_filsys ext2_fs; > struct btrfs_root *root; > struct btrfs_root *ext2_root; > + struct extent_io_tree free_tree; > + struct extent_io_tree orig_free_tree; > > + extent_io_tree_init(&free_tree); > + extent_io_tree_init(&orig_free_tree); > ret = open_ext2fs(devname, &ext2_fs); > if (ret) { > fprintf(stderr, "unable to open the Ext2fs\n"); > @@ -2359,13 +2400,23 @@ int do_convert(const char *devname, int datacsum, int > packing, int noxattr) > fprintf(stderr, "filetype feature is missing\n"); > goto fail; > } > - for (i = 0; i < 7; i++) { > - ret = ext2_alloc_block(ext2_fs, 0, blocks + i); > - if (ret) { > - fprintf(stderr, "not enough free space\n"); > - goto fail; > - } > - blocks[i] *= blocksize; > + ret = ext2_cache_free_extents(ext2_fs, &orig_free_tree); > + if (ret) { > + fprintf(stderr, "error during cache_free_extents %d\n", ret); > + goto fail; > + } > + /* preserve first 64KiB, just in case */ > + clear_extent_dirty(&orig_free_tree, 0, BTRFS_SUPER_INFO_OFFSET - 1, > 0); > + > + ret = copy_dirtiness(&free_tree, &orig_free_tree); > + if (ret) { > + fprintf(stderr, "error during copy_dirtiness %d\n", ret); > + goto fail; > + } > + adjust_free_extents(ext2_fs, &free_tree); > + ret = alloc_blocks(&free_tree, blocks, 7, blocksize); > + if (ret) { > + goto fail; > } > super_bytenr = blocks[0]; > fd = open(devname, O_RDWR); > @@ -2391,17 +2442,9 @@ int do_convert(const char *devname, int datacsum, int > packing, int noxattr) > fprintf(stderr, "unable to open ctree\n"); > goto fail; > } > - ret = cache_free_extents(root, ext2_fs); > - if (ret) { > - fprintf(stderr, "error during cache_free_extents %d\n", ret); > - goto fail; > - } > + copy_dirtiness(&root->fs_info->free_space_cache, &free_tree); > + extent_io_tree_cleanup(&free_tree); > root->fs_info->extent_ops = &extent_ops; > - /* recover block allocation bitmap */ > - for (i = 0; i < 7; i++) { > - blocks[i] /= blocksize; > - ext2_free_block(ext2_fs, blocks[i]); > - } > ret = init_btrfs(root); > if (ret) { > fprintf(stderr, "unable to setup the root tree\n"); > @@ -2419,11 +2462,12 @@ int do_convert(const char *devname, int datacsum, int > packing, int noxattr) > fprintf(stderr, "unable to create subvol\n"); > goto fail; > } > - ret = create_ext2_image(ext2_root, ext2_fs, "image"); > + ret = create_ext2_image(ext2_root, "image", &orig_free_tree);
extent_io_tree is not very space efficient. caching free space in several places is not good. I prefer adding a function that checks if a given block is used to the 'convert_fs' structure. > if (ret) { > fprintf(stderr, "error during create_ext2_image %d\n", ret); > goto fail; > } > + extent_io_tree_cleanup(&orig_free_tree); > printf("cleaning up system chunk.\n"); > ret = cleanup_sys_chunk(root, ext2_root); > if (ret) { > -- > 1.6.4.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html