iov_iter_truncate()

Now It Can Be Done(tm) - we don't need to do iov_shorten() in
generic_file_direct_write() anymore, now that all ->direct_IO()
instances are converted to proper iov_iter methods and honour
iter->count and iter->iov_offset properly.

Get rid of count/ocount arguments of generic_file_direct_write(),
while we are at it.

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

1 files changed, 5 insertions, 4 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 762bb3e148a6..c997aa2751b2 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -626,7 +626,7 @@ xfs_file_dio_aio_write(
         const struct iovec      *iovp,
         unsigned long           nr_segs,
         loff_t                  pos,
-        size_t                  ocount)
+        size_t                  count)
 {
         struct file             *file = iocb->ki_filp;
         struct address_space    *mapping = file->f_mapping;
@@ -634,7 +634,6 @@ xfs_file_dio_aio_write(
         struct xfs_inode        *ip = XFS_I(inode);
         struct xfs_mount        *mp = ip->i_mount;
         ssize_t                 ret = 0;
-        size_t                  count = ocount;
         int                     unaligned_io = 0;
         int                     iolock;
         struct xfs_buftarg      *target = XFS_IS_REALTIME_INODE(ip) ?
@@ -645,6 +644,8 @@ xfs_file_dio_aio_write(
         if ((pos | count) & target->bt_logical_sectormask)
                 return -XFS_ERROR(EINVAL);
 
+        iov_iter_init(&from, WRITE, iovp, nr_segs, count);
+
         /* "unaligned" here means not aligned to a filesystem block */
         if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
                 unaligned_io = 1;
@@ -676,6 +677,7 @@ xfs_file_dio_aio_write(
         ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
         if (ret)
                 goto out;
+        iov_iter_truncate(&from, count);
 
         if (mapping->nrpages) {
                 ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
@@ -697,8 +699,7 @@ xfs_file_dio_aio_write(
         }
 
         trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
-        iov_iter_init(&from, WRITE, iovp, nr_segs, count);
-        ret = generic_file_direct_write(iocb, &from, pos, count, ocount);
+        ret = generic_file_direct_write(iocb, &from, pos);
 
 out:
         xfs_rw_iunlock(ip, iolock);