drivers/block/loop.c:max_loop

Hello,

I run a relatively large FTP server, and I've just reached
the max_loop limit of loop devices here (I use loopback mount of ISO 9660 images of Linux distros here). Is there any reason for keeping the max_loop variable in loop.c set to 8?

Thanks,

-Yenya

\ Jan "Yenya" Kasprzak <kas at fi.muni.cz>       http://www.fi.muni.cz/~kas/
\\ PGP: finger kas at aisa.fi.muni.cz   0D99A7FB206605D7 8B35FCDE05B18A5E //
\\\             Czech Linux Homepage:  http://www.linux.cz/              ///
Mantra: "everything is a stream of bytes". Repeat until enlightened. --Linus

Memory requirements -- nothing prevents you from loading it with a bigger max count though...

Jens Axboe

Jens Axboe wrote:
: On Mon, Apr 16 2001, Jan Kasprzak wrote:
: > Hello,
: >
: > I run a relatively large FTP server, and I've just reached
: > the max_loop limit of loop devices here (I use loopback mount of ISO 9660 : > images of Linux distros here). Is there any reason for keeping : > the max_loop variable in loop.c set to 8?
:
: Memory requirements -- nothing prevents you from loading it with a : bigger max count though...
:
I would suggest to make the limit configurable by /proc or
ioctl() in run-time. Or even better, to make all allocations on first /dev/loopN open. Should I try to implement something like that?

-Yenya

\ Jan "Yenya" Kasprzak <kas at fi.muni.cz>       http://www.fi.muni.cz/~kas/
\\ PGP: finger kas at aisa.fi.muni.cz   0D99A7FB206605D7 8B35FCDE05B18A5E //
\\\             Czech Linux Homepage:  http://www.linux.cz/              ///
Mantra: "everything is a stream of bytes". Repeat until enlightened. --Linus

Overkill, imo. If you use a module setup, add a max_loop to your /etc/modules.conf. If not, add the identical max_loop to your lilo.conf append line.

Ok, just noticed that the module option is missing. Attached patch should rectify that oversight.

Jens Axboe

@@ -476,7 +476,7 @@
 	 */
 	bh = loop_get_buffer(lo, rbh);
 	bh->b_private = rbh;
-	IV = loop_get_iv(lo, bh->b_rsector);
+	IV = loop_get_iv(lo, rbh->b_rsector);
 	if (rw == WRITE) {
 		set_bit(BH_Dirty, &bh->b_state);
 		if (lo_do_transfer(lo, WRITE, bh->b_data, rbh->b_data,

@@ -620,7 +620,6 @@
 		 * If we can't read - sorry. If we only can't write - well,
 		 * it's going to be read-only.
 		 */
-		error = -EINVAL;
 		if (!aops->readpage)
 			goto out_putf;
 

@@ -1034,6 +1033,8 @@
 
 module_init(loop_init);
 module_exit(loop_exit);
+
+MODULE_PARM(max_loop, "i");
 
 #ifndef MODULE
 static int __init max_loop_setup(char *str)

duh, already there of course.

Jens Axboe