site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Thank you Kevin. That's the route that I have been trying to go down. However, I'm not working out the unmount incantation. This is especially difficult with a USB disk. I seems that I need to get all of the IOMedia to be recreated after changing to the state. Thoughts on how that can be accomplished? Thanks again! ...Duane On Feb 11, 2010, at 4:00 PM, Kevin Elliott wrote:

You should not be changing this state while the media is mounted. Doing so has unpredictable consequences, varying between "bizarre" and "catastrophic". A read/write filesystem expects to be able to write data to it's target, so changing that value unpredictably will corrupt the file system as it's metadata writes fail to complete.

On the other hand, if you only change the state when the volume is unmounted (unmount, make read only, remount, etc..) my experience has been that very thing will work as expected.

-Kevin

On Feb 11, 2010, at 2:54 PM, Duane Murphy wrote:

...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256

We have a block storage driver kext that can we would like to be able to change from read-write to read-only dynamically.

I've worked out how to change the driver to read-only and the underlying IOMedia object. But the read-only change doesn't propagate any further to the file system IOMedia objects or the file system.

If the underlying media is changed to read-only then an error is returned by the file system. However, if the media is then changed back to read-write, the file system continues to display an error. I'm fine with the error, the problem in this case is getting the file system to try again so that it is successful.

How can I go about updating the file system so that it is aware that the media has changed to read-only and then later back to read-write?

Thanks for any tips,

...Duane

-----BEGIN PGP SIGNATURE----- Version: PGP Desktop 9.10.0 (Build 500) Charset: US-ASCII

wsBVAwUBS3SKo0rg9acQ4r2CAQj5DwgA9zRRyL5bb8B2HkBs0bH0BhJwzc3LUukj sWMKIkM2ZMw80gED7ZT1ZPckxVReSDAaEKfe3usM8G3R1KMmq+CQansvm6y6J5lu R6r4sDb66POoR2l3xgQ8+iwo/Wl/oCCr/kNQC2DcgmQnD3X41+im3P0YV/NTafZB loaitvKGu95nXzVs8eEAkV0oz36Cxi0DhiPWBAzcA/A67sWot0NvaSo3Q0xec49M ztfJamVtNhOYrT2FknHXxUWKoiEDJcg+RNbdoRQa3W/JuOeiEL/X2mL1BA4ZuFYE SsNqk5aJixcVtcZ1w7KSGfR69oAu6vzOlrRErfxKrHUUaax9mcdc2g== =g48r -----END PGP SIGNATURE----- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/kelliott%40mac.com

This email sent to kelliott@mac.com

...Duane -----BEGIN PGP SIGNATURE----- Version: PGP Desktop 9.10.0 (Build 500) Charset: US-ASCII wsBVAwUBS3Skn0rg9acQ4r2CAQjQcwgAoFVm4q/0AnveLBcUczRoEdtMRUTC6oic OC5FEsphFL5SY3bhsqbFEEbTZ9g9HlqYg9Yh4nWBWx+/tdCaI7P5vGPIvdgmz/hD ilDkn6/L2xdKAjDeaTH8trnj0D2uboab1GEzaXJ6u2r1N/VY4/8N2qSKsmcnh3q9 2CN3iMP9YPrvJTgBbHgX8+ggRkaIowCe3sc6JAIugrettYl5QF4x14894XqADM3g nLnLtG+DWkyEZ+CM+I02SnBsaG7vSwj2ecxfHHJR5la6vlVck4+nf+tZvyMDCkYV 3M8PHAo5hotBmKnYM+YbaCpI2inPHOKIeH7X61LXUUAqUYMbTbTpLg== =5yrG -----END PGP SIGNATURE----- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com