Experimental Physics and
Industrial Control System

Tim Mooney <[email protected]> · Tue, 16 Apr 2013 10:18:26 -0500 (CDT)

Hi Vesna,

Thanks for the information.  I haven't tested sscan on vxWorks 6.9, though
I'm told it works on vxWorks 6.8.  I don't think creat() uses O_RDRW as a
file-permission mask, and I don't understand why open() would work while
creat() does not.  I'm ok with making this change, but I'd like to understand
it better first.

Tim

----- Original Message -----
> From: "Vesna Samardzic-Boban" <[email protected]>
> To: [email protected]
> Sent: Monday, April 15, 2013 8:52:30 PM
> Subject: sscan/ saveData problem with RW permission, and not an NFS issue
> 
> Hi All,
> 
> 
> Found a problem as follows:
> 
> Running a scan record on a vxWorks IOC and when entering 'File
> system' in scan_saveData.adl screen, an error message in the 'Save
> status' field follows:
> "RW permission denied !!!"
> 
> At first I suspected NFS but after checking it found that my problem
> was in the sscan's saveData.c and/or VxWorks is 6.9
> 
> Tried two versions of sscan, 2-6-6 and 2-8-2, they gave the same
> result as above. These two versions are same regarding the
> saveData.c and its function
>     checkRWpermission(char* path)
> and specifically the line
> 
>     file= creat(tmpfile, O_RDWR);
> 
> that creates test file "rix_" with file permissions 002 (because
> O_RDRW = 2)
> (O_RDRW is flag "Open for reading and writing" or File Access
> Options)
> 
> The file permissions 002 become
> -------w-  in   terms of    rwxrwxrwx
> and hence the error "RW permission denied !!!"
> 
> Found a solution by using vxWorks function open() instead of creat().
> open() - opens a file and optionally creates a file if it does not
> exist.
> open() - also offers a parameter for "mode" i.e. file permissions,
> which i set to 0x666 in the example below
> 
>      file = open (tmpfile, O_CREAT | O_RDWR, 0666);
> 
> Then scan data can be saved as expected.
> 
> BTW
> saveData.c uses open() for creating 'subdirectory'.
>           fd = open (local_pathname, O_RDWR | O_CREAT,
>                            FSTAT_DIR | DEFAULT_DIR_PERM | 0775);
> 
> 
> Has anyone had similar problems ?
> Is this an sscan/saveData.c issue or vxWorks 6.9 issue (I do not have
> any other version of vxWorks) ?
> How about sscan/saveData on OS's other than vxWorks?
> 
> 
> Thanks Vesna
> 
> P.S.
> In my vxWorks 6.9 and its ioLib.c, creat() does not offer file
> permissions (set to 0 as below):
> int creat
>     (
>     const char *name,           /* name of the file to create */
>     int         flag            /* file permissions */
>     )
>     {
>     return (ioCreateOrOpen (name, flag, 0, TRUE));
>     }
> 
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System