Hi devs!
I've been trying using emacs to view some files mounted by FUSE. Sadly file attr in the system says the file size is 0 bytes, just like files under /proc
emacs can open the file but only can open it partially. I've checked the code to handle find-file and narrow down to
```c
/* emacs/src/fileio.c:4587 */
if (seekable || !NILP (end))
total = end_offset - beg_offset;
else
/* For a special file, all we can do is guess. */
total = READ_BUF_SIZE;
```
Judging from the code, it assume the total size would be READ_BUF_SIZE
which seems to be not a very big number ( or not, I'm not sure)
```c
/* emacs/src/fileio.c:3692 */
enum { READ_BUF_SIZE = MAX_ALLOCA };
```
```h
/* emacs/src/lisp.h:5300 */
enum MAX_ALLOCA { MAX_ALLOCA = 16 * 1024 };
```
since vscode, vim, cat, and less can read this file properly, I would like to clarify whether it is a bug to fix or there another way to open a big file like this (say the actual size is 2MB~ but showing as 0 byte on stat)