ceph_sync_read: stop poking into iov_iter guts

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

fs/ceph/file.c

@@ -418,7 +418,7 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
 	struct page **pages;
 	u64 off = iocb->ki_pos;
 	int num_pages, ret;
-	size_t len = i->count;
+	size_t len = iov_iter_count(i);
 
 	dout("sync_read on file %p %llu~%u %s\n", file, off,
 	     (unsigned)len,
@@ -436,25 +436,26 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
 
 	if (file->f_flags & O_DIRECT) {
 		while (iov_iter_count(i)) {
-			void __user *data = i->iov[0].iov_base + i->iov_offset;
-			size_t len = i->iov[0].iov_len - i->iov_offset;
+			size_t start;
+			ssize_t n;
 
-			num_pages = calc_pages_for((unsigned long)data, len);
-			pages = ceph_get_direct_page_vector(data,
-							    num_pages, true);
-			if (IS_ERR(pages))
-				return PTR_ERR(pages);
+			n = iov_iter_get_pages_alloc(i, &pages, INT_MAX, &start);
+			if (n < 0)
+				return n;
+
+			num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;
 
-			ret = striped_read(inode, off, len,
+			ret = striped_read(inode, off, n,
 					   pages, num_pages, checkeof,
-					   1, (unsigned long)data & ~PAGE_MASK);
+					   1, start);
+
 			ceph_put_page_vector(pages, num_pages, true);
 
 			if (ret <= 0)
 				break;
 			off += ret;
 			iov_iter_advance(i, ret);
-			if (ret < len)
+			if (ret < n)
 				break;
 		}
 	} else {
@@ -466,25 +467,14 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
 					num_pages, checkeof, 0, 0);
 		if (ret > 0) {
 			int l, k = 0;
-			size_t left = len = ret;
+			size_t left = ret;
 
 			while (left) {
-				void __user *data = i->iov[0].iov_base
-							+ i->iov_offset;
-				l = min(i->iov[0].iov_len - i->iov_offset,
-					left);
-
-				ret = ceph_copy_page_vector_to_user(&pages[k],
-								    data, off,
-								    l);
-				if (ret > 0) {
-					iov_iter_advance(i, ret);
-					left -= ret;
-					off += ret;
-					k = calc_pages_for(iocb->ki_pos,
-							   len - left + 1) - 1;
-					BUG_ON(k >= num_pages && left);
-				} else
+				int copy = min_t(size_t, PAGE_SIZE, left);
+				l = copy_page_to_iter(pages[k++], 0, copy, i);
+				off += l;
+				left -= l;
+				if (l < copy)
 					break;
 			}
 		}

include/linux/ceph/libceph.h

@@ -222,8 +222,6 @@ extern void ceph_copy_to_page_vector(struct page **pages,
 extern void ceph_copy_from_page_vector(struct page **pages,
 				    void *data,
 				    loff_t off, size_t len);
-extern int ceph_copy_page_vector_to_user(struct page **pages, void __user *data,
-				    loff_t off, size_t len);
 extern void ceph_zero_page_vector_range(int off, int len, struct page **pages);
 
 

net/ceph/pagevec.c

@@ -53,6 +53,9 @@ void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
 			set_page_dirty_lock(pages[i]);
 		put_page(pages[i]);
 	}
+	if (is_vmalloc_addr(pages))
+		vfree(pages);
+	else
 		kfree(pages);
 }
 EXPORT_SYMBOL(ceph_put_page_vector);
@@ -164,36 +167,6 @@ void ceph_copy_from_page_vector(struct page **pages,
 }
 EXPORT_SYMBOL(ceph_copy_from_page_vector);
 
-/*
- * copy user data from a page vector into a user pointer
- */
-int ceph_copy_page_vector_to_user(struct page **pages,
-					 void __user *data,
-					 loff_t off, size_t len)
-{
-	int i = 0;
-	int po = off & ~PAGE_CACHE_MASK;
-	int left = len;
-	int l, bad;
-
-	while (left > 0) {
-		l = min_t(int, left, PAGE_CACHE_SIZE-po);
-		bad = copy_to_user(data, page_address(pages[i]) + po, l);
-		if (bad == l)
-			return -EFAULT;
-		data += l - bad;
-		left -= l - bad;
-		if (po) {
-			po += l - bad;
-			if (po == PAGE_CACHE_SIZE)
-				po = 0;
-		}
-		i++;
-	}
-	return len;
-}
-EXPORT_SYMBOL(ceph_copy_page_vector_to_user);
-
 /*
  * Zero an extent within a page vector.  Offset is relative to the
  * start of the first page.