ceph_sync_direct_write: stop poking into iov_iter guts

all needed primitives are there...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 672b0fe..f689640 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -546,7 +546,6 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
        int written = 0;
        int flags;
        int check_caps = 0;
-       int page_align;
        int ret;
        struct timespec mtime = CURRENT_TIME;
        loff_t pos = iocb->ki_pos;
@@ -575,10 +574,9 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
        iov_iter_init(&i, WRITE, iov, nr_segs, count);
 
        while (iov_iter_count(&i) > 0) {
-               void __user *data = i.iov->iov_base + i.iov_offset;
-               u64 len = i.iov->iov_len - i.iov_offset;
-
-               page_align = (unsigned long)data & ~PAGE_MASK;
+               u64 len = iov_iter_single_seg_count(&i);
+               size_t start;
+               ssize_t n;
 
                snapc = ci->i_snap_realm->cached_context;
                vino = ceph_vino(inode);
@@ -594,20 +592,21 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
                        break;
                }
 
-               num_pages = calc_pages_for(page_align, len);
-               pages = ceph_get_direct_page_vector(data, num_pages, false);
-               if (IS_ERR(pages)) {
-                       ret = PTR_ERR(pages);
-                       goto out;
+               n = iov_iter_get_pages_alloc(&i, &pages, len, &start);
+               if (unlikely(n < 0)) {
+                       ret = n;
+                       ceph_osdc_put_request(req);
+                       break;
                }
 
+               num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;
                /*
                 * throw out any page cache pages in this range. this
                 * may block.
                 */
                truncate_inode_pages_range(inode->i_mapping, pos,
-                                  (pos+len) | (PAGE_CACHE_SIZE-1));
-               osd_req_op_extent_osd_data_pages(req, 0, pages, len, page_align,
+                                  (pos+n) | (PAGE_CACHE_SIZE-1));
+               osd_req_op_extent_osd_data_pages(req, 0, pages, n, start,
                                                false, false);
 
                /* BUG_ON(vino.snap != CEPH_NOSNAP); */
@@ -619,22 +618,20 @@ ceph_sync_direct_write(struct kiocb *iocb, const struct iovec *iov,
 
                ceph_put_page_vector(pages, num_pages, false);
 
-out:
                ceph_osdc_put_request(req);
-               if (ret == 0) {
-                       pos += len;
-                       written += len;
-                       iov_iter_advance(&i, (size_t)len);
-
-                       if (pos > i_size_read(inode)) {
-                               check_caps = ceph_inode_set_size(inode, pos);
-                               if (check_caps)
-                                       ceph_check_caps(ceph_inode(inode),
-                                                       CHECK_CAPS_AUTHONLY,
-                                                       NULL);
-                       }
-               } else
+               if (ret)
                        break;
+               pos += n;
+               written += n;
+               iov_iter_advance(&i, n);
+
+               if (pos > i_size_read(inode)) {
+                       check_caps = ceph_inode_set_size(inode, pos);
+                       if (check_caps)
+                               ceph_check_caps(ceph_inode(inode),
+                                               CHECK_CAPS_AUTHONLY,
+                                               NULL);
+               }
        }
 
        if (ret != -EOLDSNAPC && written > 0) {