9eec299fab
Keeping consumers open when device is closed is very hard. We need to open consumers sometimes to update metadata, etc. Many hacks was introduced in the past to made it possible. You cannot be sure that you can open consumer for writing always, even if you think it should be allowed. If one of the mirror components is for example da0 and you try to open it, you can get EPERM when da0s1 is opened for reading (because BSD class opens consumers (da0) with an extra 'e' bit set). Waiting for the events queue to be empty may do the trick, but it makes code much uglier (as you cannot always call g_waitidle()), it doesn't solve all edge cases and it can introduce deadlocks if there are events in the queue that wait for gmirror. I removed those hacks. Now all consumers are open r1w1e1 always, even if device is closed. Maybe it is less clean from GEOM perspective, but simpify code a lot and make it much more reliable. The only issue was retaste event which is sent when we close consumers opened for writing. I ignore retaste event by not detaching consumer immediately (so retaste event is not send to my class) and sending event right after it to detach and destroy consumer.
This is the top level of the FreeBSD source directory. This file was last revised on: $FreeBSD$ For copyright information, please see the file COPYRIGHT in this directory (additional copyright information also exists for some sources in this tree - please see the specific source directories for more information). The Makefile in this directory supports a number of targets for building components (or all) of the FreeBSD source tree, the most commonly used one being ``world'', which rebuilds and installs everything in the FreeBSD system from the source tree except the kernel, the kernel-modules and the contents of /etc. The ``buildkernel'' and ``installkernel'' targets build and install the kernel and the modules (see below). Please see the top of the Makefile in this directory for more information on the standard build targets and compile-time flags. Building a kernel is a somewhat more involved process, documentation for which can be found at: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig.html And in the config(8) man page. Note: If you want to build and install the kernel with the ``buildkernel'' and ``installkernel'' targets, you might need to build world before. More information is available in the handbook. The sample kernel configuration files reside in the sys/<arch>/conf sub-directory (assuming that you've installed the kernel sources), the file named GENERIC being the one used to build your initial installation kernel. The file NOTES contains entries and documentation for all possible devices, not just those commonly used. It is the successor of the ancient LINT file, but in contrast to LINT, it is not buildable as a kernel but a pure reference and documentation file. Source Roadmap: --------------- bin System/user commands. contrib Packages contributed by 3rd parties. crypto Cryptography stuff (see crypto/README). etc Template files for /etc. games Amusements. gnu Various commands and libraries under the GNU Public License. Please see gnu/COPYING* for more information. include System include files. kerberos5 Kerberos5 (Heimdal) package. lib System libraries. libexec System daemons. release Release building Makefile & associated tools. sbin System commands. secure Cryptographic libraries and commands. share Shared resources. sys Kernel sources. tools Utilities for regression testing and miscellaneous tasks. usr.bin User commands. usr.sbin System administration commands. For information on synchronizing your source tree with one or more of the FreeBSD Project's development branches, please see: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/synching.html