FreeBSD src
1ee624b31d
mechanism so that early processing on mbufs can be performed before a context switch to the NFS server threads. Because of this, if the socket code is running without Giant, the NFS server also needs to be able to run the upcall code without relying on the presence on Giant. This change modifies the NFS server to run using a "giant code lock" covering operation of the whole subsystem. Work is in progress to move to data-based locking as part of the NFSv4 server changes. Introduce an NFS server subsystem lock, 'nfsd_mtx', and a set of macros to operate on the lock: NFSD_LOCK_ASSERT() Assert nfsd_mtx owned by current thread NFSD_UNLOCK_ASSERT() Assert nfsd_mtx not owned by current thread NFSD_LOCK_DONTCARE() Advisory: this function doesn't care NFSD_LOCK() Lock nfsd_mtx NFSD_UNLOCK() Unlock nfsd_mtx Constify a number of global variables/structures in the NFS server code, as they are not modified and contain constants only: nfsrvv2_procid nfsrv_nfsv3_procid nonidempotent nfsv2_repstat nfsv2_type nfsrv_nfsv3_procid nfsrvv2_procid nfsrv_v2errmap nfsv3err_null nfsv3err_getattr nfsv3err_setattr nfsv3err_lookup nfsv3err_access nfsv3err_readlink nfsv3err_read nfsv3err_write nfsv3err_create nfsv3err_mkdir nfsv3err_symlink nfsv3err_mknod nfsv3err_remove nfsv3err_rmdir nfsv3err_rename nfsv3err_link nfsv3err_readdir nfsv3err_readdirplus nfsv3err_fsstat nfsv3err_fsinfo nfsv3err_pathconf nfsv3err_commit nfsrv_v3errmap There are additional structures that should be constified but due to their being passed into general purpose functions without const arguments, I have not yet converted. In general, acquire nfsd_mtx when accessing any of the global NFS structures, including struct nfssvc_sock, struct nfsd, struct nfsrv_descript. Release nfsd_mtx whenever calling into VFS, and acquire Giant for calls into VFS. Giant is not required for any part of the operation of the NFS server with the exception of calls into VFS. Giant will never by acquired in the upcall code path. However, it may operate entirely covered by Giant, or not. If debug.mpsafenet is set to 0, the system calls will acquire Giant across all operations, and the upcall will assert Giant. As such, by default, this enables locking and allows us to test assertions, but should not cause any substantial new amount of code to be run without Giant. Bugs should manifest in the form of lock assertion failures for now. This approach is similar (but not identical) to modifications to the BSD/OS NFS server code snapshot provided by BSDi as part of their SMPng snapshot. The strategy is almost the same (single lock over the NFS server), but differs in the following ways: - Our NFS client and server code bases don't overlap, which means both fewer bugs and easier locking (thanks Peter!). Also means NFSD_*() as opposed to NFS_*(). - We make broad use of assertions, whereas the BSD/OS code does not. - Made slightly different choices about how to handle macros building packets but operating with side effects. - We acquire Giant only when entering VFS from the NFS server daemon threads. - Serious bugs in BSD/OS implementation corrected -- the snapshot we received was clearly a work in progress. Based on ideas from: BSDi SMPng Snapshot Reviewed by: rick@snowhite.cis.uoguelph.ca Extensive testing by: kris |
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| bin | ||
| contrib | ||
| crypto | ||
| etc | ||
| games | ||
| gnu | ||
| include | ||
| kerberos5 | ||
| lib | ||
| libexec | ||
| release | ||
| rescue | ||
| sbin | ||
| secure | ||
| share | ||
| sys | ||
| tools | ||
| usr.bin | ||
| usr.sbin | ||
| COPYRIGHT | ||
| installworld_newk | ||
| installworld_oldk | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc1 | ||
| README | ||
| UPDATING | ||
| UPDATING.64BTT | ||
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