f2fs: swap: remove dead codes

After commit af4b6b8e ("f2fs: introduce check_swap_activate_fast()"),
we will never run into original logic of check_swap_activate() before
f2fs supports non 4k-sized page, so let's delete those dead codes.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -3830,66 +3830,7 @@ int f2fs_migrate_page(struct address_space *mapping,
 #endif
 
 #ifdef CONFIG_SWAP
-static int f2fs_is_file_aligned(struct inode *inode)
-{
-	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-	block_t main_blkaddr = SM_I(sbi)->main_blkaddr;
-	block_t cur_lblock;
-	block_t last_lblock;
-	block_t pblock;
-	unsigned long nr_pblocks;
-	unsigned int blocks_per_sec = BLKS_PER_SEC(sbi);
-	unsigned int not_aligned = 0;
-	int ret = 0;
-
-	cur_lblock = 0;
-	last_lblock = bytes_to_blks(inode, i_size_read(inode));
-
-	while (cur_lblock < last_lblock) {
-		struct f2fs_map_blocks map;
-
-		memset(&map, 0, sizeof(map));
-		map.m_lblk = cur_lblock;
-		map.m_len = last_lblock - cur_lblock;
-		map.m_next_pgofs = NULL;
-		map.m_next_extent = NULL;
-		map.m_seg_type = NO_CHECK_TYPE;
-		map.m_may_create = false;
-
-		ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP);
-		if (ret)
-			goto out;
-
-		/* hole */
-		if (!(map.m_flags & F2FS_MAP_FLAGS)) {
-			f2fs_err(sbi, "Swapfile has holes");
-			ret = -ENOENT;
-			goto out;
-		}
-
-		pblock = map.m_pblk;
-		nr_pblocks = map.m_len;
-
-		if ((pblock - main_blkaddr) & (blocks_per_sec - 1) ||
-			nr_pblocks & (blocks_per_sec - 1)) {
-			if (f2fs_is_pinned_file(inode)) {
-				f2fs_err(sbi, "Swapfile does not align to section");
-				ret = -EINVAL;
-				goto out;
-			}
-			not_aligned++;
-		}
-
-		cur_lblock += nr_pblocks;
-	}
-	if (not_aligned)
-		f2fs_warn(sbi, "Swapfile (%u) is not align to section: 1) creat(), 2) ioctl(F2FS_IOC_SET_PIN_FILE), 3) fallocate()",
-			  not_aligned);
-out:
-	return ret;
-}
-
-static int check_swap_activate_fast(struct swap_info_struct *sis,
+static int check_swap_activate(struct swap_info_struct *sis,
 				struct file *swap_file, sector_t *span)
 {
 	struct address_space *mapping = swap_file->f_mapping;
@@ -3984,113 +3925,6 @@ static int check_swap_activate_fast(struct swap_info_struct *sis,
 	return ret;
 }
 
-/* Copied from generic_swapfile_activate() to check any holes */
-static int check_swap_activate(struct swap_info_struct *sis,
-				struct file *swap_file, sector_t *span)
-{
-	struct address_space *mapping = swap_file->f_mapping;
-	struct inode *inode = mapping->host;
-	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-	unsigned blocks_per_page;
-	unsigned long page_no;
-	sector_t probe_block;
-	sector_t last_block;
-	sector_t lowest_block = -1;
-	sector_t highest_block = 0;
-	int nr_extents = 0;
-	int ret = 0;
-
-	if (PAGE_SIZE == F2FS_BLKSIZE)
-		return check_swap_activate_fast(sis, swap_file, span);
-
-	ret = f2fs_is_file_aligned(inode);
-	if (ret)
-		goto out;
-
-	blocks_per_page = bytes_to_blks(inode, PAGE_SIZE);
-
-	/*
-	 * Map all the blocks into the extent list.  This code doesn't try
-	 * to be very smart.
-	 */
-	probe_block = 0;
-	page_no = 0;
-	last_block = bytes_to_blks(inode, i_size_read(inode));
-	while ((probe_block + blocks_per_page) <= last_block &&
-			page_no < sis->max) {
-		unsigned block_in_page;
-		sector_t first_block;
-		sector_t block = 0;
-
-		cond_resched();
-
-		block = probe_block;
-		ret = bmap(inode, &block);
-		if (ret)
-			goto out;
-		if (!block)
-			goto bad_bmap;
-		first_block = block;
-
-		/*
-		 * It must be PAGE_SIZE aligned on-disk
-		 */
-		if (first_block & (blocks_per_page - 1)) {
-			probe_block++;
-			goto reprobe;
-		}
-
-		for (block_in_page = 1; block_in_page < blocks_per_page;
-					block_in_page++) {
-
-			block = probe_block + block_in_page;
-			ret = bmap(inode, &block);
-			if (ret)
-				goto out;
-			if (!block)
-				goto bad_bmap;
-
-			if (block != first_block + block_in_page) {
-				/* Discontiguity */
-				probe_block++;
-				goto reprobe;
-			}
-		}
-
-		first_block >>= (PAGE_SHIFT - inode->i_blkbits);
-		if (page_no) {	/* exclude the header page */
-			if (first_block < lowest_block)
-				lowest_block = first_block;
-			if (first_block > highest_block)
-				highest_block = first_block;
-		}
-
-		/*
-		 * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
-		 */
-		ret = add_swap_extent(sis, page_no, 1, first_block);
-		if (ret < 0)
-			goto out;
-		nr_extents += ret;
-		page_no++;
-		probe_block += blocks_per_page;
-reprobe:
-		continue;
-	}
-	ret = nr_extents;
-	*span = 1 + highest_block - lowest_block;
-	if (page_no == 0)
-		page_no = 1;	/* force Empty message */
-	sis->max = page_no;
-	sis->pages = page_no - 1;
-	sis->highest_bit = page_no - 1;
-out:
-	return ret;
-bad_bmap:
-	f2fs_err(sbi, "Swapfile has holes");
-	return -EINVAL;
-}
-
 static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
 				sector_t *span)
 {