6 files changed, 19 insertions, 23 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ae6af072b635..9fe20c2052af 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1669,15 +1669,13 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb,
         loff_t endbyte;
         int err;
 
-        written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
-                                            count, ocount);
+        iov_iter_init(&i, iov, nr_segs, count, 0);
+        written = generic_file_direct_write(iocb, &i, pos, count, ocount);
 
         if (written < 0 || written == count)
                 return written;
 
         pos += written;
-        count -= written;
-        iov_iter_init(&i, iov, nr_segs, count, written);
         written_buffered = __btrfs_buffered_write(file, &i, pos);
         if (written_buffered < 0) {
                 err = written_buffered;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 96d513e01a5d..126deb5d0a9c 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1235,15 +1235,13 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
                 goto out;
 
         if (file->f_flags & O_DIRECT) {
-                written = generic_file_direct_write(iocb, iov, &nr_segs, pos, 
-                                                    count, ocount);
+                iov_iter_init(&i, iov, nr_segs, count, 0);
+                written = generic_file_direct_write(iocb, &i, pos, count, ocount);
                 if (written < 0 || written == count)
                         goto out;
 
                 pos += written;
-                count -= written;
 
-                iov_iter_init(&i, iov, nr_segs, count, written);
                 written_buffered = fuse_perform_write(file, mapping, &i, pos);
                 if (written_buffered < 0) {
                         err = written_buffered;
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 8970dcf74de5..d6d78c2aa96e 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2251,6 +2251,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
         int full_coherency = !(osb->s_mount_opt &
                                OCFS2_MOUNT_COHERENCY_BUFFERED);
         int unaligned_dio = 0;
+        struct iov_iter from;
 
         trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
                 (unsigned long long)OCFS2_I(inode)->ip_blkno,
@@ -2365,16 +2366,15 @@ relock:
         if (ret)
                 goto out_dio;
 
+        iov_iter_init(&from, iov, nr_segs, count, 0);
         if (direct_io) {
-                written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
+                written = generic_file_direct_write(iocb, &from, *ppos,
                                                     count, ocount);
                 if (written < 0) {
                         ret = written;
                         goto out_dio;
                 }
         } else {
-                struct iov_iter from;
-                iov_iter_init(&from, iov, nr_segs, count, 0);
                 current->backing_dev_info = file->f_mapping->backing_dev_info;
                 written = generic_perform_write(file, &from, *ppos);
                 if (likely(written >= 0))
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 951a2321ee01..8617497867c7 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -641,6 +641,7 @@ xfs_file_dio_aio_write(
         int                     iolock;
         struct xfs_buftarg      *target = XFS_IS_REALTIME_INODE(ip) ?
                                         mp->m_rtdev_targp : mp->m_ddev_targp;
+        struct iov_iter         from;
 
         /* DIO must be aligned to device logical sector size */
         if ((pos | count) & target->bt_logical_sectormask)
@@ -698,8 +699,8 @@ xfs_file_dio_aio_write(
         }
 
         trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
-        ret = generic_file_direct_write(iocb, iovp,
-                        &nr_segs, pos, count, ocount);
+        iov_iter_init(&from, iovp, nr_segs, count, 0);
+        ret = generic_file_direct_write(iocb, &from, pos, count, ocount);
 
 out:
         xfs_rw_iunlock(ip, iolock);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 878031227c57..262f96e579b8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2407,8 +2407,8 @@ int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isbl
 extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long);
 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
-extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
-                unsigned long *, loff_t, size_t, size_t);
+extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *,
+                loff_t, size_t, size_t);
 extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
diff --git a/mm/filemap.c b/mm/filemap.c
index 000a220e2a41..a840890ed39f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2385,9 +2385,8 @@ int pagecache_write_end(struct file *file, struct address_space *mapping,
 EXPORT_SYMBOL(pagecache_write_end);
 
 ssize_t
-generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
-                unsigned long *nr_segs, loff_t pos,
-                size_t count, size_t ocount)
+generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
+                loff_t pos, size_t count, size_t ocount)
 {
         struct file     *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
@@ -2397,9 +2396,9 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
         pgoff_t         end;
 
         if (count != ocount)
-                *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
+                from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count);
 
-        write_len = iov_length(iov, *nr_segs);
+        write_len = iov_length(from->iov, from->nr_segs);
         end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
 
         written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
@@ -2426,7 +2425,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
                 }
         }
 
-        written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
+        written = mapping->a_ops->direct_IO(WRITE, iocb, from->iov, pos, from->nr_segs);
 
         /*
          * Finally, try again to invalidate clean pages which might have been
@@ -2443,6 +2442,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
 
         if (written > 0) {
                 pos += written;
+                iov_iter_advance(from, written);
                 if (pos > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
                         i_size_write(inode, pos);
                         mark_inode_dirty(inode);
@@ -2645,11 +2645,10 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
         if (unlikely(file->f_flags & O_DIRECT)) {
                 loff_t endbyte;
 
-                written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos,
+                written = generic_file_direct_write(iocb, &from, pos,
                                                         count, ocount);
                 if (written < 0 || written == count)
                         goto out;
-                iov_iter_advance(&from, written);
 
                 /*
                  * direct-io write to a hole: fall through to buffered I/O