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There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| include/linux | ||
| lnet | ||
| lustre | ||
| Kconfig | ||
| Makefile | ||
| README.txt | ||
| TODO | ||
Lustre Parallel Filesystem Client ================================= The Lustre file system is an open-source, parallel file system that supports many requirements of leadership class HPC simulation environments. Born from from a research project at Carnegie Mellon University, the Lustre file system is a widely-used option in HPC. The Lustre file system provides a POSIX compliant file system interface, can scale to thousands of clients, petabytes of storage and hundreds of gigabytes per second of I/O bandwidth. Unlike shared disk storage cluster filesystems (e.g. OCFS2, GFS, GPFS), Lustre has independent Metadata and Data servers that clients can access in parallel to maximize performance. In order to use Lustre client you will need to download lustre client tools from https://downloads.hpdd.intel.com/public/lustre/latest-feature-release/ the package name is lustre-client. You will need to install and configure your Lustre servers separately. Mount Syntax ============ After you installed the lustre-client tools including mount.lustre binary you can mount your Lustre filesystem with: mount -t lustre mgs:/fsname mnt where mgs is the host name or ip address of your Lustre MGS(management service) fsname is the name of the filesystem you would like to mount. Mount Options ============= noflock Disable posix file locking (Applications trying to use the functionality will get ENOSYS) localflock Enable local flock support, using only client-local flock (faster, for applications that require flock but do not run on multiple nodes). flock Enable cluster-global posix file locking coherent across all client nodes. user_xattr, nouser_xattr Support "user." extended attributes (or not) user_fid2path, nouser_fid2path Enable FID to path translation by regular users (or not) checksum, nochecksum Verify data consistency on the wire and in memory as it passes between the layers (or not). lruresize, nolruresize Allow lock LRU to be controlled by memory pressure on the server (or only 100 (default, controlled by lru_size proc parameter) locks per CPU per server on this client). lazystatfs, nolazystatfs Do not block in statfs() if some of the servers are down. 32bitapi Shrink inode numbers to fit into 32 bits. This is necessary if you plan to reexport Lustre filesystem from this client via NFSv4. verbose, noverbose Enable mount/umount console messages (or not) More Information ================ You can get more information at OpenSFS website: http://lustre.opensfs.org/about/ Intel HPDD wiki: https://wiki.hpdd.intel.com Out of tree Lustre client and server code is available at: http://git.whamcloud.com/fs/lustre-release.git Latest binary packages: http://lustre.opensfs.org/download-lustre/