Re: fanotify: fix support of large files

From: Heinrich Schuchardt
Date: Mon Apr 22 2013 - 14:49:35 EST


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@xxxxxx> 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@xxxxxxxxxxxxxxx).

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


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