From: Ilya Dryomov Date: Mon, 16 Dec 2013 17:26:32 +0000 (+0200) Subject: rbd: enable extended devt in single-major mode X-Git-Tag: v3.14-rc1~71^2~56 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7e513d43669a0505ee3b122344176147a674bcbf;p=pandora-kernel.git rbd: enable extended devt in single-major mode If single-major device number allocation scheme is turned on, instead of reserving 256 minors per device, which imposes a limit of 4096 images mapped at once, reserve 16 minors per device and enable extended devt feature. This results in a theoretical limit of 65536 images mapped at once, and still allows to have more than 15 partititions: partitions starting with 16th are mapped under major 259 (Block Extended Major): $ rbd showmapped id pool image snap device 0 rbd b5 - /dev/rbd0 # no partitions 1 rbd b2 - /dev/rbd1 # 40 partitions 2 rbd b3 - /dev/rbd2 # 2 partitions $ cat /proc/partitions 251 0 1024 rbd0 251 16 1024 rbd1 251 17 0 rbd1p1 251 18 0 rbd1p2 ... 251 30 0 rbd1p14 251 31 0 rbd1p15 259 0 0 rbd1p16 259 1 0 rbd1p17 ... 259 23 0 rbd1p39 259 24 0 rbd1p40 251 32 1024 rbd2 251 33 0 rbd2p1 251 34 0 rbd2p2 (major 251 was assigned dynamically at module load time) Signed-off-by: Ilya Dryomov Reviewed-by: Josh Durgin --- Reading git-diff-tree failed