iomap: remove unneeded variable in iomap_dio_rw()

The 'start' variable indicates the start of a filemap and is set to the
iocb's position, which we have already cached as 'pos', upon function
entry.

'pos' is used as a cursor indicating the current position and updated
later in iomap_dio_rw(), but not before the last use of 'start'.

Remove 'start' as it's synonym for 'pos' before we're entering the loop
calling iomapp_apply().

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index b75cd0b..2383792 100644 (file)
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -405,7 +405,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
        struct address_space *mapping = iocb->ki_filp->f_mapping;
        struct inode *inode = file_inode(iocb->ki_filp);
        size_t count = iov_iter_count(iter);
-       loff_t pos = iocb->ki_pos, start = pos;
+       loff_t pos = iocb->ki_pos;
        loff_t end = iocb->ki_pos + count - 1, ret = 0;
        unsigned int flags = IOMAP_DIRECT;
        struct blk_plug plug;
@@ -461,14 +461,14 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
        }
 
        if (iocb->ki_flags & IOCB_NOWAIT) {
-               if (filemap_range_has_page(mapping, start, end)) {
+               if (filemap_range_has_page(mapping, pos, end)) {
                        ret = -EAGAIN;
                        goto out_free_dio;
                }
                flags |= IOMAP_NOWAIT;
        }
 
-       ret = filemap_write_and_wait_range(mapping, start, end);
+       ret = filemap_write_and_wait_range(mapping, pos, end);
        if (ret)
                goto out_free_dio;
 
@@ -479,7 +479,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
         * pretty crazy thing to do, so we don't support it 100%.
         */
        ret = invalidate_inode_pages2_range(mapping,
-                       start >> PAGE_SHIFT, end >> PAGE_SHIFT);
+                       pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
        if (ret)
                dio_warn_stale_pagecache(iocb->ki_filp);
        ret = 0;