Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <2c15f117-19f4-66cb-d5a9-5b570fce19cd@redhat.com>
Date:   Sat, 30 Apr 2022 12:43:43 -0400
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.7.0
Subject: Re: [PATCH] nfsrahead: fix oops caused by non-starndard naming
 schemes
Content-Language: en-US
To:     Thiago Becker <tbecker@redhat.com>, linux-nfs@vger.kernel.org
Cc:     trbecker@gmail.com
References: <20220425195948.2627428-1-tbecker@redhat.com>
From:   Steve Dickson <steved@redhat.com>
In-Reply-To: <20220425195948.2627428-1-tbecker@redhat.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 4/25/22 3:59 PM, Thiago Becker wrote:
> brtfs uses a non standard naming scheme for its fs structures, which
> causes nfsrahead to take a long time scanning all the memory
> available and then crashes. This causes the udev to take forever to
> quiesce and delays the system startup.
> 
> This t=patch refactors the way the device number is obtained to handle
> this situation.
> 
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2078147
> Signed-off-by: Thiago Becker <tbecker@redhat.com>
Committed... Thanks!

steved.

> ---
>   tools/nfsrahead/main.c | 23 +++++++++++++++--------
>   1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/nfsrahead/main.c b/tools/nfsrahead/main.c
> index b3af3aa8..83a389f7 100644
> --- a/tools/nfsrahead/main.c
> +++ b/tools/nfsrahead/main.c
> @@ -26,27 +26,31 @@ struct device_info {
>   };
>   
>   /* Convert a string in the format n:m to a device number */
> -static dev_t dev_from_arg(const char *device_number)
> +static int fill_device_number(struct device_info *info)
>   {
> -	char *s = strdup(device_number), *p;
> +	char *s = strdup(info->device_number), *p;
>   	char *maj_s, *min_s;
>   	unsigned int maj, min;
> -	dev_t dev;
> +	int err = -EINVAL;
>   
>   	maj_s = p = s;
> -	for ( ; *p != ':'; p++)
> +	for ( ; *p != ':' && *p != '\0'; p++)
>   		;
>   
> +	if (*p == '\0')
> +		goto out_free;
> +
> +	err = 0;
>   	*p = '\0';
>   	min_s = p + 1;
>   
>   	maj = strtol(maj_s, NULL, 10);
>   	min = strtol(min_s, NULL, 10);
>   
> -	dev = makedev(maj, min);
> -
> +	info->dev = makedev(maj, min);
> +out_free:
>   	free(s);
> -	return dev;
> +	return err;
>   }
>   
>   #define sfree(ptr) if (ptr) free(ptr)
> @@ -55,7 +59,7 @@ static dev_t dev_from_arg(const char *device_number)
>   static void init_device_info(struct device_info *di, const char *device_number)
>   {
>   	di->device_number = strdup(device_number);
> -	di->dev = dev_from_arg(device_number);
> +	di->dev = 0;
>   	di->mountpoint = NULL;
>   	di->fstype = NULL;
>   }
> @@ -76,6 +80,8 @@ static int get_mountinfo(const char *device_number, struct device_info *device_i
>   	char *target;
>   
>   	init_device_info(device_info, device_number);
> +	if ((ret = fill_device_number(device_info)) < 0)
> +		goto out_free_device_info;
>   
>   	mnttbl = mnt_new_table();
>   
> @@ -101,6 +107,7 @@ out_free_fs:
>   	mnt_free_fs(fs);
>   out_free_tbl:
>   	mnt_free_table(mnttbl);
> +out_free_device_info:
>   	free(device_info->device_number);
>   	device_info->device_number = NULL;
>   	return ret;