Commit 76a0294e authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
Browse files

fuse: convert from readpages to readahead 

Implement the new readahead operation in fuse by using __readahead_batch()
to fill the array of pages in fuse_args_pages directly.  This lets us
inline fuse_readpages_fill() into fuse_readahead().

[willy@infradead.org: build fix]
  Link: http://lkml.kernel.org/r/20200415025938.GB5820@bombadil.infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarWilliam Kucharski <william.kucharski@oracle.com>
Acked-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-25-willy@infradead.org


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e20a7693

fs/fuse/file.c

+28 −72
Original line number Diff line number Diff line
@@ -915,84 +915,40 @@ static void fuse_send_readpages(struct fuse_io_args *ia, struct file *file) 
	fuse_readpages_end(fc, &ap->args, err);

}



struct fuse_fill_data {

	struct fuse_io_args *ia;

	struct file *file;

	struct inode *inode;

	unsigned int nr_pages;

	unsigned int max_pages;

};



static int fuse_readpages_fill(void *_data, struct page *page)

static void fuse_readahead(struct readahead_control *rac)

{

	struct fuse_fill_data *data = _data;

	struct fuse_io_args *ia = data->ia;

	struct fuse_args_pages *ap = &ia->ap;

	struct inode *inode = data->inode;

	struct inode *inode = rac->mapping->host;

	struct fuse_conn *fc = get_fuse_conn(inode);

	unsigned int i, max_pages, nr_pages = 0;



	fuse_wait_on_page_writeback(inode, page->index);

	if (is_bad_inode(inode))

		return;



	if (ap->num_pages &&

	    (ap->num_pages == fc->max_pages ||

	     (ap->num_pages + 1) * PAGE_SIZE > fc->max_read ||

	     ap->pages[ap->num_pages - 1]->index + 1 != page->index)) {

		data->max_pages = min_t(unsigned int, data->nr_pages,

					fc->max_pages);

		fuse_send_readpages(ia, data->file);

		data->ia = ia = fuse_io_alloc(NULL, data->max_pages);

		if (!ia) {

			unlock_page(page);

			return -ENOMEM;

		}

		ap = &ia->ap;

	}

	max_pages = min_t(unsigned int, fc->max_pages,

			fc->max_read / PAGE_SIZE);



	if (WARN_ON(ap->num_pages >= data->max_pages)) {

		unlock_page(page);

		fuse_io_free(ia);

		return -EIO;

	}

	for (;;) {

		struct fuse_io_args *ia;

		struct fuse_args_pages *ap;



	get_page(page);

	ap->pages[ap->num_pages] = page;

	ap->descs[ap->num_pages].length = PAGE_SIZE;

	ap->num_pages++;

	data->nr_pages--;

	return 0;

		nr_pages = readahead_count(rac) - nr_pages;

		if (nr_pages > max_pages)

			nr_pages = max_pages;

		if (nr_pages == 0)

			break;

		ia = fuse_io_alloc(NULL, nr_pages);

		if (!ia)

			return;

		ap = &ia->ap;

		nr_pages = __readahead_batch(rac, ap->pages, nr_pages);

		for (i = 0; i < nr_pages; i++) {

			fuse_wait_on_page_writeback(inode,

						    readahead_index(rac) + i);

			ap->descs[i].length = PAGE_SIZE;

		}



static int fuse_readpages(struct file *file, struct address_space *mapping,

			  struct list_head *pages, unsigned nr_pages)

{

	struct inode *inode = mapping->host;

	struct fuse_conn *fc = get_fuse_conn(inode);

	struct fuse_fill_data data;

	int err;



	err = -EIO;

	if (is_bad_inode(inode))

		goto out;



	data.file = file;

	data.inode = inode;

	data.nr_pages = nr_pages;

	data.max_pages = min_t(unsigned int, nr_pages, fc->max_pages);

;

	data.ia = fuse_io_alloc(NULL, data.max_pages);

	err = -ENOMEM;

	if (!data.ia)

		goto out;



	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);

	if (!err) {

		if (data.ia->ap.num_pages)

			fuse_send_readpages(data.ia, file);

		else

			fuse_io_free(data.ia);

		ap->num_pages = nr_pages;

		fuse_send_readpages(ia, rac->file);

	}

out:

	return err;

}



static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to)
@@ -3373,10 +3329,10 @@ static const struct file_operations fuse_file_operations = { 


static const struct address_space_operations fuse_file_aops  = {

	.readpage	= fuse_readpage,

	.readahead	= fuse_readahead,

	.writepage	= fuse_writepage,

	.writepages	= fuse_writepages,

	.launder_page	= fuse_launder_page,

	.readpages	= fuse_readpages,

	.set_page_dirty	= __set_page_dirty_nobuffers,

	.bmap		= fuse_bmap,

	.direct_IO	= fuse_direct_IO,

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