January 2005 - Darwin-kernel

Re: VFS-Lock patch on MAC OS X
by Nikita Danilov 16 Jan '05

16 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Yogesh P writes: > Hi Folks, Hello, Yogesh, > > I am working on the VFS-Lock patch on linux which gives the > functionality for locking and unlocking of filesystem. > > Is there any patch available on MAC for locking and unlocking of > filesystem for a fraction of time????OR is the darwinkernel has VFS-Lock > functionality built in???? > > Any pointers,reply certainly helps. If you fail to find any existing interface to do this you can easily do this yourself: embed struct lock__bsd__ fs_lock; in your super block. In all your VFS_FOO() operations and in VOP_LOCK(vnode) do: lockmgr(&super_block->fs_lock, LK_SHARED | LK_CANRECURSE, NULL, proc); As Mac OS X kernel usually calls VOP_LOCK(vnode) before calling any other VOP operation, this will guarantee that super_block->fs_lock is taken in shared mode when file system code is entered. LK_CANRECURSE is needed, because VOP_LOCK can be called twice against the same vnode during single system call. NOTE: in a few (unfortunate) places VOP_GETATTR() is called _without_ taking vnode lock, so you will have to take super_block->fs_lock there explicitly. Now, to "lock" whole file system one just does: lockmgr(&super_block->fs_lock, LK_EXCLUSIVE, NULL, proc); Don't forget to unlock. :) > > Thanks, > YOGESH PAHILWAN > (SOFTWARE ENGINNER) Nikita. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Question on VFS-Lock
by Robert Gordon 16 Jan '05

16 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Scanning the code, i didn't see the exact functionality that you'll need; vfs_busy() was as close as it gets, and fails; it uses the mnt_lock in the mount struct.. On Jan 10, 2005, at 11:13 PM, Yogesh P wrote: _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… I am basically looking for the mechanism of locking the I/O's at file system level (VFS level) for a fraction of time so that i can copy out the specific data block for achieving the block level Snapshot on Mac OS X. This email sent to site_archiver(a)lists.apple.com

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Question on Filter scheme driver example
by Yogesh P 15 Jan '05

15 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Hi folks, I had gone through the Mass storage driver pdf and according to the example given in the pdf for Developing filter scheme driver write sample filter scheme driver and it works fine for the diskimage which i had created through hdiutil In this example i specify "Content Hint" property as MySoftwareCompany_MyContent in the IOKit personality for driver matching and read/write calls in my filter scheme driver works fine when i write or read on this partition. But when i specify "Content Hint" property as Apple_HFS which i think is the default content hint for the partitions created on MAC OS X and load my filter scheme driver which also has this property with the value Apple_HFS i doesn't get the read/write IOLogs on the console and sees only start and init function IOLogs repeatedly. I have four partitons with Apple_HFS content hint which i had created during installation of MAC OS X. I want to know if i specify the "Content Hint" as Apple_HFS will my filter scheme driver work for all the four partitions other than the diskimage partition i have created using hdiutil??? Thanks in advance, YOGESH PAHILWAN (SOFTWARE ENGINNER) S P Software Technologies (I) Pvt. Ltd. (An ISO 9001:2000 Company) Pune, Maharashtra, India - 411 004. Tel : 91-20-4006154, 4006983, 4007503. Fax : 91-20-4006153. Email : pahilwan.yogesh(a)spsoftindia.com Visit us at : www.spsoftindia.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Exploring locks in darwin
by Yogesh P 15 Jan '05

15 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Hi Chris, Yes we are trying to add snapshot to HFS+ and for the same purpose we need to freeze the I/O's for initializing the snapshot. What do u think will be the better approach for the freezing or locking the I/O for achieving this functionality in HFS+??? Thanks, YOGESH PAHILWAN (SOFTWARE ENGINNER) S P Software Technologies (I) Pvt. Ltd. (An ISO 9001:2000 Company) Pune, Maharashtra, India - 411 004. Tel : 91-20-4006154, 4006983, 4007503. Fax : 91-20-4006153. Email : pahilwan.yogesh(a)spsoftindia.com Visit us at : www.spsoftindia.com On Fri, 2005-01-14 at 20:48, Chris Bergmann wrote: > from my (limited) understanding of the vfs, this is not what you're > looking for. > > I think vn_lock acts (as the name suggests) on a single vnode, not the > whole filesystem. It won't suit your purposes if you're trying to lock > out all writes to the entire volume. > > are you trying to add snapshots to HFS+ specifically, or just in a > general way to all vfs file systems? > > > On 15/01/2005, at 1:05, Yogesh P wrote: > > > Hi Folks, > > > > I am going through the implementation of the locking available in vfs > > for holding the write call for fraction of time to initialize the > > snapshot module. > > > > Can somebody point me about the vn_lock function which is used by lots > > of syscall under bsd kernel. > > > > Can we directly use the vn_lock function to lock the write calls? > > > > Is there any reference document which will make me understand the > > functionality of simple_lock,simple_unlock,VOP_LOCK and VOP_UNLOCK > > under > > darwin kernel. > > _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: IORegistryEntry->getProperty() method
by Godfrey van der Linden 15 Jan '05

15 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Godfrey On Jan 14, , at 15:46, Brian Jorgage wrote: The IORegistryEntry->getproperty() methods all return objects of type OSObject*. The problem I have is that the kernel is continually crashing when I try to use this method. I think I need to instantiate an object to hold the return value but OSObject is an abstract base class and hence cannot be directly instantiated. So how does one handle/instantiate the OSObject so the kernel doesn't crash ? _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… Can we see the paniclog? You don't have to create an OSObject at all, there must be something wrong with the property table you are trying to read. This email sent to site_archiver(a)lists.apple.com

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IORegistryEntry->getProperty() method
by Brian Jorgage 14 Jan '05

14 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com The IORegistryEntry->getproperty() methods all return objects of type OSObject*. The problem I have is that the kernel is continually crashing when I try to use this method. I think I need to instantiate an object to hold the return value but OSObject is an abstract base class and hence cannot be directly instantiated. So how does one handle/instantiate the OSObject so the kernel doesn't crash ? Brian Jorgage _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Exploring locks in darwin
by Chris Bergmann 14 Jan '05

14 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On 15/01/2005, at 1:05, Yogesh P wrote: Hi Folks, I am going through the implementation of the locking available in vfs for holding the write call for fraction of time to initialize the snapshot module. Can somebody point me about the vn_lock function which is used by lots of syscall under bsd kernel. Can we directly use the vn_lock function to lock the write calls? _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… from my (limited) understanding of the vfs, this is not what you're looking for. I think vn_lock acts (as the name suggests) on a single vnode, not the whole filesystem. It won't suit your purposes if you're trying to lock out all writes to the entire volume. are you trying to add snapshots to HFS+ specifically, or just in a general way to all vfs file systems? Is there any reference document which will make me understand the functionality of simple_lock,simple_unlock,VOP_LOCK and VOP_UNLOCK under darwin kernel. This email sent to site_archiver(a)lists.apple.com

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Re: Exploring locks in darwin
by hugang＠soulinfo.com 14 Jan '05

14 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com User-agent: Mutt/1.3.28i On Fri, Jan 14, 2005 at 08:35:14PM +0530, Yogesh P wrote: > Hi Folks, > > I am going through the implementation of the locking available in vfs > for holding the write call for fraction of time to initialize the > snapshot module. > > Can somebody point me about the vn_lock function which is used by lots > of syscall under bsd kernel. > > Can we directly use the vn_lock function to lock the write calls? > > Is there any reference document which will make me understand the > functionality of simple_lock,simple_unlock,VOP_LOCK and VOP_UNLOCK under > darwin kernel. > Basically, Filesystem in Darwin is like Filesytem in *BSD system, *BSD filesytem will are good reference for you. -- Hu Gang .-. /v\ // \\ Linux User /( )\ [204016] GPG Key ID ^^-^^ http://soulinfo.com/~hugang/hugang.asc _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Exploring locks in darwin
by Yogesh P 14 Jan '05

14 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Hi Folks, I am going through the implementation of the locking available in vfs for holding the write call for fraction of time to initialize the snapshot module. Can somebody point me about the vn_lock function which is used by lots of syscall under bsd kernel. Can we directly use the vn_lock function to lock the write calls? Is there any reference document which will make me understand the functionality of simple_lock,simple_unlock,VOP_LOCK and VOP_UNLOCK under darwin kernel. Thanks in advance, YOGESH PAHILWAN (SOFTWARE ENGINNER) S P Software Technologies (I) Pvt. Ltd. (An ISO 9001:2000 Company) Pune, Maharashtra, India - 411 004. Tel : 91-20-4006154, 4006983, 4007503. Fax : 91-20-4006153. Email : pahilwan.yogesh(a)spsoftindia.com Visit us at : www.spsoftindia.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: struct proc
by Peter Lovell 14 Jan '05

14 Jan '05

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Jan 13, 2005, at 11:23 PM, Matt Jaffa wrote: Hi, Where is the struct proc defined? Thanks, Matt It's in <sys/proc.h>, about line 110. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… I know this is a bad question, but I have spent forever for looking for this again. I already know this but can't find the answer anymore. Searched all the Kernel headers, but looks like not hard enough. There use to be a linux header site that helped on this, but can't find it anymore. But the definition is marked as "Apple private", basically for rreasons of binary compatibility This email sent to site_archiver(a)lists.apple.com

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