freebsd with flexible iflib nic queues
4ff1c77d22
* There is no need for the delayed destruction of znodes via taskqueue, now that we do not need to fear recursion from getnewvnode into zfs_inactive and zfs_freebsd_reclaim, thus making znode/vnode state machine a bit simpler. * More complete porting of zfs_inactive from Solaris VFS model to FreeBSD vop_inactive and vop_reclaim model. All destructive actions are done in zfs_freebsd_reclaim. This allows to simplify zfs_zget logic. * Allow zfs_zget to return a doomed vnode if the current thread already has an exclusive lock on the vnode. * Clean up Solaris-isms like bailing out of reclaim/inactive on certain values of v_usecount (aka v_count) or directly messing with this counter. * Do not clear z_vnode while znode is still accessible. z_vnode should be cleared only after zfs_znode_dmu_fini. Otherwise zfs_zget may get an effectively half-deconstructed znode. This allows to simplify zfs_zget logic further. The above changes fix at least two known/reported problems: o An indefinite wait in the following code path: vgone -> VOP_RECLAIM -> zfs_freebsd_reclaim -> vnode_destroy_vobject -> put_pages -> zfs_write -> zil_commit -> zfs_zget This happened because vgone marks a vnode as VI_DOOMED before calling VOP_RECLAIM, but zfs_zget would not return a doomed vnode under any circumstances. The fix in this change is not complete as it won't fix a deadlock between two threads doing VOP_RECLAIM where one thread is in zil_commit trying to zfs_zget a znode/vnode being reclaimed by the other thread, which would be blocked trying to enter zil_commit. This type of deadlock has not been reported as of now. o An indefinite wait in the unmount path caused by a znode "falling through the cracks" in inactive+reclaim. This would happen if the znode is unlinked while its vnode is still active. To Do: pass locking flags parameter to zfs_zget, so that the zfs-vfs glue code doesn't have to re-lock a vnode but could ask for proper locking from the very start. This would also allow for the higher level code to obtain a doomed vnode when it is expected/requested. Or to avoid blocking when it is not allowed (see zil_commit example above). ffs_vgetf seems like a good source of inspiration. Tested by: Willem Jan Withagen <wjw@digiware.nl> MFC after: 6 weeks |
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| 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