Re: [PATCH 2/2] squashfs: implement readahead

[Phillip Lougher <phillip@squashfs.org.uk>]

On 16/05/2022 17:01, kernel test robot wrote:
> Hi Hsin-Yi,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on next-20220513]
> [cannot apply to akpm-mm/mm-everything v5.18-rc7 v5.18-rc6 v5.18-rc5 v5.18-rc7]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch]

This is fixed by

[PATCH 3/2] squashfs: always build "file direct" version of page actor

Which I have just sent.

Phillip

> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Hsin-Yi-Wang/Implement-readahead-for-squashfs/20220516-185438
> base:    1e1b28b936aed946122b4e0991e7144fdbbfd77e
> config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20220516/202205162301.zVca8ZpM-lkp@intel.com/config)
> compiler: m68k-linux-gcc (GCC) 11.3.0
> reproduce (this is a W=1 build):
>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>          chmod +x ~/bin/make.cross
>          # https://github.com/intel-lab-lkp/linux/commit/573e1f2ced0df097c30c595d5bf5a9e7a5fcb8d5
>          git remote add linux-review https://github.com/intel-lab-lkp/linux
>          git fetch --no-tags linux-review Hsin-Yi-Wang/Implement-readahead-for-squashfs/20220516-185438
>          git checkout 573e1f2ced0df097c30c595d5bf5a9e7a5fcb8d5
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>     fs/squashfs/file.c: In function 'squashfs_readahead':
>>> fs/squashfs/file.c:526:17: error: implicit declaration of function 'squashfs_page_actor_init_special'; did you mean 'squashfs_page_actor_init'? [-Werror=implicit-function-declaration]
>       526 |         actor = squashfs_page_actor_init_special(pages, max_pages, 0);
>           |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>           |                 squashfs_page_actor_init
>     fs/squashfs/file.c:526:15: warning: assignment to 'struct squashfs_page_actor *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
>       526 |         actor = squashfs_page_actor_init_special(pages, max_pages, 0);
>           |               ^
>     fs/squashfs/file.c: At top level:
>>> fs/squashfs/file.c:577:9: error: request for member 'readahead' in something not a structure or union
>       577 |         .readahead = squashfs_readahead
>           |         ^
>     cc1: some warnings being treated as errors
> 
> 
> vim +526 fs/squashfs/file.c
> 
>     498	
>     499	static void squashfs_readahead(struct readahead_control *ractl)
>     500	{
>     501		struct inode *inode = ractl->mapping->host;
>     502		struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
>     503		size_t mask = (1UL << msblk->block_log) - 1;
>     504		size_t shift = msblk->block_log - PAGE_SHIFT;
>     505		loff_t req_end = readahead_pos(ractl) + readahead_length(ractl);
>     506		loff_t start = readahead_pos(ractl) &~ mask;
>     507		size_t len = readahead_length(ractl) + readahead_pos(ractl) - start;
>     508		struct squashfs_page_actor *actor;
>     509		unsigned int nr_pages = 0;
>     510		struct page **pages;
>     511		u64 block = 0;
>     512		int bsize, res, i, index;
>     513		int file_end = i_size_read(inode) >> msblk->block_log;
>     514		unsigned int max_pages = 1UL << shift;
>     515	
>     516		readahead_expand(ractl, start, (len | mask) + 1);
>     517	
>     518		if (readahead_pos(ractl) + readahead_length(ractl) < req_end ||
>     519		    file_end == 0)
>     520			return;
>     521	
>     522		pages = kmalloc_array(max_pages, sizeof(void *), GFP_KERNEL);
>     523		if (!pages)
>     524			return;
>     525	
>   > 526		actor = squashfs_page_actor_init_special(pages, max_pages, 0);
>     527		if (!actor)
>     528			goto out;
>     529	
>     530		for (;;) {
>     531			nr_pages = __readahead_batch(ractl, pages, max_pages);
>     532			if (!nr_pages)
>     533				break;
>     534	
>     535			if (readahead_pos(ractl) >= i_size_read(inode) ||
>     536			    nr_pages < max_pages)
>     537				goto skip_pages;
>     538	
>     539			index = pages[0]->index >> shift;
>     540			if ((pages[nr_pages - 1]->index >> shift) != index)
>     541				goto skip_pages;
>     542	
>     543			bsize = read_blocklist(inode, index, &block);
>     544			if (bsize == 0)
>     545				goto skip_pages;
>     546	
>     547			res = squashfs_read_data(inode->i_sb, block, bsize, NULL,
>     548						 actor);
>     549	
>     550			if (res >= 0)
>     551				for (i = 0; i < nr_pages; i++)
>     552					SetPageUptodate(pages[i]);
>     553	
>     554			for (i = 0; i < nr_pages; i++) {
>     555				unlock_page(pages[i]);
>     556				put_page(pages[i]);
>     557			}
>     558		}
>     559	
>     560		kfree(actor);
>     561		kfree(pages);
>     562		return;
>     563	
>     564	skip_pages:
>     565		for (i = 0; i < nr_pages; i++) {
>     566			unlock_page(pages[i]);
>     567			put_page(pages[i]);
>     568		}
>     569	
>     570		kfree(actor);
>     571	out:
>     572		kfree(pages);
>     573	}
>     574	
>     575	const struct address_space_operations squashfs_aops = {
>     576		.read_folio = squashfs_read_folio
>   > 577		.readahead = squashfs_readahead
>