site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Hi Imran, Let us draw a picture. (A) IOMedia IOMedia (1) | | (B) SpsoftSnapDriver SpsoftSnapDriver (2) | | (C) IOMedia IOMedia (3) |_________________| | IOApplePartitionScheme | You can obtain the partition name with media->getName(). Dan On 6 May 2005, at 10:45 AM, Imran Kazi wrote: Hi Dan, Awaiting your valuable reply. Thanks Imran From: Dan Markarian [mailto:markarian@apple.com] Sent: Friday, May 06, 2005 3:11 AM To: Imran Kazi Cc: darwin Mailing List Subject: Re: Write on specific IOMedia through filter driver Hi Imran, Dan On 5 May 2005, at 9:14 AM, Imran Kazi wrote: Hi folks, Awaiting your response Thanks once again for all valuable help. _______________________________________________ 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... What we are looking is to write a buffer on the specific one partition, so we are not able to find how to issue a write call for the specific partition as our filter driver is loaded for both the partitions. You have a pointer to (B) and a pointer to (2). You can write to (C) with the pointer to (B). You can write to (3) with the pointer to (2). You have total control over the choice. Our aim is to intercept the write call at one partition and read the data from this partition in a buffer which is going to be modified by the write call and write this buffer to the another partition. This is the reason we have loaded our filter driver for the two partitions. (This is a kind of Snapshot of one partition on other partition) You are welcome to have (B) and (2) rendezvous with each other as I had described before. You wish to differentiate them I take it. Is there not information in your data structures on disk that can differentiate them? You are welcome to differentiate the (B) and (2) with a partition name as you have proposed. The partition name is not the volume name, keep in mind. You should set your partition name alongside your partition hint of 'SpsoftSnap' using pdisk. Partition map (with 512 byte blocks) on '/dev/rdisk1' #: type name length base ( size ) 1: Apple_partition_map Apple 63 @ 1 2: SpsoftSnap Primary 33292288 @ 64 ( 15.9G) 3: SpsoftSnap Secondary 33292288 @ 33292288 ( 15.9G) We may not be able to explain the complete picture to you. Let me put it again We have the filter driver whose content hint is ‘SpsoftSnap’ now we have two partitions whose content hint is ‘SpsoftSnap’. (We want our filter driver to be loaded for both the partitions). And all the writes on these partition goes through our filter driver, but when we issue the write call with a buffer in that case the buffer goes to both the partitions. What we are looking is to write a buffer on the specific one partition, so we are not able to find how to issue a write call for the specific partition as our filter driver is loaded for both the partitions. Our aim is to intercept the write call at one partition and read the data from this partition in a buffer which is going to be modified by the write call and write this buffer to the another partition. This is the reason we have loaded our filter driver for the two partitions. (This is a kind of Snapshot of one partition on other partition) I hope I am able to explain you the situation, if not please let me know I will try my best to put the details. You seem to want a global disk area to store information about all the filters. It seems the information is better kept per filter rather than in a global disk area, but I am unable to guess what purpose it serves at the moment, of course. You can have the global disk area initialized with a signature and the other areas without a signature, and somehow have your other drivers rendezvous with the global one at start() time. After a good amount of effort we are now able to successfully write on the disk using filter scheme driver. Now my user-space buffer successfully passes to kernel through user- client. Thanks for all your valuable help. Thanks specially to Dan, GodFrey, Garth and Parav for helping me out to solve the problem. Now my driver exposes two IOMedia's named /Volume/Vol1 and /Volume/ Vol2 and my driver writes the user-space buffer on both the media at particular byte offset. Is there any way that my driver write routine writes only on one specific IOMedia say (/Volume/Vol1),even if my driver matches for both IOMedia's. Is it possible to get the name of the media from the IORegistry or is there any API available to get the partition name from the IORegistry. So that we can match the partition name which we get from the IORegistry and if the match gets successful then only my driver write routine writes on that particular IOMedia say (/Volume/ Vol1)only and not on (/Volume/Vol2). Imran This email sent to site_archiver@lists.apple.com