Re: fanotify: fix support of large files

[Heinrich Schuchardt <xypron.glpk@gmx.de>]

Hello Justin,

I downloaded the example,
http://www.lanedo.com/~aleksander/fanotify/fanotify-example.c
compiled it without modification
$ gcc fanotify-example.c -o fanotify-example
and started the executable. In a separate windows I executed
truncate -s 2048m 2048m

This is the output of the first window:
$ sudo ./fanotify-example /home/user/temp/
Started monitoring directory '/home/user/temp/'...
Received event in path '/home/user/temp/2048m' pid=3659 (truncate):
         FAN_OPEN
Received event in path '/home/user/temp/2048m' pid=3659 (truncate):
         FAN_CLOSE_WRITE

$ uname -a
Linux family2 3.8.0 #1 SMP Fri Feb 22 22:07:58 CET 2013 i686 GNU/Linux

To reproduce your problem, could you, please, provide the Linux 
configuration file (look in your /boot directory) and a link to the 
source of the Linux kernel version you use. Then I can use your 
configuration file to compile that kernel version.

Best regards

Heinrich Schuchardt

On 19.04.2013 21:23, Justin Maggard wrote:
> On Sat, Apr 13, 2013 at 4:54 AM, Heinrich Schuchardt<xypron.glpk@gmx.de>  wrote:
>> Dear Justin,
>>
>> looking at the example at
>> http://www.lanedo.com/~aleksander/fanotify/fanotify-example.c
>> the large file support is enabled by passing O_LARGEFILE to fanotify_init:
>>
>>    if ((fanotify_fd = fanotify_init (FAN_CLOEXEC,
>>                                      O_RDONLY | O_CLOEXEC | O_LARGEFILE))<
>> 0)
>>
>> Could you, please, check if this solves your issue.
>>
>> (I am resending this message because HTML was rejected by
>> linux-kernel@vger.kernel.org).
>>
>> Best regards
>>
>> Heinrich Schuchardt
>>
>
> No, unfortunately that doesn't help.  I slightly modifed
> fanotify-example.c to call perror() when read() fails, and here's the
> output:
>
> jmaggard@jmaggard-W520:~/fanotify-test$ sudo ./fanotify-example .&
> [1] 7248
> jmaggard@jmaggard-W520:~/fanotify-test$ Started monitoring directory '.'...
> truncate -s 2047m 2047m
> Received event in path '/home/jmaggard/fanotify-test/2047m' pid=7250 (unknown):
> FAN_OPEN
> FAN_CLOSE_WRITE
> jmaggard@jmaggard-W520:~/fanotify-test$ truncate -s 2048m 2048m
> read: Value too large for defined data type
>
> -Justin
>