Messages in this thread | | | Date | Thu, 11 Jul 2013 15:10:35 -0700 | Subject | Re: fanotify: fix support of large files | From | Justin Maggard <> |
| |
On Mon, Apr 22, 2013 at 11:49 AM, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote: > > 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 >
Ah yes, that's the reason. I'm running on x86_64. 32-bit platforms actually work if you set O_LARGEFILE. From /usr/incude/bits/fcntl.h:
#ifdef __USE_LARGEFILE64 # if __WORDSIZE == 64 # define O_LARGEFILE 0 # else # define O_LARGEFILE 0100000 # endif #endif
If I include <asm/fcntl.h> instead of <fcntl.h>, it gets set to 0x8000, and my large file fanotify test works. Or, of course, I can define that flag locally and use it. But it feels like I shouldn't have to do that.
-Justin
> > 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 >> >
| |