Messages in this thread Patch in this message | | | Subject | [PATCH 5/6] fuse: rework fuse_perform_write() | From | Maxim Patlasov <> | Date | Fri, 07 Sep 2012 21:41:49 +0400 |
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The patch allocates as many page pointers in fuse_req as needed to cover interval [pos .. pos+len-1]. FUSE_WR_PAGES macro is introduced to hide this cumbersome arithmetics. --- fs/fuse/file.c | 15 +++++++++++---- 1 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 9a6dcc6..84cc83c 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -815,7 +815,8 @@ static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, static ssize_t fuse_fill_write_pages(struct fuse_req *req, struct address_space *mapping, - struct iov_iter *ii, loff_t pos) + struct iov_iter *ii, loff_t pos, + unsigned nr_pages) { struct fuse_conn *fc = get_fuse_conn(mapping->host); unsigned offset = pos & (PAGE_CACHE_SIZE - 1); @@ -875,11 +876,16 @@ 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 < nr_pages && offset == 0); return count > 0 ? count : err; } +#define FUSE_WR_PAGES(pos, len) 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) @@ -895,14 +901,15 @@ 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_multipage(fc, FUSE_MAX_PAGES_PER_REQ); + req = fuse_get_req_multipage(fc, nr_pages); if (IS_ERR(req)) { err = PTR_ERR(req); break; } - count = fuse_fill_write_pages(req, mapping, ii, pos); + count = fuse_fill_write_pages(req, mapping, ii, pos, nr_pages); if (count <= 0) { err = count; } else {
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