[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: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Miklos Szeredi 2006-01-16 22:14:46 -08:00 committed by Linus Torvalds
parent 361b1eb55e
commit c1aa96a52e

View file

@ -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;
}