fs: Allow a NULL pos pointer to __kernel_read
Match the behaviour of new_sync_read() and __kernel_write().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/read_write.c b/fs/read_write.c
index 516eb51..498cc00 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -449,11 +449,12 @@
return warn_unsupported(file, "read");
init_sync_kiocb(&kiocb, file);
- kiocb.ki_pos = *pos;
+ kiocb.ki_pos = pos ? *pos : 0;
iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len);
ret = file->f_op->read_iter(&kiocb, &iter);
if (ret > 0) {
- *pos = kiocb.ki_pos;
+ if (pos)
+ *pos = kiocb.ki_pos;
fsnotify_access(file);
add_rchar(current, ret);
}
