FreeBSD src
ea37f51942
the pass(4) and enc(4) drivers and devfs. The pass(4) driver uses the destroy_dev_sched() routine to schedule its device node for destruction in a separate thread context. It does this because the passcleanup() routine can get called indirectly from the passclose() routine, and that would cause a deadlock if the close routine tried to destroy its own device node. In any case, once a particular passthrough driver number, e.g. pass3, is destroyed, CAM considers that unit number (3 in this case) available for reuse. The problem is that devfs may not be done cleaning up the previous instance of pass3, and will panic if isn't done cleaning up the previous instance. The solution is to get a callback from devfs when the device node is removed, and make sure we hold a reference to the peripheral until that happens. Testing exposed some other cases where we have reference counting issues, and those were also fixed in the pass(4) driver. cam_periph.c: In camperiphfree(), reorder some of the operations. The peripheral destructor needs to be called before the peripheral is removed from the peripheral is removed from the list. This is because once we remove the peripheral from the list, and drop the topology lock, the peripheral number may be reused. But if the destructor hasn't been called yet, there may still be resources hanging around (like devfs nodes) that haven't been fully cleaned up. cam_xpt.c: Add an argument to xpt_remove_periph() to indicate whether the topology lock is already held. scsi_enc.c: Acquire an extra reference to the peripheral during registration, and release it once we get a callback from devfs indicating that the device node is gone. Call destroy_dev_sched_cb() in enc_oninvalidate() instead of calling destroy_dev() in the cleanup routine. scsi_pass.c: Add reference counting to handle peripheral and devfs object lifetime issues. Add a reference to the peripheral and the devfs node in the peripheral registration. Don't attempt to add a physical path alias if the peripheral has been marked invalid. Release the devfs reference once the initial physical path alias taskqueue run has completed. Schedule devfs node destruction in the passoninvalidate(), and release our peripheral reference in a new routine, passdevgonecb() once the devfs node is gone. This allows the peripheral to fully go away, and the peripheral destructor, passcleanup(), will get called. MFC after: 3 days Sponsored by: Spectra Logic |
||
|---|---|---|
| bin | ||
| cddl | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| LOCKS | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| ObsoleteFiles.inc | ||
| README | ||
| UPDATING | ||
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 ``world'' target should only be used in cases where the source tree has not changed from the currently running version. See: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html for more information, including setting make(1) variables. 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. cddl Various commands and libraries under the Common Development and Distribution License. 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. rescue Build system for statically linked /rescue utilities. 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