From f8dbdf81821b5ab4c5e86e7b2bd7edb892c159c2 Mon Sep 17 00:00:00 2001 From: Maxim Patlasov Date: Fri, 26 Oct 2012 19:48:51 +0400 Subject: [PATCH] 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 Signed-off-by: Miklos Szeredi --- fs/fuse/file.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 882877125c1d..5fd06bae1790 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -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; -- 2.20.1