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Commit c1aa96a5 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[PATCH] fuse: use asynchronous READ requests for readpages 



This patch changes fuse_readpages() to send READ requests asynchronously.

This makes it possible for userspace filesystems to utilize the kernel
readahead logic instead of having to implement their own (resulting in double
caching).

Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 361b1eb5

fs/fuse/file.c

+27 −17
Original line number Diff line number Diff line
@@ -265,7 +265,7 @@ void fuse_read_fill(struct fuse_req *req, struct file *file, 
	req->file = file;

	req->in.numargs = 1;

	req->in.args[0].size = sizeof(struct fuse_read_in);

	req->in.args[0].value = &inarg;

	req->in.args[0].value = inarg;

	req->out.argpages = 1;

	req->out.argvar = 1;

	req->out.numargs = 1;
@@ -311,21 +311,33 @@ static int fuse_readpage(struct file *file, struct page *page) 
	return err;

}



static int fuse_send_readpages(struct fuse_req *req, struct file *file,

			       struct inode *inode)

static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)

{

	loff_t pos = page_offset(req->pages[0]);

	size_t count = req->num_pages << PAGE_CACHE_SHIFT;

	unsigned i;

	req->out.page_zeroing = 1;

	fuse_send_read(req, file, inode, pos, count);

	int i;



	fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */



	for (i = 0; i < req->num_pages; i++) {

		struct page *page = req->pages[i];

		if (!req->out.h.error)

			SetPageUptodate(page);

		else

			SetPageError(page);

		unlock_page(page);

	}

	return req->out.h.error;

	fuse_put_request(fc, req);

}



static void fuse_send_readpages(struct fuse_req *req, struct file *file,

				struct inode *inode)

{

	struct fuse_conn *fc = get_fuse_conn(inode);

	loff_t pos = page_offset(req->pages[0]);

	size_t count = req->num_pages << PAGE_CACHE_SHIFT;

	req->out.page_zeroing = 1;

	req->end = fuse_readpages_end;

	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);

	request_send_background(fc, req);

}



struct fuse_readpages_data {
@@ -345,12 +357,12 @@ static int fuse_readpages_fill(void *_data, struct page *page) 
	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||

	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||

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

		int err = fuse_send_readpages(req, data->file, inode);

		if (err) {

		fuse_send_readpages(req, data->file, inode);

		data->req = req = fuse_get_request(fc);

		if (!req) {

			unlock_page(page);

			return err;

			return -EINTR;

		}

		fuse_reset_request(req);

	}

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

	req->num_pages ++;
@@ -375,10 +387,8 @@ static int fuse_readpages(struct file *file, struct address_space *mapping, 
		return -EINTR;



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

	if (!err && data.req->num_pages)

		err = fuse_send_readpages(data.req, file, inode);

	fuse_put_request(fc, data.req);

	fuse_invalidate_attr(inode); /* atime changed */

	if (!err)

		fuse_send_readpages(data.req, file, inode);

	return err;

}