Failed to load a garmin map

[agnonchik@…]

Hi,

Navit failed to load a garmin map:

garmin.c:193:1|libgarmin 0.1-r278 initializing as GPS Backend
garmin.c:447:1|Loading /usr/local/share/navit/maps/50.img as TDB
garmin_tdb.c:66:1|Can not open:[/usr/local/share/navit/maps/50.img] errno=1(Operation not permitted)
garmin.c:226:1|Implement me

I'll appload the map.

Thanks, Val.

[agnonchik@…]

The map is downloadable from the web: ​http://www.gpsportal.ru/cgi-bin/CMS/getfile.cgi?file=50.img&ident=53616c7465645f5f494c694e66d5ad41984c3ac0acc31897a05e8cfc4a87bf7f2272a77af26efc078162cf147cace70ccb0ed215630631b79f5ebd5e47ce8462

Thanks, Val.

[anonymous]

Some more details: If the map is owned the user who is running navit the map does work. (although the user who is running navit has full right on the file, file is world readable)

[Ed]

I think i found a workarround:

after strace-ing navit i find that i get the following error:

nav4.16148:open("/data/data2/canada/00068676.img", O_RDONLY|O_NOATIME) = -1 EPERM (Operation not permitted)

Acording to man 2 open:

EPERM The O_NOATIME flag was specified, but the effective user ID of the caller did not match the owner of
the file and the caller was not privileged (CAP_FOWNER).

Which seems to confirm that it only happens if the file is not owned by the user running navit.

So as a proof-of-concept, i removed the O_NOATIME flag:

diff ./src/libgarmin_priv.h ./src/libgarmin_priv.h.org

20c20

'< #define OPENFLAGS (O_RDONLY|O_BINARY)'

---

'> #define OPENFLAGS (O_RDONLY|O_NOATIME|O_BINARY)'

i did a make, make install and did the same for navit.

Now the error is gone and navit is working again.

Can you please fix this ( in a more elegant way....)

[KaZeR]

Comments from Zaxl (libgarmin's author):

I've read the ticket but i dont like the solution. Changing the ownership is easy for now. NO_ATIME gives a quite big speedup on slow media, like my sd card. I can detect the EPERM from the open and remove the flag. That's the plan! :)

[zaxl]

Plan completed. If open fails with EPERM retry without O_NOATIME.