fuse: rework fuse_readpages()

The patch uses 'nr_pages' argument of fuse_readpages() as heuristics for the
number of page pointers to allocate.

This can be improved further by taking in consideration fc->max_read and gaps
between page indices, but it's not clear whether it's worthy or not.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
This commit is contained in:
Maxim Patlasov 2012-10-26 19:48:51 +04:00 committed by Miklos Szeredi
parent 4d53dc99ba
commit f8dbdf8182

View File

@ -641,6 +641,7 @@ struct fuse_fill_data {
struct fuse_req *req;
struct file *file;
struct inode *inode;
unsigned nr_pages;
};
static int fuse_readpages_fill(void *_data, struct page *page)
@ -656,16 +657,25 @@ 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 nr_alloc = min_t(unsigned, data->nr_pages,
FUSE_MAX_PAGES_PER_REQ);
fuse_send_readpages(req, data->file);
data->req = req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ);
data->req = req = fuse_get_req(fc, nr_alloc);
if (IS_ERR(req)) {
unlock_page(page);
return PTR_ERR(req);
}
}
if (WARN_ON(req->num_pages >= req->max_pages)) {
fuse_put_request(fc, req);
return -EIO;
}
page_cache_get(page);
req->pages[req->num_pages] = page;
req->num_pages++;
data->nr_pages--;
return 0;
}
@ -676,6 +686,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_fill_data data;
int err;
int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ);
err = -EIO;
if (is_bad_inode(inode))
@ -683,7 +694,8 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
data.file = file;
data.inode = inode;
data.req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ);
data.req = fuse_get_req(fc, nr_alloc);
data.nr_pages = nr_pages;
err = PTR_ERR(data.req);
if (IS_ERR(data.req))
goto out;