30930fba21
DISCARD (REQ_DISCARD, BLKDISCARD) is useful for thin provisioning. It allows ZVOL clients to discard (unmap, trim) block ranges from a ZVOL, thus optimizing disk space usage by allowing a ZVOL to shrink instead of just grow. We can't use zfs_space() or zfs_freesp() here, since these functions only work on regular files, not volumes. Fortunately we can use the low-level function dmu_free_long_range() which does exactly what we want. Currently the discard operation is not added to the log. That's not a big deal since losing discard requests cannot result in data corruption. It would however result in disk space usage higher than it should be. Thus adding log support to zvol_discard() is probably a good idea for a future improvement. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> |
||
|---|---|---|
| cmd | ||
| config | ||
| dracut | ||
| etc | ||
| include | ||
| lib | ||
| man | ||
| module | ||
| patches | ||
| scripts | ||
| udev | ||
| .gitignore | ||
| AUTHORS | ||
| COPYING | ||
| COPYRIGHT | ||
| ChangeLog | ||
| DISCLAIMER | ||
| META | ||
| Makefile.am | ||
| Makefile.in | ||
| OPENSOLARIS.LICENSE | ||
| PKGBUILD-zfs-modules.in | ||
| PKGBUILD-zfs.in | ||
| README.markdown | ||
| ZFS.RELEASE | ||
| autogen.sh | ||
| configure | ||
| configure.ac | ||
| zfs-modules.spec.in | ||
| zfs-script-config.sh.in | ||
| zfs.spec.in | ||
| zfs_config.h.in | ||
README.markdown
Native ZFS for Linux! ZFS is an advanced file system and volume manager which was originally developed for Solaris. It has been successfully ported to FreeBSD and now there is a functional Linux ZFS kernel port too. The port currently includes a fully functional and stable SPA, DMU, and ZVOL with a ZFS Posix Layer (ZPL) on the way!
$ ./configure
$ make pkg
Full documentation for building, configuring, and using ZFS can be found at: http://zfsonlinux.org