dax: Remove pointless writeback from dax_do_io()
dax_do_io() is calling filemap_write_and_wait() if DIO_LOCKING flags is
set. Presumably this was copied over from direct IO code. However DAX
inodes have no pagecache pages to write so the call is pointless. Remove
it.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
diff --git a/fs/dax.c b/fs/dax.c
index 7c0036d..2375814 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -268,15 +268,8 @@
memset(&bh, 0, sizeof(bh));
bh.b_bdev = inode->i_sb->s_bdev;
- if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ) {
- struct address_space *mapping = inode->i_mapping;
+ if ((flags & DIO_LOCKING) && iov_iter_rw(iter) == READ)
inode_lock(inode);
- retval = filemap_write_and_wait_range(mapping, pos, end - 1);
- if (retval) {
- inode_unlock(inode);
- goto out;
- }
- }
/* Protects against truncate */
if (!(flags & DIO_SKIP_DIO_COUNT))
@@ -297,7 +290,6 @@
if (!(flags & DIO_SKIP_DIO_COUNT))
inode_dio_end(inode);
- out:
return retval;
}
EXPORT_SYMBOL_GPL(dax_do_io);