| Bug #65120 | LOAD_FILE won't read files in /tmp | ||
|---|---|---|---|
| Submitted: | 26 Apr 2012 18:00 | Modified: | 27 Apr 2012 3:35 |
| Reporter: | Doug Campbell | Email Updates: | |
| Status: | Not a Bug | Impact on me: | |
| Category: | MySQL Server: Command-line Clients | Severity: | S3 (Non-critical) |
| Version: | 5.5.22 | OS: | Linux |
| Assigned to: | CPU Architecture: | Any | |
[26 Apr 2012 18:08]
Sveta Smirnova
Thank you for the report.
I can not repeat described behavior:
mysql> select load_file('/tmp/bar');
+-----------------------+
| load_file('/tmp/bar') |
+-----------------------+
| foo
|
+-----------------------+
1 row in set (0.00 sec)
mysql> \! df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda3 126388036 90910968 29056896 76% /
tmpfs 3968960 720 3968240 1% /dev/shm
...
mysql> select load_file('/dev/shm/bar');
+---------------------------+
| load_file('/dev/shm/bar') |
+---------------------------+
| foo
|
+---------------------------+
1 row in set (0.00 sec)
Please provide output of df command.
[26 Apr 2012 18:44]
Doug Campbell
Okay. After much testing, I discovered that this issue is caused by Fedora using something called PrivateTmp. If I alter the systemd mysqld.service file and comment out the line that has PrivateTmp=true then LOAD_FILE works as expected in /tmp. So, I am not sure if this is a bug or not. It is confusing though.
[26 Apr 2012 20:13]
Sveta Smirnova
Thank you for the feedback. This is permission issue, not MySQL bug.
[27 Apr 2012 3:35]
Doug Campbell
I wouldn't say it is a permissions issue. I don't fully understand the use of PrivateTmp namespaces but it seems the issue stems from the fact that MySQL is treating /tmp as a different location than most services running on the system. Anyway, I agree with you, as I think about it more and more that this is not a bug in MySQL. Thanks!
Description: Using LOAD_FILE to read file into MySQL. When file is read from /tmp directory, result is always NULL. How to repeat: Fedora 16 SELinux Disabled Using root mysql user File permissions for /tmp drwxrwxrwt 15 root root 4096 Apr 27 01:18 /tmp File permissions for test.htm file -rwxrwxrwx 1 mysql root 2607540 Apr 26 23:40 /tmp/test.htm mysql> SELECT LOAD_FILE('/tmp/test.htm'); If I create a new directory /temp with the exact same permissions and place test.htm within it and attempt my test again using /temp/test.htm, LOAD_FILE will work as expected.