ocfs2: use __generic_file_write_iter()

we can do that now - all we need is to clear IOCB_DIRECT from ->ki_flags in
"can't do dio" case.

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

1 files changed, 7 insertions, 57 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index cd37f6cd4d51..913fc250d85a 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2259,11 +2259,11 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
         u32 old_clusters;
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file);
-        struct address_space *mapping = file->f_mapping;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
         int full_coherency = !(osb->s_mount_opt &
                                OCFS2_MOUNT_COHERENCY_BUFFERED);
         int unaligned_dio = 0;
+        int dropped_dio = 0;
 
         trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
@@ -2351,7 +2351,9 @@ relock:
                 rw_level = -1;
 
                 direct_io = 0;
+                iocb->ki_flags &= ~IOCB_DIRECT;
                 iov_iter_reexpand(from, orig_count);
+                dropped_dio = 1;
                 goto relock;
         }
 
@@ -2375,67 +2377,15 @@ relock:
         /* communicate with ocfs2_dio_end_io */
         ocfs2_iocb_set_rw_locked(iocb, rw_level);
 
-        if (direct_io) {
-                loff_t endbyte;
-                ssize_t written_buffered;
-                written = generic_file_direct_write(iocb, from, iocb->ki_pos);
-                if (written < 0 || !iov_iter_count(from)) {
-                        ret = written;
-                        goto out_dio;
-                }
-
-                /*
-                 * for completing the rest of the request.
-                 */
-                written_buffered = generic_perform_write(file, from, iocb->ki_pos);
-                /*
-                 * If generic_file_buffered_write() returned a synchronous error
-                 * then we want to return the number of bytes which were
-                 * direct-written, or the error code if that was zero. Note
-                 * that this differs from normal direct-io semantics, which
-                 * will return -EFOO even if some bytes were written.
-                 */
-                if (written_buffered < 0) {
-                        ret = written_buffered;
-                        goto out_dio;
-                }
-
-                /* We need to ensure that the page cache pages are written to
-                 * disk and invalidated to preserve the expected O_DIRECT
-                 * semantics.
-                 */
-                endbyte = iocb->ki_pos + written_buffered - 1;
-                ret = filemap_write_and_wait_range(file->f_mapping, iocb->ki_pos,
-                                endbyte);
-                if (ret == 0) {
-                        iocb->ki_pos += written_buffered;
-                        written += written_buffered;
-                        invalidate_mapping_pages(mapping,
-                                        iocb->ki_pos >> PAGE_CACHE_SHIFT,
-                                        endbyte >> PAGE_CACHE_SHIFT);
-                } else {
-                        /*
-                         * We don't know how much we wrote, so just return
-                         * the number of bytes which were direct-written
-                         */
-                }
-        } else {
-                current->backing_dev_info = inode_to_bdi(inode);
-                written = generic_perform_write(file, from, iocb->ki_pos);
-                if (likely(written >= 0))
-                        iocb->ki_pos = iocb->ki_pos + written;
-                current->backing_dev_info = NULL;
-        }
-
-out_dio:
+        written = __generic_file_write_iter(iocb, from);
         /* buffered aio wouldn't have proper lock coverage today */
-        BUG_ON(ret == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT));
+        BUG_ON(written == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT));
 
         if (unlikely(written <= 0))
                 goto no_sync;
 
-        if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) ||
-            ((file->f_flags & O_DIRECT) && !direct_io)) {
+        if (((file->f_flags & O_DSYNC) && !direct_io) ||
+            IS_SYNC(inode) || dropped_dio) {
                 ret = filemap_fdatawrite_range(file->f_mapping,
                                                iocb->ki_pos - written,
                                                iocb->ki_pos - 1);