Messages in this thread Patch in this message | | | Date | Sun, 28 Dec 2003 19:45:46 -0800 | From | Walt H <> | Subject | Re: Can't eject a previously mounted CD? |
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Ed Sweetman wrote: > I'd have to say the december 17th listed changes are the culprit here. > I'm definitely not up to figuring out what change is the bad one. If > any of the cdrom/ide-cd people wanna have me get some data from them > then just tell me how. I've tried viewing the debug output from the > modules with no success in figuring out the problem. > >
Luckily for me, I built my cdrom drivers as modules, so I could play :) I turned on debugging, and noticed that cdi->use_count continues to increment by 2 for each access. In cdrom_release, only one cdi->use_count-- exists, so the driver never gets to 0 use count and releases. I noticed in drivers/cdrom/cdrom.c line 753:
if (!ret) cdi->use_count++;
Which is our second increment, but I can't find two decrements, because the check further down won't ever be true if the above is true. Hence, two increments and only 1 dec when we reach cdrom_release. What I did, was add a conditional decrement right before the open_for_data call, which makes the value of use_count like it used to be prior to the Mt. Rainier patches. Seems kinda hacky :)
-Walt
--- /usr/src/linux/drivers/cdrom/cdrom.c 2003-12-25 09:53:59.000000000 -0800 +++ linux-2.6.0-mm1/drivers/cdrom/cdrom.c 2003-12-28 19:42:04.174098225 -0800 @@ -744,4 +744,7 @@ }
+ if (cdi->use_count > 0) + cdi->use_count--; + /* if this was a O_NONBLOCK open and we should honor the flags, * do a quick open without drive/disc integrity checks. */ @@ -931,5 +934,5 @@ struct cdrom_device_ops *cdo = cdi->ops;
- cdinfo(CD_CLOSE, "entering cdrom_release\n"); + cdinfo(CD_CLOSE, "entering cdrom_release\n");
if (cdi->use_count > 0)
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