February 2006 - Darwin-kernel

Re: VFS KPI: Are knotes auto-generated?
by Jim Magee 14 Feb '06

14 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Feb 13, 2006, at 11:15 AM, Jim Magee wrote: Sadly, this is a correct assessment. --Jim _______________________________________________ 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.… On Feb 13, 2006, at 6:43 PM, Brian Bergstrand wrote: There is nothing in Tiger/Darwin 8 to generate kevents at the VFS layer. But that is being worked on for a future release. When it arrives, network filesystems will have locally-driven changes auto- reflected into the kevent/knote system. They will also have a way to be informed when someone is watching a file locally so they can subscribe to whatever remote event system their protocol might support and then reflect remote changes into the kevent system as well. Thanks Jim, that's all good news. But for the present there is no way for a third-party VFS plugin to provide knotes while remaining KPI compliant (not linking against the kernel proper)? So moving my file system plugin from 10.3 to 10.4 has now lost me knote and advisory locking support (vfs_setlocklocal() is private and my old locking code was associating context with a proc struct). Again, I apologize. But the knote interfaces and data structures (inside the kernel) just aren't up to KPI standards for maintainability - and we couldn't get the VFS-layer implementation out in time for Tiger. Those are always tough tradeoffs/decisions to make. This email sent to site_archiver(a)lists.apple.com

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Re: VFS KPI: advisory locking
by Terry Lambert 14 Feb '06

14 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Advisory locking is changed in Tiger. As of Tiger, there are two types of locks: o Locally maintained locks (these are hung off the vnode) Hope that helps! -- Terry -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Feb 13, 2006, at 11:15 AM, Jim Magee wrote: --Jim On Feb 11, 2006, at 2:01 PM, Brian Bergstrand wrote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) iD8DBQFD7jSfedHYW7bHtqIRApeLAKDaEbK7lhHQTdDl+4Ym8hkWYA534ACdHeb/ IO8DwLm+URmSbspo1L3kZl0= =dk9Q -----END PGP SIGNATURE----- _______________________________________________ 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/jmagee%40apple.com Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) iD8DBQFD8RmbedHYW7bHtqIRAsOYAJ9OgCaCFmQu43kV1d2CsVLAGFHcZwCcCu6v G1m05TFfD6CXFBNfyHjgkUU= =YTm9 -----END PGP SIGNATURE----- _______________________________________________ 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/tlambert%40apple.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.… Prior to Tiger, advisory locks were maintained by the the vnop_advlock entry point in the file system VNOPS table. The FS was responsible for providing an in-core inode or cnode or other structure, with a pointer which it then used to hang the lock list off by passing the address of an element in a per FS structure. In addition, for each FS that supported advisory locking, there was an FS-specific implementation of the advisory locking code that knew about the per inode lock list. This was problematic, in that it forced you to make the calls into the lf_advlock() and other calls directly, and each FS required specific support for locking be integrated at the FS layer (and this did not occur in many FS's). o Remotely maintained locks (these are proxied to a server, which maintains them for you) For locally maintained advisory locks, the locks are hung off the vnode (&vp->v_lockf is the list head). In other words, they are hung off the vnode. The net upshot of this is that advisory locking "just works" for any vnode, as long as it's a not a FIFO/pipe/socket. For remotely maintained advisory locks, the VNOP_ADVLOCK entry point of the FS is called with the lock information, as before. If you want the system to maintain the advisory locks for you (i.e. you have a local file system, and you aren't trying to change the semantics from the POSIX semantics for some reason), then in the FS's mount routine, you call vfs_setlocklocal() in the mount routine, on the mount point (this sets the MNTK_LOCK_LOCAL flag into the mp's mnt_kern_flag field, and recursively modifies outstanding vnodes of the FS whose mp you call this on to set a flag on them to indicate local locking semantics). Right now, this is technically not KPI, and there's some cleanup that's bound to happen down the road before it can be formalized as KPI, so in order to use this, you will need to link against the raw kernel symbols, rather than the KPI symbol sets (this has been discussed before, and you can get information on how to do this from developer.apple.com) Again:: for remote FS's this should not be an issue for you, since nothing should change; it's only on local FS's where you were calling into the advisory locking routines directly that it is an issue. If you already have a local implementation of your own per-FS locking code, and you don't want to change over to the new system until the KPIs are more baked, then everything should still work - just base your code off the argument list into the NFS VNOPs from the Open Darwin sources. On Feb 13, 2006, at 3:43 PM, Brian Bergstrand wrote: There is nothing in Tiger/Darwin 8 to generate kevents at the VFS layer. But that is being worked on for a future release. When it arrives, network filesystems will have locally-driven changes auto- reflected into the kevent/knote system. They will also have a way to be informed when someone is watching a file locally so they can subscribe to whatever remote event system their protocol might support and then reflect remote changes into the kevent system as well. Thanks Jim, that's all good news. But for the present there is no way for a third-party VFS plugin to provide knotes while remaining KPI compliant (not linking against the kernel proper)? So moving my file system plugin from 10.3 to 10.4 has now lost me knote and advisory locking support (vfs_setlocklocal() is private and my old locking code was associating context with a proc struct). Since the knote interface is no longer public, does this mean that knotes are auto-generated by the kernel? This is for a local file system, but I'd be interested the status for network file systems too. I had a quick look at the VFS source and didn't see anything to suggest this is the case, but thought maybe the new kernel event system generated corresponding knotes. Then again, both HFS and UFS still generate their own notes... If knotes are not auto-generated, is there a way for VFS plugins to do so while still remaining KPI compliant? Knotes and byte-range locking (vfs_setlocklocal) seem to be some rather big oversights in the KPI. This email sent to jmagee(a)apple.com This email sent to tlambert(a)apple.com This email sent to site_archiver(a)lists.apple.com

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Re: VFS KPI: Are knotes auto-generated?
by Brian Bergstrand 13 Feb '06

13 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Feb 13, 2006, at 11:15 AM, Jim Magee wrote: --Jim On Feb 11, 2006, at 2:01 PM, Brian Bergstrand wrote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) iD8DBQFD8RmbedHYW7bHtqIRAsOYAJ9OgCaCFmQu43kV1d2CsVLAGFHcZwCcCu6v G1m05TFfD6CXFBNfyHjgkUU= =YTm9 -----END PGP SIGNATURE----- _______________________________________________ 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.… There is nothing in Tiger/Darwin 8 to generate kevents at the VFS layer. But that is being worked on for a future release. When it arrives, network filesystems will have locally-driven changes auto- reflected into the kevent/knote system. They will also have a way to be informed when someone is watching a file locally so they can subscribe to whatever remote event system their protocol might support and then reflect remote changes into the kevent system as well. Thanks Jim, that's all good news. But for the present there is no way for a third-party VFS plugin to provide knotes while remaining KPI compliant (not linking against the kernel proper)? So moving my file system plugin from 10.3 to 10.4 has now lost me knote and advisory locking support (vfs_setlocklocal() is private and my old locking code was associating context with a proc struct). Since the knote interface is no longer public, does this mean that knotes are auto-generated by the kernel? This is for a local file system, but I'd be interested the status for network file systems too. I had a quick look at the VFS source and didn't see anything to suggest this is the case, but thought maybe the new kernel event system generated corresponding knotes. Then again, both HFS and UFS still generate their own notes... If knotes are not auto-generated, is there a way for VFS plugins to do so while still remaining KPI compliant? Knotes and byte-range locking (vfs_setlocklocal) seem to be some rather big oversights in the KPI. iD8DBQFD7jSfedHYW7bHtqIRApeLAKDaEbK7lhHQTdDl+4Ym8hkWYA534ACdHeb/ IO8DwLm+URmSbspo1L3kZl0= =dk9Q -----END PGP SIGNATURE----- _______________________________________________ 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/jmagee% 40apple.com This email sent to jmagee(a)apple.com This email sent to site_archiver(a)lists.apple.com

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Re: VFS KPI: Are knotes auto-generated?
by Jim Magee 13 Feb '06

13 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com --Jim On Feb 11, 2006, at 2:01 PM, Brian Bergstrand wrote: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) _______________________________________________ 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.… There is nothing in Tiger/Darwin 8 to generate kevents at the VFS layer. But that is being worked on for a future release. When it arrives, network filesystems will have locally-driven changes auto- reflected into the kevent/knote system. They will also have a way to be informed when someone is watching a file locally so they can subscribe to whatever remote event system their protocol might support and then reflect remote changes into the kevent system as well. Since the knote interface is no longer public, does this mean that knotes are auto-generated by the kernel? This is for a local file system, but I'd be interested the status for network file systems too. I had a quick look at the VFS source and didn't see anything to suggest this is the case, but thought maybe the new kernel event system generated corresponding knotes. Then again, both HFS and UFS still generate their own notes... If knotes are not auto-generated, is there a way for VFS plugins to do so while still remaining KPI compliant? Knotes and byte-range locking (vfs_setlocklocal) seem to be some rather big oversights in the KPI. iD8DBQFD7jSfedHYW7bHtqIRApeLAKDaEbK7lhHQTdDl+4Ym8hkWYA534ACdHeb/ IO8DwLm+URmSbspo1L3kZl0= =dk9Q -----END PGP SIGNATURE----- _______________________________________________ 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/jmagee% 40apple.com This email sent to jmagee(a)apple.com This email sent to site_archiver(a)lists.apple.com

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VFS KPI: Are knotes auto-generated?
by Brian Bergstrand 11 Feb '06

11 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Brian Bergstrand <http://www.bergstrand.org/brian/> PGP Key ID: 0xB6C7B6A2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) iD8DBQFD7jSfedHYW7bHtqIRApeLAKDaEbK7lhHQTdDl+4Ym8hkWYA534ACdHeb/ IO8DwLm+URmSbspo1L3kZl0= =dk9Q -----END PGP SIGNATURE----- _______________________________________________ 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.… Since the knote interface is no longer public, does this mean that knotes are auto-generated by the kernel? This is for a local file system, but I'd be interested the status for network file systems too. I had a quick look at the VFS source and didn't see anything to suggest this is the case, but thought maybe the new kernel event system generated corresponding knotes. Then again, both HFS and UFS still generate their own notes... If knotes are not auto-generated, is there a way for VFS plugins to do so while still remaining KPI compliant? Knotes and byte-range locking (vfs_setlocklocal) seem to be some rather big oversights in the KPI. This email sent to site_archiver(a)lists.apple.com

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Re: Two machine debugging of Intel code
by Garth Cummings 10 Feb '06

10 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.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: Anyway to call syscall in kernel extension?
by Mike Smith 10 Feb '06

10 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Feb 10, 2006, at 2:33 AM, Lex Dejavu wrote: Kernel threads don't receive signals. That's because it's meant to be called from user space. = Mike _______________________________________________ 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 want to change signal mask of a kernel thread (in kext) but find no way, though it's easy to do in user space by syscall pthread_sigmask(). If we can't call syscall in kernel, is there any other way to change signal mask for a kernel thread? Another question, I found that sock_ioctl(...SIOCGIFCONF,...) doesn't work in kernel because it always try to copy result to user space. It sounds like you are writing code that should not be in the kernel at all. Perhaps you should consider moving it to user space? This email sent to site_archiver(a)lists.apple.com

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Anyway to call syscall in kernel extension?
by Lex Dejavu 10 Feb '06

10 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=bHdVJpRDiZAC8HJNCG+Pif7BqmW/fK1PIx8o3D2GGrDv2mpZespTRDFpQ2QuEPeZscGJDCxL70ZdJFNBlG4vejaEImRhhT4hFg/G2CqQvhkPsl94Hy0ukTKUGWCjNO7bhhkQm160Bf5N5jdI7zf54IR17HGa4VH3uaRWDK5heNQ= ; _______________________________________________ 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: how to write and override IOBlockStorageDriver???
by Mike Smith 10 Feb '06

10 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.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: Two machine debugging of Intel code
by Derek Kumar 10 Feb '06

10 Feb '06

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Folks, Thanks, Ron Aldrich Software Architects, Inc. _______________________________________________ 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/drk%40apple.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.… Yes--you must launch the debugger with "gdb -arch <target- arch>" (i386 in the first case), and load either architecture- specific or universal images (non-stripped, of course). You should use the latest version of gdb (the one shipped with Xcode 2.2 or newer, I believe) for best results. Also, there's apparently a problem with the Macsbug gdb plugin when connecting to x86 targets, so you should probably skip loading that if you use it. Derek On Feb 9, 2006, at 8:03 PM, Ron Aldrich wrote: One quick question - Using GDB, is it possible to debug kernel code running on an Intel based Macintosh using a PPC based Macintosh (or vice-versa)? This email sent to drk(a)apple.com This email sent to site_archiver(a)lists.apple.com

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