freebsd-nq/cmd/zinject
Etienne Dechamps ee5fd0bb80 Set zvol discard_granularity to the volblocksize.
Currently, zvols have a discard granularity set to 0, which suggests to
the upper layer that discard requests of arbirarily small size and
alignment can be made efficiently.

In practice however, ZFS does not handle unaligned discard requests
efficiently: indeed, it is unable to free a part of a block. It will
write zeros to the specified range instead, which is both useless and
inefficient (see dnode_free_range).

With this patch, zvol block devices expose volblocksize as their discard
granularity, so the upper layer is aware that it's not supposed to send
discard requests smaller than volblocksize.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #862
2012-08-07 14:55:31 -07:00
..
.gitignore Add .gitignore files to exclude build products 2010-01-08 11:35:17 -08:00
Makefile.am Combine libraries: spl, avl, efi, share, unicode. 2012-01-17 15:19:50 -08:00
Makefile.in Set zvol discard_granularity to the volblocksize. 2012-08-07 14:55:31 -07:00
translate.c Documentation updates 2011-02-04 16:14:34 -08:00
zinject.c Remove HAVE_ZPL from commands and libraries 2011-02-04 16:14:34 -08:00
zinject.h Update core ZFS code from build 121 to build 141. 2010-05-28 13:45:14 -07:00