Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753224Ab1E0F7q (ORCPT ); Fri, 27 May 2011 01:59:46 -0400 Received: from mx2.fusionio.com ([66.114.96.31]:39172 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751189Ab1E0F7p (ORCPT ); Fri, 27 May 2011 01:59:45 -0400 X-ASG-Debug-ID: 1306475983-01de280c1e05680001-xx1T2L X-Barracuda-Envelope-From: JAxboe@fusionio.com Message-ID: <4DDF3DCD.40501@fusionio.com> Date: Fri, 27 May 2011 07:59:41 +0200 From: Jens Axboe MIME-Version: 1.0 To: Namhyung Kim CC: "linux-kernel@vger.kernel.org" , Laurent Vivier Subject: Re: [PATCH] loop: export module parameters References: <1306302242-7019-1-git-send-email-namhyung@gmail.com> <1306472258.2544.6.camel@leonhard> X-ASG-Orig-Subj: Re: [PATCH] loop: export module parameters In-Reply-To: <1306472258.2544.6.camel@leonhard> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1306475983 X-Barracuda-URL: http://10.101.1.181:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using global scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.64787 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2662 Lines: 73 On 2011-05-27 06:57, Namhyung Kim wrote: > 2011-05-25 (수), 14:44 +0900, Namhyung Kim: >> Export 'max_loop' and 'max_part' parameters to sysfs so user can know >> that how many devices are allowed and how many partitions are supported. >> >> If 'max_loop' is 0, there is no restriction on the number of loop devices. >> User can create/use the devices as many as minor numbers available. If >> 'max_part' is 0, it means simply the device doesn't support partitioning. >> >> Also note that 'max_part' can be adjusted to power of 2 minus 1 form if >> needed. User should check this value after the module loading if he/she >> want to use that number correctly (i.e. fdisk, mknod, etc.). >> >> Signed-off-by: Namhyung Kim >> Cc: Laurent Vivier >> --- >> drivers/block/loop.c | 17 ++++++++++++++--- >> 1 files changed, 14 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/block/loop.c b/drivers/block/loop.c >> index c59a672a3de0..76c8da78212b 100644 >> --- a/drivers/block/loop.c >> +++ b/drivers/block/loop.c >> @@ -1540,9 +1540,9 @@ static const struct block_device_operations lo_fops = { >> * And now the modules code and kernel interface. >> */ >> static int max_loop; >> -module_param(max_loop, int, 0); >> +module_param(max_loop, int, S_IRUGO); >> MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); >> -module_param(max_part, int, 0); >> +module_param(max_part, int, S_IRUGO); >> MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); >> MODULE_LICENSE("GPL"); >> MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); >> @@ -1688,9 +1688,20 @@ static int __init loop_init(void) >> */ >> >> part_shift = 0; >> - if (max_part > 0) >> + if (max_part > 0) { >> part_shift = fls(max_part); >> >> + /* >> + * Adjust max_part according to part_shift as it is exported >> + * to user space so that user can decide correct minor number >> + * if [s]he want to create more devices. >> + * >> + * Note that -1 is required because partition 0 is reserved >> + * for the whole disk. >> + */ >> + max_part = (1UL << part_shift) - 1; >> + } >> + >> if ((1UL << part_shift) > DISK_MAX_PARTS) >> return -EINVAL; >> > > Hi Jens, > > Could you please consider applying this in your tree too? It's exactly > the same thing what I did for brd series. Applied now, missed it yesterday. Thanks! -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/