From 261507a02ccba9afda919852263b6bc1581ce1ef Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 17 Dec 2010 14:21:50 +0800 Subject: btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan --- fs/btrfs/inode.c | 82 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 51 insertions(+), 31 deletions(-) (limited to 'fs/btrfs/inode.c') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 5f9194438f7c..ba563b2a5d6c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -122,10 +122,10 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, size_t cur_size = size; size_t datasize; unsigned long offset; - int use_compress = 0; + int compress_type = BTRFS_COMPRESS_NONE; if (compressed_size && compressed_pages) { - use_compress = 1; + compress_type = root->fs_info->compress_type; cur_size = compressed_size; } @@ -159,7 +159,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, btrfs_set_file_extent_ram_bytes(leaf, ei, size); ptr = btrfs_file_extent_inline_start(ei); - if (use_compress) { + if (compress_type != BTRFS_COMPRESS_NONE) { struct page *cpage; int i = 0; while (compressed_size > 0) { @@ -176,7 +176,7 @@ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, compressed_size -= cur_size; } btrfs_set_file_extent_compression(leaf, ei, - BTRFS_COMPRESS_ZLIB); + compress_type); } else { page = find_get_page(inode->i_mapping, start >> PAGE_CACHE_SHIFT); @@ -263,6 +263,7 @@ struct async_extent { u64 compressed_size; struct page **pages; unsigned long nr_pages; + int compress_type; struct list_head list; }; @@ -280,7 +281,8 @@ static noinline int add_async_extent(struct async_cow *cow, u64 start, u64 ram_size, u64 compressed_size, struct page **pages, - unsigned long nr_pages) + unsigned long nr_pages, + int compress_type) { struct async_extent *async_extent; @@ -290,6 +292,7 @@ static noinline int add_async_extent(struct async_cow *cow, async_extent->compressed_size = compressed_size; async_extent->pages = pages; async_extent->nr_pages = nr_pages; + async_extent->compress_type = compress_type; list_add_tail(&async_extent->list, &cow->extents); return 0; } @@ -332,6 +335,7 @@ static noinline int compress_file_range(struct inode *inode, unsigned long max_uncompressed = 128 * 1024; int i; int will_compress; + int compress_type = root->fs_info->compress_type; actual_end = min_t(u64, isize, end + 1); again: @@ -381,12 +385,16 @@ again: WARN_ON(pages); pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); - ret = btrfs_zlib_compress_pages(inode->i_mapping, start, - total_compressed, pages, - nr_pages, &nr_pages_ret, - &total_in, - &total_compressed, - max_compressed); + if (BTRFS_I(inode)->force_compress) + compress_type = BTRFS_I(inode)->force_compress; + + ret = btrfs_compress_pages(compress_type, + inode->i_mapping, start, + total_compressed, pages, + nr_pages, &nr_pages_ret, + &total_in, + &total_compressed, + max_compressed); if (!ret) { unsigned long offset = total_compressed & @@ -493,7 +501,8 @@ again: * and will submit them to the elevator. */ add_async_extent(async_cow, start, num_bytes, - total_compressed, pages, nr_pages_ret); + total_compressed, pages, nr_pages_ret, + compress_type); if (start + num_bytes < end) { start += num_bytes; @@ -515,7 +524,8 @@ cleanup_and_bail_uncompressed: __set_page_dirty_nobuffers(locked_page); /* unlocked later on in the async handlers */ } - add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0); + add_async_extent(async_cow, start, end - start + 1, + 0, NULL, 0, BTRFS_COMPRESS_NONE); *num_added += 1; } @@ -640,6 +650,7 @@ retry: em->block_start = ins.objectid; em->block_len = ins.offset; em->bdev = root->fs_info->fs_devices->latest_bdev; + em->compress_type = async_extent->compress_type; set_bit(EXTENT_FLAG_PINNED, &em->flags); set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); @@ -656,11 +667,13 @@ retry: async_extent->ram_size - 1, 0); } - ret = btrfs_add_ordered_extent(inode, async_extent->start, - ins.objectid, - async_extent->ram_size, - ins.offset, - BTRFS_ORDERED_COMPRESSED); + ret = btrfs_add_ordered_extent_compress(inode, + async_extent->start, + ins.objectid, + async_extent->ram_size, + ins.offset, + BTRFS_ORDERED_COMPRESSED, + async_extent->compress_type); BUG_ON(ret); /* @@ -1670,7 +1683,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) struct btrfs_ordered_extent *ordered_extent = NULL; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_state *cached_state = NULL; - int compressed = 0; + int compress_type = 0; int ret; bool nolock = false; @@ -1711,9 +1724,9 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) trans->block_rsv = &root->fs_info->delalloc_block_rsv; if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) - compressed = 1; + compress_type = ordered_extent->compress_type; if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { - BUG_ON(compressed); + BUG_ON(compress_type); ret = btrfs_mark_extent_written(trans, inode, ordered_extent->file_offset, ordered_extent->file_offset + @@ -1727,7 +1740,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) ordered_extent->disk_len, ordered_extent->len, ordered_extent->len, - compressed, 0, 0, + compress_type, 0, 0, BTRFS_FILE_EXTENT_REG); unpin_extent_cache(&BTRFS_I(inode)->extent_tree, ordered_extent->file_offset, @@ -1829,6 +1842,8 @@ static int btrfs_io_failed_hook(struct bio *failed_bio, if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { logical = em->block_start; failrec->bio_flags = EXTENT_BIO_COMPRESSED; + extent_set_compress_type(&failrec->bio_flags, + em->compress_type); } failrec->logical = logical; free_extent_map(em); @@ -4930,8 +4945,10 @@ static noinline int uncompress_inline(struct btrfs_path *path, size_t max_size; unsigned long inline_size; unsigned long ptr; + int compress_type; WARN_ON(pg_offset != 0); + compress_type = btrfs_file_extent_compression(leaf, item); max_size = btrfs_file_extent_ram_bytes(leaf, item); inline_size = btrfs_file_extent_inline_item_len(leaf, btrfs_item_nr(leaf, path->slots[0])); @@ -4941,8 +4958,8 @@ static noinline int uncompress_inline(struct btrfs_path *path, read_extent_buffer(leaf, tmp, ptr, inline_size); max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); - ret = btrfs_zlib_decompress(tmp, page, extent_offset, - inline_size, max_size); + ret = btrfs_decompress(compress_type, tmp, page, + extent_offset, inline_size, max_size); if (ret) { char *kaddr = kmap_atomic(page, KM_USER0); unsigned long copy_size = min_t(u64, @@ -4984,7 +5001,7 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_trans_handle *trans = NULL; - int compressed; + int compress_type; again: read_lock(&em_tree->lock); @@ -5043,7 +5060,7 @@ again: found_type = btrfs_file_extent_type(leaf, item); extent_start = found_key.offset; - compressed = btrfs_file_extent_compression(leaf, item); + compress_type = btrfs_file_extent_compression(leaf, item); if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { extent_end = extent_start + @@ -5089,8 +5106,9 @@ again: em->block_start = EXTENT_MAP_HOLE; goto insert; } - if (compressed) { + if (compress_type != BTRFS_COMPRESS_NONE) { set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + em->compress_type = compress_type; em->block_start = bytenr; em->block_len = btrfs_file_extent_disk_num_bytes(leaf, item); @@ -5124,12 +5142,14 @@ again: em->len = (copy_size + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); em->orig_start = EXTENT_MAP_INLINE; - if (compressed) + if (compress_type) { set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + em->compress_type = compress_type; + } ptr = btrfs_file_extent_inline_start(item) + extent_offset; if (create == 0 && !PageUptodate(page)) { - if (btrfs_file_extent_compression(leaf, item) == - BTRFS_COMPRESS_ZLIB) { + if (btrfs_file_extent_compression(leaf, item) != + BTRFS_COMPRESS_NONE) { ret = uncompress_inline(path, inode, page, pg_offset, extent_offset, item); @@ -6479,7 +6499,7 @@ struct inode *btrfs_alloc_inode(struct super_block *sb) ei->ordered_data_close = 0; ei->orphan_meta_reserved = 0; ei->dummy_inode = 0; - ei->force_compress = 0; + ei->force_compress = BTRFS_COMPRESS_NONE; inode = &ei->vfs_inode; extent_map_tree_init(&ei->extent_tree, GFP_NOFS); -- cgit v1.2.3 From b83cc9693f39689490970c19f6c5b866f6719a70 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 20 Dec 2010 16:04:08 +0800 Subject: Btrfs: Add readonly snapshots support Usage: Set BTRFS_SUBVOL_RDONLY of btrfs_ioctl_vol_arg_v2->flags, and call ioctl(BTRFS_I0CTL_SNAP_CREATE_V2). Implementation: - Set readonly bit of btrfs_root_item->flags. - Add readonly checks in btrfs_permission (inode_permission), btrfs_setattr, btrfs_set/remove_xattr and some ioctls. Changelog for v3: - Eliminate btrfs_root->readonly, but check btrfs_root->root_item.flags. - Rename BTRFS_ROOT_SNAP_RDONLY to BTRFS_ROOT_SUBVOL_RDONLY. Signed-off-by: Li Zefan --- fs/btrfs/inode.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs/btrfs/inode.c') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 5f9194438f7c..956f1eb913b1 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3671,8 +3671,12 @@ static int btrfs_setattr_size(struct inode *inode, struct iattr *attr) static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; + struct btrfs_root *root = BTRFS_I(inode)->root; int err; + if (btrfs_root_readonly(root)) + return -EROFS; + err = inode_change_ok(inode, attr); if (err) return err; @@ -7206,6 +7210,10 @@ static int btrfs_set_page_dirty(struct page *page) static int btrfs_permission(struct inode *inode, int mask) { + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (btrfs_root_readonly(root) && (mask & MAY_WRITE)) + return -EROFS; if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE)) return -EACCES; return generic_permission(inode, mask, btrfs_check_acl); -- cgit v1.2.3