From d07f09f509fb21482096e1975f160b694c0edf84 Mon Sep 17 00:00:00 2001 From: Maxim Patlasov Date: Fri, 26 Oct 2012 19:49:00 +0400 Subject: [PATCH] fuse: rework fuse_perform_write() The patch allocates as many page pointers in fuse_req as needed to cover interval [pos .. pos+len-1]. Inline helper fuse_wr_pages() is introduced to hide this cumbersome arithmetic. Signed-off-by: Maxim Patlasov Signed-off-by: Miklos Szeredi --- fs/fuse/file.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 5fd06bae1790..b9972502f43a 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -881,11 +881,19 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req, if (!fc->big_writes) break; } while (iov_iter_count(ii) && count < fc->max_write && - req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0); + req->num_pages < req->max_pages && offset == 0); return count > 0 ? count : err; } +static inline unsigned fuse_wr_pages(loff_t pos, size_t len) +{ + return min_t(unsigned, + ((pos + len - 1) >> PAGE_CACHE_SHIFT) - + (pos >> PAGE_CACHE_SHIFT) + 1, + FUSE_MAX_PAGES_PER_REQ); +} + static ssize_t fuse_perform_write(struct file *file, struct address_space *mapping, struct iov_iter *ii, loff_t pos) @@ -901,8 +909,9 @@ static ssize_t fuse_perform_write(struct file *file, do { struct fuse_req *req; ssize_t count; + unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii)); - req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ); + req = fuse_get_req(fc, nr_pages); if (IS_ERR(req)) { err = PTR_ERR(req); break; -- 2.45.2