[PATCH] FUSE - readpages operation
This patch adds readpages support to FUSE.
With the help of the readpages() operation multiple reads are bundled
together and sent as a single request to userspace. This can improve
reading performace.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 96ea302..86ffb6d 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -227,6 +227,72 @@
return err;
}
+static int fuse_send_readpages(struct fuse_req *req, struct file *file,
+ struct inode *inode)
+{
+ loff_t pos = (loff_t) req->pages[0]->index << PAGE_CACHE_SHIFT;
+ size_t count = req->num_pages << PAGE_CACHE_SHIFT;
+ unsigned i;
+ req->out.page_zeroing = 1;
+ fuse_send_read(req, file, inode, pos, count);
+ for (i = 0; i < req->num_pages; i++) {
+ struct page *page = req->pages[i];
+ if (!req->out.h.error)
+ SetPageUptodate(page);
+ unlock_page(page);
+ }
+ return req->out.h.error;
+}
+
+struct fuse_readpages_data {
+ struct fuse_req *req;
+ struct file *file;
+ struct inode *inode;
+};
+
+static int fuse_readpages_fill(void *_data, struct page *page)
+{
+ struct fuse_readpages_data *data = _data;
+ struct fuse_req *req = data->req;
+ struct inode *inode = data->inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ if (req->num_pages &&
+ (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) {
+ unlock_page(page);
+ return err;
+ }
+ fuse_reset_request(req);
+ }
+ req->pages[req->num_pages] = page;
+ req->num_pages ++;
+ return 0;
+}
+
+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_readpages_data data;
+ int err;
+ data.file = file;
+ data.inode = inode;
+ data.req = fuse_get_request_nonint(fc);
+ if (!data.req)
+ 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);
+ return err;
+}
+
static ssize_t fuse_send_write(struct fuse_req *req, struct file *file,
struct inode *inode, loff_t pos, size_t count)
{
@@ -331,6 +397,7 @@
.readpage = fuse_readpage,
.prepare_write = fuse_prepare_write,
.commit_write = fuse_commit_write,
+ .readpages = fuse_readpages,
.set_page_dirty = fuse_set_page_dirty,
};